Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0738 AM CDT Fri Mar 21 2025

Valid 211300Z - 221200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast today.

...Synopsis...
Within a largely zonal flow regime, embedded shortwave troughs will
move from the Great Plains to the OH Valley, and inland over the
Pacific Northwest and northern Rockies.  The Great Plains trough
will move over NE/IA by this afternoon/evening with an associated
surface trough/weak cold front.  Despite very limited low-level
moisture, surface heating beneath cold midlevel temperatures
(approaching -30 C at 500 mb) will allow for steep low-midlevel
lapse rates and weak surface-based buoyancy this afternoon/evening. 
A few high-based, low-topped thunderstorms will be possible this
afternoon through late evening.  The steep lapse rates and
moderately strong midlevel flow suggest some potential for gusty
outflow winds and small hail/graupel with the convection, but the
threat appears too limited to warrant severe probabilities.

Otherwise, isolated lightning flashes will be possible later today
into tonight from the WA Cascades into the northern Rockies.

..Thompson/Bentley.. 03/21/2025