216  
ACUS02 KWNS 031726  
SWODY2  
SPC AC 031725  
 
DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1225 PM CDT FRI NOV 03 2017  
 
VALID 041200Z - 051200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
THE RISK FOR SEVERE STORMS APPEARS NEGLIGIBLE ACROSS THE U.S.,  
SATURDAY THROUGH SATURDAY NIGHT.  
   
..DISCUSSION
 
 
A PROMINENT SUBTROPICAL HIGH APPEARS LIKELY TO REMAIN CENTERED NEAR  
OR ACROSS THE MEXICAN PLATEAU THROUGH THIS PERIOD. HOWEVER, A SHORT  
WAVE PERTURBATION PROGRESSING AROUND ITS PERIPHERY (ACROSS THE  
SOUTHERN PLAINS INTO LOWER MISSISSIPPI VALLEY AT THE PRESENT TIME)  
MAY CONTRIBUTE TO WEAKENING OF RIDGING CURRENTLY EXTENDING EASTWARD  
ACROSS THE EASTERN GULF OF MEXICO/FLORIDA/BAHAMAS/CARIBBEAN VICINITY  
BY 12Z SATURDAY. MODELS SUGGEST THAT THE STRONGER PORTION OF THE  
REMNANT IMPULSE WILL THEN DIG ACROSS THE EASTERN GULF OF MEXICO  
THROUGH EARLY SUNDAY, WITH MID-LEVEL HEIGHT RISES IN ITS WAKE  
SPREADING FROM THE OZARK PLATEAU/SOUTHERN PLAINS THROUGH MUCH OF THE  
SOUTHEAST.  
 
MEANWHILE, MUCH OF THE NORTHERN TIER OF THE U.S. INTO SOUTHERN  
CANADA WILL REMAIN UNDER THE INFLUENCE OF A GENERALLY ZONAL BRANCH  
OF WESTERLIES EMANATING FROM THE NORTHERN MID-LATITUDE PACIFIC.  
WITHIN THIS REGIME, ONE SIGNIFICANT SHORT WAVE TROUGH (NOW BEGINNING  
TO PROGRESS INLAND OF THE PACIFIC NORTHWEST COAST) IS FORECAST TO  
ACCELERATE ACROSS AND EAST NORTHEAST OF THE CANADIAN PRAIRIES, AS  
ANOTHER DIGS NEAR THE BRITISH COLUMBIA INTO PACIFIC NORTHWEST COAST.  
 
IN RESPONSE TO THE LEAD IMPULSE, MODELS INDICATE THAT MODEST  
CYCLOGENESIS MAY COMMENCE NEAR THE CENTRAL CANADIAN/U.S. BORDER  
AREA. AS THE DEVELOPING LOW TRACKS ACROSS SOUTHERN MANITOBA INTO  
NORTHWEST ONTARIO BY LATE SATURDAY NIGHT, ANOTHER SURGE OF COLDER  
AIR IS EXPECTED TO THE LEE OF THE NORTHERN U.S. ROCKIES, INTO THE  
UPPER MISSISSIPPI/MID MISSOURI VALLEYS AND CENTRAL PLAINS BY 12Z  
SUNDAY.  
 
A PRECEDING FRONT MAY ALREADY BE IN THE PROCESS OF  
ADVANCING/REDEVELOPING NORTHWARD INTO/THROUGH PORTIONS OF THE  
SOUTHERN GREAT LAKES REGION, THE MIDDLE MISSISSIPPI VALLEY AND  
SOUTH CENTRAL PLAINS. THIS WILL OCCUR COINCIDENT WITH A CONTINUING  
SOUTHERLY RETURN FLOW OF MOISTURE OFF THE WESTERN GULF OF MEXICO.  
AT THE PRESENT TIME, IT APPEARS THAT THE PRIMARY FOCUS FOR ANY  
THUNDERSTORM DEVELOPMENT WILL BE WITHIN AN AREA OF ENHANCED  
LARGE-SCALE ASCENT SUPPORTED BY LOWER/MID TROPOSPHERIC WARM  
ADVECTION, EXPECTED TO SPREAD FROM NEAR/SOUTHWEST OF THE SOUTHERN  
LAKE MICHIGAN VICINITY THROUGH THE LOWER GREAT LAKES REGION DURING  
THE DAY. ADDITIONAL WARM ADVECTION DRIVEN THUNDERSTORM ACTIVITY  
APPEARS POSSIBLE ACROSS PARTS OF THE LOWER MISSOURI VALLEY TOWARD  
SOUTHERN PORTIONS OF THE GREAT LAKES REGION SATURDAY NIGHT, BUT  
MODEL OUTPUT REMAINS A BIT MORE UNCLEAR CONCERNING THIS POTENTIAL.  
REGARDLESS, IT STILL SEEMS UNLIKELY THAT ENVIRONMENTAL CONDITIONS  
WILL BECOME CONDUCIVE TO SEVERE STORMS THROUGH THIS PERIOD.  
 
..KERR.. 11/03/2017  
 

 
 
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