211  
ACUS01 KWNS 191632  
SWODY1  
SPC AC 191630  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1030 AM CST SUN FEB 19 2017  
 
VALID 191630Z - 201200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS A LARGE  
PART OF CENTRAL TEXAS INTO SOUTHERN OKLAHOMA...  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE  
SOUTHERN PLAINS SURROUNDING THE SLIGHT RISK...  
   
..SUMMARY
 
 
SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF THE SOUTHERN  
PLAINS LATE TODAY AND THIS EVENING, DEVELOPING FARTHER SOUTHWARD  
ACROSS THE TEXAS HILL COUNTRY AND SOUTH TEXAS TONIGHT. LARGE HAIL  
AND SPORADIC WIND DAMAGE ARE POSSIBLE, AND A TORNADO OR TWO COULD  
OCCUR.  
   
..SYNOPSIS
 
 
A SOUTHERN-STREAM UPPER LOW PRESENTLY OVER THE SOUTHERN ROCKIES AT  
LATE MORNING WILL GRADUALLY PROGRESS GENERALLY EASTWARD OVER THE  
NEXT 24 HOURS, ESSENTIALLY EVOLVING INTO SPLIT STREAMS WITH ONE  
PORTION APPROACHING THE CENTRAL HIGH PLAINS AND THE OTHER  
OVERSPREADING NORTHERN MEXICO.  
   
..SOUTHERN PLAINS
 
 
AHEAD OF THE PREVIOUSLY DESCRIBED EVOLVING UPPER SYSTEM, NEAR 60F  
SURFACE DEWPOINTS CONTINUE TO DEVELOP NORTHWARD, AS FAR NORTH AS THE  
RED RIVER VICINITY AS OF 16Z, WHILE MIDDLE/UPPER 60S F SURFACE  
DEWPOINTS ARE SEMI-PREVALENT ALONG THE TX COAST AND HILL COUNTRY.  
THIS AMPLIFIED/MERIDIONAL LARGE-SCALE PATTERN WILL CONTINUE TO YIELD  
AMPLE HIGHER-LEVEL CLOUD COVER, WHICH CASTS SOME UNCERTAINTY ON  
POCKETS OF STRONGER HEATING/DESTABILIZATION COINCIDENT WITH  
OTHERWISE MOISTENING BOUNDARY LAYER.  
 
REGARDLESS, INDICATIONS ARE THAT THE POTENTIAL FOR SURFACE-BASED  
THUNDERSTORMS SHOULD INITIALLY BE FOCUSED LATE THIS AFTERNOON/EARLY  
EVENING ACROSS PARTS OF WESTERN NORTH TEXAS INTO  
SOUTHWEST/SOUTH-CENTRAL OK. PRESUMING SOME CLOUD BREAKS/MODEST  
DESTABILIZATION, WIND PROFILES/LOW-LEVEL HODOGRAPHS WOULD SUPPORT  
INITIAL SUPERCELLS POTENTIALLY INCLUDING A HAIL/TORNADO RISK,  
ALTHOUGH WITH TIME, FLOW WEAKNESS AROUND 700 MB IS SUGGESTIVE OF A  
MESSY AND MORE LINEAR MODE BY EARLY INTO MID-EVENING.  
 
FARTHER SOUTH, WITH THE ARRIVAL OF LARGE-SCALE FORCING FOR ASCENT,  
BANDS OF SCATTERED STORMS SEEMS LIKELY TO INCREASE LATE THIS EVENING  
INTO THE OVERNIGHT ACROSS THE HILL COUNTRY AND RIO GRANDE VICINITY.  
SOME HAIL WILL INITIALLY BE POSSIBLE, BUT DAMAGING WINDS SHOULD BE  
THE PRIMARY RISK GIVEN FORECAST WIND PROFILES.  
 
..GUYER/MOSIER.. 02/19/2017  
 

 
 
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