Forecasting and Monitoring Intense Thunderstorms in the Hindu Kush Himalayan Region: Spring 2018 Forecasting Experiment

Some of the most intense thunderstorms on the planet occur in the Hindu Kush Himalayan (HKH) region of South Asia — where many organizations lack the capacity needed to predict, observe and/or effectively respond to the threats associated with high-impact convective weather. Among the convective hazards include tornadoes, damaging straight-line winds, large hail, and flash flooding, which typically peak in the pre-wet-monsoon season (~March through May). Previous studies have documented a disproportionately large number of casualties associated with severe thunderstorms in this region; therefore, it is the goal of this project to increase situational awareness of these hazards through improved short-term modeling and satellite assessment tools.

As part of the NASA/SERVIR Applied Sciences Program, this project combines innovative numerical weather prediction (NWP) strategies, satellite-based precipitation products, and land-imagery techniques into a high-impact weather assessment toolkit (HIWAT). The HIWAT is being developed over the next 1-2 years, with the goal of transitioning capabilities to weather-sensitive agencies in the HKH region, in order to improve situational awareness and warning decision support. The short-term NWP strategies involve developing a real-time regional deterministic and mini-ensemble system, which is the focus of this presentation. A daily deterministic simulation produces severe weather indices (e.g., SCP, STP, DCP, SHIP) over a targeted area of the HKH region, initially focusing on Nepal, Bhutan, and Bangladesh. The mini-ensemble will output products similar to the Storm-Scale Ensemble of Opportunity at the Storm Prediction Center (i.e., “paintball” maps, neighborhood probabilities of specific model fields, diurnal summary plots, etc.) to depict the most likely areas for severe weather over a 48-hour outlook. Satellite products (e.g., GPM) and land-cover processing techniques will then be used to observe convective characteristics and provide datasets to aid in potential damage assessment activities following an event.

This presentation provides an overview of the implementation of a real-time Spring Forecasting Experiment over the HKH region during March to May 2018. The cloud computing hardware and software solution is described, along with the details of the deterministic and ensemble model configuration. Real-time NWP model output are produced on a daily basis for day-1 and day-2 severe weather guidance focusing on northeastern India, Nepal, and Bangladesh. Model products are disseminated to collaborating organizations with NASA/SERVIR and hosted on a modeling web site.