187
ACUS01 KWNS 210556
SWODY1
SPC AC 210554
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT SUN JUN 21 2026
VALID 211200Z - 221200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
CENTRAL/SOUTHERN PLAINS INTO THE OZARKS AND OHIO VALLEY...
..SUMMARY
SEVERE STORMS ARE POSSIBLE FROM THE CENTRAL HIGH PLAINS INTO THE
OHIO VALLEY, MAINLY THIS AFTERNOON INTO TONIGHT. LARGE TO VERY LARGE
HAIL, SEVERE WINDS, AND TORNADOES WILL BE POSSIBLE. SOME
STRONG-TORNADO POTENTIAL COULD DEVELOP ACROSS PARTS OF MISSOURI,
ILLINOIS, AND INDIANA DURING THE AFTERNOON AND EARLY EVENING.
..PARTS OF MO INTO THE OHIO VALLEY
AN ALL-HAZARDS SEVERE THREAT, INCLUDING SOME CONDITIONAL
STRONG-TORNADO POTENTIAL, IS STILL EVIDENT FROM PARTS OF MO INTO THE
OHIO VALLEY LATER TODAY, THOUGH UNCERTAINTY REMAINS REGARDING THE
MAGNITUDE AND MOST FAVORED CORRIDOR OF THE GREATEST THREAT. NO
UPGRADE WAS MADE WITH THIS OUTLOOK, THOUGH GREATER TORNADO AND/OR
WIND PROBABILITIES MAY EVENTUALLY BE NEEDED, DEPENDING ON HOW THE
UNCERTAINTIES ARE RESOLVED.
GUIDANCE GENERALLY SUGGESTS THAT AN MCV CURRENTLY EVOLVING ACROSS KS
WILL MOVE ACROSS CENTRAL/NORTHERN MO THROUGH THE MORNING, BEFORE
MOVING INTO PARTS OF THE MIDWEST AND OHIO VALLEY THROUGH THE
AFTERNOON. IN ASSOCIATION WITH THE MCV, A SURFACE LOW MAY DEEPEN
ALONG A FRONT AND MOVE ACROSS PARTS OF CENTRAL MO/IL. GUIDANCE
VARIES REGARDING THE STRENGTH OF THE SURFACE LOW, ENHANCEMENT TO
LOW-LEVEL SHEAR/SRH, AND MAGNITUDE OF DESTABILIZATION IN ADVANCE OF
THE MCV. HOWEVER, IN GENERAL, RICH MOISTURE AND ENLARGED LOW-LEVEL
HODOGRAPHS WILL SUPPORT DEVELOPMENT OF A STORM CLUSTER WITH EMBEDDED
SUPERCELLS AND/OR MESOVORTICES, IF SUFFICIENT DIURNAL
DESTABILIZATION OCCURS. TORNADOES AND DAMAGING WINDS COULD ACCOMPANY
ANY ORGANIZED CELLS/CLUSTERS. STRONG-TORNADO POTENTIAL COULD EVOLVE
IF ANY SUPERCELLS CAN BE SUSTAINED WITHIN THIS REGIME.
IN THE WAKE OF THE MCV, RELATIVELY STRONG HEATING WILL SUPPORT AT
LEAST MODERATE DESTABILIZATION ALONG THE TRAILING FRONT ACROSS PARTS
OF CENTRAL/SOUTHERN MO. WHILE SOME WEAKENING/VEERING OF LOW-LEVEL
FLOW IS EXPECTED AFTER THE PASSAGE OF THE MCV, DEEP-LAYER SHEAR WILL
REMAIN SUFFICIENT FOR ORGANIZED DEVELOPMENT ALONG THE BOUNDARY,
WHICH COULD POSE AN ALL-HAZARDS SEVERE THREAT FROM LATE AFTERNOON
INTO THE EVENING FROM SOUTH-CENTRAL MO INTO THE LOWER OH VALLEY.
..CENTRAL HIGH PLAINS INTO THE OZARKS
A MID/UPPER-LEVEL SHORTWAVE TROUGH INITIALLY OVER WY WILL MOVE
TOWARD KS/NE LATER TODAY. A 35-50 KT MIDLEVEL JET MAXIMUM ATTENDANT
TO THIS SHORTWAVE WILL IMPINGE UPON PARTS OF THE CENTRAL AND
SOUTHERN HIGH PLAINS. AN OUTFLOW-INFLUENCED FRONT WILL LIKELY EXTEND
ACROSS PARTS OF SOUTHERN KS, WITH MOIST EASTERLY FLOW EXPECTED NORTH
OF THIS BOUNDARY BY LATE AFTERNOON, WHILE STRONG HEATING WILL OCCUR
SOUTH OF THE BOUNDARY. SCATTERED AFTERNOON STORM DEVELOPMENT IS
EXPECTED WITHIN THE POST-FRONTAL REGIME FROM SOUTHEAST WY/NORTHEAST
CO INTO WESTERN NE/KS. MODERATE BUOYANCY AND FAVORABLE DEEP-LAYER
SHEAR WILL SUPPORT SUPERCELL DEVELOPMENT, WITH A THREAT OF LARGE TO
VERY LARGE HAIL, LOCALIZED SEVERE GUSTS, AND POSSIBLY A TORNADO.
WIDELY SCATTERED AFTERNOON STORM DEVELOPMENT WILL ALSO BE POSSIBLE
IN THE VICINITY OF THE SURFACE FRONT, FROM NORTHWEST OK INTO
SOUTHEAST KS/SOUTHWEST MO. MODERATE TO STRONG BUOYANCY AND
SUFFICIENT DEEP-LAYER SHEAR WILL SUPPORT SUPERCELL DEVELOPMENT WITH
INITIAL STORMS ALONG THE FRONT, WITH SOME CLUSTERING POSSIBLE LATER
IN THE CONVECTIVE EVOLUTION. LARGE TO VERY LARGE HAIL, DAMAGING
WINDS, AND SOME TORNADO POTENTIAL COULD ACCOMPANY THE STRONGEST
AFTERNOON/EVENING STORMS.
LATE TONIGHT INTO EARLY MONDAY MORNING, GUIDANCE GENERALLY SUGGESTS
DEVELOPMENT OF ONE OR MORE UPSCALE GROWING CLUSTERS, EVOLVING FROM
EITHER DIURNAL CONVECTION, OR NOCTURNAL ELEVATED REDEVELOPMENT.
SWATHS OF STRONG TO SEVERE GUSTS COULD ACCOMPANY ANY UPSCALE GROWTH,
THOUGH GUIDANCE VARIES CONSIDERABLY REGARDING THE MOST FAVORABLE
CORRIDORS LATE IN THE FORECAST PERIOD.
..DEAN/SQUITIERI.. 06/21/2026
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