National Weather Service United States Department of Commerce

Significant Winter Storm to Bring Heavy Snow and Ice Impacts; Dangerously Cold Temperatures Expands Across the East; Severe Storm Threat in the Gulf States Sunday

A significant winter storm is underway, bringing widespread heavy snow, sleet, and freezing rain from the Southern Rockies to New England through Monday. Extremely cold air will follow, prolonging dangerous travel and infrastructure impacts into next week. Severe thunderstorms may produce damaging gusts and tornadoes across the eastern Gulf Coast states Sunday morning and afternoon. 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.