139  
ACUS48 KWNS 270943  
SWOD48  
SPC AC 270941  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0341 AM CST WED JAN 27 2021  
 
VALID 301200Z - 041200Z  
   
..DISCUSSION
 
 
MEDIUM-RANGE MODELS CONTINUE TO EXHIBIT REASONABLE LARGE-SCALE  
AGREEMENT WITH RESPECT TO EVOLUTION OF THE UPPER PATTERN, THROUGH  
ROUGHLY DAY 7. BEYOND THAT, DIFFERENCES QUICKLY ARISE WITH HANDLING  
OF A LARGE TROUGH CROSSING THE WEST LATE IN THE PERIOD.  
 
PRIOR TO THEN, THE PATTERN ALOFT WILL BE CHARACTERIZED BY THE  
PROGRESSION OF A TROUGH -- INITIALLY SITUATED OVER THE SOUTHERN  
ROCKIES/CENTRAL AND SOUTHERN HIGH PLAINS. AS THIS FEATURE  
EVOLVES/SHIFTS EASTWARD WITH TIME, IT WILL BE ACCOMPANIED BY A  
WELL-DEVELOPED SURFACE LOW/FRONTAL SYSTEM, THAT MODELS SUGGEST WILL  
MOVE FROM THE HIGH PLAINS EARLY DAY 4 (SATURDAY), TO NEAR/OFF THE  
EAST COAST BY THE END OF DAY 6 (TUESDAY MORNING).  
 
DESPITE THE WELL-DEVELOPED NATURE OF THIS SURFACE SYSTEM, ITS WARM  
SECTOR WILL LIKELY REMAIN NOTABLY LACKING IN INSTABILITY, DUE TO THE  
ANTECEDENT CP AIRMASS INTRUSION THROUGH THE GULF OF MEXICO, AND  
PERSISTENCE OF RIDGING ALOFT ACROSS THE WESTERN ATLANTIC AND INTO  
THE GULF. AS SUCH, THOUGH PRECIPITATION -- INCLUDING  
WEAK/LOW-TOPPED CONVECTION -- WILL ACCOMPANY PASSAGE OF THE SYSTEM,  
SEVERE WEATHER IS NOT EXPECTED.  
 
..GOSS.. 01/27/2021  
 
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