####018002019####
ACUS48 KWNS 210854

SWOD48

SPC AC 210853



Day 4-8 Convective Outlook  

NWS Storm Prediction Center Norman OK

0353 AM CDT Sun Apr 21 2024



Valid 241200Z - 291200Z



...DISCUSSION...

...Wednesday/Day 4 to Friday/Day 6...

An upper-level ridge is forecast to remain in place across the

Rockies on Wednesday, and then move eastward across the Great Plains

on Thursday. To the west of the ridge, a shortwave trough is

forecast to move through the Desert Southwest on Thursday. At the

surface on Thursday, a well-developed dryline is forecast from west

Texas northward to west-central Kansas. Isolated strong to severe

thunderstorms will be possible during the mid to late afternoon to

the east of the dryline. Large hail and wind damage are expected to

be the primary threats, although an isolated tornado threat could

also develop.



On Friday, the shortwave trough is forecast to become negatively

tilted, moving through the central Plains and mid Missouri Valley. A

corridor of moderate instability is forecast from the southern

Plains northward into the Upper Midwest. As a mid-level jet moves

over the warm sector during the day, scattered strong to severe

thunderstorms will be possible. Large hail, wind damage, and a few

tornadoes are expected across parts of the warm sector Friday

afternoon and evening. 



...Saturday/Day 7 and Sunday/Day 8...

On Saturday and Sunday, an upper-level trough is forecast in the

western U.S., with a mid-level anticyclone located over the eastern

half of the nation. A corridor of maximized low-level moisture is

forecast from the southern Plains and Ark-La-Tex north-northeastward

to the Upper Midwest and southern Great Lakes. Strong to severe

thunderstorms will be possible across parts of the warm sector each

afternoon and evening, mainly in areas that have sufficient

deep-layer shear. However, model spread is significant at this

range, and predictability remains low.



..Broyles.. 04/21/2024