492
ACUS01 KWNS 151644
SWODY1
SPC AC 151643
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1143 AM CDT THU OCT 15 2026
VALID 151630Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDWEST...
..SUMMARY
THUNDERSTORMS CAPABLE OF SEVERE WIND GUSTS AND A TORNADO OR TWO ARE
POSSIBLE TODAY ACROSS PARTS OF THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS.
..MIDWEST/OHIO VALLEY
EXTREME/RECORD-CALIBER SEASONAL MOISTURE CONTENT EXISTS OVER THE
REGION WITH WARM-SECTOR PREVALENT 2+ INCH PRECIPITABLE WATER VALUES
AND SURFACE DEWPOINTS IN EXCESS OF 70F. A SURFACE WAVE OVER THE
MIDDLE PART OF MISSOURI LATE THIS MORNING SHOULD GRADUALLY/MODESTLY
DEEPEN AS IT PROGRESSES EAST-NORTHEASTWARD NEAR A NORTHWARD-SHIFTING
WARM FRONT, ALTHOUGH THE FRONT/WARM SECTOR ARE A BIT MUDDLED BY
ONGOING CONVECTION ACROSS SOUTHERN PORTIONS OF MISSOURI AND
ILLINOIS.
CURRENT SPLIT FLOW OVER THE GREAT PLAINS WILL QUICKLY RESOLVE, WITH
A CENTRAL PLAINS SHORTWAVE TROUGH/SPEED MAX PHASING WITH A
BROADER-SCALE UPPER TROUGH OVER THE UPPER MIDWEST THROUGH TONIGHT.
THE NET RESULT WILL BE A STRENGTHENING OF DEEP-LAYER WINDS
ALONG/NORTH OF THE WARM SECTOR THAT WILL SHIFT POLEWARD, ALTHOUGH TO
WHAT EXACT DEGREE/SPATIAL EXTENT IS UNCERTAIN GIVEN SOME OF THE
ONGOING CONVECTION.
AT LEAST SOME SCATTERING OF WARM-SECTOR CLOUD COVER, DIURNAL HEATING
AND THE INCREASING MOISTURE CONTENT WITH NORTHWARD EXTENT WILL ALLOW
FOR MODEST COOL SEASON DESTABILIZATION, WITH SBCAPE POTENTIALLY
EXCEEDING 1000 J/KG ACROSS THE LOWER WABASH VALLEY AND
SOUTHERN/DOWNSTATE PORTIONS OF ILLINOIS AND INDIANA. THIS SHOULD
ALLOW FOR RE-DEVELOPMENT/INTENSIFICATION OF STORMS THIS AFTERNOON,
ALTHOUGH THE EXACT MAGNITUDE OF TODAY'S SEVERE RISK IS STILL A BIT
UNCERTAIN AND CONTINGENT ON SURFACE HEATING/DESTABILIZATION. BUT
THIS SCENARIO COULD INCLUDE A FEW SUPERCELLS, WITH THE POSSIBILITY
OF A SEMI-FOCUSED SEVERE/SOME TORNADO RISK NEAR THE WARM FRONT,
WHICH MAY BE AUGMENTED BY SOME OF THE PRIOR CONVECTION, AND AHEAD OF
THE SURFACE LOW. SUPERCELLS ASIDE, SOME SEMI-ORGANIZED CLUSTERS
CAPABLE OF WIND DAMAGE SHOULD EVOLVE WITHIN THE HIGH-MOISTURE
CONTENT ENVIRONMENT AND 40+ KT EFFECTIVE SHEAR. OVERALL STORM
INTENSITY IS LIKELY TO WANE WITHIN A COUPLE HOURS OF SUNSET,
GENERALLY BY LATE EVENING.
..NORTH/WEST TEXAS
AN OUTFLOW-AUGMENTED COLD FRONT WILL CONTINUE TO SPREAD
SOUTHEASTWARD. THE TENDENCY FOR POST-FRONTAL CONVECTION SHOULD
REMAIN THE DOMINANT SCENARIO WITH BOUNDARY-PARALLEL DEEP-LAYER FLOW
CONTRIBUTING TO A MORE ANAFRONTAL CHARACTER. GRADUAL DIURNAL HEATING
COULD SUPPORT SOME INTENSIFICATION OF STORMS ALONG THE LEADING EDGE
OF THE COMPOSITE BOUNDARY THIS AFTERNOON. AS SUCH, SOME STRONGER
WIND GUSTS ARE PLAUSIBLE, BUT THIS SCENARIO AND RELATED POTENTIAL
FOR ORGANIZED SEVERE STORMS IS CURRENTLY EXPECTED TO REMAIN LIMITED.
..GUYER/MARSH.. 10/15/2026
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