727  
ACUS01 KWNS 171612  
SWODY1  
SPC AC 171610  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1110 AM CDT THU SEP 17 2026  
 
VALID 171630Z - 181200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON  
AND EVENING OVER PARTS OF IDAHO/UTAH...AND A SMALL PART OF THE  
CENTRAL HIGH PLAINS....  
   
..SUMMARY
 
 
THUNDERSTORMS WITH ISOLATED SEVERE WIND GUSTS AND HAIL WILL BE  
POSSIBLE OVER PARTS OF THE INTERMOUNTAIN WEST THIS AFTERNOON AND  
EVENING. A FEW STRONG TO SEVERE GUSTS MAY ALSO OCCUR ACROSS PORTIONS  
OF THE CENTRAL HIGH PLAINS.  
   
..ID/UT
 
 
MORNING WATER VAPOR IMAGERY SHOWS AN UPPER LOW OVER NORTHERN CA,  
WITH A BAND OF STRONG FLOW ALOFT WITH ASSOCIATED EMBEDDED SHORTWAVE  
TROUGHS EXTENDING ACROSS NV INTO UT/ID. STRONG HEATING ACROSS THIS  
AREA WILL AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS FROM  
SOUTHERN ID INTO NORTHERN UT BY MID-AFTERNOON. SUFFICIENT VERTICAL  
SHEAR IS PRESENT FOR ROTATING UPDRAFTS CAPABLE OF LARGE HAIL AND  
GUSTY/DAMAGING WINDS. WHILE COVERAGE OF STORMS WILL LIKELY BE  
LIMITED, ONE OR TWO SEVERE CELLS ARE EXPECTED LATER TODAY - MAINLY  
OVER THE EASTERN SNAKE RIVER PLAIN.  
   
..CO/KS/NE
 
 
THE REMNANTS OF A WEAK TROPICAL LOW ARE TRACKING NORTHEASTWARD  
ACROSS THE FOUR-CORNERS REGION THIS MORNING. AMPLE MOISTURE AND  
WEAK ASCENT ASSOCIATED WITH THIS FEATURE WILL LEAD TO CONSIDERABLE  
CLOUDS AND SCATTERED THUNDERSTORMS TODAY OVER THE MOUNTAINS OF CO  
AND SOUTHERN WY. THIS ACTIVITY WILL SPREAD EASTWARD INTO EASTERN CO  
AND WESTERN NE/KS WITH HIGH-BASED CONVECTION POSING A RISK OF  
LOCALLY DAMAGING WIND GUSTS. THE EXTENT OF THIS SEVERE THREAT WILL  
BE MODULATED BY DAYTIME HEATING, WHICH IS UNCERTAIN AT THIS TIME DUE  
TO LINGERING CLOUD COVER.  
 
..HART/CHALMERS.. 09/17/2026  
 

 
 
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