National Weather Service United States Department of Commerce

Tracking Storms with Impacts in the Eastern and Northwest U.S. into Friday

A storm will track north of the Great Lakes Friday with widespread rain showers across the Eastern U.S. along and ahead of its cold front. Further south along the front isolated severe thunderstorms are possible. A Pacific storm will continue moving across the Northwest U.S. into Friday with additional low elevation rain, gusty winds, and mountain snow. Read More >

12-hour helicity forecast

 

Figure 7: ETA 12 Hour Forecast of 250-850 mb Qn vectors,
thickness and isotachs valid 1200 UTC May 12, 1997.

 

18-hour helicity forecast

 

Figure 8: ETA 18 Hour Forecast of 250-850 mb Qn vectors,
thickness and isotachs valid 1800 UTC May 12, 1997.