Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 210613
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
213 AM EDT TUE OCT 21 2014

.SYNOPSIS....A LEAD SHORTWAVE TROUGH ALOFT WILL CROSS OUR REGION
THIS MORNING...FOLLOWED BY THE PASSAGE OF A COLD FRONT THIS
AFTERNOON AND EVENING. AN UPPER LEVEL LOW WILL SETTLE SOUTHEAST
ACROSS THE MIDDLE ATLANTIC REGION TONIGHT THROUGH WEDNESDAY.

&&

.NEAR TERM /TONIGHT/...
AS OF 10 PM MONDAY...

S/W ENERGY MOVING THROUGH AN AMPLIFYING L/W TROUGH ACROSS THE
EASTERN U.S. IS HELPING TO PRODUCE A SMALL BAND OF LIGHT SHOWERS
AND/OR SPRINKLES ACROSS THE NORTHERN PIEDMONT THIS EVENING... ALONG
WITH INCREASING MID TO UPPER LEVEL CLOUDS. THUS... HAVE ADDED A
SLIGHT CHANCE OF SHOWERS TO THE FORECAST ACROSS THE NORTHERN
PIEDMONT FOR THIE EVENING INTO EARLY TUESDAY MORNING (MOST SITES
ONLY WITH TRACE AMOUNTS THOUGH... THUS... KEEPING POPS LOW THOUGH).
THE MID LEVEL DISTURBANCE IS EXPECTED TO PUSH TO THE EAST OF CENTRAL
NC BY AROUND DAYBREAK... YIELDING MOSTLY CLEAR SKIES BY THEN. GIVEN
THE ADDED CLOUD COVER FOR MOST OF THE NIGHT... AND ACCOMPANYING
SURFACE TROUGH MOVING THE REGION... WE SHOULD SEE LOW TEMPS A BIT
WARMER TONIGHT. EXPECT LOW TEMPS IN THE MID TO UPPER 40S... WITH
PERHAPS SOME LOWS AROUND 50 ACROSS THE SOUTHEAST.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 310 PM MONDAY...

A STRONGER UPPER LEVEL DISTURBANCE WILL DIVE SE FROM THE EASTERN
GREAT LAKES INTO THE CENTRAL APPALACHIANS/NORTHERN MID ATLANTIC.
THIS FEATURE WILL DRAG A COLD FRONT ACROSS CENTRAL NC LATE TUESDAY
INTO TUESDAY NIGHT. WLY FLOW PROCEEDING THE FRONT WILL LIMIT
MOISTURE ADVECTION. IN FACT MOISTURE IS PROJECTED TO BE CONFINED TO
A 5K FT LAYER BETWEEN 850-700MB. WHILE AN ISOLATED SHOWER OR
SPRINKLES POSSIBLE WITH THE FROPA...MOST LOCATIONS WILL NOT SEE ANY
RAIN.

WEST-SW FLOW AHEAD OF THE FRONT ALONG WITH PARTIAL SUNSHINE WILL
PUSH TEMPS INTO THE LOW AND MID 70S. LOW LEVEL COLD AIR ADVECTION
WILL INITIALLY BE OFFSET BY DOWNSLOPE COMPONENT OF NW LOW LEVEL WIND
THOUGH AS SFC WINDS VEER TO A NLY DIRECTION BY DAYBREAK
WEDNESDAY...NOTICEABLY COOLER AIR WILL BE REALIZED. MIN TEMPS MID
40S NW TO THE UPPER 40S/AROUND 50 SE.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 225 PM MONDAY...

THE LOW JUST TO THE NORTHEAST OF CENTRAL NC ON WEDNESDAY WILL
GRADUALLY MOVE EAST AND NORTHEAST...LINGERING OVER THE ATLANTIC
COAST AND INTO NEW ENGLAND THROUGH THE END OF THE WEEK. THE
ASSOCIATED TROUGH EXTENDING SOUTH THROUGH THE CAROLINAS WILL SLOWLY
PUSH OFF THE COAST LATE IN THE WEEK...RESULTING IN NW FLOW OVER THE
REGION FOR THURSDAY AND FRIDAY. DESPITE THE STRONG FORCING ALOFT AND
THE LOW IN CLOSE PROXIMITY TO CENTRAL NC...THE ABUNDANT DRY AIR OVER
THE AREA SHOULD LIMIT THE POTENTIAL FOR PRECIPITATION. THE BEST
MOISTURE WILL BE NORTH AND EAST OF THE TRIANGLE...RESULTING IN THE
BEST CHANCES FOR CLOUDS AND POSSIBLY A SPRINKLE OR TWO...BUT FOR NOW
WILL KEEP THE FORECAST DRY. TEMPERATURES WILL BE SIMILAR TO ONE
ANOTHER BOTH WEDNESDAY AND THURSDAY...HIGHS IN THE LOW TO MID 60S
AND LOWS IN THE LOW TO MID 40S. AS THE MAIN LOW LIFTS NORTH AWAY
FROM THE AREA...A SHORTWAVE IS FORECAST TO DIVE SSE OVER THE REGION
FRIDAY AND SATURDAY...BEFORE MOVING OFF THE COAST SUNDAY.
PRECIPITATION IS NOT EXPECTED WITH THIS DISTURBANCE AS IT TRAVERSES
THE REGION GIVEN THE CONTINUED LACK OF ANY DEEP MOISTURE AND
PERSISTENT NW FLOW. TEMPERATURES SHOULD MODERATE SLIGHTLY THROUGH
THE WEEKEND...HIGHS IN THE MID 60S TO LOW 70S AND LOWS IN THE MID
40S TO AROUND 50 DEGREES.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 210 AM TUESDAY...

AN UPPER LEVEL TROUGH AND ASSOCIATED MID LEVEL CLOUD BAND AND VIRGA -
OR ISOLATED SPRINKLES AT THE SURFACE - WILL MOVE EAST ACROSS CENTRAL
NC THROUGH 10Z. OTHERWISE...A LIGHT SSW SURFACE WIND WILL INCREASE
INTO THE 5-10 KT FROM THE WSW AHEAD OF A COLD FRONT THAT WILL MOVE
SOUTHEAST ACROSS THE AREA BETWEEN 20Z-01Z THIS AFTERNOON AND
EVENING. THE PASSAGE OF THE FRONT WILL CAUSE SURFACE WINDS TO VEER
TO WNW AND INCREASE INTO THE 8-14 KT RANGE WITH A FEW GUSTS INTO THE
MID-UPPER TEENS KTS. SCATTERED TO BROKEN CUMULUS WITH BASES BETWEEN
4500-7000 FT AND TOPS BETWEEN 9-13 THOUSAND FT - THE DEEPEST OF
WHICH WILL BE CAPABLE OF PRODUCING A LIGHT SHOWER OR SPRINKLE - WILL
ALSO DEVELOP IN THE VICINITY OF THE PASSING FRONT...WITH THE
RELATIVE GREATER CLOUD COVERAGE AND CHANCE OF A SHOWER AT KRDU AND
KRWI. A STEADY WNW TO NW SURFACE WIND...WITH AN OCCASIONAL GUST INTO
THE MID-UPPER TEENS KTS...WILL CONTINUE AS COLDER AIR MOVES IN
BEHIND THE FRONT THIS EVENING.

OUTLOOK: THE DEVELOPMENT OF AN UPPER LOW OVER THE MIDDLE ATLANTIC
STATES TONIGHT AND WED WILL RESULT IN PERIODS OF LOW VFR CEILINGS
(BETWEEN 3500-5000 FT) AND A CHANCE OF SHOWERS MAINLY FROM KRDU AND
KRWI NORTHEAST TOWARD THE CHESAPEAKE BAY. COASTAL LOW PRESSURE ALONG
THE MIDDLE ATLANTIC AND NORTHEAST COAST WILL PRODUCE NW SURFACE
WINDS IN THE LOW-MID TEENS KTS WITH GUSTS AROUND 20 KTS WED...AND TO
A LESSER DEGREE ON THU.


&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...KCP
AVIATION...MWS


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