923  
FXUS62 KRAH 251933  
AFDRAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RALEIGH NC  
330 PM EDT WED APR 25 2018  
   
SYNOPSIS
 
 
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH CENTRAL NC  
FROM THE WEST THURSDAY, AND CROSS OUR AREA LATE THURSDAY NIGHT  
AND FRIDAY. A MORE TRANQUIL WEATHER PATTERN WILL TAKE HOLD OF  
THE CAROLINAS THIS WEEKEND.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 330 PM WEDNESDAY...  
 
DEEP, MATURE UPPER LEVEL LOW OVER CENTRAL NC THIS MORNING HAS  
CONTINUED TO DRIFT EAST-NORTHEAST, AND APPEARS TO BE OPENING UP (PER  
WATER VAPOR IMAGERY). SUBSIDENCE BEHIND THIS DEPARTING SYSTEM AND  
THE INCLUSION OF DRIER AIR INTO THE MID-UPPER LEVELS OF THE  
ATMOSPHERE SHOULD LIMIT ADDITIONAL SHOWER ACTIVITY. THUS EXPECT JUST  
A FEW SHOWERS ALONG AND EAST OF I-95 THROUGH LATE AFTERNOON, WITH  
MOST OF THE SHOWERS CONFINED TO OUR EXTREME NORTHEAST SECTOR.  
 
OTHERWISE, EXPECT A GENERAL DISSIPATING TREND IN CLOUD COVERAGE  
THROUGH THE EVENING WITH MOSTLY CLEAR/PARTLY CLOUDY ANTICIPATED  
OVERNIGHT. MIN TEMPS GENERALLY IN THE LOW-MID 50S.  
 

 
   
SHORT TERM /THURSDAY THROUGH FRIDAY/
 
 
AS OF 330 PM WEDNESDAY...  
 
ANOTHER WELL DEFINED CYCLONE, THIS ONE CURRENTLY CROSSING THE  
CENTRAL PLAINS INTO THE OZARKS, WILL CONTINUE TO MOVE EASTWARD INTO  
THE TN VALLEY THURSDAY, AND ENCROACHING UPON THE SOUTHERN  
APPALACHIANS LATE AFTERNOON. WHILE THE DAY WILL START OUT PARTLY  
CLOUDY ACROSS CENTRAL NC, EXPECT CLOUDS TO INCREASE/THICKEN ACROSS  
THE WESTERN COUNTIES BY MID DAY, AND ACROSS THE REMAINDER OF CENTRAL  
NC IN THE AFTERNOON. INCREASING DIFFLUENCE ALOFT WILL PROVIDE ENOUGH  
LIFT TO TRIGGER A FEW SHOWERS BY LATE IN THE DAY ACROSS THE WESTERN  
PIEDMONT. MAX TEMPS WILL VARY FROM THE UPPER 60S/AROUND 70 IN THE  
WEST-NW WHERE CLOUDS WILL THICKEN EARLIER IN THE DAY, TO THE MID 70S  
ACROSS THE EAST.  
 
THURSDAY NIGHT WILL SEE THE HIGHEST CHANCE FOR SHOWERS/ISOLATED  
THUNDERSTORMS AS THE MID/UPPER LEVEL LOW LIFTS NEWD UP THE SPINE OF  
THE APPALACHIANS. THE GREATEST CONCENTRATION FOR SHOWERS/STORMS WILL  
BE ACROSS THE WESTERN PIEDMONT. EXPECT A FEW STORMS OVERNIGHT,  
PRIMARILY WEST OF HIGHWAY 1 AS MID LEVEL LAPSE RATES BETWEEN 6.5-7  
DEG C/KM PASSES OVERHEAD. IN ADDITION, SOME OF THE STORMS MAY  
DISPLAY GOOD ORGANIZATION AND POSSIBLY SOME MID LEVEL ROTATION AS  
BULK SHEAR 35-40KTS EXPECTED. A DETERRENT TO THE DEVELOPMENT OF  
STRONG/SEVERE STORMS WILL BE LIMITED LOW LEVEL INSTABILITY. THUS, AN  
ISOLATED STRONG/SEVERE STORM CANNOT BE RULED OUT. HOWEVER, THE MAIN  
WEATHER HAZARD MAY BE LOCALLY HEAVY DOWNPOURS. AREA CREEK AND  
STREAMS ARE RUNNING A LITTLE HIGHER THAN NORMAL DUE TO RECENT  
RAINFALL. IF SHOWERS/STORMS DEVELOP INTO A TRAINING PATTERN, COULD  
SEE FLOODING OF SMALL TRIBUTARIES OCCUR.  
 
FRIDAY, THE LOW PRESSURE SYSTEM WILL LIFT NWD, SLOWLY DRAGGING A  
COLD FRONT ACROSS THE REGION DURING THE DAY. DURING MAX HEATING,  
COULD SEE A FEW SHOWERS/STORMS DEVELOP ALONG THIS BOUNDARY IN THE  
AFTERNOON, MAINLY ALONG AND EAST OF HIGHWAY 1. A MIXTURE OF SUN AND  
CLOUDS AND WEST-SW LOW LEVEL FLOW SHOULD BOOST AFTERNOON  
TEMPERATURES INTO THE LOW-MID 70S.  
 

 
   
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
 
 
AS OF 155 PM WEDNESDAY...  
 
THE FORECAST IS EXPECTED TO BE DRY DURING THIS PERIOD, WITH NEAR TO  
SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH MONDAY, MODERATING TO  
AROUND TO SLIGHTLY ABOVE NORMAL BY WEDNESDAY.  
 
AS THE SHORTWAVE LOW MOVES AWAY FROM THE AREA, GETTING ABSORBED IN  
THE LONGWAVE TROUGH, ANOTHER SHORTWAVE WILL SWING THROUGH THE DEEP  
SOUTH/GULF COAST FRIDAY NIGHT AND OUT OVER THE ATLANTIC BY SATURDAY  
AFT/EVE. MEANWHILE, THE PARENT LOW WILL SWING THROUGH THE GREAT  
LAKES AND INTO NEW ENGLAND THROUGH SUNDAY. THE LONGWAVE TROUGH AXIS  
WILL EXTEND SOUTHWARD, MOVING OVER THE ATLANTIC BY SUNDAY NIGHT. THE  
GENERAL NORTHWEST FLOW PATTERN AND A REINFORCING DRY COLD FRONTAL  
PASSAGE SATURDAY/SATURDAY NIGHT WILL RESULT IN TEMPERATURES NEAR TO  
SLIGHTLY BELOW NORMAL FOR LATE APRIL. HIGH PRESSURE WILL REMAIN OVER  
THE REGION THROUGH MONDAY, SHIFTING OFFSHORE TUESDAY. AS A RESULT,  
EXPECT A RETURN TO MORE SOUTHERLY FLOW AND INCREASING TEMPERATURES  
TUESDAY AND WEDNESDAY.  
 

 
   
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
 
 
AS OF 125 PM WEDNESDAY...  
 
AVIATION CONDITIONS WILL GRADUALLY IMPROVE ACROSS CENTRAL NC THROUGH  
THIS EVENING. CURRENT MVFR/LOW END VFR CEILINGS WILL GRADUALLY LIFT  
AND DISSIPATE THROUGH 22Z, WITH MOSTLY CLEAR-PARTLY CLOUDY SKIES  
EXPECTED TONIGHT. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL  
CONTINUE TO DRIFT TO THE EAST-NORTHEAST ACROSS THE EASTERN PIEDMONT  
AND MOST OF THE COASTAL PLAIN THROUGH 22Z. THE HEAVIER SHOWERS AND  
ISOLATED STORMS WILL BE ACCOMPANIED BY SMALL HAIL. THIS HAIL THREAT  
APPEARS TO BE HIGHEST IMMEDIATELY NORTH OF THE KRDU AND KRWI  
TERMINALS.  
 
MOSTLY VFR PARAMETERS EXPECTED LATER TONIGHT THROUGH THURSDAY.  
ANOTHER LOW PRESSURE SYSTEM WILL AFFECT CENTRAL NC THURSDAY NIGHT  
INTO FRIDAY WITH MVFR CEILINGS AND SCATTERED-NUMEROUS SHOWERS AND  
ISOLATED THUNDERSTORMS. THE CONVECTIVE COVERAGE APPEARS TO BE  
HIGHEST LATE THURSDAY EVENING THROUGH EARLY FRIDAY MORNING.  
 
A COLD FRONT WILL CROSS CENTRAL NC FRIDAY AFTERNOON. A DRIER AND A  
MORE STABLE AIR MASS WILL OVERSPREAD THE REGION, LEADING TO VFR  
PARAMETERS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.  
 

 
   
RAH WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
 

 
 

 
 
SYNOPSIS...WSS  
NEAR TERM...WSS  
SHORT TERM...WSS  
LONG TERM...KC  
AVIATION...WSS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab NC Page Main Text Page