-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 080021
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
721 PM EST FRI MAR 7 2014

.SYNOPSIS...
STRENGTHENING LOW PRESSURE ALONG THE CAROLINA COAST WILL MOVE
FURTHER OFFSHORE TONIGHT. A WEAK COLD FRONT WILL CROSS THE REGION
FROM THE NORTHWEST LATE SATURDAY NIGHT...WITH WEAK HIGH PRESSURE
BUILDING INTO THE REGION LATE SUNDAY AND SUNDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 PM FRIDAY...

...WINTER STORM WARNING AND WINTER STORM ADVISORY PREVIOUSLY IN
EFFECT UNTIL 4 PM HAS BEEN CANCELLED...

...WINTER WEATHER ADVISORY FOR BLACK ICE NOW IN EFFECT FROM 9 PM
THIS EVENING UNTIL 9 AM SATURDAY MORNING...

PRECIPITATION: THE HEAVY BAND OF PRECIP CURRENTLY OVER THE AREA IS
ASSOCIATED WITH STRONG DIFFLUENCE ALOFT AND STRONG MID-LEVEL
FRONTOGENESIS ON THE NW PERIPHERY OF THE H85-H5 LOW TRACKING ENE .
EXPECT THIS SW-NE ORIENTED BAND TO PROGRESS SLOWLY EAST ACROSS
CENTRAL NC THROUGH THE AFTERNOON...GRADUALLY PIVOTING TO A MORE SSW-
NNE OR S-N ORIENTATION IS IT SHIFTS INTO EASTERN PORTIONS OF THE
STATE BETWEEN 00-03Z. WITH THE ABOVE IN MIND... WILL INDICATE PRECIP
CHANCES GRADUALLY ENDING FROM WEST-EAST LATE THIS AFTERNOON THROUGH
MIDNIGHT WITH AN INCREASINGLY TIGHT REFLECTIVITY GRADIENT ON THE
BACK (WESTERN) EDGE AS THE BAND PROGRESSES EAST.

PRECIPITATION TYPE: THERMAL PROFILES ARE SUPPORTIVE OF ALL RAIN FOR
THE REMAINDER OF THIS AFT/EVE...THOUGH A VERY SMALL CHANCE FOR A
BRIEF (NO-IMPACT) RATE-DRIVEN CHANGEOVER TO SNOW CANNOT BE
COMPLETELY RULED OUT IN THE NORTHERN PIEDMONT THROUGH 500 PM. SINCE
TEMPERATURES ARE ABOVE FREEZING AND PRECIP IS ALL RAIN...THE
WARNINGS AND ADVISORIES PREVIOUSLY IN EFFECT UNTIL 4 PM THIS
AFTERNOON HAVE ALREADY BEEN CANCELLED.

BLACK ICE: A POST-EVENT WINTER WEATHER ADVISORY FOR BLACK ICE HAS
BEEN ISSUED FOR 9 PM THIS EVENING THROUGH 9 AM SATURDAY MORNING
ACROSS PORTIONS OF THE NORTHERN AND NORTHWESTERN PIEDMONT WHERE
SIGNIFICANT ICE/SNOW ACCUMULATION OCCURRED LATE YESTERDAY EVENING
AND EARLY THIS MORNING...AND WHERE TEMPERATURES COULD FALL BELOW
FREEZING (INTO THE UPPER 20S TO LOWER 30S) AS SKIES CLEAR FROM WEST-
EAST BETWEEN 00-06Z. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM FRIDAY...

TO START THIS PERIOD OF THE FORECAST...A MUCH DIFFERENT SATURDAY IS
EXPECTED COMPARED TO TODAY...WITH DRY CONDITIONS AND A MUCH WARMER
BOUNDARY LAYER DEVELOPING AS WINDS ALOFT ON GFS BUFR SOUNDINGS
QUICKLY BACK FROM NORTH TO NORTHWEST VERY EARLY SATURDAY...TO DEEP
WESTERLY BY SATURDAY AFTERNOON. GUIDANCE TEMPERATURES SUPPORT HIGHS
REBOUNDING NICELY TO THE LOWER TO MID 60S SATURDAY AFTERNOON...AND
THE 1000-850MB THICKNESSES...WHICH GRADUALLY RISE OVERNIGHT AND
CONTINUE TO RISE SATURDAY...CORRESPOND TO SUCH HIGHS AS WELL.
OVERNIGHT LOWS SATURDAY NIGHT QUITE POSSIBLY WILL BE HIGHER THAN
DAYTIME HIGHS TODAY...IN ADVANCE OF AN APPROACHING COLD FRONT ONLY
FALLING TO THE LOWER TO MID 40S.

CURRENTLY ANTICIPATE A COLD FRONT MOVING THROUGH SUNDAY TO MOVE
THROUGH DRY...WITH BOTH THE GFS AND ECMWF PRODUCING NO QPF FOR
CENTRAL NORTH CAROLINA WITH THE FRONTAL PASSAGE. THE GFS BUFR
SOUNDINGS FOR THE AREA SUGGEST POSSIBLY ENOUGH MID-LEVEL MOISTURE
FOR A FEW SPRINKLES OR PATCH OF LIGHT RAIN...MOST LIKELY NORTH OF
U.S. 64 EARLY SUNDAY WHERE THE NAM FORECASTS MINIMAL QPF AND ITS
GUIDANCE POPS ARE HIGHER. LATER FORECASTS MAY NEED TO INTRODUCE SOME
SPRINKLES OR A SMALL CHANCE FOR LIGHT RAIN THEN. BY SUNDAY NIGHT
GOOD DRYING TAKES PLACE BEHIND THE FRONT THOUGH WITH GFS BUFR
SOUNDINGS TOWARD KFAY SHOWING SOME SHALLOW MOISTURE REMAINING NEAR
THE INVERSION AT 850MB TO KEEP PARTLY CLOUDY CONDITIONS IN THAT PART
OF CENTRAL NORTH CAROLINA FOR THE OVERNIGHT HOURS. WILL FORECAST
HIGHS NEAR THE COOLER MAV GUIDANCE FOR SUNDAY DUE TO THE FRONTAL
PASSAGE AND ANTICIPATED CLOUDS...BUT STILL THIS SHOULD RESULT IN
HIGHS IN THE MID TO UPPER 60S WITH SKIES BECOMING AT LEAST PARTLY
SUNNY. LOWS SUNDAY NIGHT IN THE MID 30S TO AROUND 40.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 240 PM FRIDAY...

TEMPERATURES SHOULD BE ABOVE NORMAL EARLY IN THIS PERIOD AS DRY
CONDITIONS CONTINUE. TEMPERATURES COULD REACH HIGHS IN THE LOWER TO
MID 70S TUESDAY AHEAD OF A LOW PRESSURE SYSTEM THAT WILL MOVE OVER
OR NEAR CENTRAL NORTH CAROLINA WEDNESDAY. THIS SHOULD PROVIDE A GOOD
CHANCE OF SHOWERS TO THE AREA THEN...AND MODEL SOUNDINGS AND
THICKNESSES ARE WELL WARM FOR ANYTHING BUT LIQUID. SOME OF THE
LATEST MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR ELEVATED
INSTABILITY...AND SUCH INSTABILITY APPEARS LIMITED CURRENTLY...BUT
GIVEN THE STRENGTH OF THE LOW AND ITS ASSOCIATED MID-LEVEL SHORTWAVE
WILL INTRODUCE FOR NOW AT LEAST A SLIGHT CHANCE OF THUNDER IN THE
FORECAST FOR THE DAY WEDNESDAY IN THE GRIDDED DATA. TEMPERATURES ARE
DIFFICULT WEDNESDAY DUE TO THE TIMING OF PRECIPITATION AND THE TRACK
OF THE LOW...BUT WILL ANTICIPATE THE POTENTIAL FOR A GOOD GRADIENT
IN TEMPERATURE NORTH TO SOUTH THEN...WITH HIGHS POSSIBLY ONLY NEAR
60 TOWARD THE VIRGINIA BORDER TO AROUND 70 IN THE FAR SOUTH.
TEMPERATURES WILL RETURN COOLER WITH DRIER CONDITIONS EXPECTED FOR
THE END OF THE WEEK AS GFS BUFR SOUNDINGS ARE QUITE DRY FROM
THURSDAY THROUGH THE DAY ON FRIDAY. OF THESE TWO DAYS...THURSDAY
SHOULD BE BREEZIER IN A TIGHTER GRADIENT BEHIND LOW PRESSURE
FOLLOWED BY HIGH PRESSURE AND LIGHTER WINDS ON FRIDAY.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 719 PM FRIDAY...

PRECIPITATION IS SLOWLY EXITING THE AREA FROM WEST TO EAST AS THE
COASTAL LOW PRESSURE SYSTEM MOVES OFF TO THE NORTHEAST. THERE IS THE
POTENTIAL FOR FOG TO DEVELOP ACROSS THE AREA... WITH HIGHEST
CONFIDENCE AT KGSO AND KINT WHERE CLOUD COVER HAS DIMINISHED AND
WINDS WILL BECOME LIGHT OVER THE NEXT FEW HOURS AS THE PRESSURE
GRADIENT WEAKENS FURTHER AWAY FROM THE COASTAL SYSTEM. CONDITIONS
WILL RETURN TO VFR BY 14-15Z SATURDAY MORNING WITH CLEAR SKIES AS
HIGH PRESSURE BUILDS IN TO THE SOUTHEAST.

BEYOND THE TAF PERIOD...THERE COULD BE BRIEF...HIGH MVFR CONDITIONS
IN CU/SC SUNDAY. THERE WILL BE AN INCREASING POTENTIAL OF ADVERSE
AVIATION CONDITIONS LATE TUESDAY NIGHT INTO WEDNESDAY AS A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. WITH THE LOW PRESSURE
SYSTEM WILL BE A GOOD CHANCE OF SHOWERS...AND POSSIBLY A
THUNDERSTORM OR TWO...ON WEDNESDAY.
-- End Changed Discussion --

&&

.RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 9
PM THIS EVENING TO 9 AM EST SATURDAY FOR NCZ007>009-021>025-038>040.

&&

$$

SYNOPSIS...VINCENT/DJF
NEAR TERM...VINCENT
SHORT TERM...DJF
LONG TERM...DJF
AVIATION...SEC/DJF