Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000
FXUS62 KRAH 050754
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
350 AM WED AUG 5 2015

.SYNOPSIS...A COLD FRONT WILL APPROACH FROM THE NORTHWEST AND SETTLE
INTO NORTH CAROLINA TODAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 310 AM WEDNESDAY...

A COLD FRONT CURRENTLY ORIENTED W-E ACROSS THE OHIO VALLEY AND
NORTHERN MID ATLANTIC REGION WILL SLOWLY DRIFT SOUTH TO THE VA/NC
BORDER BY THIS EVENING...THEN GRADUALLY MOVE SOUTHWARD ACROSS NC
THROUGH THE NIGHT.  LOOK FOR MOSTLY FAIR WEATHER IN ADVANCE OF THE
FRONT DURING THE DAYTIME TODAY...ALTHOUGH AN ISOLATED SHOWER/TSTM
CAN`T BE RULED OUT LATER IN THE DAY AS THE FRONT APPROACHES.  THIS
EVENING AND TONIGHT...A FEW SHOWERS WILL BE POSSIBLE MAINLY ALONG
AND NORTH OF THE BOUNDARY (BEST CHANCE N OF HWY 64) AS SYNOP SCALE
FORCING IMPROVES FROM THE WEST WITH THE APPROACH OF A MID LEVEL
SHORT WAVE.  FORECAST SOUNDINGS AND LATEST GUIDANCE CONTINUES TO
SHOW HOT CONDITIONS AHEAD OF THE FRONT...HIGHS IN THE MID-UPPER
90S...AND LOWS AROUND 70.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 350 AM WEDNESDAY...

A SERIES OF CONVECTIVE DISTURBANCES OVER THE FRONT RANGE THIS
MORNING WILL MERGE TODAY AND TRACK EAST TOWARD THE TOWARD THE TN/OH
VALLEY REGION TODAY AND TONIGHT...POTENTIALLY AMPLIFYING QUITE A BIT
BEFORE CROSSING CENTRAL NC LATE THURSDAY AND EARLY FRIDAY.
MEANWHILE...A COLD FRONT PROGGED TO SINK SOUTH INTO CENTRAL NC
TONIGHT WILL RETREAT NORTHWARD DURING THE DAY ON THURSDAY AND IS LIKELY TO
END UP NEAR THE NC/VA BORDER (BASED ON A ECMWF/NAM MODEL
PREFERENCE...WHICH ARE FURTHER NORTH THAN THE GFS).  CONVECTIVE
INITIATION...PRIMARILY NEAR THE FRONTAL ZONE THURSDAY
AFTERNOON...WILL BE AIDED BY INCREASING DCVA ASSOCIATED WITH THE
AFOREMENTIONED UPPER DISTURBANCE THURSDAY EVENING AND SHOULD
CONTINUE INTO THURSDAY NIGHT AS A WEAK SURFACE WAVE DEVELOPS AND
EVENTUALLY MOVES EAST OFF THE NC COAST ON FRIDAY.  WEAK LAPSE RATES
ALOFT AND INCREASING MID/HIGH CLOUDS MAY HINDER HEATING AND DESTABILIZATION
THURSDAY...BUT FORECAST SOUNDINGS SUGGEST AT LEAST SOME POCKETS OF
MODERATE INSTABILITY WILL EXIST ON THE WARM SIDE OF THE
BOUNDARY...WHICH...WHEN COMBINED WITH 0-6KM BULK SHEAR AROUND 30KT
(MORE SO NORTH) MAY RESULT IN A FEW SEVERE STORM CLUSTERS.

HIGHS THURSDAY ARE TRICKY BASED ON THE FRONTAL LOCATION ISSUES
MENTIONED ABOVE.  AREAS NEAR THE VA BORDER ARE MORE LIKELY TO REMAIN
IN THE 80S DUE TO CLOUDS AND SHOWERS/STORMS...BUT GFS/MAV GUIDANCE
SEEMS TOO COOL GIVEN THAT IT IS STILL EARLY AUGUST AND IT WON`T TAKE
MUCH HEATING TO MIX THE FRONT BACK TO THE NORTH WITHOUT A BETTER
HIGH PRESSURE TO THE NORTH. WILL LOWER HIGHS ACROSS THE NORTH INTO
THE MID/UPPER 80S BUT KEEP MID 90S TO THE SOUTH.  LOWS THURSDAY
NIGHT IN THE LOWER 70S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 350 AM WEDNESDAY...

RECENT MODEL RUNS HAVE WAVERED QUITE A BIT REGARDING HOW QUICKLY THE
SURFACE LOW THAT DEVELOPS OVER NC LATE THURSDAY WILL MOVE EAST AND
OFFSHORE ON FRIDAY...WITH THE 00Z ECMWF NOW KEEP THE LOW OVER
EASTERN NC UNTIL FRIDAY NIGHT.  BEHIND THE INITIAL UPPER DISTURBANCE
ON THURSDAY... A SECOND...SHALLOWER DISTURBANCE IS FORECAST TO DIVE
ACROSS THE OHIO VALLEY ON FRIDAY AND THEN FINALLY KICK THE ENTIRE
SYSTEM EAST.  WILL NEED TO HANG ON TO POPS THROUGH FRIDAY AFTERNOON
BEFORE TRENDING DOWN QUICKLY FRIDAY NIGHT AS HIGH PRESSURE NOSE BACK
IN FOR SATURDAY.   SATURDAY SHOULD THEN BE DRY...FOLLOWED BY A
ANOTHER PERIOD OF NORTHWESTERLY FLOW ALOFT AND LOW FORECAST
CONFIDENCE IN THE TIMING AND IMPACT OF DISTURBANCES WITHIN THAT
NORTHWESTERLY FLOW.  GUIDANCE GENERALLY SUGGESTS POPS NEAR CLIMO BY
MONDAY/TUESDAY...WITH ANOTHER FRONT POSSIBLE BY MIDWEEK.

HIGHS WILL RUN BELOW NORMAL FRIDAY AND SATURDAY...CREEPING BACK UP
TO AROUND NORMAL...87-91...EARLY NEXT WEEK.

&&

.AVIATION /06Z WEDNESDAY THROUGH SATURDAY/...
AS OF 310 AM WEDNESDAY...

MAINLY VFR CONDITIONS EXPECTED TODAY...ALTHOUGH AN ISOLATED SHOWER
OR TSTM IS POSSIBLE DURING THE LATE AFTERNOON AND EVENING WITH THE
FRONT DROPPING SOUTH...WHICH COULD BRIEFLY REDUCE FLT CONDITIONS TO
MVFR OR IFR.

LOOKING BEYOND THE 24 HOUR TAF PERIOD...ISOLD TO SCATTERED SHOWERS
AND TSTMS WILL BE POSSIBLE EACH DAY...UNTIL HIGH PRESSURE BUILDS
OVER THE REGION LATER THIS WEEKEND.

&&

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

&&

$$

SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...22
LONG TERM...22
AVIATION...RAH


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