095  
ACUS03 KWNS 240648  
SWODY3  
SPC AC 240647  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0147 AM CDT SUN SEP 24 2017  
 
VALID 261200Z - 271200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
THE SEVERE THREAT ACROSS MOST OF THE COUNTRY SHOULD REMAIN VERY  
SPARSE WEDNESDAY.  
   
..SYNOPSIS
 
 
A PERSISTENT LONGWAVE TROUGH ACROSS THE WESTERN STATES WILL FINALLY  
BREAK DOWN AS A SUBSTANTIAL, YET SHORTER-LENGTH MID-LEVEL TROUGH  
MIGRATES EAST TOWARD THE UPPER MISSISSIPPI VALLEY. FARTHER  
SOUTHWEST, MODELS SUGGEST THAT THE REMNANT PORTION OF THE TROUGH  
OVER THE WESTERN GREAT BASIN WILL EVOLVE INTO A CLOSED LOW. HEIGHT  
RISES WILL BE NOTED DOWNSTREAM OF THIS CLOSED LOW ACROSS THE  
SOUTHERN PLAINS AS A RIDGE STRENGTHENS SOME OVER THE LOWER  
MISSISSIPPI RIVER VALLEY - AND MODEST STRENGTHENING OF MID-LEVEL  
FLOW SHOULD OCCUR ACROSS WESTERN NEW MEXICO AND VICINITY.  
 
AT THE SURFACE, A COLD FRONT WILL CONTINUE TO MIGRATE SOUTHWARD  
ACROSS THE SOUTHERN PLAINS AND EXTEND FROM NEAR THE BIG BEND OF  
TEXAS NORTHEASTWARD TO CENTRAL MISSOURI AND ON TO ANOTHER WEAK LOW  
LOCATED NEAR THE UPPER PENINSULA OF MICHIGAN EARLY WEDNESDAY  
EVENING. A MODIFIED MARITIME AIRMASS WILL REMAIN IN PLACE AHEAD OF  
THE FRONT AND FOSTER ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT  
THROUGHOUT THE DAY, WITH PEAK COVERAGE OCCURRING DURING THE  
AFTERNOON AND EARLY EVENING. OVERALL, THE LACK OF STRONG DEEP SHEAR  
AND MARGINAL MID-LEVEL LAPSE RATES WILL KEEP ANY SEVERE RISK TO A  
MINIMUM - ALTHOUGH AREAS OF NEW MEXICO MAY EXPERIENCE A LOW RISK OF  
HAIL AND GUSTY WINDS WEDNESDAY AFTERNOON.  
   
..SOUTHERN INTO WESTERN NEW MEXICO
 
 
EASTERLY LOW-LEVEL TRAJECTORIES WILL ADVECT MOISTURE INTO THE HIGHER  
TERRAIN OF THE SOUTHERN ROCKIES, FOSTERING THE DEVELOPMENT OF A FEW  
STORMS IN THAT AREA DURING THE AFTERNOON HOURS. THESE STORMS MAY BE  
ENHANCED BY THE PRESENCE OF THE MID-LEVEL CUT-OFF LOW JUST WEST OF  
THE AREA, AND ~7 DEG C/KM MID-LEVEL LAPSE RATES MAY COMBINE WITH  
JUST ENOUGH DEEP SHEAR TO PROVIDE A RISK OF HAIL AND GUSTY WINDS.  
MARGINAL (5%) SEVERE PROBABILITIES MAY BE NEEDED IN LATER OUTLOOKS  
IF MODELS REMAIN CONSISTENT IN DEPICTING THIS LOW HAIL/WIND RISK -  
WHICH MAY END UP BEING CLOSELY TIED TO THE EVOLUTION OF THE CLOSED  
MID-LEVEL LOW OVER THE SOUTHWEST.  
 
..COOK.. 09/24/2017  
 

 
 
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