084  
ACUS48 KWNS 010739  
SWOD48  
SPC AC 010738  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0138 AM CST FRI DEC 01 2017  
 
VALID 041200Z - 091200Z  
   
..DISCUSSION
 
 
THE MID/UPPER PATTERN WILL AMPLIFY CONSIDERABLY NEXT WEEK, AS A DEEP  
TROUGH DEVELOPS ACROSS THE EASTERN US AND HEIGHTS BUILD OVER THE  
WESTERN US. THIS TRANSITION WILL BRING A COLD, CONTINENTAL AIR MASS  
TO MANY LOCATIONS EAST OF THE ROCKIES DURING THE SECOND HALF OF THE  
WEEK, SIGNIFICANTLY REDUCING SEVERE POTENTIAL FROM D5/TUESDAY  
ONWARD. HOWEVER, BEFORE THEN, SOME POTENTIAL EXISTS FOR A STRONGLY  
FORCED BAND OF CONVECTION ALONG THE COLD FRONT, PERHAPS FROM  
PORTIONS OF THE SOUTHERN PLAINS / OZARKS NORTHWARD TO THE MID  
MISSISSIPPI VALLEY. WHILE SURFACE-BASED BUOYANCY IS UNLIKELY TO BE  
HIGHER THAN 500-750 J/KG IN ANY ONE LOCATION, NORTHWARD MOISTURE  
RETURN SHOULD BE SUFFICIENT FOR AT LEAST WEAK BUOYANCY. MEDIUM-RANGE  
GUIDANCE DEPICTS DIFFERENCES IN THE AMPLITUDE OF A SHORTWAVE TROUGH  
ADVANCING ACROSS THE CENTRAL US THOUGH, SUCH THAT MID-LEVEL LAPSE  
RATE FORECASTS REMAIN UNCERTAIN, CONSIDERABLY IMPACTING FORECAST  
CAPE. THEREFORE, WHILE NO HIGHLIGHTS ARE INTRODUCED AT THIS TIME FOR  
D4/MONDAY, CONSIDERING THE STRENGTH OF THE WIND FIELD, BUOYANCY ON  
THE HIGHER END OF THE FORECAST SPECTRUM WOULD LIKELY NECESSITATE  
SEVERE PROBABILITIES IN LATER FORECASTS.  
 
..PICCA.. 12/01/2017  
 
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