SPC Nov 23, 2024 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0641 AM CST Sat Nov 23 2024

Valid 231300Z - 241200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are unlikely through tonight.

...Synopsis/Discussion...
In mid/upper levels, the presence of a cyclone near the coastal
Northeast, and progressive synoptic ridging moving eastward over the
central CONUS, should contribute to keeping most of the lower 48
states too dry and/or stable in low/middle levels for thunderstorms.
A substantial synoptic-scale trough is apparent in moisture-channel
imagery from north-central BC south-southwestward, offshore from the
Pacific Northwest and CA.  Shortwave troughs and vorticity lobes
will continue to eject inland within southwest flow, across the
Pacific Northwest and northern Rockies, as a cutoff cyclone forms
offshore from Vancouver Island and retrogrades southwestward.  

One of those shortwave perturbations is evident from central OR to
northern CA, and will destabilize a marginally moist low/middle-
level profile enough to support isolated thunderstorms as far inland
today as portions of MT.  This feature should develop a small,
closed cyclone overnight near the southern part of the AB/SK border,
while a trailing perturbation crosses northern CA and the northern
Great Basin.  Ahead of that feature, and beneath cold midlevel
temperatures closer to the cyclone core, isolated thunderstorms will
be possible near the Pacific Coast, from northwestern CA to the
Olympic Peninsula.  The greatest buoyancy and deepest convective
towers accessing the marine layer should remain offshore, though
strong gusts or small hail may accompany the strongest near-shore
cells inland a short distance.  Severe potential appears too
isolated and conditional to warrant an outlook area.

..Edwards/Leitman.. 11/23/2024

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