830  
ACUS48 KWNS 170744  
SWOD48  
SPC AC 170743  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0243 AM CDT FRI AUG 17 2018  
 
VALID 201200Z - 251200Z  
   
..DISCUSSION
 
 
GUIDANCE DIFFERS MARKEDLY REGARDING THE POTENTIAL AMPLIFICATION OF A  
SHORTWAVE TROUGH EXPECTED TO BE OVER THE CENTRAL GREAT PLAINS/LOWER  
MO VALLEY AT 12Z MONDAY. THE GFS IS AN OUTLIER COMPARED TO THE  
ECMWF/UKMET/CMC, BUT A FEW GEFS MEMBERS DO DEPICT THE SUBSTANTIAL  
AMPLIFICATION NOTED BY NON-GFS GUIDANCE. THE NON-GFS GUIDANCE PHASES  
THIS SHORTWAVE IMPULSE WITH ANOTHER NORTHERN-STREAM IMPULSE EJECTING  
FROM THE PRAIRIE PROVINCES WITH CYCLOGENESIS OCCURRING OVER THE  
GREAT LAKES ON DAY 5/TUESDAY. LOW-LEVEL WIND FIELDS WOULD BE  
SUFFICIENT FOR AT LEAST A DAMAGING-WIND RISK IN THE LOWER GREAT  
LAKES TO CENTRAL APPALACHIANS VICINITY. EVEN SO, THE THERMODYNAMIC  
ENVIRONMENT WILL LIKELY BE CHARACTERIZED BY POOR MID/UPPER-LEVEL  
LAPSE RATES AMID PRECIPITABLE WATER VALUES AROUND 2 INCHES. SEVERE  
POTENTIAL SHOULD BE MODULATED BY THE DEGREE OF SURFACE HEATING THAT  
CAN OCCUR DOWNSTREAM/IN THE WAKE OF EARLY-DAY (POSSIBLY WIDESPREAD)  
CONVECTION.  
 
..GRAMS.. 08/17/2018  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page