598  
ACUS48 KWNS 290857  
SWOD48  
SPC AC 290855  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0355 AM CDT SAT AUG 29 2026  
 
VALID 011200Z - 061200Z  
   
..DISCUSSION  
 
MEDIUM RANGE GUIDANCE CONSENSUS DEPICTS A PERSISTENT RIDGE FORTIFIED  
ACROSS THE CENTRAL CONUS THROUGH THE DAYS 4-8 (TUESDAY-SATURDAY)  
PERIOD. MULTIPLE MID-LEVEL SHORTWAVE TROUGHS AND SMALLER SCALE  
IMPULSES WILL PIVOT AROUND THE BROADER UPPER RIDGE AND TRAVERSE THE  
PACIFIC NORTHWEST TO NORTHERN PLAINS, GREAT LAKES, AND NORTHEAST  
THROUGH THE WEEK. THE BEST CHANCE FOR ROUNDS OF ORGANIZED STRONG TO  
SEVERE THUNDERSTORMS WILL BE WITH IMPULSES OVERSPREADING A MOIST  
BOUNDARY LAYER FROM THE UPPER MS VALLEY TO THE SOUTHERN NEW  
ENGLAND/MID-ATLANTIC REGIONS. DETAILS REGARDING THE TIMING AND  
PLACEMENT OF SOME OF THESE IMPULSES VARIES AMONG MEDIUM-RANGE  
GUIDANCE, RENDERING PREDICTABILITY TOO LOW FOR SEVERAL POTENTIAL  
SEVERE SCENARIOS.  
   
..DAYS 4-7 (TUESDAY-FRIDAY) - NORTHEAST/MID-ATLANTIC  
 
THE NORTHEAST TO MID-ATLANTIC WILL EXPERIENCE THE EAST-NORTHEAST  
PERIPHERY OF THE AFOREMENTIONED UPPER RIDGE, WITH MULTIPLE IMPULSES  
EXPECTED TO OVERSPREAD THE REGION THROUGH THE MIDDLE OF THE WEEK. AT  
LEAST ISOLATED TO SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED EACH  
DAY TUESDAY-FRIDAY. AT THE MOMENT, MEDIUM RANGE GUIDANCE CONSENSUS  
SHOWS THE STRONGEST SIGNAL IN A MID-LEVEL IMPULSE IMPINGING ON  
SOUTHERN NEW ENGLAND AND THE MID-ATLANTIC ON DAY 5/WEDNESDAY, WHERE  
SEVERE PROBABILITIES HAVE BEEN MAINTAINED.  
 
GUIDANCE ALSO DEPICTS THESE SAME REGIONS TO HAVE ADEQUATE VERTICAL  
WIND SHEAR AND INSTABILITY TUESDAY AND THURSDAY, PERHAPS EVEN  
EXTENDING INTO DAY 7/FRIDAY. LIKE WEDNESDAY, SEVERAL MEMBERS OF  
MEDIUM RANGE ML/AI GENERATED GUIDANCE ALSO HAS SEVERE PROBABILITIES  
OVER THESE REGIONS DAYS 4-7. UNLIKE WEDNESDAY THOUGH, DETERMINISTIC  
MEDIUM RANGE GUIDANCE VARIES IN PLACE AND TIME OF THE MORE SUBTLE  
IMPULSES EXPECTED TO SUPPORT SEVERE WEATHER OVER THE NORTHEAST. IT  
IS ACKNOWLEDGED THAT SEVERE PROBABILITIES WILL LIKELY BE NEEDED IN  
THE FUTURE. HOWEVER, PROBABILITIES HAVE BEEN WITHHELD OUTSIDE OF  
WEDNESDAY OUT OF PRUDENCE GIVEN THE DEGREE OF CHANGES IN FORECAST  
DETAILS EXPECTED IN THE COMING DAYS.  
 
..SQUITIERI.. 08/29/2026  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page