309  
FXUS62 KRAH 261935  
AFDRAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RALEIGH NC  
335 PM EDT THU MAY 26 2016  
   
SYNOPSIS
 
BERMUDA HIGH PRESSURE WILL EXTEND OVER THE AREA THROUGH  
FRIDAY. MEANWHILE, A STORM SYSTEM WILL DEVELOP OVER THE SUB-TROPICAL  
ATLANTIC AND DRIFT TOWARD THE SOUTHEAST U.S. COAST THROUGH THE  
HOLIDAY WEEKEND.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 335 PM THURSDAY...  
 
A SLIGHTLY UNSTABLE LOW LEVEL AIR MASS COUPLED WITH A WEAK UPPER  
DISTURBANCE STALLED OVER THE WESTERN PIEDMONT MAY SUPPORT THE  
DEVELOPMENT OF AN ISOLATED SHOWER OR STORM THROUGH SUNSET. THE  
APPROACH OF ANOTHER DISTURBANCE (RESPONSIBLE FOR THE CONVECTION  
CROSSING THE LOWER OH VALLEY THIS AFTERNOON) MAY TRIGGER A FEW  
SHOWERS OVERNIGHT ACROSS THE FAR NORTHWEST-NORTHERN PIEDMONT. NOT  
EXPECTING ANY STRONG OR SEVERE CONVECTION AT THIS TIME AS PARAMETERS  
FOR SUSTAINED UPDRAFTS VIRTUALLY NON-EXISTENT AS THE SHEAR IS VERY  
WEAK AND INSTABILITY WEAK/MARGINAL.  
 
THE CONTINUED MODIFICATION OF THE LOW LEVEL ATMOSPHERE ALONG WITH  
PATCHY MID LEVEL CLOUDINESS WILL SUPPORT MILD OVERNIGHT  
TEMPERATURES. MIN TEMPS IN THE MID 60S.  
 

 
   
SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/
 
 
AS OF 335 PM THURSDAY...  
 
A NARROW RIDGE OF HIGH PRESSURE ALOFT WILL EXTEND WEST-EAST ACROSS  
CENTRAL NC. THIS FEATURE WILL MAINTAIN A MID LEVEL CAP AND INHIBIT  
CONVECTIVE DEVELOPMENT OVER MOST OF THE REGION. THE EXCEPTION MAY BE  
THE FAR WEST-NW WHERE OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION  
AND LINGER WEAK UPPER LEVEL DISTURBANCE MAY ENABLE AN ISOLATED  
SHOWER OR STORM TO DEVELOP DURING THE HEAT OF THE DAY.  
 
LOW LEVEL THICKNESSES COMPARABLE TO TODAY, SUPPORTIVE OF AFTERNOON  
TEMPS WELL INTO THE 80S, NEAR 90 IN THE SANDHILLS AND COASTAL PLAIN.  
CONTINUED MILD OVERNIGHT WITH MIN TEMPS IN THE MID 60S.  
 

 
   
LONG TERM /SATURDAY THROUGH THURSDAY/
 
 
AS OF 230 PM THURSDAY...  
 
THE MAIN FORECAST CONCERN FOR THIS PERIOD CONTINUES TO BE THE  
POTENTIAL TROPICAL/SUB-TROPICAL DEVELOPMENT OF AN AREA OF LOW  
PRESSURE BETWEEN THE BAHAMAS AND BERMUDA THIS WEEKEND.  
 
THE UPPER LEVEL RIDGE RESPONSIBLE FOR THE RECENT QUIET WEATHER WILL  
BREAK DOWN AS THE COASTAL LOW DEVELOPS. TO THE WEST, AN UPPER LEVEL  
TROUGH WILL LINGER FOR THE WEEKEND. A SHORTWAVE WILL PROGRESS FROM  
THE SOUTHERN ROCKIES NORTHEASTWARD ALONG THE TROUGH AXIS TOWARD THE  
GREAT LAKES.  
 
AS THE UPPER LEVEL SHORT WAVE MOVES THROUGH THE GREAT LAKES, THE  
NORTHEASTWARD MOVING COASTAL (TROPICAL) LOW WILL PROGRESS TOWARD THE  
SC COAST. AS OF THE MOST RECENT RUNS, THE MODELS INDICATE THESE TWO  
FEATURES INTERACTING SUNDAY NIGHT/MONDAY. THE UPPER LEVEL SHORTWAVE  
COULD ABSORB THE COASTAL LOW (POSSIBLE TROPICAL SYSTEM) ON MONDAY.  
THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY ON WHETHER THE LOW WILL  
MOVE UP THE MID-ATLANTIC COAST OR HAND OUT ALONG THE CAROLINA COAST  
BEFORE SLOWLY MOVING INLAND. REGARDLESS OF THIS, THE MAJORITY OF  
THIS PERIOD APPEARS TO BE FAIRLY UNSETTLED, WITH CHANCES FOR  
CONVECTION, HIGHEST IN THE AFT/EVE, EVERYDAY. MUCH OF THE COVERAGE,  
DURATION, AND TIMING OF CONVECTION WILL DEPEND ON HOW THE SYSTEM EVOLVES  
AND THUS CONFIDENCE IS STILL SOMEWHAT LOW. WITH THE STRONG ADVECTION  
OF ATLANTIC MOISTURE INTO THE REGION ON THE NORTHERN EDGE OF THE  
LOW, EXPECT INCREASING CLOUDS FROM THE EAST ON SATURDAY, THOUGH MUCH  
OF THE DAY WILL REMAIN DRY. CLOUDY SKIES COULD PERSIST THROUGH MUCH  
OF THE PERIOD.  
 
TEMPERATURES THROUGH THE PERIOD: WITH THE INCREASING CLOUDS AND  
CHANCES FOR RAINFALL, EXPECT HIGHS TO DECREASE FROM THE MID 80S ON  
SATURDAY, TO UPPER 70S TO LOW 80S SUNDAY. HIGHS SHOULD SLOWLY  
MODERATE BACK INTO THE MID 80S BY THE MIDDLE OF THE WEEK. OVERNIGHT  
LOWS WILL REMAIN FAIRLY STEADY IN THE MID TO UPPER 60S.  
 

 
   
AVIATION /18Z THURSDAY THROUGH TUESDAY/
 
 
AS OF 115 PM THURSDAY...  
 
IT'S HIGHLY LIKELY THAT VFR CONDITIONS WILL PERSIST ACROSS CENTRAL  
NC THROUGH FRIDAY. THE EXCEPTION WILL BE A SMALL RISK FOR EARLY  
MORNING FOG, LIMITING THE VISIBILITY TO MVFR CRITERIA FOR A BRIEF  
PERIOD. IN ADDITION, ISOLATED CONVECTION LATE THIS AFTERNOON THROUGH  
THIS EVENING, AND AGAIN FRIDAY AFTERNOON THROUGH THE EVENING, WILL  
PRODUCE INSTANCES OF MVFR CEILING AND VISIBILITY.  
 
AVIATION CONDITIONS ON SATURDAY WILL VARY BETWEEN VFR AND MVFR  
CRITERIA AS INCREASING MOISTURE RESULTS IN LOWERING CLOUD BASES AND  
AN ENHANCED THREAT FOR AFTERNOON AND EVENING SCATTERED CONVECTION.  
SUB VFR CONDITIONS APPEAR MORE LIKELY SUNDAY AND MEMORIAL DAY DUE TO  
AN AREA OF LOW PRESSURE PROJECTED TO BE POSITIONED OFF THE GA/SC  
COAST. CIRCULATION AROUND THIS FEATURE COULD SEND ABUNDANT MOISTURE  
INTO CENTRAL NC, RESULTING IN WIDESPREAD CLOUD COVER AND SCATTERED  
TO NUMEROUS SHOWERS AND THUNDERSTORMS. AVIATION CONDITIONS MAY  
SLOWLY IMPROVE BY TUESDAY, THOUGH PERIODS OF MVFR CONDITIONS ARE  
PROBABLE.  
 

 
   
RAH WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
SYNOPSIS...CBL/BLS  
NEAR TERM...WSS  
SHORT TERM...WSS  
LONG TERM...KC  
AVIATION...WSS  
 
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