978  
ACUS02 KWNS 300520  
SWODY2  
SPC AC 300520  
 
DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1220 AM CDT THU MAR 30 2017  
 
VALID 311200Z - 011200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY AFTERNOON  
ACROSS PARTS OF THE MID ATLANTIC COAST REGION...  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY EVENING  
ACROSS PARTS OF THE CENTRAL HIGH PLAINS...  
   
..SUMMARY
 
 
STRONG THUNDERSTORMS MAY IMPACT PARTS OF THE MID ATLANTIC COAST  
REGION FRIDAY AFTERNOON, AND PORTIONS OF THE CENTRAL HIGH PLAINS  
FRIDAY EVENING, ACCOMPANIED BY AT LEAST SOME RISK FOR SEVERE  
WEATHER.  
   
..SYNOPSIS
 
 
SIGNIFICANT SHORT WAVE PERTURBATIONS CONTINUE TO EMERGE FROM A  
STRONG BELT OF WESTERLIES OVER THE MID-LATITUDE PACIFIC. ANOTHER IN  
THE SERIES IS NOW DIGGING INLAND ACROSS THE PACIFIC NORTHWEST COAST,  
AND FORECAST TO CONTINUE SOUTHEASTWARD TODAY, WITH AN EMBEDDED  
LOWER/MID TROPOSPHERIC CYCLONE DEVELOPING/DEEPENING AS IT CROSSES  
MUCH OF THE SOUTHERN GREAT BASIN BY 12Z FRIDAY. AS THIS OCCURS, THE  
FORWARD PROGRESSION LIKELY WILL SLOW, BUT MODELS SUGGEST THAT CENTER  
OF CIRCULATION WILL GRADUALLY REDEVELOP EAST SOUTHEAST OF THE FOUR  
CORNERS REGION FRIDAY THROUGH FRIDAY NIGHT, PROBABLY BROADENING AND  
WEAKENING AS IT DOES.  
 
AS DOWNSTREAM SHORT WAVE RIDGING BUILDS ACROSS THE SOUTHERN PLAINS  
THROUGH THE LOWER/MIDDLE MISSISSIPPI VALLEY REGION, THE REMNANTS OF  
THE CLOSED LOW/SHORT WAVE TROUGH CURRENTLY PROGRESSING INTO THE  
MISSISSIPPI VALLEY ARE FORECAST TO ACCELERATE EAST SOUTHEAST OF THE  
LOWER OHIO VALLEY, ACROSS AND EAST OF THE MID ATLANTIC COAST BY 12Z  
SATURDAY.  
 
IN RESPONSE TO THESE FEATURES, IN LOWER LEVELS, MODEST SURFACE  
CYCLOGENESIS MAY OCCUR, FROM THE LEE OF THE CENTRAL APPALACHIANS  
THROUGH NORTHERN MID ATLANTIC COASTAL AREAS, AND TO THE LEE OF THE  
SOUTHERN ROCKIES. THIS IS EXPECTED TO BE GENERALLY FOCUSED ALONG A  
SURFACE FRONTAL ZONE THAT MAY ADVANCE EAST OF MUCH OF THE MID  
ATLANTIC COAST, WHILE STALLING IN MORE OR LESS EAST-WEST FASHION  
ACROSS PARTS OF THE SOUTHEAST INTO THE SOUTHERN PLAINS.  
 
IT APPEARS THE FRONT WILL BE PRECEDED BY ONE OR MORE CONVECTIVE  
OUTFLOWS ACROSS PARTS OF THE SOUTHEAST AND NORTHEASTERN GULF OF  
MEXICO, BUT AT LEAST SEASONABLY MODEST LOW-LEVEL MOISTURE IS  
EXPECTED TO ADVECT INTO THE MID ATLANTIC STATES AHEAD OF THE FRONTAL  
PASSAGE. A SOUTHERLY RETURN FLOW MAY COMMENCE ACROSS THE LOWER RIO  
GRANDE VALLEY AND WESTERN GULF COAST INTO THE SOUTHERN PLAINS, BUT A  
SUBSTANTIVE/DEEP LOW-LEVEL MOISTURE RETURN APPEARS UNLIKELY THROUGH  
AT LEAST 12Z SATURDAY.  
   
..MID ATLANTIC COAST
 
 
MODELS ARE SUGGESTIVE THAT FORCING FOR ASCENT ASSOCIATED WITH THE  
APPROACHING UPPER IMPULSE MAY SUPPORT WEAK EARLY PERIOD CONVECTION  
OVERSPREADING THE REGION. IN THE WAKE OF THIS ACTIVITY, LOW-LEVEL  
MOISTENING, PERHAPS SOME INSOLATION ASSOCIATED WITH BREAKS IN  
OVERCAST, AND MID-LEVEL COOLING MAY ALL CONTRIBUTE TO SUFFICIENT  
DESTABILIZATION FOR STRENGTHENING CONVECTIVE DEVELOPMENT NEAR/EAST  
OF THE BLUE RIDGE MOUNTAINS. IN THE PRESENCE OF MODESTLY STRONG AND  
SHEARED LOWER/MID TROPOSPHERIC WIND FIELDS (30-50 KT), IT APPEARS  
THE ENVIRONMENT MAY BECOME AT LEAST MARGINALLY CONDUCIVE TO  
ORGANIZED THUNDERSTORM DEVELOPMENT. THIS MAY BE ACCOMPANIED BY A  
RISK FOR MARGINALLY SEVERE HAIL, POTENTIALLY DAMAGING WIND GUSTS,  
AND PERHAPS EVEN AN ISOLATED TORNADO OR TWO BEFORE FAVORABLE  
MID/UPPER FORCING SHIFTS NORTHEAST OF THE REGION FRIDAY EVENING.  
   
..SOUTH CENTRAL HIGH PLAINS
 
 
ALTHOUGH MODELS SUGGEST CONSIDERABLE WEAKENING OF THE APPROACHING  
CLOSED LOW AND ASSOCIATED WIND FIELDS WILL OCCUR DURING THIS PERIOD,  
AN INITIAL PERTURBATION PIVOTING ACROSS THE ROCKIES MAY STILL BE  
ACCOMPANIED BY A 50-70 KT SOUTHWESTERLY 500 MB SPEED MAXIMUM ACROSS  
EASTERN NEW MEXICO AND THE TEXAS PANHANDLE REGION BY FRIDAY EVENING.  
EVEN WITH LIMITED LOW-LEVEL MOISTENING ALONG THE STALLING FRONTAL  
ZONE ACROSS THE PANHANDLE REGION, IN THE PRESENCE OF LOWER/MID  
TROPOSPHERIC LAPSE RATES THAT ARE FORECAST TO BECOME RATHER STEEP,  
MODEST CAPE (AT LEAST 500 J/KG+) APPEARS POSSIBLE NEAR AND TO THE  
COOL SIDE OF THE FRONT. INITIAL STORM DEVELOPMENT EXPECTED NEAR THE  
RATON MESA BY LATE FRIDAY AFTERNOON, IS EXPECTED TO BE MAINTAINED BY  
STRONG FORCING FOR ASCENT AND VERTICAL SHEAR, EASTWARD ALONG THE  
FRONT ACROSS THE HIGH PLAINS FRIDAY EVENING. AS THIS OCCURS, THE  
ENVIRONMENT MAY BECOME AT LEAST MARGINALLY CONDUCIVE TO A NARROW  
SWATH OF SEVERE HAIL AND WIND.  
 
..KERR.. 03/30/2017  
 

 
 
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