792  
ACUS03 KWNS 160725  
SWODY3  
SPC AC 160724  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0224 AM CDT WED OCT 16 2019  
 
VALID 181200Z - 191200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
SEVERE THUNDERSTORMS ARE NOT EXPECTED ON FRIDAY.  
   
..SYNOPSIS
 
 
A BROAD UPPER-LEVEL TROUGH WILL DEVELOP OVER THE WESTERN TWO-THIRDS  
OF THE COUNTRY ON FRIDAY, WHILE AN AMPLIFIED UPPER RIDGE OVERSPREADS  
THE EASTERN STATES. A COUPLE OF EMBEDDED SHORTWAVE TROUGH WILL  
MIGRATE THROUGH THE LARGER-SCALE CYCLONIC FLOW ACROSS THE WESTERN  
STATES AND PLAINS DURING THE PERIOD. THE FIRST SHORTWAVE TROUGH WILL  
EJECT ACROSS THE ROCKIES DURING THE AFTERNOON, AND MUCH OF THE  
PLAINS OVERNIGHT. A SURFACE TROUGH WILL DEVELOP IN RESPONSE TO  
FALLING HEIGHTS ACROSS THE PLAINS, AND LOW LEVEL SOUTHERLY FLOW WILL  
BRING MODEST SURFACE DEWPOINTS (45-55 F) NORTHWARD FROM TX/OK TO  
IA/MN. AS THE PARENT LOW OVER MANITOBA LIFTS NORTHEAST, A WEAK COLD  
FRONT WILL MOVE ACROSS THE PLAINS, EXTENDING FROM WESTERN WI TO  
CENTRAL OK BY SATURDAY MORNING. MODEST WARM ADVECTION AND ELEVATED  
INSTABILITY/STEEPENING LAPSE RATES WILL SUPPORT ISOLATED OVERNIGHT  
THUNDERSTORMS ACROSS PARTS OF THE OK/KS TO EASTERN IA. A SECOND,  
MORE INTENSE SHORTWAVE TROUGH WILL MOVE TOWARD THE PACIFIC NORTHWEST  
COAST LATE IN THE PERIOD. COOLING ALOFT WILL RESULT IN STEEPENING  
LAPSE RATES AND MODEST ELEVATED INSTABILITY. AS DEEP-LAYER WESTERLY  
FLOW INCREASES, A FEW THUNDERSTORMS WILL BE POSSIBLE DURING THE  
NIGHTTIME HOURS.  
 
ADDITIONAL ISOLATED THUNDERSTORMS WILL BE POSSIBLE LATE IN THE  
PERIOD ACROSS THE NORTHERN GULF COAST AS A WARM FRONT LIFTS  
NORTHWARD. OF NOTE, SOME GUIDANCE DEVELOPS A WEAK SURFACE LOW ALONG  
A SURFACE TROUGH EXTENDING FROM THE NORTH-CENTRAL GULF TOWARD THE  
BAY OF CAMPECHE, AND TRACKS THE LOW TOWARD THE NORTHERN GULF COAST  
BY SATURDAY MORNING. THE NATIONAL HURRICANE CENTER CURRENTLY HAS A  
40% CHANCE OF THIS FEATURE DEVELOPING INTO A TROPICAL CYCLONE OVER  
THE NEXT SEVERAL DAYS (REF TROPICAL WEATHER OUTLOOK). THIS COULD  
HAVE IMPLICATIONS FOR NORTHWARD MOISTURE RETURN AND POSSIBLY SEVERE  
POTENTIAL IN THE VICINITY OF THE GULF COAST DEPENDING ON THE  
EVOLUTION OF THIS FEATURE.  
 
..LEITMAN.. 10/16/2019  
 

 
 
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