420
ACUS01 KWNS 130601
SWODY1
SPC AC 130559
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT SAT JUN 13 2026
VALID 131200Z - 141200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
KANSAS...MUCH OF WESTERN AND CENTRAL MISSOURI...AND NORTHEASTERN
OKLAHOMA...
..SUMMARY
SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF THE
CENTRAL AND SOUTHERN PLAINS INTO THE MISSOURI VALLEY. SWATHS OF
DAMAGING WIND GUSTS, LARGE HAIL, AND A COUPLE OF TORNADOES ARE ALL
POSSIBLE.
..SYNOPSIS
WITHIN THE BASE OF A BROAD LARGE-SCALE TROUGH AND ACCOMPANYING BELT
OF STRONG MIDLEVEL WESTERLIES OVER THE NORTHERN CONUS, AN EMBEDDED
POSITIVE-TILT MIDLEVEL TROUGH WILL OVERSPREAD THE NORTHERN PLAINS
THROUGH THE PERIOD. IN THE LOW-LEVELS, A WEAK SURFACE LOW WILL MOVE
SLOWLY EASTWARD ACROSS WESTERN/CENTRAL KS DURING THE DAY, BEFORE
BEING OVERTAKEN BY A COLD FRONT INTO THE EVENING HOURS.
..CENTRAL/SOUTHERN PLAINS INTO THE MISSOURI VALLEY
AT THE START OF THE PERIOD, A CLUSTER OF ELEVATED THUNDERSTORMS
SHOULD BE TRACKING EASTWARD FROM NE INTO IA -- ALONG THE NOSE OF A
GRADUALLY WEAKENING NOCTURNAL LOW-LEVEL JET. STEEP MIDLEVEL LAPSE
RATES AND 40-50 KT OF EFFECTIVE SHEAR WILL FAVOR LARGE HAIL WITH
THIS ACTIVITY. AT THE SAME TIME, A CONVECTIVELY AUGMENTED MIDLEVEL
IMPULSE AND LINGERING CONVECTION SHOULD BE ADVANCING EASTWARD FROM
EASTERN KS INTO MO. DIURNAL HEATING OF A MOIST AIR MASS SHOULD FAVOR
A GRADUAL INCREASE IN CONVECTIVE COVERAGE AND INTENSITY ALONG
RELATED OUTFLOW INTO THE AFTERNOON HOURS. MODERATE SURFACE-BASED
BUOYANCY AND 30-40 KT OF EFFECTIVE SHEAR WILL SUPPORT ORGANIZED
CLUSTERS AND POTENTIALLY SUPERCELLS STRUCTURES, WITH A RISK OF
DAMAGING WIND GUSTS AND LARGE HAIL. SOME GUIDANCE SUGGESTS THAT THIS
ACTIVITY MAY GROW UPSCALE INTO ONE OR MORE ORGANIZED CLUSTERS WHILE
MOVING EAST-SOUTHEASTWARD INTO THE EVENING HOURS.
FARTHER WEST, STRONG DIURNAL HEATING/STEEPENING LOW-LEVEL LAPSE
RATES PRECEDING THE SURFACE LOW WILL RESULT IN SCATTERED
THUNDERSTORM DEVELOPMENT FROM THE CENTRAL PLAINS INTO THE LOWER MO
VALLEY. STEEP MIDLEVEL LAPSE RATES ATOP RICH BOUNDARY-LAYER MOISTURE
WILL YIELD A STRONGLY UNSTABLE AIR MASS, WHICH COMBINED WITH AROUND
40 KT OF EFFECTIVE SHEAR, WILL FAVOR ORGANIZED CLUSTERS AND
SEMI-DISCRETE SUPERCELLS. LARGE HAIL AND LOCALLY SEVERE WIND GUSTS
WILL BE THE MAIN CONCERNS WITH INITIALLY SEMI-DISCRETE STORMS. WITH
TIME, ADDITIONAL THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG THE
SOUTHEASTWARD-MOVING COLD FRONT. AS A RESULT, SEVERAL
INTENSE/ORGANIZED CLUSTERS WILL SPREAD EAST-SOUTHEASTWARD THROUGH A
CORRIDOR OF STRONG SURFACE-BASED BUOYANCY -- POSING AN INCREASING
RISK OF SCATTERED SEVERE WIND GUSTS (SOME 75+ MPH). DESPITE THE
EXPECTATION FOR UPSCALE GROWTH, EMBEDDED SUPERCELLS WILL REMAIN
POSSIBLE, AND GIVEN AMPLE LOW-LEVEL SHEAR AND RICH MOISTURE, A
COUPLE TORNADOES WILL ALSO BE POSSIBLE.
..WEINMAN.. 06/13/2026
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