604
ACUS01 KWNS 201959
SWODY1
SPC AC 201957
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT SAT JUN 20 2026
VALID 202000Z - 211200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS...
..SUMMARY
SEVERE THUNDERSTORMS REMAIN LIKELY ACROSS PARTS OF THE CENTRAL
PLAINS MAINLY THIS AFTERNOON AND EVENING. LARGE TO VERY LARGE HAIL,
SEVERE WINDS (SOME 75+ MPH), AND A FEW TORNADOES ARE POSSIBLE.
..20Z UPDATE WY/NE/CO/KS
SCATTERED SEVERE STORMS ARE LIKELY OVER MUCH OF THE CENTRAL HIGH
PLAINS THIS AFTERNOON AND EVENING. INCIPIENT CONVECTION IS
DEVELOPING OVER THE HIGHER TERRAIN/FOOTHILLS AND SHOULD SPREAD
EASTWARD INTO A MOIST AND DESTABILIZING AIR MASS. AIDED BY STRONG
ASCENT FROM AN UPPER TROUGH AND MID-LEVEL JET (OBSERVED VIA 18Z
RAOBS), SUPERCELLS AND ORGANIZED CLUSTERS REMAIN LIKELY. ALL HAZARDS
ARE EXPECTED, WITH A FOCUS FOR A FEW MORE PERSISTENT SUPERCELLS AND
A STRONG TORNADO OR TWO ALONG A NOTABLE DIFFERENTIAL HEATING AXIS IN
SOUTHWESTERN NE. WITH TIME UPSCALE GROWTH INTO AND MCS IS LIKELY
TONIGHT WITH A RISK FOR DAMAGING WINDS INTO THE CENTRAL PLAINS.
MINOR ADJUSTMENTS WERE MADE TO THE PROBABILITIES FOR THE LATEST
OBSERVED TRENDS. FOR SHORT TERM INFORMATION SEE MCD #1212.
..GREAT BASIN
SCATTERED THUNDERSTORMS HAVE DEVELOPED OVER PARTS OF NV AND SOUTHERN
ID ALONG A DIFFUSE FRONTAL ZONE. WHILE MOISTURE IS LIMITED, ENOUGH
INSTABILITY BENEATH THE PASSING UPPER TROUGH WILL SUPPORT THE
POTENTIAL FOR A FEW SEVERE GUSTS. 5% WIND PROBABILITIES WERE
EXTENDED WESTWARD. SEE MCD #1213 FOR MORE INFO.
..SOUTHEAST
SCATTERED TO WIDESPREAD THUNDERSTORMS CONTINUE ACROSS MUCH OF THE
GULF COAST AND SOUTHEAST STATES THIS AFTERNOON. SPORADIC DAMAGING
GUSTS REMAIN POSSIBLE WITH THE STRONGER CLUSTERS ACROSS NORTHERN FL
AND SOUTHERN LA. WEAK SHEAR WILL PRECLUDE MUCH IF ANY STORM
ORGANIZATION. 5% WIND PROBABILITIES WERE ADJUSTED TO BETTER MATCH
DAMAGING WIND POTENTIAL.
..LYONS.. 06/20/2026
PREV DISCUSSION
/ISSUED 1109 AM CDT SAT JUN 20 2026/
..CENTRAL PLAINS
WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH OVER ID/UT TRACKING
EASTWARD TOWARD THE CENTRAL HIGH PLAINS. SOUTHERLY/SOUTHEASTERLY
LOW-LEVEL WINDS AHEAD OF THIS FEATURE OVER PARTS OF EASTERN
CO/WESTERN NE/KS WILL HELP TO MAINTAIN A MOIST AND MODERATELY
UNSTABLE AIR MASS ACROSS THE REGION, ESPECIALLY AS LOW CLOUDS
CONTINUE TO BURN OFF AND AFTERNOON HEATING COMMENCES. SCATTERED
THUNDERSTORM DEVELOPMENT IS EXPECTED BY MID-AFTERNOON OVER CENTRAL
WY DOWN INTO CENTRAL CO IN FAVORED TERRAIN/CONVERGENCE AREAS. THIS
ACTIVITY WILL SPREAD EASTWARD INTO A PROGRESSIVELY MORE
MOIST/UNSTABLE AIR MASS AND INTENSIFY INTO SUPERCELLS. A CORRIDOR
OF FAVORABLE VERTICAL SHEAR WILL DEVELOP LATER TODAY FROM NORTHEAST
CO INTO SOUTHWEST NE/NORTHWEST KS FOR ISOLATED TORNADOES.
OTHERWISE, VERY LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN
CONCERNS. ACTIVITY IS LIKELY TO ORGANIZE UPSCALE DURING THE EVENING
AND SPREAD ACROSS KS WITH A DAMAGING WIND RISK PERSISTING MUCH OF
THE NIGHT.
..SOUTHEAST
A VERY MOIST AND MODERATELY UNSTABLE AIR MASS IS PRESENT AGAIN TODAY
OVER MUCH OF THE SOUTHEAST US. MOST CAM SOLUTIONS SUGGEST SCATTERED
AFTERNOON THUNDERSTORMS ACROSS THIS AREA, INCLUDING ALONG THE FL
EAST COAST. DEWPOINTS IN THE 70S AND PWAT VALUES AROUND 2 INCHES,
COUPLED WITH STRONG DAYTIME HEATING AND STEEP LOW-LEVEL LAPSE RATES
SUGGEST A RISK OF LOCALLY GUSTY/DAMAGING WIND GUSTS IN THE MOST
INTENSE CORES.
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