314  
ACUS01 KWNS 291241  
SWODY1  
SPC AC 291239  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0639 AM CST WED NOV 29 2017  
 
VALID 291300Z - 301200Z  
   
..NO SEVERE THUNDERSTORM AREAS FORECAST
 
 
   
..SUMMARY
 
 
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS  
THE OZARKS THE NEXT FEW HOURS. A FEW THUNDERSTORMS WILL ALSO BE  
POSSIBLE OVER AND NEAR SOUTHEAST FLORIDA.  
   
..SYNOPSIS
 
 
IN MID/UPPER LEVELS, A LOW-AMPLITUDE LONGWAVE PATTERN WILL  
PREDOMINATE ACROSS THE DOMAIN, DOMINATED BY PROGRESSIVE SHORTWAVES  
OF VARIOUS AMPLITUDES. THE MOST CONVECTIVELY PERTINENT AMONG THOSE  
INCLUDES A COMPACT 500-MB CYCLONE NOW EVIDENT IN MOISTURE-CHANNEL  
IMAGERY OVER NORTHEASTERN OK, WITH TROUGH SOUTH-SOUTHWESTWARD TO  
PARTS OF NORTH-CENTRAL/NORTHEAST TX. THIS FEATURE WILL MOVE  
EASTWARD AND WEAKEN CONSIDERABLY THROUGH THE PERIOD, AS A MUCH  
HIGHER-AMPLITUDE SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE  
NORTHERN/CENTRAL PLAINS AND UPPER MISSISSIPPI VALLEY.  
 
AT THE SURFACE, A COLD FRONT WAS DRAWN AT 11Z FROM NORTHERN NY TO  
THE LOWER OHIO VALLEY AND OZARKS, INTO A FRONTAL-WAVE LOW BETWEEN  
MLC-TUL THAT WAS CLOSELY POSITIONED WITH RESPECT TO ITS PARENT  
MID/UPPER VORTICITY MAX. THE FRONT THEN ARCHED FROM THAT LOW  
SOUTHWARD ACROSS NORTHEAST TX AND SOUTHWESTWARD BETWEEN DRT-LRD.  
THE LOW SHOULD MOVE EASTWARD TO NORTHEASTWARD THROUGH THE OZARKS AND  
WEAKEN, WHILE FRONTOLYSIS OCCURS FROM TX TO THE APPALACHIANS. A  
LONG-LIVED, WEAK, QUASISTATIONARY FRONTAL ZONE OVER SOUTHERN FL AND  
NEARBY WATERS ALSO SHOULD WEAKEN THROUGH THIS PERIOD.  
   
..OZARKS REGION
 
 
A CLUSTER OF CONVECTIVE AND STRATIFORM PRECIP, WITH EMBEDDED  
THUNDERSTORMS, IS ONGOING OVER THE WESTERN PARTS OF THE OUTLOOK  
AREA. THIS ACTIVITY IS EXPECTED TO SHIFT EASTWARD AND GRADUALLY  
WEAKEN THROUGH MIDDAY, AS THE PARENT TROUGH WEAKENS, ALONG WITH ALL  
THE ASSOCIATED UVV CONTRIBUTORS TO THUNDERSTORM POTENTIAL (WARM  
ADVECTION, JET-LEVEL ASCENT, DCVA, LOW-LEVEL CONVERGENCE/LIFT TO  
LFC, ETC.). VERY ISOLATED/BRIEF THUNDERSTORMS CANNOT BE RULED OUT  
FARTHER EAST TOWARD THE WEST EDGE OF THE MISSISSIPPI VALLEY THIS  
AFTERNOON; HOWEVER, AREAL PROBABILITIES DIMINISH BELOW THE 10%  
CATEGORICAL THRESHOLD.  
   
..SOUTHERN PENINSULAR FL
 
 
ISOLATED, EPISODIC THUNDERSTORMS WILL REMAIN POSSIBLE, PRIMARILY  
THROUGH THIS EVENING, NEAR THE SOUTHEASTERN COAST AND ACROSS THE  
KEYS/STRAITS. THIS ACTIVITY WILL BE SUPPORTED BY A COMBINATION OF  
RICH LOW-LEVEL MOISTURE IN AND SOUTH OF THE FRONT, ALONG WITH WEAK  
LIFT IN THE LOW LEVELS. MORNING SOUNDINGS FROM EYW/MFL/NASSAU  
SAMPLE MLCAPE FROM 400-1400 J/KG, THOUGH THE LARGER VALUES OF  
BUOYANCY MAY NOT GET FULLY REALIZED BECAUSE OF THE WEAKNESS OF  
BOUNDARY-LAYER FORCING. STILL, SPORADIC UPDRAFT PULSES SHOULD  
PENETRATE INTO ICING LAYERS SUITABLE FOR LIGHTNING PRODUCTION.  
 
..EDWARDS.. 11/29/2017  
 

 
 
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