177
ACUS03 KWNS 211938
SWODY3
SPC AC 211937
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT TUE APR 21 2026
VALID 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
MID-MISSOURI VALLEY VICINITY INTO SOUTHERN KANSAS AND NORTHERN
OKLAHOMA...
..SUMMARY
SEVERE THUNDERSTORMS WILL BE POSSIBLE FROM NORTHERN OKLAHOMA INTO
SOUTHERN MINNESOTA ON THURSDAY. LARGE HAIL TO VERY LARGE HAIL,
DAMAGING WINDS, AND A FEW TORNADOES ARE POSSIBLE.
..SYNOPSIS
TWO SHORTWAVE TROUGHS WITHIN A LARGER-SCALE TROUGH OVER MUCH OF THE
ROCKIES WILL PIVOT NORTHEAST ON THURSDAY. THE INITIAL SHORTWAVE WILL
IMPACT PARTS OF THE CENTRAL PLAINS AND MID-MISSOURI VALLEY. A
SECOND, COMPACT SHORTWAVE WILL PIVOT INTO PARTS OF OKLAHOMA AND
KANSAS. AT THE SURFACE, MOISTURE RETURN WILL CONTINUE AHEAD OF A
PACIFIC COLD FRONT IN THE CENTRAL PLAINS. A WEAK SURFACE LOW IS
EXPECTED TO DEVELOP ALONG THE OKLAHOMA/KANSAS BORDER AND TRACK
EASTWARD. ATTENDANT TO THIS LOW, A DRYLINE WILL DRAPE SOUTHWARD INTO
THE PERMIAN BASIN.
..CENTRAL AND SOUTHERN KANSAS...OKLAHOMA
WITH MID-LEVEL ASCENT ARRIVING MID/LATE AFTERNOON, STORMS ARE LIKELY
TO INITIATE ALONG THE COLD FRONT AS WELL AS NEAR THE TRIPLE POINT
ASSOCIATED WITH THE WEAK SURFACE LOW ALONG THE KS/OK BORDER.
SUPERCELLS ARE MOST LIKELY NEAR THE TRIPLE POINT AND COULD PERSIST
SO LONG AS STORM INTERACTIONS REMAIN MINIMAL. 40-45 KTS OF SHEAR AND
2000-3000 J/KG MLCAPE WILL PROMOTE STORMS CAPABLE OF ALL HAZARDS,
INCLUDING TORNADOES AND VERY-LARGE HAIL. A STRONG LOW-LEVEL JET WILL
DEVELOP AHEAD OF THIS ACTIVITY DURING THE EVENING. THE TORNADO
THREAT COULD INCREASE FOR STORMS THAT CAN REMAIN DISCRETE.
IN OKLAHOMA, IF AND HOW MANY STORMS DEVELOP REMAINS UNCERTAIN ALONG
THE DRYLINE. NORTHERN PORTIONS OF OKLAHOMA ARE MORE LIKELY TO HAVE
SEVERE STORMS GIVEN THE PROXIMITY TO THE SURFACE LOW. A SIMILAR
ENVIRONMENT WILL EXIST EAST OF THE DRYLINE AS DOES FARTHER NORTH
INTO SOUTHERN KANSAS. THERE IS A CONDITIONAL THREAT FOR ALL SEVERE
HAZARDS.
..MID-MISSOURI VALLEY
STORMS ARE EXPECTED TO DEVELOP ALONG THE COLD FRONT POTENTIALLY AS
EARLY AS MID AFTERNOON. HOWEVER, CAPPING APPEARS STRONG ENOUGH IN
FORECAST SOUNDINGS THAT INITIATION COULD DELAY UNTIL LATE AFTERNOON.
STEEP MID-LEVEL LAPSE RATES WILL BE IN PLACE ALONG AND AHEAD OF THE
FRONT. DEEP-LAYER SHEAR WILL BE 30-40 KTS, BUT GENERALLY PARALLEL TO
THE FRONT. INITIAL STORMS COULD BE SUPERCELLULAR AND PRODUCE LARGE
TO VERY-LARGE HAIL EARLY IN THE CONVECTIVE CYCLE. UPSCALE GROWTH
APPEARS LIKELY TO OCCUR RATHER QUICKLY. DAMAGING/SEVERE WINDS WOULD
BECOME THE PRIMARY RISK AT THAT POINT. TORNADOES ARE ALSO POSSIBLE
GIVEN THE LOW-LEVEL SHEAR, BOTH WITH INITIAL SUPERCELLS AND PERHAPS
WITH QLCS CIRCULATIONS.
..WENDT.. 04/21/2026
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