782  
ACUS01 KWNS 251639  
SWODY1  
SPC AC 251637  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1137 AM CDT SAT JUL 25 2026  
 
VALID 251630Z - 261200Z  
 
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR CENTRAL  
INTO EASTERN SOUTH DAKOTA...  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN CENTRAL AND  
EASTERN MONTANA...  
   
..SUMMARY
 
 
WIDESPREAD SEVERE GUSTS ARE POSSIBLE ACROSS SOUTH DAKOTA LATE THIS  
AFTERNOON THROUGH THE EVENING.  
   
..SD INTO ADJACENT PARTS OF IA/MN
 
 
A PROMINENT UPPER RIDGE CENTERED OVER THE CENTRAL/SOUTHERN ROCKIES  
WILL FEATURE THE SOUTHERN PERIPHERY OF APPRECIABLY STRONG MID TO  
HIGH-LEVEL FLOW EXTENDING FROM THE PACIFIC NORTHWEST ACROSS THE  
NORTHERN HIGH PLAINS AND INTO THE NORTH-CENTRAL STATES. LATE  
MORNING SURFACE ANALYSIS SHOWS VERY HOT TEMPERATURES ENSUING ACROSS  
WESTERN NE INTO THE WESTERN HALF OF SD WITH RICHER MOISTURE (SURFACE  
DEWPOINTS IN THE LOWER TO MID 70S F) LOCATED OVER THE EASTERN HALF  
OF NE/SD. VISIBLE-SATELLITE IMAGERY SHOWS SOME MID TO HIGH CLOUDS  
ACROSS NORTHERN WY MOVING TOWARDS THE BLACK HILLS. THIS PATCH OF  
CLOUDS APPEARS ASSOCIATED WITH A WEAK DISTURBANCE FORECAST TO MOVE  
INTO WESTERN SD LATER THIS AFTERNOON.  
 
DOWNSTREAM ACROSS SD, FORECAST SOUNDINGS SHOW VERY STEEP SURFACE TO  
500-MB LAPSE RATES DEVELOPING AS TEMPERATURES RISE INTO THE 100S F.  
EXPECTING INITIALLY ISOLATED TO WIDELY SCATTERED STORMS TO DEVELOP  
NEAR THE BLACK HILLS, AS CONVECTIVE TEMPERATURES ARE BREACHED.  
MODELS SHOW THE GRADUAL DEVELOPMENT OF A CLUSTER MOVING EAST ACROSS  
SD EARLY THIS EVENING. HAVE INCREASED SEVERE-WIND PROBABILITIES TO  
ACCOUNT FOR OBSERVATIONAL AND MODEL-BASED TRENDS TOWARDS AN MCS  
CAPABLE OF PEAK GUSTS IN THE 75-90 MPH RANGE. THIS ACTIVITY WILL  
PROBABLY SLOWLY WEAKEN TOWARDS THE MN/IA/SD BORDER BUT PERHAPS  
CONTINUE INTO EARLY OVERNIGHT WITH A WIND THREAT.  
   
..MT
 
 
ISOLATED TO SCATTERED STORMS WILL LIKELY FORM NEAR THE HIGHER  
TERRAIN OF SOUTHERN MT LATER THIS AFTERNOON WITH A GRADUAL INCREASE  
IN STORM COVERAGE AS THIS MOVES EAST DURING THE EARLY EVENING. A  
HOT AND WELL-MIXED BOUNDARY LAYER WILL SUPPORT SEVERE GUSTS WITH THE  
STRONGER CORES AND ASSOCIATED OUTFLOW. THERE IS SOME INDICATION  
THIS ACTIVITY WILL CLUSTER AND POTENTIALLY REACH PARTS OF  
EASTERN/SOUTHEAST MT BY THE LATE EVENING.  
   
..UPPER MIDWEST/UPPER GREAT LAKES
 
 
CONDITIONAL SEVERE POTENTIAL EXISTS ACROSS PARTS OF THE UPPER  
MIDWEST SPANNING MINNESOTA TO UPPER MICHIGAN INTO WISCONSIN. MODELS  
CONTINUE TO SHOW LOW STORM CHANCES AS MID-LEVEL HEIGHTS RISE THROUGH  
THE LATE EVENING. NONETHELESS, APPRECIABLE HEATING OF A SEASONABLY  
MOIST BOUNDARY LAYER WILL RESULT IN STRONG POTENTIAL BUOYANCY LATER  
TODAY INTO TONIGHT. ELONGATED HODOGRAPHS WILL SUPPORT ORGANIZED  
STORMS CAPABLE OF A WIND/HAIL THREAT. GIVEN A MUTED DIURNAL STORM  
SIGNAL IN MODELS, THE GREATER CHANCE FOR ISOLATED STORMS APPEARS TO  
BE ASSOCIATED WITH WARM ADVECTION ACTIVITY LATE TONIGHT.  
   
..NORTHEAST NV/NORTHERN UT/EASTERN ID
 
 
STORM DEVELOPMENT IS EXPECTED DURING THE AFTERNOON ACROSS PARTS OF  
NORTHEAST NEVADA, ALONG THE WESTERN PERIPHERY OF THE UPPER RIDGE.  
THESE STORMS WILL SPREAD INTO ADJACENT PARTS OF SOUTHEAST IDAHO AND  
NORTHWEST UTAH WITH TIME. ISOLATED SEVERE GUSTS MAY ACCOMPANY THE  
STRONGER DOWNDRAFTS.  
   
..SOUTH-CENTRAL/SOUTHEAST AZ
 
 
HIGH-BASED CONVECTION IS AGAIN EXPECTED ACROSS SOUTHEAST ARIZONA  
DURING THE AFTERNOON, WITH INITIAL DOWNBURST POTENTIAL. A MODEST  
ENHANCEMENT TO EASTERLY FLOW ALONG THE SOUTHERN PERIPHERY OF THE  
UPPER RIDGE MAY ALLOW FOR LOCALIZED STRONG TO SEVERE WIND GUSTS TO  
SPREAD WESTWARD INTO PARTS OF SOUTH-CENTRAL ARIZONA, BEFORE  
CONVECTION WEAKENS TONIGHT.  
 
..SMITH/MOORE.. 07/25/2026  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page