####018002115####
ACUS48 KWNS 100900

SWOD48

SPC AC 100859



Day 4-8 Convective Outlook  

NWS Storm Prediction Center Norman OK

0359 AM CDT Wed Apr 10 2024



Valid 131200Z - 181200Z



...DISCUSSION...

Primary feature of concern will be an amplified upper low that is

initially off the CA coast at 12Z Saturday. This low should dampen

as it steadily progresses across the Southwest, before amplifying

once again as it emerges onto the central Great Plains sometime on

D6, as a separate shortwave trough digs towards the Pacific

Northwest. Timing spread within the 00Z deterministic and ensemble

guidance appears larger relative to yesterday, with the 00Z ECMWF

decidedly trending farther east over the past 24 hours. It appears

to be on the eastern envelope compared to its ensemble members. The

overall forecast impact is with regard to dryline placement and

surface cyclone evolution during the day on Monday and beyond. 



The actual severe weather setup appears substantial. Air mass

modification will ensue northward from the western Gulf on D3, with

multiple days to improve the low-level moisture profile amid well

above-normal surface temperatures and a pronounced elevated mixed

layer. With the likely flow field amplification through the

troposphere, all ingredients appear present for a significant severe

weather day on D6/Monday. The areal uncertainty of the synoptic

features is the primary limiting factor. For now, have added a

confined 30 percent highlight to indicate the higher-end potential

and the most probable corridor, while broadening the previous 15

percent area. 



A lesser severe threat will probably continue into D7/Tuesday. But

even further spatial uncertainty, in conjunction with the impact of

the prior day convection and consensus signal for the deep cyclone

to occlude northeastward, renders low confidence for highlighting a

severe threat area yet. The area-of-interest appears to have shifted

more to the east relative to yesterday, in an arc around the eastern

Corn Belt to the Ark-La-Tex.



..Grams.. 04/10/2024