471  
ACUS48 KWNS 230930  
SWOD48  
SPC AC 230929  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0329 AM CST FRI FEB 23 2018  
 
VALID 261200Z - 031200Z  
   
..DISCUSSION
 
   
..MONDAY/DAY 4 TO WEDNESDAY/DAY 6
 
 
THE MEDIUM-RANGE MODELS INCLUDING THE ECMWF, GFS, UKMET AND CANADIAN  
SOLUTIONS MOVE A SHORTWAVE TROUGH ACROSS THE EASTERN STATES ON  
MONDAY. AT THE SURFACE, A COLD FRONT IS FORECAST TO MOVE TO NEAR THE  
CENTRAL GULF COAST AND EXTEND EAST-NORTHEASTWARD INTO SOUTH-CENTRAL  
GEORGIA. A FEW THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THE FRONT IN  
NORTHERN FLORIDA MONDAY AFTERNOON. ON TUESDAY, THE FOUR MODELS MOVE  
A LOW-AMPLITUDE UPPER-LEVEL RIDGE ACROSS THE EASTERN STATES.  
MOISTURE ADVECTION IS FORECAST ALONG THE TEXAS COASTAL PLAINS AND IN  
THE LOWER MISSISSIPPI VALLEY WHERE ISOLATED TO SCATTERED  
THUNDERSTORMS WILL BE POSSIBLE AND A MARGINAL SEVERE THREAT CANNOT  
BE RULED OUT. ON WEDNESDAY, THE ECMWF, GFS AND UKMET MOVE AN  
UPPER-LEVEL TROUGH QUICKLY ACROSS THE ROCKIES AS A MID-LEVEL JET  
EJECTS NORTHEASTWARD ACROSS THE SOUTHERN PLAINS AND ARKLATEX. THESE  
SOLUTIONS SUGGEST A SEVERE THREAT WILL BE POSSIBLE FROM PARTS OF  
CENTRAL AND NORTH TEXAS NORTHEASTWARD INTO THE MID MISSISSIPPI  
VALLEY FROM WEDNESDAY AFTERNOON INTO THE EVENING. THE MAGNITUDE OF  
ANY SEVERE THREAT WOULD LIKELY DEPEND UPON HOW MUCH MOISTURE RETURN  
CAN TAKE PLACE.  
   
..THURSDAY/DAY 7 AND FRIDAY/DAY 8
 
 
MODEL SOLUTIONS DIVERGE MARKEDLY LATE IN THE DAY 4 TO 8 PERIOD. THE  
ECMWF MAINTAINS WEST TO SOUTHWEST MID-LEVEL FLOW ACROSS THE SOUTHERN  
HALF OF THE U.S. AND MOVES A COLD FRONT ACROSS THE SOUTHEAST. THE  
GFS HAS THE COLD FRONT IN THE SOUTHEAST AS WELL BUT ALSO DEVELOPS AN  
UPPER-LEVEL TROUGH IN THE SOUTHERN PLAINS. THE TWO SOLUTIONS DO  
SUGGEST THAT A MARGINAL SEVERE THREAT COULD DEVELOP ALONG THE COLD  
FRONT DURING THE AFTERNOON FROM THE CENTRAL GULF COAST NORTHEASTWARD  
INTO THE CAROLINAS. ON FRIDAY, THE MODELS HAVE A LARGE SPREAD OF  
SOLUTIONS. ONE COMMONALITY IS THAT A DRY AIRMASS COULD BE IN PLACE  
ACROSS MUCH OF THE CONUS KEEPING THE POTENTIAL FOR THUNDERSTORM  
DEVELOPMENT LOW.  
 
..BROYLES.. 02/23/2018  
 
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