215
ACUS02 KWNS 090554
SWODY2
SPC AC 090552
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1252 AM CDT TUE SEP 09 2025
VALID 101200Z - 111200Z
..NO SEVERE THUNDERSTORM AREAS FORECAST
..SUMMARY
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER PARTS OF THE
NORTHWEST, NORTHERN ROCKIES WITH MORE ISOLATED STORMS OVER THE HIGH
PLAINS WEDNESDAY. A STRONGER STORM OR TWO IS POSSIBLE, BUT SEVERE
POTENTIAL IS OVERALL LOW.
..HIGH PLAINS
EAST OF A DEEPENING UPPER LOW AND 40-50 KT MID-LEVEL JET OVER THE
GREAT BASIN AND NORTHWEST, SHORTWAVE RIDGING WILL PERSIST ACROSS THE
ROCKIES AND ADJACENT HIGH PLAINS. A BROAD LEE TROUGH IS EXPECTED TO
SHARPEN THROUGH THE AFTERNOON AS WEAK ASCENT FROM THE UPPER TROUGH
AND MID-LEVEL JET GLANCE THE WESTERN EDGE OF THE UPPER RIDGE. THE
STRONGEST ASCENT WILL BE FOCUSED NORTH AND WEST OVER MT WHERE A WEAK
SURFACE CYCLONE IS EXPECTED TO FORM BY WEDNESDAY AFTERNOON. THIS
WILL HELP DRAW RICHER LOW-LEVEL MOISTURE WESTWARD LATER IN THE
AFTERNOON/EVENING. THE LATE ARRIVAL OF THE MORE ROBUST MOISTURE
SUGGESTS BUOYANCY WILL BE LIMITED, WHILE CAPPING REMAINS STOUT OVER
THE NORTHERN AND CENTRAL HIGH PLAINS. STILL, ROBUST HEATING AND
SUFFICIENT LOW-LEVEL MOISTENING WILL ALLOW FOR ISOLATED HIGH-BASED
THUNDERSTORMS ALONG THE LENGTH OF THE SURFACE TROUGH ACROSS EASTERN
MT/WY AND WESTERN SD. A STRAY GUST OR TWO IS POSSIBLE, BUT LIMITED
BUOYANCY AND FORCING SUGGEST THE SEVERE RISK IS LOW.
FARTHER SOUTH, A WEAK SECONDARY LOW IS EXPECTED TO FORM OVER THE
RATON MESA. ENHANCED EASTERLY LOW-LEVEL UPSLOPE FLOW COULD SUPPORT
ISOLATED STORMS LATE AFTERNOON OR INTO EARLY EVENING. HOWEVER, WEAK
SUBSIDENCE AND WARM MID-LEVEL TEMPERATURES BENEATH THE UPPER RIDGE
SUGGEST REMNANT CAPPING IS LIKELY TO REMAIN IN PLACE, LIMITING STORM
COVERAGE/INTENSITY. WHILE MODERATE BUOYANCY IS EXPECTED (1500-2500
J/KG) AND AN ISOLATED STRONGER GUST IS POSSIBLE, OVERALL SEVERE
POTENTIAL APPEARS RATHER LIMITED.
..NORTHWEST AND NORTHERN ROCKIES
BENEATH THE UPPER LOW, BROAD ASCENT AND THE SOUTHERLY MID-LEVEL JET
WILL OVERSPREAD MODEST LOW-LEVEL MOISTURE AHEAD OF A WEAK COLD FRONT
OVER THE INTERMOUNTAIN WEST. FILTERED DAYTIME HEATING BETWEEN
REMNANT CLOUD COVER WILL AIDE IN SCATTERED STORM DEVELOPMENT ACROSS
THE HIGHER TERRAIN FROM EASTERN WA/OR INTO NORTHERN ID AND WESTERN
MT WEDNESDAY AFTERNOON. THE INCREASE IN SOUTHERLY FLOW ALOFT WILL
ELONGATE MID AND UPPER-LEVEL HODOGRAPHS TO SOME DEGREE, WITH 20-30
KT OF BULK SHEAR EXPECTED. THIS COULD SUPPORT A FEW STRONGER STORMS,
ESPECIALLY OVER PORTIONS OF CENTRAL ID AND INTO WESTERN MT WHERE
ASCENT WILL BE MAXIMIZED. GIVEN THE STEEP LOW AND MID-LEVEL LAPSE
RATES, A FEW STRONG GUSTS ARE POSSIBLE. HOWEVER, THE THREAT FOR MORE
ORGANIZED/PERSISTENT SEVERE STORMS APPEARS LIMITED BY WEAKER
BUOYANCY (MLCAPE ~500 J/KG) AND MOISTURE.
..LYONS.. 09/09/2025
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page