812
ACUS03 KWNS 201924
SWODY3
SPC AC 201924
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0224 PM CDT WED MAY 20 2026
VALID 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS...
..SUMMARY
SCATTERED STRONG TO SEVERE STORMS WILL BE POSSIBLE ACROSS PORTIONS
OF THE SOUTHERN PLAINS WITH POTENTIAL FOR LARGE HAIL AND DAMAGING
WIND.
..SYNOPSIS
A SHORT-WAVE TROUGH INITIALLY OVER THE NORTHERN AND CENTRAL HIGH
PLAINS FRIDAY MORNING IS EXPECTED TO BECOME NEGATIVELY TILTED AS IT
TRANSLATES INTO THE UPPER MS VALLEY FRIDAY NIGHT. A BELT OF ENHANCED
MID/UPPER-LEVEL FLOW WILL ACCOMPANY THAT FEATURE ACROSS THE CENTRAL
PLAINS. A SEPARATE, WEAKER DISTURBANCE IS EXPECTED TO BE LOOSELY
PHASED WITH THE NORTH-CENTRAL U.S. SYSTEM, TRACKING FROM THE OZARK
PLATEAU AND LOWER MS VALLEY INTO THE OH AND TN VALLEYS.
AT THE SURFACE, A COLD FRONT ASSOCIATED WITH THE FORMER DISTURBANCE
MENTIONED ABOVE IS FORECAST TO MOVE THROUGH THE NORTHERN AND CENTRAL
PLAINS WITH THE TRAILING EXTENSION OF THAT BOUNDARY PUSHING INTO THE
SOUTHERN HIGH PLAINS, WHERE IT WILL LINK WITH A SURFACE LOW. FARTHER
EAST, A SECONDARY SURFACE LOW (TIED TO THE LOWER-LATITUDE IMPULSE)
IS EXPECTED TO DEVELOP FROM THE LOWER MS INTO OH VALLEY WITH AN
ASSOCIATED WARM FRONT LIFTING NORTH THROUGH THE TN INTO OH VALLEY.
..SOUTHERN PLAINS
DESPITE RISING MID-LEVEL HEIGHTS THROUGH THE DAY, CONVERGENCE ALONG
THE FRONT AND/OR UPSLOPE FLOW IN ITS IMMEDIATE WAKE ARE EXPECTED TO
SUPPORT WIDELY SCATTERED THUNDERSTORM DEVELOPMENT OVER PARTS OF
NORTHEAST/EAST-CENTRAL NM INTO THE TX PANHANDLE BY MID TO LATE
AFTERNOON. THE COMBINATION OF STEEP LOW/MID-LEVEL LAPSE RATES AND
BOUNDARY-LAYER DEWPOINTS IN THE 50S TO LOW 60S WILL SUPPORT A
MODERATELY UNSTABLE AIR MASS AMIDST A KINEMATIC ENVIRONMENT
FEATURING A VERTICALLY VEERING WIND PROFILE WITH EFFECTIVE BULK
SHEAR OF 30-35 KT. THAT PARAMETER SPACE WILL SUPPORT ORGANIZED
MULTICELL OR SUPERCELL STORM MODES INITIALLY WITH THE PREDOMINANT
HAZARD BEING LARGE HAIL. THE 12Z MODELS SUGGEST UPSCALE GROWTH OF
THE INITIAL STORMS INTO AN MCS WITH AN ISOLATED HAIL AND WIND THREAT
CONTINUING EAST ACROSS PARTS OF OK AND NORTHWEST TX FRIDAY EVENING
INTO FRIDAY NIGHT.
..CENTRAL PLAINS
AN AXIS OF 50S TO LOW 60S DEWPOINTS ARE EXPECTED TO SPREAD NORTH
FROM KS INTO EASTERN NE AHEAD OF THE COLD FRONT. HOWEVER, WIDESPREAD
CLOUDS AND AREAS OF PRECIPITATION ARE EXPECTED TO LIMIT
BOUNDARY-LAYER HEATING AND AIR MASS DESTABILIZATION. SO, DESPITE
INCREASED FORCING FOR ASCENT AND STRENGTHENING LOW-LEVEL AND
DEEP-LAYER SHEAR, THE UNFAVORABLE THERMODYNAMIC ENVIRONMENT IS
EXPECTED TO PRECLUDE SEVERE-STORM POTENTIAL.
..TN AND OH VALLEYS
NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THE FORECAST
PERIOD ALONG AND SOUTH OF THE WARM FRONT, AIDING BY FORCING FOR
ASCENT ASSOCIATED WITH THE SHORT-WAVE TROUGH MOVING THROUGH THE
REGION. GENERALLY WEAK LAPSE RATES ARE EXPECTED TO LIMIT AIR MASS
DESTABILIZATION, DESPITE THE PRESENCE OF BOUNDARY-LAYER DEWPOINTS IN
THE 60S TO LOW 70S. HOWEVER, A MODEST ENHANCEMENT OF MID-LEVEL WINDS
ATTENDING THE SHORT-WAVE TROUGH, AND MORE SO, INTENSIFYING 850-MB
FLOW FRIDAY AFTERNOON INTO NIGHT, WILL RESULT IN STRENGTHENING
VERTICAL SHEAR, ESPECIALLY ACROSS THE OH VALLEY FRIDAY NIGHT. AS
SUCH, POTENTIAL WILL EXIST FOR TRANSIENT SUPERCELL STRUCTURES TO BE
EMBEDDED IN THE BROADER-SCALE CONVECTIVE SHIELD WITH A NON-ZERO RISK
FOR A BRIEF TORNADO.
..MEAD.. 05/20/2026
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