782
ACUS01 KWNS 121250
SWODY1
SPC AC 121248
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0748 AM CDT SAT SEP 12 2026
VALID 121300Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL/SOUTHERN PLAINS...
..SUMMARY
ISOLATED TO SCATTERED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
LARGE TO VERY LARGE HAIL AND SEVERE/DAMAGING WINDS MAY OCCUR ACROSS
PARTS OF THE CENTRAL/SOUTHERN PLAINS INTO THE OZARKS THIS AFTERNOON
AND EVENING.
..CENTRAL/SOUTHERN PLAINS INTO THE OZARKS
MAINLY ELEVATED THUNDERSTORMS HAVE PERSISTED OVERNIGHT INTO THE
EARLY MORNING ACROSS SOUTHERN NE INTO EASTERN KS/WESTERN MO, AIDED
BY A MODEST LOW-LEVEL JET. THIS ACTIVITY WILL PROBABLY TEND TO
WEAKEN THROUGH THE REMAINDER OF THE MORNING, BUT SOME RECENT
GUIDANCE SUGGESTS ADDITIONAL THUNDERSTORMS DEVELOPING ALONG ITS
OUTFLOW ACROSS SOUTHERN KS/NORTHERN OK OVER THE NEXT FEW HOURS. IF
THIS DEVELOPMENT OCCURS, IT WOULD POTENTIALLY COMPLICATE
DESTABILIZATION AND SEVERE POTENTIAL LATER TODAY. RECENT SURFACE
OBSERVATIONS ALSO SHOW A FAIRLY STRONG COLD FRONT DRAPED FROM
EASTERN CO INTO KS AND NORTHWEST MO. THIS BOUNDARY WILL LIKELY SERVE
AS A FOCUS FOR ROBUST THUNDERSTORM DEVELOPMENT THIS
AFTERNOON/EVENING AS WELL. WITH A RATHER MOIST LOW-LEVEL AIRMASS
FORECAST TO BE PRESENT ALONG/SOUTH OF THE FRONT, CURRENT
EXPECTATIONS ARE FOR A NARROW ZONE OF MODERATE TO STRONG INSTABILITY
(MLCAPE 2000-3500 J/KG) TO DEVELOP THIS AFTERNOON FROM THE EASTERN
OK/TX PANHANDLES INTO SOUTHERN KS/NORTHERN OK. WEAK LOW-LEVEL WINDS
WILL VEER TO WEST-NORTHWESTERLY AND STRENGTHEN SOME WITH HEIGHT
THROUGH MID/UPPER LEVELS, SUPPORTING AROUND 30-40 KT OF DEEP-LAYER
SHEAR AND UPDRAFT ORGANIZATION. WHILE LARGE-SCALE ASCENT WILL REMAIN
FAIRLY WEAK/NEBULOUS ACROSS THE SOUTHERN/CENTRAL PLAINS, MOST
GUIDANCE SHOWS AT LEAST ISOLATED ROBUST THUNDERSTORM DEVELOPMENT
ALONG THE FRONT BY 21-23Z AS CONVECTIVE TEMPERATURES ARE REACHED.
WHILE THERE IS STILL UNCERTAINTY REGARDING CONVECTIVE EVOLUTION AND
PERSISTENCE OF ONGOING THUNDERSTORMS THIS MORNING, SOME SIGNAL
EXISTS IN MOST RECENT SHORT-TERM GUIDANCE THAT ISOLATED TO SCATTERED
CONVECTION WILL FORM ALONG MUCH OF THE LENGTH OF THE FRONT LATER
TODAY IN A RATHER FAVORABLE ENVIRONMENT TO SUPPORT SEVERE
THUNDERSTORMS. ANY SUSTAINED SUPERCELLS WOULD POSE A THREAT FOR
LARGE TO VERY LARGE HAIL, WITH STEEP MID-LEVEL LAPSE RATES AND AMPLE
INSTABILITY IN THE HAIL-GROWTH ZONE SUPPORTING POTENTIAL FOR 2+ INCH
DIAMETER HAIL ON AN ISOLATED BASIS. SOMEWHAT HIGHER-BASED CONVECTION
ALSO APPEARS PROBABLE FROM THE EASTERN OK/TX PANHANDLES INTO PARTS
OF SOUTHWEST/SOUTH-CENTRAL KS AND NORTHERN OK, WHERE A VERY
WELL-MIXED BOUNDARY LAYER WITH STEEP LOW/MID-LEVEL LAPSE RATES
SHOULD PROMOTE AN ENVIRONMENT THAT SUPPORTS SCATTERED SEVERE
DOWNDRAFT WINDS. SOME GUSTS COULD EXCEED 75 MPH. THE POTENTIAL FOR
CLUSTERING THIS AFTERNOON AND EVENING REMAINS UNCLEAR, BUT SOME
CHANCE FOR AT LEAST ISOLATED SEVERE/DAMAGING WINDS MAY PERSIST INTO
MUCH OF OK AND THE OZARKS, DEPENDENT ON UPSTREAM CONVECTIVE
EVOLUTION IN KS/WESTERN MO.
..UPPER OHIO VALLEY
A NARROW CORRIDOR OF FILTERED DIURNAL HEATING AND RELATED MODERATE
INSTABILITY SHOULD DEVELOP ACROSS PARTS OF THE UPPER OH VALLEY THIS
AFTERNOON BETWEEN DENSER CLOUDS AND PRECIPITATION OCCURRING ACROSS
OH, AND A STATIONARY BOUNDARY TO THE EAST. THUNDERSTORMS WILL
GRADUALLY INCREASE IN COVERAGE AND INTENSITY THROUGH THE AFTERNOON,
AIDED BY FORCING FOR ASCENT ASSOCIATED WITH AN APPROACHING WEAK
MID-LEVEL SHORTWAVE TROUGH. WHILE MID-LEVEL LAPSE RATES WILL REMAIN
POOR, SUFFICIENT DEEP-LAYER SHEAR COUPLED WITH MODEST STEEPENING OF
LOW-LEVEL LAPSE RATES SUGGEST SOME RISK FOR OCCASIONAL DAMAGING
WINDS WITH ANY LOOSELY ORGANIZED CLUSTERS/LINE SEGMENTS THAT CAN
FORM.
..GLEASON/LYONS.. 09/12/2026
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