LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Sun Jul 27 2025
Valid 280100Z - 281200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR FAR EASTERN
SOUTH DAKOTA INTO CENTRAL AND SOUTHERN MINNESOTA...
...SUMMARY...
Severe-wind producing storms remain a threat through tonight across
the Upper Mississippi Valley, with more isolated strong storms
possible over the northern Plains. Strong wind gusts will remain a
concern for eastern North Carolina for a few more hours.
...Synopsis and Discussion...
Surface ridging persists across the central and eastern CONUS, with
multiple mid-level perturbations traversing the ridge and supporting
episodic strong to severe thunderstorms from the northern Plains to
the East Coast.
Across the Upper MS Valley, a loosely organized MCS with intense
embedded multicells and supercells, with a history of all severe
hazards, continues to sag southward. The MCS line orientation
roughly aligns with the mean wind and deep-layer shear vector, which
appears to be the main inhibiting factor for a higher-end severe
threat. Nonetheless, given 4000-6000 J/kg MLCAPE preceding these
storms, additional severe gusts appear likely, and a couple
tornadoes cannot be ruled out wherever mesovortices or embedded
supercell mesocyclones can materialize. To the southwest, along a
diffuse frontal boundary, isolated storms continue to percolate in
intensity. It is not clear how long these storms will persist. The
current thinking is that these storms may pose an isolated threat
for all severe hazards for at least a couple more hours, before
nocturnal cooling and MLCINH increase.
More isolated storms may persist from central MT or southwestern
Manitoba as they approach the northern Plains. Any storms that do
sustain themselves should be isolated, though the presence of strong
instability and 40+ kts of effective bulk shear suggest that severe
hail/wind could accompany any storm that can mature. It is possible
that an MCS could evolve over eastern MT into western ND a couple of
hours before the 12Z timeframe, which might involve a higher
concentration of severe winds. However, overall confidence in MCS
organization before 12Z is low at this time.
Multicells sagging southward across NC should wane in intensity
tonight. However, for at least a couple more hours, enough
instability may be in place to support a damaging gust or two.
..Squitieri.. 07/28/2025
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