SPC Dec 7, 2023 1300 UTC Day 1 Convective Outlook

[NorthGeorgiaWX]

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0639 AM CST Thu Dec 07 2023

Valid 071300Z - 081200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected through tonight.

...Synopsis/Discussion...
The mid/upper-level pattern will evolve toward a progressive,
high-amplitude western CONUS trough through the period, as
associated increasingly cyclonic flow is traversed by a series of
shortwaves.  Accompanying cold midlevel air (-20 to -34 deg C)
500-mb temperatures will spread eastward/inland across a vast
section of the northwestern CONUS through the period, from the
northern Great Basin northward, and the central/northern Rockies
westward.  Mesobeta-scale shots of localized, enhanced large-scale
lift, where moving atop pockets of marginally favorable low/middle-
level moisture, may prompt transient bursts of shallow cells with
very isolated/brief thunder potential, almost anywhere in that
swath.  

However, the most favorable areas for 10% or greater thunderstorm
coverage appears to be 1) near-coastal Northwest from northern CA to
WA, from portions of the Cascades westward, where the coldest air
aloft will overlie the greatest low-level moisture content near its
Pacific source, and 2) eastern OR/southwestern ID and vicinity.  A
strong shortwave trough now nearing the coast has contributed to
some lightning offshore and near coastal southwestern OR the last
few hours, and that potential should continue and shift inland
through the remainder of the morning and afternoon.  Another round
of potential this evening may accompany a field of ascent preceding
a perturbation now well west of Vancouver Island, and progged to dig
southeastward toward the northern OR Coast.

..Edwards/Kerr.. 12/07/2023

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