Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000
FXUS62 KRAH 161919
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
220 PM EST TUE DEC 16 2014

.SYNOPSIS...A COLD FRONT WILL PUSH EAST THROUGH THE REGION THIS
EVENING. HIGH PRESSURE WILL BUILD SLOWLY INTO THE AREA THROUGH
FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 PM TUESDAY...

PREFRONTAL RAIN BAND IS CURRENTLY OVER THE INTERSTATE 95 CORRIDOR
AND CONTINUES TO PROGRESS RAPIDLY EAST. MEANWHILE...LOW LEVEL
WESTERLY FLOW ACROSS THE GULF STATES WILL CUT OFF MOISTURE ADVECTION
BY MID AFTERNOON. AS SUCH...NOT EXPECTING ANY ADDITIONAL PRECIP TO
DEVELOP AND WILL END POPS A LITTLE QUICKER...BY LATE AFTERNOON IN
THE WEST TO EARLY EVENING IN THE EAST. TEMPERATURES HAVE BEEN QUITE
THE CHALLENGE...WITH AREAS AHEAD OF THE RAIN WARMING TO THE UPPER
50S AND SOME LOWER 60S BEFORE EVAPORATIVE COOLING KNOCKED THEM BACK
INTO THE LOW TO MID 50S. WILL MAINTAIN A NEAR STEADY TREND...WITH A
FEW DEGREES WARMUP POSSIBLE...ESPECIALLY WEST WHERE CLEARING IS
PROGRESSING EAST AS THE LOW CLOUDINESS SLOWLY MIXES OUT.

THE SURFACE FRONT WILL SWEEP EAST...SCOURING OUT LINGERING MOISTURE
IN THE 00-06Z TIME FRAME...WITH MOSTLY CLEAR SKIES AND NO
REDEVELOPMENT OF FOG WITH A LIGHT NORTHWEST WIND NUDGING DEW POINTS
SLOWLY BUT STEADILY DOWNWARD THROUGH THE 30S. DOWNSLOPE FLOW AND
MIXING WILL KEEP TEMPS FROM CRASHING HARD AS SKIES CLEAR...WITH MINS
FROM THE UPPER 30S WEST TO LOWER 40S SOUTHEAST.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 220 PM TUESDAY...

UPPER TROF SHIFTS OFFSHORE AND FAIR WEATHER IS EXPECTED WEDNESDAY AS
WE TRANSTION TO NEAR ZONAL UPPER FLOW. AT THE SURFACE...HIGH
PRESSURE OVER THE CENTRAL US WILL BE BUILDING EASTWARD WITH NEAR
NEUTRAL TEMPERATURE ADVECTION AND LOW LEVEL THICKNESSES CONCURRING
WITH MOS TRENDS FOR MID 50S UNDER FULL SUN. SOUTHERN TIER COULD
SEE A FEW LOCATIONS HIT 60.

AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD WILL BE
RACING EAST IN THE FAST FLOW...AND COULD SPREAD ACROSS THE NORTHERN
TIER OF THE AREA IN THE AFTERNOON WEDNESDAY...WITH INCREASING HIGH
CLOUDINESS OVER ALL OF THE AREA WEDNESDAY NIGHT. CLOUD COVERAGE WILL
HAMPER OVERNIGHT CRASH...WITH MOST AREAS STAYING IN THE LOW TO MID
30S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 245 AM TUESDAY...

THROUGH FRIDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO
THE REGION THROUGH FRIDAY. THE ZONAL FLOW ALOFT WILL SLOWLY BECOME
MORE AMPLIFIED THROUGH THIS PERIOD...WITH GENERALLY WEST-NORTHWEST
FLOW OVER CENTRAL NC. EXPECT DRY WEATHER TO DOMINATE DURING THIS
TIME...HOWEVER THE MODELS ARE TRYING TO GENERATE SOME LIGHT PRECIP
FOR A BRIEF PERIOD ON THURSDAY...MAINLY IN THE FAR NW. FOR NOW WILL
KEEP THIS PART OF THE FORECAST DRY UNTIL THE MODELS SHOW A BIT MORE
RUN-TO-RUN CONSISTENCY WITH THE PRECIP. HIGHS IN THE UPPER 40S NORTH
TO MAINLY MID 50S SOUTH THURSDAY AND FRIDAY. EXPECT THURSDAY NIGHT
LOWS MAINLY IN THE LOW TO MID 30S.

FRIDAY NIGHT SATURDAY NIGHT: EXPECT RAPIDLY INCREASING CLOUDINESS
FRIDAY NIGHT AS A LOW PRESSURE SYSTEM APPROACHES FROM THE GULF. THE
INCREASED CLOUD COVER MAY YIELD LOWS A FEW DEGREES HIGHER THAN
PREVIOUS NIGHTS...GENERALLY IN THE MID 30S. IT APPEARS AS THOUGH THE
MODELS HAVE TRENDED TOWARD ONE ANOTHER OVER THE PAST FEW RUNS WITH
RESPECT TO THE APPROACHING UPPER LEVEL TROUGH/SHORTWAVE AND SURFACE
LOW. THE ECMWF IS STILL A BIT MORE AMPLIFIED THAN THE GFS ALOFT...
BUT THEY ARE MUCH CLOSER THAN PREVIOUS RUNS. THE GFS IS STILL JUST A
BIT FASTER...LARGELY DUE TO THE TROUGH BEING LESS AMPLIFIED...BUT
BOTH HAVE PRECIP MOVING INTO THE AREA FROM THE WEST-SOUTHWEST BY 12Z
SATURDAY. FOR NOW EXPECT TEMPS ACROSS OUR AREA TO REMAIN ABOVE
FREEZING FRIDAY NIGHT...THUS DO NOT EXPECT ANY WINTERY PRECIP AT
THIS TIME. HOWEVER...IF THE HIGH RIDGING IN FROM THE NE FRIDAY NIGHT
RESULTS IN TEMPS FALLING BELOW FREEZING THE CHANCE FOR PRECIP OF THE
FROZEN VARIETY MAY BE IN THE REALM OF POSSIBILITY. THE SURFACE LOW
IS EXPECTED TO MOVE ALONG THE GULF COAST AND UP ALONG THE CAROLINA
COAST SATURDAY AND SATURDAY NIGHT AND PRECIP CHANCES AND AMOUNT WILL
DEPEND ON THE EXACT TRACK THE LOW TAKES AS IT MOVES THROUGH THE
REGION. GIVEN THE CURRENT LOW TRACK...ANY THUNDERSTORMS WILL BE
LIMITED TO THE FAR SOUTHEAST AND COASTAL AREAS. TEMPS WILL ALSO
DEPEND ON WHERE THE LOW TRACKS...BUT FOR NOW EXPECT HIGHS AROUND 40
DEGREES IN THE NW TO LOW 50S IN THE SE. OVERNIGHT LOWS VERY SIMILAR
TO FRIDAY NIGHT...MAINLY IN THE MID 30S.

SUNDAY AND MONDAY: THE MAIN UPPER LEVEL SHORTWAVE MOVES OUT OF THE
REGION TO THE NORTHEAST SUNDAY MORNING...WHILE THE SURFACE LOW
REMAINS OFF THE COAST OF THE CAROLINAS THROUGH THE DAY. THE MODELS
INDICATE THE CHANCE FOR SOME LIGHT PRECIP TO LINGER ACROSS THE EAST
THROUGH SUNDAY AS THE SURFACE LOW REMAINS IN CLOSE PROXIMITY... WITH
CHANCES DECREASING LATE SUNDAY AND SUNDAY NIGHT AS THE LOW RAPIDLY
MOVES OFF TO THE NE AND AWAY FROM NC. FOR NOW...EXPECT SUNDAY NIGHT
AND MONDAY TO BE DRY. HIGHS SUNDAY AND MONDAY WILL GENERALLY BE IN
THE MID 40S NORTH TO AROUND 50S DEGREES SOUTH...WITH OVERNIGHT LOWS
IN THE UPPER 20S TO LOW 30S.

&&

.AVIATION /18 TUESDAY THROUGH SUNDAY/...
AS OF 1250 PM TUESDAY...

24 HOUR TAF PERIOD: LOW LEVEL MOISTURE REMAINS HIGH WITH MVFR/IFR
CONDITIONS IN THE WAKE OF A PREFRONTAL RAIN BAND MOVING RAPIDLY
ACROSS THE INTERSTATE 95 CORRIDOR EARLY THIS AFTERNOON. ALREADY
SEEING MIXING OUT OF THE LOWER CLOUDINESS ON THE WESTERN FRINGE OF
THE CLOUDINESS IN ADVANCE OF THE SURFACE FRONT WHICH WILL MOVE
ACROSS THE MOUNTAINS INTO THE FOOTHILLS BY MID AFTERNOON...WITH
CONDITIONS IMPROVING TO VFR IN THE TRIAD SITES BY 00Z.

FURTHER EAST...EXPECT CONDITIONS TO LINGER UNTIL THE FRONT
PASSES...WHEN WINDS VEERING WEST THEN NORTHWEST WILL PRODUCE RAPID
CLEARING EASTWARD ACROSS THE REMAINDER OF CENTRAL NC BY 03Z-ISH.
DRYING WILL PRECLUDE REDEVELOPMENT OF FOG OVERNIGHT...WITH CLEAR
SKIES AND NORTHWEST WINDS TO 10 KNOTS EXPECTED TOMORROW.

OUTLOOK...VFR CONDITIONS SHOULD DOMINATE WEDNESDAY THROUGH EARLY
FRIDAY. A LOW PRESSURE SYSTEM TRACKING FROM THE GULF OF MEXICO
NORTHEASTWARD ALONG THE SOUTHEAST COAST WILL RESULT IN ADVERSE
AVIATION CONDITIONS LATE FRIDAY AND INTO THE WEEKEND.

&&

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

&&

$$

SYNOPSIS...MLM
NEAR TERM...MLM
SHORT TERM...MLM
LONG TERM...KC
AVIATION...MLM



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