325  
ACUS01 KWNS 271943  
SWODY1  
SPC AC 271941  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0241 PM CDT SAT SEP 27 2025  
 
VALID 272000Z - 281200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
A SEVERE THREAT IS NOT EXPECTED TO DEVELOP ACROSS THE CONTINENTAL  
U.S. TODAY AND TONIGHT.  
   
..20Z UPDATE
 
 
NO CHANGES WERE MADE TO THE OUTLOOK, SEVERE POTENTIAL IS LIMITED.  
SCATTERED THUNDERSTORMS SHOULD CONTINUE UNDERNEATH A BROAD UPPER LOW  
OVER THE SOUTHWEST. MODEST MLCAPE, POOR MID-LEVEL LAPSE RATES AND  
DECREASING VERTICAL SHEAR WILL LIMIT STORM INTENSITY.  
 
A SIMILAR SITUATION IS EXPECTED BENEATH THE UPPER LOW OVER THE  
SOUTHEAST. HIGHER PWATS AND SOME CLUSTERING OF STORMS COULD PROMOTE  
AN OCCASIONAL WET MICROBURST. HOWEVER, LITTLE STORM ORGANIZATION AND  
THUS LOW SEVERE POTENTIAL IS EXPECTED. SEE THE PRIOR OUTLOOK FOR  
MORE INFO.  
 
..LYONS.. 09/27/2025  
   
PREV DISCUSSION
 
/ISSUED 1123 AM CDT SAT SEP 27 2025/  
   
..SYNOPSIS AND DISCUSSION
 
 
UPPER RIDGING CURRENTLY EXTENDS FROM THE ARKLATEX/LOWER MS VALLEY  
THROUGH THE CENTRAL HIGH PLAINS WITH UPPER LOWS FLANKING THIS  
RIDGING ON EACH SIDE. THE WESTERN UPPER LOW IS CENTERED OVER  
SOUTHERN CA/LOWER CO RIVER VALLEY. THIS LOW IS DISPLACED WELL SOUTH  
OF THE WESTERLIES ALONG THE US/CANADA BORDER AND IS NOT EXPECTED TO  
MOVE MUCH THROUGHOUT THE DAY. IN GENERAL, POOR LAPSE RATES SHOULD  
TEMPER THE BUOYANCY NEAR AND DOWNSTREAM OF THIS LOW (I.E. FROM THE  
LOWER CO VALLEY INTO AZ), MITIGATING THE OVERALL SEVERE POTENTIAL.  
THE GREATEST BUOYANCY IS EXPECTED ACROSS FAR EASTERN SOUTHERN CA AND  
SOUTHWESTERN AZ, NEAR THE CENTER OF THE UPPER LOW WHERE MID-LEVEL  
TEMPERATURES ARE COOLEST. HERE, A FEW STRONGER STORMS ARE POSSIBLE  
DURING THE AFTERNOON AND EVENING. SEVERE COVERAGE IS STILL EXPECTED  
TO BE TOO LOW TO MERIT ANY PROBABILITIES.  
 
THE EASTERN UPPER LOW, CURRENTLY CENTERED OVER THE SOUTHERN  
APPALACHIANS, HAS A MORE BROAD CIRCULATION THAN THE SOUTHERN CA LOW,  
WITH MOST GUIDANCE SUGGESTING IT DEVOLVES AND SHIFTS NORTHEASTWARD  
INTO THE MID-ATLANTIC THROUGHOUT THE PERIOD. MODERATE MID-LEVEL  
SOUTHWESTERLIES WILL PERSIST WITHIN THE EASTERN PERIPHERY OF THIS  
CYCLONE (I.E. FROM THE EASTERN CAROLINAS INTO NJ AND EASTERN PA)  
TODAY. BUOYANCY WILL BE MODEST, BUT THE STRONGER SHEAR FROM THESE  
SOUTHWESTERLIES COULD HELP SUPPORT A FEW STRONGER MULTICELLS CAPABLE  
OF DAMAGING GUSTS. OVERALL SEVERE COVERAGE IS STILL EXPECTED TO BE  
TOO LOW TO MERIT ANY PROBABILITIES.  
 

 
 
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