National Weather Service United States Department of Commerce

Storm Impacting the Northwest U.S.; Fire Weather Conditions in Southern California; Severe Weather in the South

A Pacific storm is bringing areas of low elevation rain, moderate to heavy mountain snow, and high winds to the Northwest. Strong Santa Ana winds and very dry conditions are producing elevated to critical fire weather conditions in southern California. Isolated strong to severe thunderstorms are possible through early Wednesday morning across parts of northeast Texas into western Tennessee. Read More >

12-hour helicity forecast

 

Figure 5: ETA 12 Hour Forecast of 300 K isentropic surface,
wind and relative humidity valid 1200 UTC May 12, 1997.

 

18-hour helicity forecast

 

Figure 6: ETA 18 Hour Forecast of 300 K isentropic surface,
wind and relative humidity valid 1800 UTC May 12, 1997.