Handout (8.5 MB)
Such feedback provided motivation to take a closer look at these significant errors and pursue forecast improvement. This project seeks to do the following:
(1) Develop a Central Pennsylvania climatology of so-called “dew point bomb” days when the dew point drops at least 10°F and then rises at least 5°F. Such a rule ensures the dew point drop is because of mixing and not simply dry air advection. Results indicate dew point bomb days occur most often during the typical eastern U.S. fire weather season (spring & fall) when RH errors significantly impact fire weather operations.
(2) Identify weather patterns and environmental parameters that are favorable for the development of deep-mixing and significant RH errors. This pattern identification has helped meteorologists communicate the potential for under-performing RH values and resulted in improved fire weather forecasts, partner relationships and trust.
NWS State College meteorologists have condensed the local climatology for “dew point bomb” days, along with synoptic and mesoscale ingredients that favor rapid and pronounced surface dew point drops, into a handy reference guide for staff meteorologists to use in operations. These local research efforts have also revealed that many parts of the eastern United States are susceptible to these events, provided the right atmospheric ingredients are in place. Future work will expand upon the initial pattern and environmental pattern recognition and involve development of tools to help forecasters more-accurately forecast temperature and relative humidity values based on model guidance and model soundings.
Supplementary URL: www.weather.gov/ctp/TdB_viewer

