480
ACUS03 KWNS 280721
SWODY3
SPC AC 280721
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0221 AM CDT FRI AUG 28 2026
VALID 301200Z - 311200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
NORTHERN AND CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY...
..SUMMARY
AT LEAST ISOLATED SEVERE STORMS, ACCOMPANIED BY MAINLY A SEVERE WIND
AND HAIL THREAT, ARE POSSIBLE ACROSS PORTIONS OF THE CENTRAL AND
NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY ON SUNDAY.
..SYNOPSIS
AN UPPER RIDGE WILL GRADUALLY DRIFT EASTWARD FROM THE CENTRAL CONUS
TO THE OH/TN VALLEY AREAS ON SUNDAY, WITH TWO MID-LEVEL SHORTWAVE
TROUGHS POISED TO CREST THE UPPER RIDGE AND OVERSPREAD THE NORTHEAST
AND NORTHERN PLAINS, RESPECTIVELY. A SURFACE LOW WILL DEVELOP ACROSS
THE NORTHERN PLAINS, PRECEDED BY A WARM FRONT THAT EXTENDS FROM THE
DAKOTAS INTO THE UPPER MS VALLEY AS A COLD FRONT SAGS
SOUTH-SOUTHEASTWARD ACROSS THE CENTRAL PLAINS. ALONG THE WARM FRONT
AND AHEAD OF THE COLD FRONT, SEASONABLE LOW-LEVEL MOISTURE WILL BE
OVERSPREAD BY MODESTLY COOLER TEMPERATURES AND STRONGER FLOW ALOFT
TO SUPPORT SOME THREAT FOR STRONG TO POTENTIALLY SEVERE
THUNDERSTORMS.
..PORTIONS OF THE NORTHERN PLAINS TO THE UPPER MS VALLEY
ONE OR MORE ROUNDS OF THUNDERSTORMS ARE EXPECTED TO OVERSPREAD THE
DAKOTAS INTO THE UPPER MS VALLEY DURING THE DAY AND EARLY OVERNIGHT
HOURS ON SUNDAY. FORECAST SOUNDINGS SHOW 7+ C/KM MID-LEVEL LAPSE
RATES OVERSPREADING 60S F SURFACE DEWPOINTS, YIELDING 1500-2000 J/KG
MLCAPE ON A WIDESPREAD BASIS, PARTICULARLY ALONG THE WARM FRONT,
WHERE SIZEABLE CURVED/ELONGATED HODOGRAPHS ALSO EXIST. THE CURRENT
THINKING IS THAT A MIX OF MULTICELLS AND SUPERCELLS ARE POSSIBLE,
WITH ONE OR MORE CLUSTERS POTENTIALLY GROWING UPSCALE INTO AN MCS.
SEVERE WIND AND HAIL WILL BE THE MAIN THREATS WITH
MULTICELL/SUPERCELL STRUCTURES, WITH PERHAPS SOME RISK OF A WIND
SWATH SHOULD AN MCS MATERIALIZE.
..PORTIONS OF THE CENTRAL PLAINS
CONVECTIVE INITIATION ALONG THE COLD FRONT IS QUITE CONDITIONAL
ACROSS NE AND SURROUNDING AREAS GIVEN APPRECIABLE MLCINH EXPECTED.
NONETHELESS, STEEP LAPSE RATES POTENTIALLY EXCEEDING 8 C/KM AMID
ELONGATED HODOGRAPHS SUGGEST SUPERCELLS STRUCTURES COULD DEVELOP IF
MLCINH ERODES SUFFICIENTLY, OR IF ISENTROPIC LIFT IN THE EARLY
EVENING AT THE TERMINUS OF A STRENGTHENING LOW-LEVEL JET CAN SUPPORT
ELEVATED CONVECTION.
..SQUITIERI.. 08/28/2026
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