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ACUS01 KWNS 131231

SWODY1

SPC AC 131230



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0730 AM CDT Sat Apr 13 2024



Valid 131300Z - 141200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF

OREGON...



...SUMMARY...

Thunderstorms with isolated severe hail and strong wind gusts will

be possible this afternoon and early evening across parts of Oregon.



...Oregon...

An upper low off the coast of northern CA this morning will move

slowly east-southeastward today towards central CA. South-

southeasterly low/mid-level flow on the northeast side of this

cyclone will help advect modest mid-level moisture and steep lapse

rates over OR through this afternoon. With daytime heating, around

500-1000 J/kg of MLCAPE should develop. Thunderstorms that initially

form over the higher terrain of central OR around 20-22Z should have

some organization, with 30-40 kt of deep-layer shear supporting a

mix of multicells and perhaps a marginal supercell or two. Isolated

severe hail may occur with the more discrete convection. Occasional

strong/gusty winds also appear possible given steep low-level lapse

rates and a well-mixed boundary layer (inverted-v type soundings).

These thunderstorms should spread north-northwestward through the

early evening before gradually weakening with the loss of daytime

heating.



...Great Lakes...

Isolated thunderstorms may develop this evening and overnight across

the Great Lakes region as a weak mid-level shortwave impulse

embedded with a northwest flow regime moves southeastward. This

activity will likely remain elevated on the northeast periphery of

capping associated with an EML extending across much of the Plains

and Upper Midwest. Weak MUCAPE is generally expected where

convection should occur, which should keep the overall severe threat

low. Still, some small hail may occur given the presence of steep

mid-level lapse rates and strong deep-layer shear in the

cloud-bearing layer.



..Gleason/Grams.. 04/13/2024



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