500  
ACUS02 KWNS 220606  
SWODY2  
SPC AC 220604  
 
DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0104 AM CDT SUN JUN 22 2025  
 
VALID 231200Z - 241200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT  
LAKES/UPPER MIDWEST INTO THE CENTRAL PLAINS...  
   
..SUMMARY  
 
STRONG TO POTENTIALLY SEVERE STORMS MAY DEVELOP ON MONDAY FROM PARTS  
OF THE GREAT LAKES INTO THE CENTRAL PLAINS.  
   
..SYNOPSIS  
 
A MID/UPPER-LEVEL SHORTWAVE TROUGH INITIALLY OVER THE NORTHERN  
PLAINS AND CANADIAN PRAIRIES WILL MOVE INTO ONTARIO ON MONDAY, AS A  
SURFACE LOW MOVES INTO QUEBEC. A TRAILING COLD FRONT WILL MOVE  
ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST/GREAT  
LAKES. AN EXPANSIVE UPPER RIDGE WILL REMAIN IN PLACE OVER MUCH OF  
THE EASTERN CONUS.  
   
..GREAT LAKES/UPPER MIDWEST  
 
SCATTERED STORMS MAY BE ONGOING MONDAY MORNING ACROSS PARTS OF  
MN/WI. WHILE THIS CONVECTION WILL LIKELY BE SOMEWHAT ELEVATED,  
MODERATE MUCAPE AND SUFFICIENT DEEP-LAYER SHEAR COULD SUPPORT AN  
ISOLATED SEVERE THREAT WITH THE STRONGEST EARLY-DAY STORMS.  
 
DIURNAL HEATING/DESTABILIZATION MAY SUPPORT INTENSIFICATION OF  
MORNING STORMS, ALONG WITH ADDITIONAL DEVELOPMENT IN THE VICINITY OF  
THE FRONT DURING THE AFTERNOON INTO THE EVENING. RELATIVELY STRONG  
DIURNAL HEATING WILL SUPPORT MODERATE TO LOCALLY STRONG BUOYANCY  
ALONG/AHEAD OF THE FRONT, IN AREAS NOT OVERLY INFLUENCED BY MORNING  
CONVECTION. UNIDIRECTIONAL WIND PROFILES AND 25-40 KT IN THE 850-700  
MB LAYER COULD SUPPORT ONE OR MORE OUTFLOW-DRIVEN CLUSTERS WITH A  
THREAT OF DAMAGING WIND AND ISOLATED HAIL.  
   
..CENTRAL PLAINS VICINITY  
 
DIURNAL STORM DEVELOPMENT WILL BE POSSIBLE MONDAY AFTERNOON ALONG  
THE FRONT ACROSS PARTS OF THE CENTRAL PLAINS, AS WELL AS WITHIN A  
POST-FRONTAL REGIME INTO PARTS OF THE HIGH PLAINS AND FRONT RANGE.  
INSTABILITY WILL BE STRONGEST ALONG/AHEAD OF THE FRONT, WHERE THE  
STRONGEST HEATING IS EXPECTED, THOUGH DEEP-LAYER SHEAR WILL BE  
RATHER WEAK ACROSS THE WARM SECTOR. A FEW STRONG MULTICELLS OR  
CLUSTERS MAY DEVELOP NEAR THE FRONT AND POSE A THREAT OF LOCALIZED  
SEVERE GUSTS. GIVEN THE EXPECTED WIDESPREAD COVERAGE OF STORMS  
WITHIN A FAVORABLE THERMODYNAMIC ENVIRONMENT (WITH STEEP PREFRONTAL  
LOW-LEVEL LAPSE RATES AND LARGE PW) FOR STRONG TO SEVERE GUSTS, THE  
SLIGHT RISK HAS BEEN EXTENDED INTO PARTS OF THE CENTRAL PLAINS.  
 
EFFECTIVE SHEAR WILL BE STRONGER TO THE COOL SIDE OF THE FRONT, DUE  
TO THE PRESENCE OF LOW-LEVEL EAST/NORTHEASTERLIES BENEATH SOUTHWEST  
FLOW ALOFT. COVERAGE AND INTENSITY OF POST-FRONTAL CONVECTION  
REMAINS SOMEWHAT UNCERTAIN, BUT ISOLATED HAIL AND STRONG TO SEVERE  
GUSTS WILL BE POSSIBLE.  
 
GUIDANCE STILL VARIES SOMEWHAT REGARDING DESTABILIZATION INTO PARTS  
OF THE CO FRONT RANGE. FAVORABLY VEERING WIND PROFILES COULD SUPPORT  
ISOLATED STRONG STORMS IN THIS AREA IF SUFFICIENT DESTABILIZATION  
CAN OCCUR.  
   
..NORTHERN NEW ENGLAND  
 
STRONG INSTABILITY WILL DEVELOP MONDAY AFTERNOON ACROSS PARTS OF THE  
NORTHEAST AND MID ATLANTIC, THOUGH THE INFLUENCE OF THE UPPER RIDGE  
WILL TEND TO SUPPRESS STORM DEVELOPMENT ACROSS MUCH OF THE REGION. A  
WARM ADVECTION REGIME WILL DEVELOP OVER NORTHERN NEW ENGLAND, AS  
WARMER LOW-LEVEL TEMPERATURES SPREAD EASTWARD. STORM DEVELOPMENT  
CANNOT BE RULED OUT WITHIN THIS REGIME, THOUGH MOST GUIDANCE  
SUGGESTS WARM TEMPERATURES ALOFT MAY TEND TO SUPPRESS CONVECTION.  
SOME GUIDANCE SUGGESTS CONVECTION MAY APPROACH NORTHERN ME FROM  
QUEBEC WITHIN A DESTABILIZING ENVIRONMENT. A CONDITIONAL MARGINAL  
RISK FOR DAMAGING GUSTS HAS BEEN ADDED FOR THIS POTENTIAL THREAT.  
 
..DEAN.. 06/22/2025  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page