Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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787
FXUS62 KRAH 072216
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
515 PM EST SUN FEB 7 2016

.SYNOPSIS... A STRONG COASTAL LOW OFF THE SOUTH CAROLINA COAST WILL
MOVE AWAY TONIGHT AND MONDAY. AN UPPER LEVEL DISTURBANCE AND COLD
FRONT WILL CROSS THE REGION LATE MONDAY...FOLLOWED BY AND EXTENDED
PERIOD OF BELOW NORMAL TEMPERATURES THROUGH THE WORK WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 PM SUNDAY...

MSAS SHOWS A SUB-1000MB (~994MB) SURFACE LOW EAST OF MYRTLE BEACH
THIS AFTERNOON...WITH FURTHER DEEPENING TO NEAR 980MB EAST OF THE
OBX FORECAST TONIGHT AS AN UPPER LOW OVER THE SAVANNAH RIVER BASIN
BEGINS TO LIFT NORTHEAST.  PRECIP RATES...A PERIOD MIX OF
RAIN...SNOW AND SLEET (AT TIMES ALL SLEET)...HAVE BEGUN TO
DECREASE...WITH MOST LOCATIONS IN THE COASTAL LAIN NOW REPORTING
LIGHT RAIN. WHILE A VERY BRIEF BURST OF SLEET IS STILL POSSIBLE OVER
EASTERN WAYNE AND EASTERN WILSON COUNTIES...THREAT/BULK OF WINTRY
MIX PRECIP HAS ENDED.  NO ADDITIONAL ACCUMULATION EXPECTED...IN
ADDITION TO THE QUARTER TO HALF INCH REPORTS ON SOME AREAS THAT IS.
SO WILL CANCEL THE WINTER WX ADVISORY BEFORE THE 6 PM EXPIRATION.

WE`LL SEE FAIRLY RAPID CLEARING OF THE CIRRUS SHIELD AFTER
MIDNIGHT...WITH OVERNIGHT LOWS EXPECTED TO DROP INTO THE UPPER 30S
AND LOWER 30S UNDER SHORTWAVE RIDGING ALOFT AND LIGHT SURFACE WINDS.
THERE MAY BE SOME BLACK ICE IN THE COASTAL PLAIN IF ROADS DO NOT DRY
OUT PRIOR TO THE CLEARING...AND THIS IS SOMETHING THAT WILL BE
MONITORED THIS EVENING.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 330 PM SUNDAY...

THERE SHORTWAVE RIDGE ALOFT BETWEEN THE DEPARTING UPPER WAVE AND ITS
KICKER WAVE APPROACHING FROM THE WEST WILL QUICKLY GIVE WAVE TO A
STRONG SHOT OF DCVA MONDAY AFTERNOON AND EVENING.  A SOUTHERLY
WIND...GUSTING TO 20-25KT BY MONDAY AFTERNOON...WILL PROVIDE A BRIEF
PERIOD OF WARMING AND MOISTEN...YIELDING STEEP LOWER TROPOSPHERIC
LOOSE RATES AND THE POTENTIAL FOR A BAND OF SHOWERS DURING THE
AFTERNOON.  FORECAST HIGHS IN THE UPPER 40S AND LOWER 50S WILL KEEP
THIS ALL LIQUID DESPITE THE LAPSE RATES AND A PATTERN THAT OFTEN
FAVORS SNOW SHOWERS.  HOWEVER...A SECONDARY BAND OF RAIN THAT
CHANGES TO SNOW IS STILL POSSIBLE LATE MONDAY EVENING AND OVERNIGHT
AS AN ARCTIC FRONT SURGES ACROSS THE AREA AND A WAVE OF LOW PRESSURE
DEVELOPS SOMEWHERE OVER SOUTHEAST VA (PER A LOOSE MODEL CONSENSUS).
THE 12Z NAM AND GFS ARE DRIER THAN IN PREVIOUS RUNS...SO CONFIDENCE
IN THIS SECOND BAND IS LOW AND POPS WILL BE LIMITED TO JUST SLIGHT
OR LOW END CHANCE VALUES FROM THE TRIANGLE NORTHEAST.  LOWS MONDAY
NIGHT WILL BE IN THE UPPER 20S AND LOWER 30S AND COLD ADVECTION
STARTS TO KICK IN BEHIND THE AFOREMENTIONED FRONT.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 400 PM SUNDAY...

COLD AND MAINLY DRY NORTHWEST FLOW...IN A HIGHLY AMPLIFIED PATTERN
CHARACTERIZED BY A STRONG WESTERN NOAM RIDGE AND EASTERN NOAM
TROUGH...WILL PREVAIL THROUGH THE UPCOMING WEEK...THOUGH AN EAST
PACIFIC TROUGH WILL BRIEFLY FLATTEN THE RIDGE NEXT WEEKEND.
ALTHOUGH MAINLY A DRY PATTERN...THERE STILL APPEARS TO BE A COUPLE
OF OPPORTUNITIES FOR LIGHT PRECIPITATION OVER PORTIONS OF CENTRAL NC
DURING THE PERIOD...ON TUE AND LATE FRI-FRI NIGHT.

THE FIRST OPPORTUNITY WILL OCCUR AS THE EASTERN NOAM TROUGH REACHES
MAXIMUM AMPLITUDE DOWN THE EAST COAST ON TUE...OWING TO THE
AMPLIFICATION OF A SHORTWAVE TROUGH AXIS ACCOMPANYING A CIRCULATION
(NOW OVER THE UPPER GREAT LAKES) INTO THE TROUGH BASE/ACROSS THE
MIDDLE ATLANTIC STATES. WITH ASSOCIATED WEAK HEIGHT FALLS ALOFT AND
AMIDST STEEP LAPSE RATES AS THE COLD UPEPR TROUGH PIVOTS EAST...
ENHANCED INSTABILITY CLOUDINESS --AND A CHANCE OF SPRINKLES/
FLURRIES...OR WORST CASE A BRIEF RAIN/SNOW SHOWER ACROSS THE
NORTHERN PIEDMONT-- WILL RESULT ON TUE.

OF POTENTIALLY GREATER CONSEQUENCE...BUT STILL WITH LOW FORECAST
CONFIDENCE GIVEN LARGER THAN AVERAGE MODEL SPREAD...THE EASTERN NOAM
TROUGH WILL BRIEFLY RELAX AND ALLOW A BRIEF EPISODE OF LOW-MID LEVEL
WAA ACCOMPANYING A CLIPPER-TYPE WAVE TO SPREAD FROM THE CENTRAL
PLAINS THU EASTWARD TO THE CAROLINAS BY LATE FRI-FRI NIGHT. THIS MAY
RESULT IN A BRIEF PERIOD OF LIGHT RAIN OR SNOW ACROSS OUR SOUTHERN
COUNTIES CENTERED AROUND FRI EVENING.

OTHERWISE...GUIDANCE HAS TRENDED COLDER THROUGHOUT THE PERIOD...WITH
HIGHS IN THE 30S-40S AND LOWS IN THE TEENS AND 20S...COLDEST WED-THU
AND AGAIN ON SUN.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 100 PM SUNDAY...

WITH A A DEEPENING SURFACE LOW OFF THE S COAST...PRECIP CONTINUES
TO SPREAD INLAND ACROSS THE NC COASTAL PLAIN.  RAIN HAS BEEN MIXING
WITH OR COMPLETELY CHANGING TO SLEET AND SNOW ALONG AN AXIS FROM
KFAY TO KRWI.  NEAR TERM MODELS SHOW THIS CONTINUING THROUGH 22Z OR
SO BEFORE PRECIP ENDS FROM WEST TO EAST AND THE NORTHEASTERLY WINDS
BECOME NORTHWESTERLY.  CEILINGS HAVE ACTUALLY REMAINED ABOVE 2000 FT
FOR THE MOST PART...AND VFR CONDITIONS HAVE EVEN BEEN PREDOMINATE AT
MANY SITES.  OUTSIDE OF THE HEAVIEST PRECIP...EXPECT THIS TREND TO
CONTINUE THROUGH THIS EVENING AND OVERNIGHT.  A FEW WIND GUSTS TO
25 KT OR SO WILL BE POSSIBLE THIS AFTERNOON AS THE LOW CONTINUES TO
DEEPEN AND PASS BY THE NC COAST. SOME MVFR VSBYS ARE ALSO POSSIBLE
FROM KFAY TOP KRWI LATE TONIGHT WHERE IT HAS BEEN PRECIPITATION ALL
DAY...ALTHOUGH GUIDANCE DOESN`T SHOW MUCH REPORT AND CONFIDENCE IS
LOW AT THIS POINT.

A SOUTHWEST WIND WILL DEVELOP ON MONDAY AHEAD OF A STRONG
DISTURBANCE DROPPING IN FROM THE NORTHWEST. WIND GUSTS NEAR 20KT AND
SHOWERS WILL INCREASE DURING THE AFTERNOON HOURS.

OUTLOOK...AFTER THE DISTURBANCE ON MONDAY PASSES BY...THE
REMAINDER OF THE WEEK SHOULD BE MOSTLY VFR...WITH GUSTY NORTHWEST
WINDS EACH DAY.

&&

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


&&

$$
SYNOPSIS...SMITH
NEAR TERM...WSS/SMITH
SHORT TERM...SMITH
LONG TERM...2
AVIATION...SMITH



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