Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KRAH 221147
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
747 AM EDT WED OCT 22 2014

.SYNOPSIS....AN UPPER LEVEL LOW WILL SETTLE SOUTHEAST ACROSS
SOUTHEASTERN VA AND NORTHEASTERN NC THIS MORNING...THEN MOVE
OFFSHORE TODAY. ASSOCIATED COASTAL LOW PRESSURE WILL DEVELOP AND
LIFT UP THE MIDDLE ATLANTIC COAST THROUGH THURSDAY...WHILE HIGH
PRESSURE OTHERWISE BUILDS IN FROM THE WEST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM WEDNESDAY...

AN UPPER LOW WILL DEVELOP/AMPLIFY SOUTHEASTWARD FROM WEST-CENTRAL VA
THIS MORNING TO JUST OFFSHORE THE NC/VA COAST THIS AFTERNOON. THE
CENTER OF THE ASSOCIATED STRONGEST MID LEVEL HEIGHT FALLS...ON THE
ORDER OF 100 M/12 HR...WILL SETTLE ACROSS EAST-CENTRAL NC THROUGH
12Z. THIS FORCING FOR ASCENT...IN CONJUNCTION WITH THE ARRIVAL OF
THE COLD POOL/STEEPENING LAPSE RATES ALOFT...HAS SUPPORTED THE
MAINTENANCE OF AN AREA OF SHOWERS INTO THE RAH NE PIEDMONT AND
NORTHERN COASTAL PLAIN THIS MORNING. THESE SHOWERS...AND
CLOUDINESS...WILL BOTH BECOME ENHANCED WITH DIURNAL HEATING OWING TO
THE PRESENCE OF THE COLD TEMPERATURES/STEEP LAPSE RATES ALOFT
ASSOCIATED WITH THE UPPER LOW - THE FORMER IN EXCESS OF MINUS 20 C
AND THE LATTER BETWEEN 6.5-7 C/KM...THROUGH EARLY-MID AFTERNOON.
SHOWERS SHOULD THEN MOVE EAST AND NORTHEAST OF THE RAH CWFA AS THE
UPPER LOW MAKES A TURN/LIFTS UP THE MIDDLE ATLANTIC COAST BY LATE
AFTERNOON-EVENING. PARTLY TO MOSTLY SUNNY ELSEWHERE TODAY. IT WILL
ALSO BE COOLER AND BREEZY...WITH NORTHWESTERLY DAYTIME WIND GUSTS UP
TO 25 MPH OWING TO THE DEEPENING OF A COASTAL LOW ACCOMPANYING THE
UPPER ONE...WITH HIGHS IN THE 60S. CLEARING AREA-WIDE AND SIMILARLY
COOLER TONIGHT...WITH A CONTINUED LIGHT NW WIND AND LOWS RANGING
FROM THE UPPER 30S OVER THE SOUTHERN AND WESTERN PIEDMONT...TO
MIDDLE 40S OVER THE COASTAL PLAIN.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 330 AM WEDNESDAY...

THE COASTAL AND UPPER LOWS WILL CONTINUE TO LIFT SLOWLY UP THE MIDDLE
ATLANTIC COAST...WHILE HEIGHT RISES ALOFT AND ASSOCIATED SUBSIDENCE
SPREAD EAST ACROSS NC THU. A NOTICEABLE NW BREEZE WILL LINGER
THROUGH THE DAY...WITH GUSTS AROUND 20 MPH THROUGH MID-AFTERNOON...
STRONGEST OVER THE NE PIEDMONT AND NORTHERN COASTAL PLAIN. DESPITE
SUNNY OR MOSTLY SO CONDITIONS...TEMPERATURES WILL REMAIN COOL IN THE
60S...TO AROUND 70 OVER THE SOUTHERN PIEDMONT AND SANDHILLS. AN
ELONGATED UPPER TROUGH OVER THE ROCKIES THIS MORNING...ONE SPANNING
BOTH THE NORTHERN AND SOUTHERN STREAMS...WILL MOVE EAST AND INTO THE
TN VALLEY AND GULF COAST STATES THU NIGHT. MID-HIGH CLOUDS
ASSOCIATED WITH THE SOUTHERN STREAM COMPONENT WILL INCREASE
THU NIGHT...WITH LOWS MOSTLY IN THE LOWER TO MIDDLE 40S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...

THE EXPANSIVE UPPER LOW OVER THE NEW ENGLAND COAST ON THURSDAY WILL
CONTINUE ON OFF TO THE NORTHEAST FRIDAY...WHILE A DISTURBANCE
CROSSING THE MIDWEST DIVES SOUTHEAST TOWARD OUR AREA.  BOTH THE GFS
AND ECMWF DEPICT THIS DISTURBANCE A RELATIVELY COMPACT VORT CENTER
BY THE TIME IT CROSSES NC FRIDAY NIGHT.  HOWEVER...DESPITE THE
STRONG DCVA ASSOCIATED WITH THIS FEATURE...WEST-NORTHWESTERLY FLOW
WILL LIMIT DEEP MOISTURE AND THE ONLY ANTICIPATED SENSIBLE IMPACT IS
SOME MID/HIGH CLOUDS ASSOCIATED WITH A STRENGTHENING UPPER JET OVER
THE SOUTHEAST US. HIGHS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH
OVERNIGHT LOWS IN THE MID 40S.

HIGH PRESSURE WILL INCH EASTWARD FROM THE MID-SOUTH SATURDAY AND
SUNDAY...SETTLING OVER NC/VA ON MONDAY.  MODELS SHOW A WEAK BACKDOOR
FRONT..ATTENDANT TO SHORTWAVE CROSSING NEW ENGLAND... SLIPPING INTO
THE AREA EARLY SUNDAY.  THIS...ALONG WITH SHALLOW MIXING BENEATH THE
HIGH PRESSURE ON MONDAY...MAY BE ENOUGH TO KEEP TEMPS SLIGHTLY
COOLER THAN THE GRADUAL RISE OF THICKNESSES INTO THE 1360-1370M
RANGE WOULD SUGGEST.  HIGHS ARE EXPECTED TO BE IN THE UPPER 60S TO
LOWER 70S.  THE HIGH WILL THEN SHIFT OFFSHORE TUESDAY AS THE UPPER
RIDGE AXIS SLIDES OVERHEAD.  THIS WILL ALLOW TEMPS TO MODERATE A
LITTLE MORE TOWARD MIDWEEK AS A SOUTHERLY WIND DEVELOPS AHEAD OF A
FRONTAL ZONE CROSSING THE CENTRAL US.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM WEDNESDAY...

THE PASSAGE OF A STRONG UPPER LEVEL LOW ACROSS SOUTHEASTERN VA AND
NORTHEASTERN NC THROUGH EARLY AFTERNOON WILL RESULT IN VICINITY/
SCATTERED SHOWERS AT KRWI THROUGH AROUND 20Z. IN ADDITION TO THE
SHOWERS...VARIABLY CLOUDY CONDITIONS WILL OCCUR THROUGH THIS
AFTERNOON...WITH CEILINGS/CLOUD BASES MOSTLY BETWEEN 3500-7000
FT...AND TOPS IN SHOWERS UP TO 17 THOUSAND FT...PARTICULARLY IN
CLOSEST PROXIMITY TO THE AFOREMENTIONED UPPER LEVEL LOW/AT KRDU AND
KRWI. OTHERWISE...NW SURFACE WINDS WILL INCREASE INTO THE LOW-MID
TEENS KTS WITH PEAK GUSTS IN THE LOWER 20S KTS...ONCE DIURNAL
HEATING/MIXING COMMENCES BY 15Z...AND IN RESPONSE TO A TIGHTENING
MSL PRESSURE GRADIENT AROUND DEVELOPING COASTAL LOW PRESSURE ALONG
THE MIDDLE ATLANTIC COAST. SURFACE WINDS SHOULD THEN BECOME
LIGHT...STILL FROM THE NW...AROUND SUNSET.

OUTLOOK: BREEZY NW WINDS AGAIN THU. OTHERWISE...VFR...UNDER THE
INFLUENCE OF HIGH PRESSURE FORECAST TO REMAIN SITUATED JUST WEST OF
THE APPALACHIANS...WHICH WILL RESULT IN A DRY WEST TO NORTHWEST WIND
IN CENTRAL NC...THROUGH THE NEXT SEVERAL DAYS.

&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...BLS
AVIATION...MWS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.