572
ACUS01 KWNS 141239
SWODY1
SPC AC 141237
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0737 AM CDT TUE APR 14 2026
VALID 141300Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR IOWA INTO
THE SOUTHERN GREAT LAKES AND PORTIONS OF OKLAHOMA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
NORTHEAST...
..SUMMARY
SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON THROUGH TONIGHT
FROM THE SOUTHERN PLAINS INTO THE MIDWEST. LARGE TO GIANT HAIL,
SEVERAL TORNADOES (SOME STRONG), AND SEVERE GUSTS WILL BE POSSIBLE,
PARTICULARLY FROM IOWA INTO THE SOUTHERN GREAT LAKES.
..MIDWEST
AN MCV NEAR THE IL-IN BORDER THIS MORNING AND SOUTHWARD-MOVING
OUTFLOW ARE LINKED TO THUNDERSTORMS OVER PARTS OF THE EASTERN CORN
BELT. THIS OUTFLOW BOUNDARY WILL LIKELY STALL WITH THE WESTERN
PORTION OF THE BOUNDARY ADVANCING NORTHWARD WITHIN A STRENGTHENING
WARM CONVEYOR THIS AFTERNOON. GUIDANCE GENERALLY DEPICTS THIS
BOUNDARY STALLING ACROSS EASTERN IA INTO SOUTHERN WI BY LATE
AFTERNOON WHEN DAYTIME HEATING AND ASCENT AHEAD OF THE UPPER WAVE
WILL ERODE INHIBITION AND PROMOTE CONVECTIVE INITIATION ALONG THE
BOUNDARY. A MOIST AIRMASS UPSTREAM OVER THE LOWER MO VALLEY WILL
ADVECT NORTHEAST BENEATH STEEP 700-500 MB LAPSE RATES (REFERENCE THE
12 UTC TOPEKA, KS RAOB). MLCAPE AT OR ABOVE 2500 J/KG IS FORECAST
BY MID-LATE AFTERNOON FROM IA INTO THE IA-WI-IL BORDER VICINITY.
INITIAL STORMS LATER THIS AFTERNOON WILL RAPIDLY BECOME SUPERCELLS
WITH ALL SEVERE HAZARDS POSSIBLE. LARGE TO GIANT HAIL AND AN
INTENSE TORNADO WILL BE POSSIBLE WITH THE MORE MATURE/STRONGEST
SUPERCELLS WHERE SRH IS LOCALLY MAXIMIZED NEAR THE BOUNDARY.
UPSCALE GROWTH INTO A SEVERE CLUSTER IS FORECAST TO EVENTUALLY
EVOLVE DURING THE EVENING AIDED BY A STRONG SOUTHWESTERLY LLJ INTO
THE SOUTHERN GREAT LAKES. IF A SUPERCELL DEVELOPS AHEAD OF THE
EASTWARD-MOVING CLUSTER, A TORNADO THREAT COULD DEVELOP AS THE
BOUNDARY LAYER QUICKLY RECOVERS/DESTABILIZES.
..KANSAS INTO OKLAHOMA AND TEXAS
MODEST HEIGHT FALLS ACROSS THE CENTRAL TO SOUTHERN PLAINS COMBINED
WITH WEAK CONVERGENCE ALONG THE DRYLINE WILL LIKELY SUPPORT
SCATTERED THUNDERSTORMS FROM EASTERN KS SOUTHWARD INTO WESTERN NORTH
TX THIS AFTERNOON INTO THE EVENING. ALIGNING WITH EARLIER THINKING,
STRONG HEATING AND PERHAPS WEAK ASCENT TIED TO A SUBTLE MID-LEVEL
WAVE, WILL FAVOR STORM DEVELOPMENT BY 20-22Z AS CONVECTIVE
INHIBITION ERODES. A VERY UNSTABLE AIRMASS CHARACTERIZED BY
2500-3000 J/KG MLCAPE AND ELONGATED HODOGRAPHS WILL STRONGLY FAVOR
SUPERCELLS. THE STRENGTH OF LOW-LEVEL SHEAR REMAINS UNCLEAR DURING
THE EARLY EVENING, WHEN THE TORNADO RISK COULD MAXIMIZE.
NONETHELESS, INCREASED CONFIDENCE IN WIDELY SCATTERED TO SCATTERED
SUPERCELLS YIELDING A RISK FOR LARGE TO GIANT HAIL PROMPTED AN
INCREASE IN HAIL AND HAIL-INTENSITY HIGHLIGHTS THIS OUTLOOK UPDATE.
..NORTHEAST
A LOW-AMPLITUDE DISTURBANCE ASSOCIATED WITH AN ONGOING MCS NEAR LAKE
ONTARIO THIS MORNING WILL MOVE EAST INTO THE NORTHEAST DURING THE
DAY. CLOUD BREAKS AND LOW-LEVEL WARM/MOIST ADVECTION WILL
CONTRIBUTE TO A DESTABILIZING AIRMASS BY MIDDAY. VEERING AND
STRENGTHENING WINDS WITH HEIGHT WILL SUPPORT STORM ORGANIZATION,
INCLUDING THE POTENTIAL FOR SUPERCELLS. EVENTUALLY A BAND OF STORMS
IS FORECAST TO EVOLVE BY MID-LATE AFTERNOON WITH WIND DAMAGE BEING
THE PRIMARY RISK. HAVE INTRODUCED LOW HAIL/TORNADO PROBABILITIES TO
ACCOUNT FOR HAZARDS ASSOCIATED WITH SUPERCELLS.
..SMITH/DEAN.. 04/14/2026
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