Flood frequency analyses and probable maximum flood (PMF) studies are integral aspects of hydrologic design requirements and provide for the establishment of policies and risk assessments to both people and property. Precipitation frequency analysis and probable maximum precipitation (PMP) estimation are often included in flood frequency and PMF computations, respectively. Both approaches, probabilistic and deterministic, have limitations that would benefit from further research. For example, both approaches often fail to account for nonstationary conditions and spatial and multivariate effects. The impact of nonstationarity on hydrometeorological extremes is difficult to quantify yet important to understand because these changes may have significant implications for risk analyses and new infrastructure design as well as operations and management of existing infrastructure. For PMP estimates, basin-specific studies or general reports (such as the NOAA Hydrometeorological Report series) have been completed for decades, yet there remains a significant amount of misunderstanding and confusion within the water resources community as to development of these estimates as well as the limitations of the usage. The need for a detailed understanding of the physical processes of the atmosphere is great, as precipitation values from either precipitation frequency analyses or PMP estimates provide the basis for almost all flood hazard studies. Values that are too high can cause an overestimate of flooding and result in costly and unnecessary modifications to dam or levee structures. Underestimates of precipitation, conversely, could generate a higher risk of hydrologic failure, which could be devastating to communities near any faulty projects. Ultimately, these precipitation estimates and flood analyses must be communicated to policy makers at all levels of the government, as well as any at-risk populations. Including estimates of uncertainty in frequency analyses and PMP may increase the usefulness of such studies to decision-makers. This session covers a vital subject that demonstrates the critical link between meteorologists and engineers, as well as the general public, with regard to the impacts and risks in the weather and water enterprise. This session is expected to focus on new and emerging methods for probabilistic and PMP analyses and the estimation of hydrometeorological extremes. Subjects within this topic can include frequency analyses, uncertainty quantification, analysis of extreme storm events, case studies addressing climate and land-use changes, and communication of flood risk to the public.

Global food security represents a major societal challenge for the coming decades. Growing human population, increased demand for water and energy, and a changing climate have contributed to expanded concerns centered on food supply, production, resiliency, and price volatility. The global food system involves production and distribution with multiple stages in supply chains. Food security is inherently an issue involving natural aspects as well as social, economic, and political dimensions. There are opportunities to link environmental observations with social and economic data to generate information and provide insights to improve assessments of food security challenges and enhance agricultural practices. Earth observations and Earth science data, models, and knowledge provide essential information and tools to support the functioning and resilience of food systems. For example, Earth observations have proven helpful with estimations of crop area and cropping intensities, agricultural productivity assessments, water planning and irrigation management, and crop yield modeling on a range of time scales. New research continues to expand the areas in which Earth observation informs food security effort. This session explores how products enabled by Earth observations can help transform food security—especially when observations are combined with information on the broader food system. We further examine how uses of remote sensing and geospatial data can enhance organizations' planning and operations as well as support broader food security assessments, commodity pricing, risk assessments, and policy analysis. We invite submissions on (i) research advancing capabilities to apply Earth observation data within models and software tools to inform agricultural decision-making; (ii) research combining data, models, and methods derived from both social science and physical science to respond to food security challenges; and (iii) examples of programmatic and technical approaches to build capacity within the food security and agricultural community to harness Earth observations to inform decision-making.

Drought is a multifaceted phenomenon that challenges our current monitoring and prediction capabilities. Taking drought prediction and hydrological applications to the next level requires advances in understanding, monitoring, communications, and water resources management. Specific topics addressed by presenters could include, but are not limited to, current drought prediction science and skill at various lead times, innovative management uses of that science, and case studies illustrating advances in understanding, monitoring, and prediction of drought and drought impacts. Further, papers addressing gaps and deficiencies in our current methods for monitoring and predicting droughts and estimating its effects on vegetation, water resources, and human populations are also invited.

The precipitation session focuses on precipitation observation, modeling, estimation, and applications of in situ and remotely sensed precipitation products. Topics include, but are not limited to, (1) precipitation processes and modeling, (2) advances in remote sensing of precipitation from satellite and radar platforms, (3) recent development pertaining to fusion and downscaling of precipitation products, (4) assimilation of precipitation and precipitation-related variables in NWP models, and (5) impacts of improving precipitation estimates on hydrologic and land surface modeling.

2018 Haurwitz Lecture

Drought is a multifaceted phenomenon that challenges our current monitoring and prediction capabilities. Taking drought prediction and hydrological applications to the next level requires advances in understanding, monitoring, communications, and water resources management. Specific topics addressed by presenters could include, but are not limited to, current drought prediction science and skill at various lead times, innovative management uses of that science, and case studies illustrating advances in understanding, monitoring, and prediction of drought and drought impacts. Further, papers addressing gaps and deficiencies in our current methods for monitoring and predicting droughts and estimating its effects on vegetation, water resources, and human populations are also invited.

The precipitation session focuses on precipitation observation, modeling, estimation, and applications of in situ and remotely sensed precipitation products. Topics include, but are not limited to, (1) precipitation processes and modeling, (2) advances in remote sensing of precipitation from satellite and radar platforms, (3) recent development pertaining to fusion and downscaling of precipitation products, (4) assimilation of precipitation and precipitation-related variables in NWP models, and (5) impacts of improving precipitation estimates on hydrologic and land surface modeling.

Global food security represents a major societal challenge for the coming decades. Growing human population, increased demand for water and energy, and a changing climate have contributed to expanded concerns centered on food supply, production, resiliency, and price volatility. The global food system involves production and distribution with multiple stages in supply chains. Food security is inherently an issue involving natural aspects as well as social, economic, and political dimensions. There are opportunities to link environmental observations with social and economic data to generate information and provide insights to improve assessments of food security challenges and enhance agricultural practices.   Earth observations and Earth science data, models, and knowledge provide essential information and tools to support the functioning and resilience of food systems. For example, Earth observations have proven helpful with estimations of crop area and cropping intensities, agricultural productivity assessments, water planning and irrigation management, and crop yield modeling on a range of time scales. New research continues to expand the areas in which Earth observation informs food security effort. This session explores how products enabled by Earth observations can help transform food security—especially when observations are combined with information on the broader food system. We further examine how uses of remote sensing and geospatial data can enhance organizations' planning and operations, as well as support broader food security assessments, commodity pricing, risk assessments, and policy analysis. We invite submissions on (i) research advancing capabilities to apply Earth observation data within models and software tools to inform agricultural decision-making; (ii) research combining data, models, and methods derived from both social science and physical science to respond to food security challenges; (iii) examples of programmatic and technical approaches to build capacity within the food security and agricultural community to harness Earth observations to inform decision-making.

Drought is a multifaceted phenomenon that challenges our current monitoring and prediction capabilities. Taking drought prediction and hydrological applications to the next level requires advances in understanding, monitoring, communications, and water resources management. Specific topics addressed by presenters could include, but are not limited to, current drought prediction science and skill at various lead times, innovative management uses of that science, and case studies illustrating advances in understanding, monitoring, and prediction of drought and drought impacts. Further, papers addressing gaps and deficiencies in our current methods for monitoring and predicting drought and estimating its effects on vegetation, water resources, and human populations are also invited.

Flood frequency analyses and probable maximum flood (PMF) studies are integral aspects of hydrologic design requirements and provide for the establishment of policies and risk assessments to both people and property. Precipitation frequency analysis and probable maximum precipitation (PMP) estimation are often included in flood frequency and PMF computations, respectively. Both approaches, probabilistic and deterministic, have limitations that would benefit from further research. For example, both approaches often fail to account for nonstationary conditions and spatial and multivariate effects. The impact of nonstationarity on hydrometeorological extremes is difficult to quantify, yet important to understand, because these changes may have significant implications for risk analyses, new infrastructure design, as well as operations and management of existing infrastructure. For PMP estimates, basin specific studies or general reports (such as the NOAA Hydrometeorological Report series) have been completed for decades, yet there remains a significant amount of misunderstanding and confusion within the water resources community as to development of these estimates as well as the limitations to the usage. The need for a detailed understanding of the physical processes of the atmosphere is great, as precipitation values from either precipitation frequency analyses or PMP estimates provide the basis for almost all flood hazard studies. Values that are too high can result in an overestimate of flooding and result in costly and unnecessary modifications to dam or levee structures. Underestimates of precipitation, conversely, could place a higher risk of hydrologic failure, which could be devastating to communities near any faulty projects. Ultimately, these precipitation estimates and flood analyses must be communicated to policy makers at all levels of the government, as well as any at-risk populations. Including estimates of uncertainty in frequency analyses and PMP may increase the usefulness of such studies to decision-makers. This session covers a vital subject that demonstrates the critical link between meteorologists and engineers, as well as the general public, with regard to the impacts and risks in the weather and water enterprise. This session is expected to focus on new and emerging methods for probabilistic and PMP analyses and the estimation of hydrometeorological extremes. Subjects within this topic can include frequency analyses, uncertainty quantification, analysis of extreme storm events, case studies addressing climate and land-use changes, and communication of flood risk to the public.

The precipitation session focuses on precipitation observation, modeling, estimation, and applications of in situ and remotely sensed precipitation products. Topics include, but are not limited to, (1) precipitation processes and modeling, (2) advances in remote sensing of precipitation from satellite and radar platforms, (3) recent development pertaining to fusion and downscaling of precipitation products, (4) assimilation of precipitation and precipitation-related variables in NWP models, and (5) impacts of improving precipitation estimates on hydrologic and land surface modeling. Please contact the session organizers, Emad Habib (habib@louisiana.edu) and Yu Zhang (yu.zhang@uta.edu) for additional information.

Severe weather with heavy precipitation could bring unexpected hydrometeorological hazards, such as flash floods and landslides/mudslides, which might lead to serious social, economic, and political problems. Severe precipitation, flash floods, or landslides might become disasters that could cause significant injuries, deaths, infrastructure damage, transportation paralysis, and/or many other problems. Therefore, it is essentially important to accurately monitor and estimate the heavy precipitation so that the occurrence and intensity of associated hydrometeorological hazards can be well measured and forecasted. Currently the most powerful technique to monitor/research the severe weather is the remote sensing technique (e.g., radar, satellite). The relevant research fields progress rapidly with the aims of providing accurate and high-resolution precipitation estimation, accurate flash flood forecasting, understanding of causation and geophysical process of these natural hazards. This session invites high quality, original research contributions from radar meteorology, satellite meteorology, flash flood forecasting, hazards monitoring, and related fields that research hydrometeorological hazards.

The Robert T. Ryan Symposium will conclude with a cocktail reception welcoming symposium attendees, along with Bob's numerous colleagues and former interns from across the weather enterprise. With a short program hosted by symposium co-chair and AMS Fellow Veronica Johnson of WJLA in Washington, D.C., this casual event will honor Bob for his distinguished career, achievements, and contributions to the American Meteorological Society.

Severe weather with heavy precipitation could bring unexpected hydrometeorological hazards, such as flash floods and landslides/mudslides, which might lead to serious social, economic, and political problems. Severe precipitation, flash floods, or landslides might become disasters that could cause significant injuries, deaths, infrastructure damage, transportation paralysis, and/or many other problems. Therefore, it is essentially important to accurately monitor and estimate the heavy precipitation so that the occurrence and intensity of associated hydrometeorological hazards can be well measured and forecasted. Currently the most powerful technique to monitor/research the severe weather is the remote sensing technique (e.g., radar, satellite). The relevant research fields progress rapidly with the aims of providing accurate and high-resolution precipitation estimation, accurate flash flood forecasting, understanding of causation and geophysical process of these natural hazards. This session invites high quality, original research contributions from radar meteorology, satellite meteorology, flash flood forecasting, hazards monitoring, and related fields that research hydrometeorological hazards.

Land–atmosphere interactions play a key role in the climate system. The land's role in the weather and climate, its impact on atmospheric means, variability, and feedbacks across a broad range of spatial and temporal scales, ranging from hours to centuries, for past, present, and future climates has been the subject of much recent exploratory research. The meteorological, hydrological, biophysical, biogeochemical, ecosystem and boundary layer processes that underlie the connections between weather/climate and soil moisture, soil temperature, vegetation, snow, and frozen soil, however, are not yet fully understood. The scarcity of relevant observations, the complexity of the underlying processes and feedbacks, and the wide range of scales involved make the necessary investigations challenging. This session focuses on (1) interfaces between weather, climate, ecosystems, and the land branches of the energy, water, and carbon cycles and the impact of land processes on climate variability and change as well as on extreme events (such as droughts and flooding); (2) dynamic, physical, and biogeochemical mechanisms and feedbacks by which the land surface (e.g., soil moisture and temperature, albedo, snow, frozen soil, vegetation) influences surface water and energy balances, atmospheric processes, and climate; (3) short and long-term predictability associated with land–atmosphere–ocean interaction and land initialization (such as soil moisture, soil temperature, snow, etc.); (4) impacts of land-cover and land-use change on climate; (5) land–atmosphere interactions in the context of climate variability and change, and (6) application and analyses of local and large-scale field data and observational networks (such as FLUXNET) and satellite observations for land–atmosphere studies. We welcome papers addressing any of these topics.

High-impact hydrometeorological events produce the most destructive and costly outcomes of any weather-driven phenomena worldwide. Furthermore, despite significant progress over the last several decades, forecasting and warning for these events still lacks the precision that could minimize loss of property and life, especially in developing nations. However, new observational platforms (in situ, remote) and data-collection methods are improving our ability to assess ongoing events as well as forecast and distinguish those that could be destructive from those that probably will not be. Excessive precipitation or runoff associated with tropical cyclones/convection, land-based convection, atmospheric rivers, ENSO, wintertime snowmelt, rain-on-snow, etc. results in both flash-flooding and large-river system floods whose characteristics often depend on local soils, vegetation/agriculture, and topography. Conversely, severe droughts create deleterious impacts on crop/food production and the water supply. In this session, papers are invited that contribute to our ability to improve real-time/operational forecasts and warnings for these kinds of extremes, especially observational and modeling approaches that may vary depending upon differing societal contexts. In addition, papers that address promising and innovative methods of assessing and modeling the statistics of observed hydrometeorological extremes as applied to real-time/operational forecasting/warning systems are encouraged. Papers that document forecast system performance vis-a-vis the effect of including new or additional observations are also encouraged, as well as new or innovative approaches to communicating vital "extremes" information to stakeholders.

Land–atmosphere interactions play a key role in the climate system. The land's role in the weather and climate, its impact on atmospheric means, variability, and feedbacks across a broad range of spatial and temporal scales, ranging from hours to centuries, for past, present, and future climates has been the subject of much recent exploratory research. The meteorological, hydrological, biophysical, biogeochemical, ecosystem, and boundary layer processes that underlie the connections between weather/climate and soil moisture, soil temperature, vegetation, snow, and frozen soil, however, are not yet fully understood. The scarcity of relevant observations, the complexity of the underlying processes and feedbacks, and the wide range of scales involved make the necessary investigations challenging. This session focuses on (1) interfaces between weather, climate, ecosystems, and the land branches of the energy, water, and carbon cycles and the impact of land processes on climate variability and change as well as on extreme events (such as droughts and flooding); (2) dynamic, physical, and biogeochemical mechanisms and feedbacks by which the land surface (e.g., soil moisture and temperature, albedo, snow, frozen soil, vegetation) influences surface water and energy balances, atmospheric processes, and climate; (3) short and long-term predictability associated with land–atmosphere–ocean interaction and land initialization (such as soil moisture, soil temperature, snow, etc.); (4) impacts of land-cover and land-use change on climate; (5) land–atmosphere interactions in the context of climate variability and change, and (6) application and analyses of local- and large-scale field data and observational networks (such as FLUXNET) and satellite observations for land–atmosphere studies. We welcome papers addressing any of these topics. Please contact the session organizers, Yongkang Xue (yxue@geog.ucla.edu), Randy Koster (randal.koster@gsfc.nasa.gov), Michael Ek, (michael.ek@noaa.gov), Joseph A. Santanello (joseph.a.santanello@nasa.gov), and Steven Quiring (quiring.10@osu.edu) for additional information.

The intense horizontal transports of water vapor by atmospheric rivers (ARs) are fundamental to the global cycles of energy and water, and also determine regional patterns of weather, water, and climate variability and extremes.  Research into atmospheric rivers now includes field experiments, model simulations and forecasts, diagnostic analyses, and climate-change projections. The science of atmospheric river benefits and impacts has begun to engender new applications in support of operations and decision support for communicating risks for hazards such as flooding and challenges such as water resources management.  This session encourages contributions that span topics from atmospheric river science to AR-related applications, such as the communication of risk and other decision support services.

High-impact hydrometeorological events produce the most destructive and costly outcomes of any weather-driven phenomena worldwide. Furthermore, despite significant progress over the last several decades, forecasting and warning for these events still lacks the precision that could minimize loss of property and life, especially in developing nations. However, new observational platforms (in situ, remote) and data-collection methods are improving our ability to assess ongoing events as well as forecast and distinguish those that could be destructive from those that probably will not be. Excessive precipitation or runoff associated with tropical cyclones/convection, land-based convection, atmospheric rivers, ENSO, wintertime snowmelt, rain-on-snow, etc. results in both flash-flooding and large-river system floods whose characteristics often depend on local soils, vegetation/agriculture, and topography. Conversely, severe droughts create deleterious impacts on crop/food production and the water supply. In this session, papers are invited that contribute to our ability to improve real-time/operational forecasts and warnings for these kinds of extremes, especially observational and modeling approaches that may vary depending upon differing societal contexts. In addition, papers that address promising and innovative methods of assessing and modeling the statistics of observed hydrometeorological extremes as applied to real-time/operational forecasting/warning systems are encouraged. Papers that document forecast system performance vis-a-vis the effect of including new or additional observations are also encouraged, as well as new or innovative approaches to communicating vital "extremes" information to stakeholders.

Land–atmosphere interactions play a key role in the climate system. The land's role in the weather and climate, its impact on atmospheric means, variability, and feedbacks across a broad range of spatial and temporal scales, ranging from hours to centuries, for past, present, and future climates has been the subject of much recent exploratory research. The meteorological, hydrological, biophysical, biogeochemical, ecosystem, and boundary layer processes that underlie the connections between weather/climate and soil moisture, soil temperature, vegetation, snow, and frozen soil, however, are not yet fully understood. The scarcity of relevant observations, the complexity of the underlying processes and feedbacks, and the wide range of scales involved make the necessary investigations challenging. This session focuses on (1) interfaces between weather, climate, ecosystems, and the land branches of the energy, water, and carbon cycles and the impact of land processes on climate variability and change as well as on extreme events (such as droughts and flooding); (2) dynamic, physical, and biogeochemical mechanisms and feedbacks by which the land surface (e.g., soil moisture and temperature, albedo, snow, frozen soil, vegetation) influences surface water and energy balances, atmospheric processes, and climate; (3) short- and long-term predictability associated with land–atmosphere–ocean interaction and land initialization (such as soil moisture, soil temperature, snow, etc.); (4) impacts of land-cover and land-use change on climate; (5) land–atmosphere interactions in the context of climate variability and change, and (6) application and analyses of local- and large-scale field data and observational networks (such as FLUXNET) and satellite observations for land–atmosphere studies. We welcome papers addressing any of these topics. Please contact the session organizers, Yongkang Xue (yxue@geog.ucla.edu), Randy Koster (randal.koster@gsfc.nasa.gov), Michael Ek, (michael.ek@noaa.gov), Joseph A. Santanello (joseph.a.santanello@nasa.gov), and Steven Quiring (quiring.10@osu.edu) for additional information.

We encourage all attendees to take the opportunity to grab a snack and coffee and spend this extended afternoon break networking with colleagues and viewing the hundreds of posters on display in the poster hall. Poster displays are grouped by conference and change each day.

A number of regional and national real-time flood forecasting systems are emerging for a variety of different flood-related applications. These new systems are taking advantage of new national hydrologic data standards, new advances in supercomputing availability and improvements in model parameterizations and meteorological forcing datasets. This session encourages contributions from all sectors of the AMS enterprise (academic, government, and the private sector) who have built and deployed such systems. Additionally, contributions are welcome from researchers who have developed novel methodologies to sense and model flood generation dynamics at a variety of time and space scales. We are also seeking abstracts that focus on hydrological modeling systems which require, and utilize high performance computing (HPC) resources to improve the overall understanding and real-time prediction of hydrologic processes at all scales (land surface, aquifer, and stream/river flows) and their extremes (especially those with high impacts on society). Also In this session, interdisciplinary researchers, from meteorologists to engineers, are encouraged to demonstrate different methodologies and tools for better understanding the spatiotemporal characteristics of tropical cyclones (TCs) and improving risk-based analysis and real-time forecasts of the rainfall and/or storm surge associated with TCs. In addition, studies involving flood mitigation from the local- to regional-scale are invited given the increasing need for protection from such events. Research and application contributions from within the United States as well as internationally are also encouraged.

Land–atmosphere interactions play a key role in the climate system. The land's role in the weather and climate—its impact on atmospheric means, variability, and feedbacks across a broad range of spatial and temporal scales, ranging from hours to centuries, for past, present, and future climates—has been the subject of much recent exploratory research. The meteorological, hydrological, biophysical, biogeochemical, ecosystem and boundary layer processes that underlie the connections between weather/climate and soil moisture, soil temperature, vegetation, snow, and frozen soil, however, are not yet fully understood. The scarcity of relevant observations, the complexity of the underlying processes and feedbacks, and the wide range of scales involved make the necessary investigations challenging. This session focuses on (1) interfaces between weather, climate, ecosystems, and the land branches of the energy, water, and carbon cycles and the impact of land processes on climate variability and change as well as on extreme events (such as droughts and flooding); (2) dynamic, physical, and biogeochemical mechanisms and feedbacks by which the land surface (e.g., soil moisture and temperature, albedo, snow, frozen soil, vegetation) influences surface water and energy balances, atmospheric processes, and climate; (3) short- and long-term predictability associated with land–atmosphere–ocean interaction and land initialization (such as soil moisture, soil temperature, snow, etc.); (4) impacts of land-cover and land-use change on climate; (5) land–atmosphere interactions in the context of climate variability and change, and (6) application and analyses of local- and large-scale field data and observational networks (such as FLUXNET) and satellite observations for land–atmosphere studies. We welcome papers addressing any of these topics. Please contact the session organizers, Yongkang Xue (yxue@geog.ucla.edu), Randy Koster (randal.koster@gsfc.nasa.gov), Michael Ek (michael.ek@noaa.gov), Joseph A. Santanello (joseph.a.santanello@nasa.gov), and Steven Quiring (quiring.10@osu.edu) for additional information.

Advances in the estimation of evapotranspiration (ET) and atmospheric evaporative demand (Eo) are made across a broad range of scales and techniques, from in situ observations to remote sensing and modeling. Specific topics for this session may include, but are not limited to, (1) estimating ET from various perspectives: remote sensing platforms, ground-based point observations and parameterizations, plant-based experimentation, and water budgets; (2) operational ET estimation; (3) land surface–atmosphere feedbacks; (4) future remote sensing missions and needs for ET; (5) Eo as an input to operational LSMs to derive ET and schedule crop irrigation, and as a metric of hydroclimatic trends and variability. New methods are emerging to more robustly partition total ET between evaporative and transpirative fluxes from both a modeling and a measurement perspective. We encourage papers with a focus on information conveyed by E and T, as well as ET. This year, recognizing that transpiration is regulated through vegetation hydrodynamics, we are particularly seeking submissions relating to both experimental and theoretical work linking plant hydrodynamics, ecology, hydrology, and meteorology. Understanding and simulating these hydraulic behaviors of vegetation and their outcomes, in terms of water and carbon flux, is key to improving land surface and hydrologic models. Advances in remote sensing of water content and new databases compiling extensive monitoring records of site- and plant-level water flux and hydraulic trait data are poised for incorporation into such models through an emerging body of vegetation hydrodynamics modeling frameworks.

High-impact hydrometeorological events produce the most destructive and costly outcomes of any weather-driven phenomena worldwide. Furthermore, despite significant progress over the last several decades, forecasting and warning for these events still lacks the precision that could minimize loss of property and life, especially in developing nations. However, new observational platforms (in situ, remote) and data-collection methods are improving our ability to assess ongoing events as well as forecast and distinguish those that could be destructive from those that probably will not be. Excessive precipitation or runoff associated with tropical cyclones/convection, land-based convection, atmospheric rivers, ENSO, wintertime snowmelt, rain-on-snow, etc. results in both flash-flooding and large-river system floods whose characteristics often depend on local soils, vegetation/agriculture, and topography. Conversely, severe droughts create deleterious impacts on crop/food production and the water supply. In this session, papers are invited that contribute to our ability to improve real-time/operational forecasts and warnings for these kinds of extremes, especially observational and modeling approaches that may vary depending upon differing societal contexts. In addition, papers that address promising and innovative methods of assessing and modeling the statistics of observed hydrometeorological extremes as applied to real-time/operational forecasting/warning systems are encouraged. Papers that document forecast system performance vis-a-vis the effect of including new or additional observations are also encouraged, as well as new or innovative approaches to communicating vital "extremes" information to stakeholders.

Advances in the estimation of evapotranspiration (ET) and atmospheric evaporative demand (Eo) are made across a broad range of scales and techniques, from in situ observations to remote sensing and modeling. Specific topics for this session may include, but are not limited to, (1) estimating ET from various perspectives: remote sensing platforms, ground-based point observations and parameterizations, plant-based experimentation, and water budgets; (2) operational ET estimation; (3) land surface–atmosphere feedbacks; (4) future remote sensing missions and needs for ET; and (5) Eo as an input to operational LSMs to derive ET, schedule crop irrigation, and as a metric of hydroclimatic trends and variability. New methods are emerging to more robustly partition total ET between evaporative and transpirative fluxes from both a modeling and a measurement perspective. We encourage papers with a focus on information conveyed by E and T, as well as ET. This year, recognizing that transpiration is regulated through vegetation hydrodynamics, we are particularly seeking submissions relating to both experimental and theoretical work linking plant hydrodynamics, ecology, hydrology, and meteorology. Understanding and simulating these hydraulic behaviors of vegetation and their outcomes, in terms of water and carbon flux, is key to improving land surface and hydrologic models. Advances in remote sensing of water content and new databases compiling extensive monitoring records of site- and plant-level water flux and hydraulic trait data are poised for incorporation into such models through an emerging body of vegetation hydrodynamics modeling frameworks.

A number of regional and national real-time flood forecasting systems are emerging for a variety of different flood-related applications. These new systems are taking advantage of new national hydrologic data standards, new advances in supercomputing availability and improvements in model parameterizations and meteorological forcing datasets. This session encourages contributions from all sectors of the AMS enterprise (academic, government and the private sector) who have built and deployed such systems. Additionally, contributions are welcome from researchers who have developed novel methodologies to sense and model flood generation dynamics at a variety of time and space scales. We are also seeking abstracts that focus on hydrological modeling systems which require, and utilize high performance computing (HPC) resources to improve the overall understanding and real-time prediction of hydrologic processes at all scales (land surface, aquifer, and stream/river flows) and their extremes (especially those with high impacts on society). Also In this session, interdisciplinary researchers, from meteorologists to engineers, are encouraged to demonstrate different methodologies and tools for better understanding the spatiotemporal characteristics of tropical cyclones (TCs) and improving risk-based analysis and real-time forecasts of the rainfall and/or storm surge associated with TCs. In addition, studies involving flood mitigation from the local to the regional scale are invited given the increasing need for protection from such events. Research and application contributions from within the United States as well as internationally are also encouraged.

This session encompasses advances in soil moisture observations, assimilation of soil moisture observations, the development and application of land data assimilation systems (LDAS), and new DA methods. Advances in the development and application of land data assimilation systems (LDAS), which merge ground- or satellite-based observations with land surface estimates from coupled land–atmosphere or offline land surface models are discussed within this session. Both soil moisture and non-soil-moisture characteristics provide crucial input for land surface interactions, hydrologic processes, boundary layer meteorology, mobility models, and climate. The most cutting edge methods for soil moisture sensing at various spatial and temporal scales are continually changing. Data assimilation of soil moisture and inclusion of soil state characteristics in forecast modeling present significant challenges due to the variability in observations, observation types, uncertainty associated with observations, and observational coverage. Contributions may include studies that evaluate or refine land DA methods; studies that assess the impact of the assimilation on the quality of the LDAS products, and/or apply LDAS within operational or routinely run forecasting/hindcasting systems; contributions that incorporate LDAS into coupled land–atmosphere systems are particularly encouraged; studies that explore assimilation of novel and/or multiple observation types; improvements and advances in in situ and proximal observation techniques and data processing; novel methods and applications for soil strength and soil crust investigations; satellite remote sensing observation and data processing techniques; use of high performance computing (HPC) for modeling soil state characteristics, improving data assimilation techniques; verification and validation efforts for spatiotemporally varying data using distinctly different data sources; performance of land surface models as compared to in situ, proximal, and remotely sensed soil moisture; data assimilation techniques for soil moisture. Searchable terms: soil moisture, land surface interactions, spatial and temporal variability, in situ and remote sensing. All topic areas are invited to include a description of the importance of communication to enable collaboration and the sharing of scientific knowledge, the importance of collaboration in advancing subject matter knowledge, enabling field work, and model development with respect to improving the science.

A number of regional and national real-time flood forecasting systems are emerging for a variety of different flood-related applications. These new systems are taking advantage of new national hydrologic data standards, new advances in supercomputing availability and improvements in model parameterizations and meteorological forcing datasets. This session encourages contributions from all sectors of the AMS enterprise (academic, government and the private sector) who have built and deployed such systems. Additionally, contributions are welcome from researchers who have developed novel methodologies to sense and model flood generation dynamics at a variety of time and space scales. We are also seeking abstracts that focus on hydrological modeling systems which require, and utilize high performance computing (HPC) resources to improve the overall understanding and real-time prediction of hydrologic processes at all scales (land surface, aquifer, and stream/river flows) and their extremes (especially those with high impacts on society). Also in this session, interdisciplinary researchers, from meteorologists to engineers, are encouraged to demonstrate different methodologies and tools for better understanding the spatiotemporal characteristics of tropical cyclones (TCs) and improving risk-based analysis and real-time forecasts of the rainfall and/or storm surge associated with TCs. In addition, studies involving flood mitigation from the local to the regional scale are invited given the increasing need for protection from such events. Research and application contributions from within the United States as well as internationally are also encouraged.

With the changing risk exposure to extreme events, there is heightened awareness among water utilities that they need to plan for future extremes. The goal of this session is to demonstrate how water utilities are incorporating weather and climate information in their short- and long-term planning. A panel of water utility managers/operators as well as researchers will focus on NOAA data, applications and activities such as the NOAA Water Initiative, NOAA Water Resources Dashboard (https://toolkit.climate.gov/topics/water/water-resources-dashboard), and regional activities (e.g., the Regional Integrated Sciences and Assessments (RISAs), River Forecast Centers, etc.). Panelists will share how they are currently engaging and using climate information to address their operational challenges, and their critical information gaps. Panel members will be chosen from submitted abstracts; those not chosen will be part of a poster session.

Increasing demand on the accuracy of weather and ocean forecasts as well as subseasonal to seasonal (S2S) and climate prediction requires advanced research on the coupled processes between the atmosphere, ocean, land, and hydrology. This session solicits contributions over a range of near-term, S2S, and climate time scales covering topics including but not limited to the study of coupled parameterizations, coupled processes, impacts of coupling, and verification of the coupled atmosphere–land, atmosphere–hydrology, land–hydrology, and ocean–hydrology. Submissions representing both global and regional applications of these prediction systems are encouraged.

We encourage all attendees to take the opportunity to grab a snack and coffee and spend this extended afternoon break networking with colleagues and viewing the hundreds of posters on display in the poster hall. Poster displays are grouped by conference and change each day.

This session encompasses advances in soil moisture observations, assimilation of soil moisture observations, the development and application of land data assimilation systems (LDAS), and new DA methods. Advances in the development and application of land data assimilation systems (LDAS), which merge ground- or satellite-based observations with land surface estimates from coupled land–atmosphere or offline land surface models are discussed within this session. Both soil moisture and non-soil-moisture characteristics provide crucial input for land surface interactions, hydrologic processes, boundary layer meteorology, mobility models, and climate. The most cutting edge methods for soil moisture sensing at various spatial and temporal scales are continually changing. Data assimilation of soil moisture and inclusion of soil state characteristics in forecast modeling present significant challenges due to the variability in observations, observation types, uncertainty associated with observations, and observational coverage. Contributions may include studies that evaluate or refine land DA methods; studies that assess the impact of the assimilation on the quality of the LDAS products, and/or apply LDAS within operational or routinely run forecasting/hindcasting systems; contributions that incorporate LDAS into coupled land–atmosphere systems are particularly encouraged; studies that explore assimilation of novel and/or multiple observation types; improvements and advances in in situ and proximal observation techniques and data processing; novel methods and applications for soil strength and soil crust investigations; satellite remote sensing observation and data processing techniques; use of high performance computing (HPC) for modeling soil state characteristics, improving data assimilation techniques; verification and validation efforts for spatiotemporally varying data using distinctly different data sources; performance of land surface models as compared to in situ, proximal, and remotely sensed soil moisture; data assimilation techniques for soil moisture. Searchable terms: soil moisture, land surface interactions, spatial and temporal variability, in situ and remote sensing. All topic areas are invited to include a description of the importance of communication to enable collaboration and the sharing of scientific knowledge, the importance of collaboration in advancing subject matter knowledge, enabling field work, and model development with respect to improving the science.

With the changing risk exposure to extreme events, there is heightened awareness among water utilities that they need to plan for future extremes. The goal of this session is to demonstrate how water utilities are incorporating weather and climate information in their short- and long-term planning. A panel of water utility managers/operators as well as researchers will focus on NOAA data, applications and activities such as the NOAA Water Initiative, NOAA Water Resources Dashboard (https://toolkit.climate.gov/topics/water/water-resources-dashboard), and regional activities [e.g., the Regional Integrated Sciences and Assessments (RISAs), River Forecast Centers, etc.]. Panelists will share how they are currently engaging and using climate information to address their operational challenges, and their critical information gaps. Panel members will be chosen from submitted abstracts; those not chosen will be part of a poster session.

The North and South American monsoons are of vital importance for regional water resources, agriculture, and ecosystems. Observations and modeling are the cornerstones of research efforts aimed at improving our understanding of the intraseasonal to interannual variability of the American monsoons and will ultimately lead to improved prediction of these systems. In this session, we invite papers on all aspects of variability and predictability of the North and South American monsoons. Papers including the role of low-level jets and associated transports of water vapor, subseasonal to seasonal (S2S) prediction, the role of land surface processes in the evolution of the American monsoons, mechanisms for the influence of MJO on monsoonal variability, interhemispheric effects, observational campaigns, and modeling efforts are especially welcome.

Increasing demand on the accuracy of weather and ocean forecasts as well as subseasonal to seasonal (S2S) and climate prediction requires advanced research on the coupled processes between the atmosphere, ocean, land, and hydrology. This session solicits contributions over a range of near-term, S2S, and climate time scales covering topics including but not limited to the study of coupled parameterizations, coupled processes, impacts of coupling, and verification of the coupled atmosphere–land, atmosphere–hydrology, land–hydrology, and ocean–hydrology. Submissions representing both global and regional applications of these prediction systems are encouraged.

The 32nd Conference on Hydrology is hosting a joint session with the 25th Conference Probability and Statistics on probabilistic hydrometeorological forecasting and uncertainty analysis. Over the last several decades, substantial progresses have been achieved in probabilistic hydrometeorological forecasting theories and applications. However, significant challenges still exist in assessing the quality and uncertainty of complex hydrometeorological processes and improving hydrometeorological predictions, especially high-impact hydrometeorological events. This session solicits papers but not limit to that focus on (1) addressing uncertainty in hydrometeorological forecasting from different sources in both offline and couple systems, and (2) hydrometeorological ensemble forecasting methods. The former might include uncertainties in forcing data (quantitative precipitation estimation, meteorological forcing data, and so on), initial conditions (such as soil moisture and heterogeneous geographical conditions), parameters, model structure (physics), calibration, and statistical postprocessing of hydrometeorological model output, and innovative methods for assessing uncertainty information from observations to modeling and postprocessing processes. The latter emphasizes integrated ensemble methods to improve individual hydrologic and atmospheric models, or coupled atmosphere–land–hydrology systems, verification methods to evaluate probabilistic hydrometeorological forecasting, and technologies to process systematic errors of hydrometeorological forecasting at different spatial and temporal scales.

Snow is a valuable freshwater reservoir throughout the globe. In regions where summer precipitation is limited and infrequent, the amount of water in the snowpack is crucial as these regions rely on annual spring melt for their water supply (both potable and agricultural). Moreover, large seasonal snow packs as well as other hydrologic characteristics (including SWE, soil moisture, ground water, frozen ground, etc.) often cause extraordinary flood hazards or may impact recreation and tourism during years with limited winter precipitation. In situ observations provide point-scale estimates of snow; however, these observations are sparse and are often not suitable for global-, regional-, or even watershed-scale investigations. Terrain, vegetation, and micrometeorological conditions often interact to cause large spatial variations in snow pack properties at sub-km scales, due to differential accumulation, redistribution, and melt, complicating the estimate of snow in mountainous regions. Therefore, satellite remote sensing and land surface modeling offer a means to address both the spatial and temporal scales of the sampling problem. Existing and novel remote sensing techniques have been developed to directly estimate snow properties. Land surface and hydrologic models have shown the use of snow properties, such as snow water equivalent, as important prognostic and diagnostic variables through modeling efforts. This session invites research on existing and novel methods for remote sensing of snow properties, modeling efforts to estimate snow properties, data assimilation techniques of using remote sensing observations within a modeling construct, and combinations of these frameworks to improve snow estimation capabilities.

Owing to changes in the Earth’s global climate, regional hydrologic components of the water cycle including precipitation and evapotranspiration (ET) are changing in terms of their mean values and associated variability. Given hydrologic extremes at local to global scales are predicted to occur more frequently and atmospheric demand on terrestrial surface moisture expected to increase, knowledge of the cumulative effects of these shifts on hydroclimate and regional water resources is greatly needed. Further, with water availability and growing scarcity of critical importance to human society, increased knowledge into changes in regional water resources such as snow cover, groundwater storage and soil moisture, and sources of regional hydroclimate variability are critical. As such, this session will bring together presentations that focus on the impacts of a changing climate on the variability of hydrological processes on the regional scale. Submissions are encouraged on all topics related to improving our understanding of natural and anthropogenic impacts on regional hydroclimate variability across the world. This includes studies using process-based models, empirical analyses, and investigations of the paleoclimate record. In keeping with the theme of the meeting, we also encourage those presentations highlighting innovative approaches toward communication and coproduction of knowledge between researchers, stakeholders, and policy makers. 

Urban climate literature consistently suggests that cities impact the water cycle through modifications in evapotranspiration, precipitation, and surface runoff processes. These impacts extend beyond the urban core into adjacent suburban, ex-urban, and rural areas. This session seeks to highlight emerging research that focuses on quantitative analysis of observations and numerical simulations surrounding hydrometeorological response to urbanization on the local and regional scale. Advancements in urban climate theory and research-to-application methods related to the water cycle are also welcome. 

This session focuses on multiple processes analysis and simulation including but not limited to land–atmosphere water and energy cycles in arid and semiarid regions, where water resources and ecosystems are vulnerable to climate change. To investigate the water and energy cycle over arid and semiarid regions, the  impact of irrigation and ground water (pumping) dynamics, and vegetation dynamics are tested, analyzed and compared from offline land surface modeling and coupled NWP model to those based on reanalysis product, remote sensing, and in situ observations. Furthermore, accuracy, uncertainty, and error analysis for each individual energy and water component is useful for physical processes understanding and data product application. The temporal scale covers from hourly to interannual and spatial scale covers from local, watershed, regional and global scale. In addition, application of these data and products to drought/flood formation mechanism, monitoring and prediction, agricultural and water resource management, and long-term trend analysis are also welcome.

Urban climate literature consistently suggests that cities impact the water cycle through modifications in evapotranspiration, precipitation, and surface runoff processes. These impacts extend beyond the urban core into adjacent suburban, exurban, and rural areas. This session seeks to highlight emerging research that focuses on quantitative analysis of observations and numerical simulations surrounding hydrometeorological response to urbanization on the local and regional scale. Advancements in urban climate theory and research-to-application methods related to the water cycle are also welcome.

The North and South American monsoons are of vital importance for regional water resources, agriculture and ecosystems. Observations and modeling are the cornerstones of research efforts aimed at improving our understanding of the intraseasonal to interannual variability of the American monsoons and will ultimately lead to improved prediction of these systems. In this session, we invite papers on all aspects of variability and predictability of the North and South American monsoons. Papers including the role of low-level jets and associated transports of water vapor, subseasonal to seasonal (S2S) prediction, the role of land surface processes in the evolution of the American monsoons, mechanisms for the influence of MJO on monsoonal variability, interhemispheric effects, observational campaigns, and modeling efforts are especially welcome.

This session focuses on multiple processes analysis and simulation including but not limited to land–atmosphere water and energy cycles in arid and semiarid regions, where water resources and ecosystems are vulnerable to climate change. To investigate the water and energy cycle over arid and semiarid regions, the impact of irrigation and ground water (pumping) dynamics, and vegetation dynamics are tested, analyzed, and compared from offline land surface modeling and coupled NWP model to those based on reanalysis product, remote sensing, and in situ observations. Furthermore, accuracy, uncertainty, and error analysis for each individual energy and water component is useful for physical processes understanding and data product application. The temporal scale covers from hourly to interannual and spatial scale covers from local, watershed, regional and global scale. In addition, application of these data and products to drought/flood formation mechanism, monitoring and prediction, agricultural and water resource management, and long-term trend analysis are also welcome.

Snow is a valuable freshwater reservoir throughout the globe. In regions where summer precipitation is limited and infrequent, the amount of water in the snowpack is crucial as these regions rely on annual spring melt for their water supply (both potable and agricultural). Moreover, large seasonal snow packs as well as other hydrologic characteristics (including SWE, soil moisture, ground water, frozen ground, etc.) often cause extraordinary flood hazards or may impact recreation and tourism during years with limited winter precipitation. In situ observations provide point-scale estimates of snow; however, these observations are sparse and are often not suitable for global-, regional-, or even watershed-scale investigations. Terrain, vegetation, and micrometeorological conditions often interact to cause large spatial variations in snow pack properties at sub-km scales, due to differential accumulation, redistribution, and melt, complicating the estimate of snow in mountainous regions. Therefore, satellite remote sensing and land surface modeling offer a means to address both the spatial and temporal scales of the sampling problem. Existing and novel remote sensing techniques have been developed to directly estimate snow properties. Land surface and hydrologic models have shown the use of snow properties, such as snow water equivalent, as important prognostic and diagnostic variables through modeling efforts. This session invites research on existing and novel methods for remote sensing of snow properties, modeling efforts to estimate snow properties, data assimilation techniques of using remote sensing observations within a modeling construct, and combinations of these frameworks to improve snow estimation capabilities.

The 32nd Conference on Hydrology is hosting a joint session with the 25th Conference Probability and Statistics on probabilistic hydrometeorological forecasting and uncertainty analysis. Over the last several decades, substantial progresses have been achieved in probabilistic hydrometeorological forecasting theories and applications. However, significant challenges still exist in assessing the quality and uncertainty of complex hydrometeorological processes and improving hydrometeorological predictions, especially high-impact hydrometeorological events. This session solicits papers but not limit to that focus on (1) addressing uncertainty in hydrometeorological forecasting from different sources in both offline and couple systems, and (2) hydrometeorological ensemble forecasting methods. The former might include uncertainties in forcing data (quantitative precipitation estimation, meteorological forcing data, and so on), initial conditions (such as soil moisture and heterogeneous geographical conditions), parameters, model structure (physics), calibration, and statistical postprocessing of hydrometeorological model output, and innovative methods for assessing uncertainty information from observations to modeling and postprocessing processes. The latter emphasizes integrated ensemble methods to improve individual hydrologic and atmospheric models, or coupled atmosphere–land–hydrology systems, verification methods to evaluate probabilistic hydrometeorological forecasting, and technologies to process systematic errors of hydrometeorological forecasting at different spatial and temporal scales.

Owing to changes in the Earth’s global climate, regional hydrologic components of the water cycle including precipitation and evapotranspiration (ET) are changing in terms of their mean values and associated variability. Given hydrologic extremes at local to global scales are predicted to occur more frequently and atmospheric demand on terrestrial surface moisture expected to increase, knowledge of the cumulative effects of these shifts on hydroclimate and regional water resources is greatly needed. Further, with water availability and growing scarcity of critical importance to human society, increased knowledge into changes in regional water resources such as snow cover, groundwater storage and soil moisture, and sources of regional hydroclimate variability are critical. As such, this session will bring together presentations that focus on the impacts of a changing climate on the variability of hydrological processes on the regional scale. Submissions are encouraged on all topics related to improving our understanding of natural and anthropogenic impacts on regional hydroclimate variability across the world. This includes studies using process-based models, empirical analyses, and investigations of the paleoclimate record. In keeping with the theme of the meeting, we also encourage those presentations highlighting innovative approaches toward communication and coproduction of knowledge between researchers, stakeholders, and policy makers.

The 32nd Conference on Hydrology is hosting a joint session with the 25th Conference Probability and Statistics on probabilistic hydrometeorological forecasting and uncertainty analysis. Over the last several decades, substantial progresses have been achieved in probabilistic hydrometeorological forecasting theories and applications. However, significant challenges still exist in assessing the quality and uncertainty of complex hydrometeorological processes and improving hydrometeorological predictions, especially high-impact hydrometeorological events. This session solicits papers that focus on, but are not limited to, (1) addressing uncertainty in hydrometeorological forecasting from different sources in both offline and couple systems, and (2) hydrometeorological ensemble forecasting methods. The former might include uncertainties in forcing data (quantitative precipitation estimation, meteorological forcing data, and so on), initial conditions (such as soil moisture and heterogeneous geographical conditions), parameters, model structure (physics), calibration, and statistical postprocessing of hydrometeorological model output, and innovative methods for assessing uncertainty information from observations to modeling and postprocessing processes. The latter emphasizes integrated ensemble methods to improve individual hydrologic and atmospheric models, or coupled atmosphere–land–hydrology systems, verification methods to evaluate probabilistic hydrometeorological forecasting, and technologies to process systematic errors of hydrometeorological forecasting at different spatial and temporal scales.

Owing to changes in the Earth’s global climate, regional hydrologic components of the water cycle including precipitation and evapotranspiration (ET) are changing in terms of their mean values and associated variability. Given hydrologic extremes at local to global scales are predicted to occur more frequently and atmospheric demand on terrestrial surface moisture expected to increase, knowledge of the cumulative effects of these shifts on hydroclimate and regional water resources is greatly needed. Further, with water availability and growing scarcity of critical importance to human society, increased knowledge into changes in regional water resources such as snow cover, groundwater storage and soil moisture, and sources of regional hydroclimate variability are critical. As such, this session will bring together presentations that focus on the impacts of a changing climate on the variability of hydrological processes on the regional scale. Submissions are encouraged on all topics related to improving our understanding of natural and anthropogenic impacts on regional hydroclimate variability across the world. This includes studies using process-based models, empirical analyses, and investigations of the paleoclimate record. In keeping with the theme of the meeting, we also encourage those presentations highlighting innovative approaches toward communication and coproduction of knowledge between researchers, stakeholders, and policy makers.