989
ACUS01 KWNS 041954
SWODY1
SPC AC 041952
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0252 PM CDT MON AUG 04 2025
VALID 042000Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE HIGH PLAINS...
..SUMMARY
THUNDERSTORMS WITH SEVERE GUSTS AND LARGE TO VERY LARGE HAIL WILL BE
POSSIBLE THIS AFTERNOON THROUGH THIS EVENING FROM PARTS OF THE
NORTHERN ROCKIES INTO THE DAKOTAS AND CENTRAL/SOUTHERN HIGH PLAINS.
..20Z UPDATE
NO CHANGES ARE NEEDED TO THE CURRENT D1 CONVECTIVE OUTLOOK. SEE
PREVIOUS DISCUSSION BELOW FOR MORE INFORMATION.
..THORNTON.. 08/04/2025
PREV DISCUSSION
/ISSUED 1136 AM CDT MON AUG 04 2025/
..CENTRAL HIGH PLAINS
AN UPPER RIDGE EXTENDING FROM NM NORTH-NORTHEASTWARD INTO THE
CENTRAL HIGH PLAINS WILL FEATURE A COUPLE OF WEAK DISTURBANCES
CRESTING THE RIDGE THROUGH EARLY TUESDAY MORNING. THE MOST NOTABLE
DISTURBANCE OVER NORTHEAST UT LATE THIS MORNING IS FORECAST TO MOVE
EAST ACROSS SOUTHERN WY BY EARLY EVENING AND POTENTIALLY PLAY A ROLE
IN STORM DEVELOPMENT LATE THIS AFTERNOON/EVENING. A SEASONABLY
MOIST AIRMASS FEATURING 55-60 DEG F DEWPOINTS INTO EASTERN WY/NE
PANHANDLE WILL UNDERGO STRONG HEATING. LOW-LEVEL SOUTHEASTERLY FLOW
WILL VEER TO NORTHWESTERLY IN THE MID LEVELS, RESULTING IN MODERATE
TO STRONG DEEP-LAYER VERTICAL SHEAR AND AN OVERALL WIND PROFILE THAT
FAVORS SUPERCELLS. AS SUCH, THERE IS CONDITIONAL RISK FOR SEVERE
THUNDERSTORMS. HOWEVER, THE FORCING MECHANISM FOR CONVECTIVE
INITIATION IS FAIRLY WEAK. THE GENERAL EXPECTATION IS THAT
LOW-LEVEL CONVERGENCE AND UPSLOPE FLOW ACROSS THE BLACK HILLS
VICINITY SHOULD BE ENOUGH FOR SCATTERED CONVECTIVE INITIATION WITH
OTHER WIDELY SCATTERED STORMS POSSIBLE FARTHER SOUTH.
THE ENVIRONMENT SUPPORTS SUPERCELLS CAPABLE OF LARGE TO VERY LARGE
HAIL AND SEVERE GUSTS. ANY SUPERCELLS THAT DEVELOP COULD LAST FOR A
FEW HOURS, BUT SHOULD EVENTUALLY TREND TOWARDS A MORE LINEAR MODE
WITH ONE OR MORE CLUSTERS EVOLVING ACROSS WESTERN/CENTRAL NE AND
NORTHEAST CO THIS EVENING. AIDED BY A 40+ KT LOW-LEVEL JET,
CONTINUED UPSCALE GROWTH SHOULD SUPPORT THESE CLUSTERS OF STRONG TO
SEVERE STORMS INTO THE OVERNIGHT HOURS WHERE DAMAGING WINDS WILL BE
POSSIBLE.
..NORTHERN ROCKIES INTO EASTERN MONTANA
WATER-VAPOR IMAGERY SHOWS A POTENT MID- TO UPPER-LEVEL SHORTWAVE
TROUGH MOVING EAST ACROSS OR THIS MORNING. THIS DISTURBANCE IS
FORECAST TO MOVE INTO THE NORTHERN ROCKIES BY EARLY EVENING AND INTO
THE NORTHERN HIGH PLAINS BY DAYBREAK. STRONG LARGE-SCALE ASCENT
ASSOCIATED WITH THIS SHORTWAVE TROUGH AS IT ACQUIRES A NEGATIVE
TILT, WILL FAVOR ISOLATED TO SCATTERED STORMS FROM THE SNAKE VALLEY
NORTHWARD INTO NORTH-CENTRAL ID AND INTO WESTERN/SOUTHWEST MT.
INITIALLY CELLULAR STORMS WILL POSE AN ISOLATED RISK FOR SEVERE WIND
GUSTS. AS STORMS MOVE INTO THE HIGH PLAINS, SLIGHTLY GREATER
LOW-LEVEL MOISTURE WILL AID IN MORE NUMEROUS STORMS DEVELOPING AND
THEIR ATTENDANT OUTFLOW. SCATTERED SEVERE GUSTS (60-75 MPH) ARE
POSSIBLE WITH THIS ACTIVITY AS IT MOVES EAST-NORTHEAST ACROSS MT.
..SOUTHERN HIGH PLAINS
STRONG HEATING ALONG A LEE TROUGH COULD SUPPORT ISOLATED TO WIDELY
SCATTERED THUNDERSTORM DEVELOPMENT FROM THE RATON MESA INTO
SOUTHEAST CO/NORTHEAST NM. AMPLE HIGH-LEVEL FLOW ATOP STRONGLY
VEERING LOW-LEVEL WINDS, COUPLED WITH A VERY UNSTABLE AIRMASS ON THE
WESTERN PERIPHERY OF RICH MOISTURE, WILL FAVOR THE POSSIBILITY FOR A
FEW SUPERCELLS BY LATE AFTERNOON. LARGE TO VERY LARGE HAIL, SEVERE
GUSTS, AND A BRIEF TORNADO ARE THE POTENTIAL HAZARDS. SOME GUIDANCE
SHOWS A CLUSTER EVOLVING DURING THE EVENING WITH SEVERE GUSTS
BECOMING THE PRIMARY HAZARD.
..CENTRAL/SOUTHEAST TEXAS
A WEAKENING SQUALL LINE WILL CONTINUE SOUTHWARD TO THE MIDDLE TX
COAST OVER THE NEXT COUPLE OF HOURS WITH OTHER WEAK THUNDERSTORM
ACTIVITY PERHAPS LINGERING ATOP THE COLD POOL. ISOLATED STRONG
GUSTS WILL PROBABLY BECOME INCREASINGLY LOCALIZED DURING THE MIDDAY.
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