Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
743 ACUS03 KWNS 260713 SWODY3 SPC AC 260712 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0212 AM CDT Fri Jul 26 2024 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST.... ...SUMMARY... Strong to severe thunderstorms are possible across portions of the central/northern Plains and the Upper Midwest. ...Synopsis... As mid-level flow strengthens across the central Rockies on Sunday, lee cyclogenesis is expected to intensify during the day. This will result in strengthening southerly flow and moisture advection across the central Plains ahead of the surface low and cold front. Thunderstorms are expected during the afternoon and evening hours along and ahead of the surface front from northern Kansas to northwest South Dakota. Shear should remain somewhat weak during the day with only around 20 to 25 knots of mid-level flow emerging over the Plains. Therefore, storms will likely remain somewhat loosely organized with marginal severe weather threat in a moderately unstable environment. The GFS, ECMWF, and NAM all show some version of a mid-level shortwave trough amplifying somewhat across the Plains Sunday evening and into the overnight hours with some differences in timing/amplitude. The arrival of this shortwave trough will result in strengthening deep-layer shear and a low-level jet response which should aid in storm development and intensity after sunset. The most likely period for a greater severe weather threat will be in this time period, likely across southeast South Dakota and eastern Nebraska when shear and instability will be maximized. Higher probabilities may need to be added in this region in later outlooks as timing and location of the overnight shortwave trough becomes more clear. ..Bentley.. 07/26/2024 $$