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AREA FORECAST DISCUSSION 
NATIONAL WEATHER SERVICE RALEIGH NC 
230 PM EDT TUE SEP 1 2015

.SYNOPSIS...A DISTURBANCE WILL DROP SOUTHEAST THROUGH THE AREA 
WEDNESDAY NIGHT THROUGH EARLY THURSDAY... BUT OTHERWISE DEEP HIGH 
PRESSURE WILL HOLD OVER THE REGION THROUGH FRIDAY... BRINGING HOT 
AND HUMID CONDITIONS. 

&&
.NEAR TERM /THROUGH TONIGHT/... 
AS OF 200 PM TUESDAY...

A QUIET EVENING AND NIGHT AHEAD. PW VALUES REMAIN NEAR OR BELOW 
NORMAL WITH DRY AIR NOTED ON WATER VAPOR IMAGERY OVER THE REGION. 
BRIEF SHORTWAVE RIDGING HOLDS OVER CENTRAL NC AHEAD OF THE NEXT 
FEATURE OF INTEREST... THE POTENT VORTEX NOW OVER EAST-CENTRAL 
INDIANA. AT THE SURFACE... HIGH PRESSURE STRETCHING ACROSS TN/KY/WV 
WILL HOLD IN PLACE TONIGHT... WITH VERY WEAK AND DIFFUSE TROUGHING 
OVER ERN NC HAVING LITTLE IMPACT GIVEN THE WEAK WIND FIELD. WILL 
MAINTAIN A MENTION OF AN ISOLATED SHOWER OR TWO OVER THE SE CWA INTO 
EARLY EVENING AS THE CU FIELD IS PRONOUNCED HERE... BUT EXPECT VERY 
LITTLE COVERAGE CONSIDERING THE LACK OF ANY MOISTURE/INSTABILITY AND 
LOW SHEAR WITHOUT A CONVECTIVE FOCUS. SKIES SHOULD BE MOSTLY CLEAR 
TO PARTLY CLOUDY TONIGHT... TRENDING TOWARD THE LATTER LATE TONIGHT 
OVER THE NORTH AND WEST CWA WHERE BLOWOFF HIGH CLOUDS FROM 
CONVECTION OFF THE TX/LA COAST MAY SPREAD IN... AS SUGGESTED BY THE 
EXPERIMENTAL HRRR. FOG SHOULD NOT BE AS WIDESPREAD OR DENSE AS THIS 
MORNING BUT THE EASTERN SECTIONS (WHERE SURFACE DEWPOINTS WILL STAY 
ELEVATED) COULD STILL SEE LIGHT FOG LATE TONIGHT WITH ANY DENSE FOG 
ISOLATED IN NATURE AND CONFINED TO THE CLIMATOLOGICALLY-FAVORED LOW-
LYING AREAS OVER THE NE CWA. LOWS IN THE UPPER 60S TO AROUND 70 WITH 
GENERALLY CALM WINDS. -GIH

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/... 
AS OF 230 PM TUESDAY...

THE LOW OVER EAST CENTRAL INDIANA IS EXPECTED TO OPEN UP AND DROP TO 
THE SE ACROSS OUR REGION LATE WED INTO WED NIGHT. THE NAM DEPICTS 
1000-2000 J/KG OF MUCAPE WITH DEEP LAYER SHEAR RISING TO AROUND 25 
KTS LATE WED AFTERNOON... NOT GREAT BUT BETTER THAN WE'RE LIKELY TO 
SEE AT OTHER TIMES THIS WEEK... ALTHOUGH THE NAM MAY BE A TAD TOO 
HIGH WITH AFTERNOON DEWPOINTS. WITH AN OVERALL WEAK WIND FIELD... 
LACK OF HIGH-LEVEL FORCING FEATURES... BARELY-NEAR-NORMAL PW... AND 
VERY LITTLE NEAR-SURFACE MASS CONVERGENCE... DON'T EXPECT ANY 
SIGNIFICANT SEVERE WEATHER DESPITE THE DPVA ACCOMPANYING THE WAVE'S 
PASSAGE. FOLLOWING THE TIMING AMONG THE NAM/GFS/SREF/NCAR ENSEMBLE 
OUTPUT... WILL BRING ISOLATED STORMS INTO THE FAR NW CWA AFTER 
18Z... SPREADING INTO THE REST OF THE PIEDMONT AFTER 21Z AND 
INCREASING TO 20-30%... THEN PROGRESSING TO THE SOUTH AND EAST 
THROUGH THE EVENING... BEFORE ENDING AS MOSTLY ISOLATED SHOWERS OVER 
THE FAR SE CWA LATE WED NIGHT. WE SHOULD BE IN A RELATIVE SUBSIDENT 
AREA POST-WAVE ON THU... WITH THE WEAKENING SHEAR AXIS STRETCHED 
OVER THE SRN NC BORDER AREA... SO EXPECT ONLY ISOLATED CONVECTION 
COVERAGE AT MOST. THICKNESSES WILL BE WELL ABOVE NORMAL... 
SUGGESTING HIGHS AROUND 90 TO 95 BOTH DAYS... IN LINE WITH 
STATISTICAL GUIDANCE. LOWS WED NIGHT NEAR 70 TO THE LOWER 70S. -GIH

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 
AS OF 220 PM TUESDAY...

A GENERAL WEAK UPPER LEVEL FLOW PATTERN WILL CHARACTERIZE THE LONG 
TERM WITH A COUPLE OF SURFACE/LOW LEVEL FEATURES THAT WILL HELP 
DRIVE SOME OF THE SENSIBLE WEATHER BUT IN GENERAL A LONG TERM 
FORECAST WROUGHT WITH UNCERTAINTY. 

AFTER THE SURFACE WAVE MOVES THROUGH THE AREA ON THURSDAY THERE IS 
NOT A LOT OF FACTORS SUPPORTING THE WETTER GFS SOLUTION OVER NIGHT 
THURSDAY NIGHT INTO FRIDAY MORNING. PREFER THE EURO SOLUTION KEEPING 
US DRY OVERNIGHT THURSDAY NIGHT BUT WILL CARRY SLIGHT CHANCE POPS 
BECAUSE OF THE UNCERTAINTY. 

SURFACE HIGH PRESSURE OVER NEW ENGLAND WILL BRING A BACK DOOR COLD 
FRONT THROUGH THE AREA ON FRIDAY EVENING...PROVIDING SOME FORCING 
FOR BETTER CHANCES FOR SHOWERS AND POTENTIALLY A THUNDERSTORM.

HIGH PRESSURE WILL CONTINUE TO SINK SOUTH LATER IN THE WEEKEND AND 
PRECIP CHANCES WILL DIMINISH OVER THE AREA.

TEMPERATURES WILL BE WARM TO BEGIN THE PERIOD WITH HIGHS IN THE LOW 
90S AND LOWS AROUND 70 DEGREES. FOR THE WEEKEND...TEMPS WILL DROP TO 
THE LOW TO MID 80S FOR HIGHS WITH LOWS IN THE MID 60S.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/... 
AS OF 1245 PM TUESDAY...

VFR CONDITIONS WILL DOMINATE AT ALL CENTRAL NC TERMINAL FORECAST 
LOCATIONS THROUGH THE NEXT 24 HRS. THIS MORNING'S FOG AND STRATUS 
AFFECTING EASTERN TERMINALS HAS LIFTED AND BECOME SCATTERED... AND 
ANY CIGS TODAY PRODUCED BY HEATING WILL BE VFR. THESE DAYTIME CLOUDS 
WILL THEN BREAK UP THIS EVENING... LEAVING MOSTLY CLEAR SKIES. THERE 
IS A SLIGHT CHANCE OF LIGHT FOG 07Z-12Z TONIGHT AT RDU/FAY... WITH A 
BETTER CHANCE OF HEAVIER FOG AND SCATTERED LOW CLOUDS AT RWI. WILL 
INCLUDE A POTENTIAL FOR MVFR FOG AT RDU/FAY LATE TONIGHT/EARLY WED 
MORNING... WITH IFR CHANCES AT RWI. ANY SUB-VFR CONDITIONS WILL LIFT 
QUICKLY TO VFR BY 14Z WED MORNING. 
 
LOOKING BEYOND 18Z WED... HIGH PRESSURE WILL EXTEND INTO CENTRAL NC 
FROM THE WEST AND NORTH THROUGH MUCH OF THE WEEK... GENERATING HIGH 
CONFIDENCE IN VFR CONDITIONS... APART FROM ISOLATED LATE DAY STORMS 
EACH AFTERNOON/EARLY EVENING. SUB-VFR LOW CLOUDS AND FOG ARE 
POSSIBLE LATE SAT NIGHT INTO EARLY SUN MORNING AS EAST AND NORTHEAST 
FLOW BRINGS LOW LEVEL ATLANTIC MOISTURE INTO THE AREA. -GIH

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD 
SHORT TERM...HARTFIELD
LONG TERM...ELLIS 
AVIATION...HARTFIELD

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