Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
906 ACUS01 KWNS 281230 SWODY1 SPC AC 281228 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Mon Sep 28 2026 Valid 281300Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm probability remains low on Monday. ... Northern Plains ... Surface high pressure centered over the Great Lakes and a developing area of low pressure over the High Plains will maintain southerly flow and an adequately moist airmass over NE and the Dakotas. Ongoing scattered showers/thunderstorms will continue to move northeast, followed by thickening mid/high-level clouds, which will likely limit destabilization. However, some gradual warming through mid afternoon will favor 500-1500 J/kg MLCAPE developing from western NE northward into ND. A surface trough will likely focus some of the isolated to scattered thunderstorms that eventually develop. Overall modest forcing for ascent and some elongation of forecast hodographs (mostly due to a 250-mb speed max) may yield a couple of strong thunderstorms developing. Uncertainty where the strongest storms develop and their intensity magnitude lend sufficient concern to preclude low-severe probabilities this outlook update. By later this evening, a re-invigoration of a southerly LLJ may continue to support elevated storms into the overnight. ... Southeast CA/southern NV/western AZ... Numerous showers and thunderstorms are expected as an anomalously moist airmass spreads north ahead of a mid-level shortwave trough forecast to move from the central Valleys to the lower CO River Valley during the period. Widespread clouds and weak midlevel lapse rates should keep instability generally limited through early afternoon before cloud cover mostly dissipates and a mid-level cold pocket arrives by early evening. A stronger storm or two is possible over this region but the stronger-storm threat combined with remaining uncertainty in where the more vigorous storms will develop, appears too low to warrant unconditional probabilities. ..Smith/Bentley.. 09/28/2026 $$