Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 120851
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
350 AM EST FRI FEB 12 2016

.SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE
CAROLINAS TODAY. IN THE WAKE OF THE DISTURBANCE...ARCTIC HIGH
PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST OVER THE
WEEKEND.

&&

.NEAR TERM /TODAY/...
AS OF 350 AM FRIDAY...

JUST MINOR ADJUSTMENTS REQUIRED TO THE NEAR TERM FORECAST. STILL
FAIRLY CERTAIN THAT WINTRY PRECIPITATION WILL AFFECT SECTIONS OF THE
COASTAL PLAIN LATER TODAY. FORECAST NOW UNCERTAIN AS TO THE AMOUNT
AND/OR EXTENT OF WINTRY PRECIPITATION OVER THE TRIANGLE AND THE
SANDHILLS.

FORECAST SCENARIO HAS CHANGED LITTLE. A RATHER POTENT S/W DEPICTED
ON WATER VAPOR IMAGERY EXITING THE MID MS VALLEY WILL CONTINUE TO
MOVE EAST-SE. AS IT GETS CLOSER TO OUR REGION...THIS FEATURE WILL
INDUCE AN AREA OF LOW PRESSURE TO FORM OFF THE SC COAST WHICH WILL
MOVE EAST-NE...PARALLELING THE SOUTHERN COAST OF NC THIS AFTERNOON-
EARLY EVENING.  IN ADDITION...THE APPROACHING S/W WILL INDUCE A SLY
FLOW TO DEVELOP JUST ABOVE THE SURFACE. THIS WILL INITIATE A LOW
LEVEL WAA SCHEME...MAINLY OVER THE SE THIRD OF OUR CWA...LATER THIS
MORNING AND THIS AFTERNOON.

MODEL RH CROSS SECTIONS DEPICT DEEPEST MOISTURE OVER THE EASTERN
THIRD OF THE FORECAST AREA WHILE MOISTURE OVER THE WESTERN HALF IS
NOT AS DEEP/EXTENSIVE. IN ADDITION...BETTER LIFT WILL BE
CONCENTRATED MORE OVER THE SANDHILLS AND COASTAL PLAIN DUE TO THE
LOW LEVEL ISENTROPIC UPGLIDE AND LIFT SUPPLIED BY THE NOSE OF A
130+KT JET.

MAIN DIFFERENCE NOTED IN THE MODELS IS THE STRENGTH OF THE PROJECTED
WARM NOSE JUST ABOVE THE SURFACE. 00Z NAM DEPICTS A FAIRLY STRONG
WARM NOSE (3-4 DEGREES C) DEVELOPING OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN BY LATE MORNING. IN CONTRAST...THE GFS HAS A WARM NOSE
OF 1-1.5 DEGREES C. IF THE NAM VERIFIES...WOULD SEE MORE LIQUID
RATHER THAN WINTRY MIX AND A BETTER CHANCE FOR A 2-3 HOUR PERIOD OF
FREEZING RAIN IN THE SANDHILLS/SOUTHERN COASTAL PLAIN AND MORE OF A
SNOW/SLEET MIXTURE FARTHER NORTH...LEADING TO LESS SNOW
ACCUMULATION. IF GFS VERIFIES...PREDOMINATE P-TYPE ACROSS THE
NORTHERN COASTAL PLAIN WILL BE SNOW...WITH A MIXTURE OF
SLEET/SNOW/RAIN OVER THE SANDHILLS/COASTAL PLAIN.

OVERALL PRECIPITATION AMOUNTS WITH THIS EVENT WILL BE LIGHT...LIKELY
TOTALING NO MORE THAN A FEW HUNDREDTHS ACROSS MOST OF THE
PIEDMONT...INCREASING TO ABOUT A TENTH OF AN INCH IN THE CENTRAL-
NORTHERN COASTAL PLAIN.

THUS...EXPECT A DRY MORNING COMMUTE FOR ABOUT ALL OF CENTRAL NC WITH
PRECIP EXPANDING IN COVERAGE AND INTENSITY OVER THE EASTERN THIRD
BETWEEN 10 AM AND 1 PM. BULK OF STEADIER PRECIPITATION SHOULD OCCUR
BETWEEN 11 AM AND 3 PM...WITH PRECIP QUICKLY DIMINISHING WEST-EAST
BETWEEN 3 AND 6 PM. FAIRLY CERTAIN THAT A LIGHT ACCUMULATION OF
SNOW/SLEET WILL OCCUR OVER THE NORTHERN HALF OF THE COASTAL PLAIN.
OVER THE SOUTHERN HALF OF THE COASTAL PLAIN AND SANDHILLS...EXPECT
TO SEE NO MORE THAN A DUSTING OF SNOW AND SLEET AND MAYBE (AND THIS
MAY BE A STRETCH)A LITTLE GLAZE HERE AND THERE. OVER THE
TRIANGLE...WHILE CERTAIN THAT LIGHT WINTRY MIX WILL OCCUR...AMOUNTS
MAY END UP BEING NO MORE THAN A DUSTING IF EVEN THAT. ACROSS THE
REMAINDER OF THE PIEDMONT INCLUDING THE TRIAD...PATCHES OF LIGHT
SNOW OR SNOW FLURRIES...MIXED AT TIMES WITH RAIN OR SLEET...EXPECTED
THOUGH AMOUNTS WILL AVERAGE A TRACE TO A HUNDREDTH OR TWO.

WHILE FEEL LESS CONFIDENT THAT ADVISORY CONDITIONS WILL OCCUR ALONG
THE WESTERN PERIPHERY OF THE CURRENT ADVISORY AREA (ESSENTIALLY THE
HIGHWAY 1 CORRIDOR)...HATE TO TAKE IT DOWN BEFORE THE SITUATION HAS
UNFOLDED. THUS WILL LEAVE CURRENT ADVISORY INTACT. FEEL THAT ANY
IMPACTS WILL BE LIMITED TO SCATTERED SLICK SPOTS...AND CONFINED
MOSTLY TO THE NORTHERN COASTAL PLAIN. EXPECT THESE SLICK SPOTS TO BE
A CONCERN/NUISANCE FOR TRAVEL IN THE NORTHERN COASTAL PLAIN THIS
AFTERNOON AND INTO TONIGHT.

PRECIPITATION FALLING THROUGH THE DRY SUB CLOUD LAYER WILL LEAD TO
EVAPORATIVE COOLING. THIS WILL LIMIT THE NORMAL DIURNAL TEMPERATURE
RECOVERY. MAX TEMPS TODAY SHOULD VARY FROM NEAR FREEZING OVER THE
NORTHERN COASTAL PLAIN TO THE MID 30S WEST AND SOUTH.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 AM FRIDAY...

ATTENDANT SFC FRONT WITH THE POTENT S/W WILL CROSS OUR REGION LATE
TONIGHT/EARLY SATURDAY. NLY WINDS BEHIND THIS FEATURE WILL ADVECT A
MUCH COLDER AIR MASS INTO CENTRAL NC...SETTING THE STAGE FOR
BITTERLY COLD CONDITIONS.  HIGH TEMPS SATURDAY WILL STRUGGLE TO
REACH FREEZING ACROSS THE NORTHERN THIRD AND ONLY WARM TO THE MID-
UPEPR 30S SOUTH. A STOUT NLY WIND WILL CREATE WIND CHILL VALUES IN
THE TEENS ACROSS THE NORTH AND THE 20S OVER THE SOUTH.

BRUTALLY COLD CONDITIONS SATURDAY NIGHT AS THE ARCTIC AIR MASS
CONTINUES TO OVERSPREAD THE REGION. OVERNIGHT TEMPS WILL FALL TO
BETWEEN 10 AND 15 ABOVE ACROSS THE NORTH...AND INTO THE MID TEENS
OVER THE SOUTH. WITH THE WIND FACTORED IN...IT WILL FEEL MORE LIKE 0
TO 5 ABOVE.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 350 AM FRIDAY...

SUNDAY THROUGH TUESDAY: ARCTIC HIGH PRESSURE WILL SETTLE OVER THE
AREA ON SUNDAY (WITH HIGHS GENERALLY IN THE 30S)... BEFORE QUICKLY
SHIFTING OFFSHORE SUNDAY NIGHT INTO MONDAY. MEANWHILE... S/W ENERGY
ALOFT WILL IS FORECAST TO DIG SOUTHEASTWARD FROM THE
CENTRAL/SOUTHERN PLAINS SUNDAY NIGHT INTO MONDAY AND AMPLIFY ACROSS
THE DEEP SOUTH... WITH A DEVELOPING SURFACE LOW. WAA IN ADVANCE OF
THIS SYSTEM WILL ALLOW FOR SOME LIGHT PRECIP TO DEVELOP ON MONDAY
MORNING... WITH THE BEST CHANCES ACROSS THE NORTHWESTERN PIEDMONT.
GIVEN THE DRY COLD AIRMASS DEPOSITED BY THE DEPARTING ARCTIC SURFACE
HIGH WE WILL LIKELY SEE THE PRECIP START OFF AS SNOW/WINTRY MIX WITH
AN IN-SITU CAD DEVELOPING. HOWEVER... THIS FIRST BAND OF PRECIP IS
EXPECTED TO BE LIGHT. MEDIUM RANGE MODEL GUIDANCE HAS TRENDED
FURTHER INLAND WITH THE TRACK OF THE PRIMARY SURFACE LOW... TRACKING
IT GENERALLY FROM SW TO NE ACROSS CENTRAL NC TUESDAY
MORNING/AFTERNOON... ALONG WITH TROUGH ALOFT BECOMING NEGATIVELY
TILTED AS IT CROSS THE REGION. IF THESE TRENDS CONTINUE... THERE
WOULD BE A POTENTIAL FOR A LIGHT WINTRY MIX (THOUGH SOME LOCATIONS
ACROSS THE EAST AND SOUTH MAY WARM TOO MUCH BEFORE PRECIP ARRIVES)
MONDAY MORNING... WITH PRECIP CHANGING TO FREEZING RAIN THEN RAIN
THROUGH THE DAY ON MONDAY IN A SOUTHEAST TO NORTHWEST FASHION. GIVEN
THE RUN TO RUN MODEL DIFFERENCES.... HAVE ELECTED TO STAY CLOSER TO
THE LATEST GFS VS THE ECMWF WITH REGARD TO THICKNESS AMD RAW
TEMPS... AS THE GFS IS MORE CONSISTENT WITH ITS PAST RUNS. THE
LATEST ECMWF IS WARMER AND TURN THE PRECIP TO ALL RAIN EVEN QUICKER.

THE MAIN BULK OF THE PRECIP IS EXPECTED TO ARRIVE ON MONDAY NIGHT
INTO TUESDAY MORNING... WITH POSSIBLY 1 TO 2 INCHES OF RAIN. WILL
NOT INCLUDE ANY THUNDER IN THE FORECAST NOW... GIVEN WE ARE STILL
TALKING ABOUT A SYSTEM THAT IS STILL OUT IN THE PACIFIC... BUT WITH
THE CURRENT ADVERTISED NEG. MID LEVEL TROUGH (BOTH ON THE ECMWF AND
GFS) WE COULD SEE SOME EMBEDDED STORMS. HIGH AND LOW TEMPS WILL BE
TRICKY DURING THIS PERIOD AND BE DRIVEN BY THE INCREASING MOISTURE
AND PRECIP... ALONG WITH THE TRACK OF THE SURFACE LOW. FOR NOW WILL
SHOW TEMPS STARTING OUT IN THE 20S MONDAY MORNING... THEN RISING
THROUGH MONDAY TUESDAY MORNING/AFTERNOON... BEFORE FALLING AGAIN MID
TO LATE TUESDAY AFTERNOON IN THE WAKE OF THE SURFACE LOW.
FOR NOW THIS YIELDS HIGH TEMPS IN THE LOWER TO MID 30S NW TO THE MID
TO UPPER 40S SE ON MONDAY... WITH LOWS DURING THE MONDAY NIGHT
PERIOD VERY SIMILAR TO HIGHS ON MONDAY (LIKELY OCCURRING DURING
MONDAY EVENING). TEMPS TUESDAY WILL DEPEND GREATLY ON THE TRACK OF
THE LOW... WITH THE POTENTIAL FOR TEMPS TO CLIMB INTO THE 60S ACROSS
SOUTHERN AND EASTERN PORTIONS OF THE AREA (THOUGH WILL NOT GO
ANYWHERE CLOSE TO THAT HIGH YET).

TUESDAY NIGHT THROUGH THURSDAY: MODELS HAVE TREND TOWARDS A L/W
TROUGH REMAINING OVER THE AREA THROUGH WEDNESDAY NIGHT... WITH
PERHAPS A MOISTURE STARVED DISTURBANCE MOVING ACROSS THE AREA ON
WEDNESDAY OR THURSDAY. THUS... HAVE LOWERED TEMPS A BIT... HIGHS
GENERALLY IN THE 50S THOUGH... WITH LOWS IN THE 30S (NEAR TO
SLIGHTLY BELOW NORMAL).

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1240 AM FRIDAY...

VFR CONDITIONS WILL PERSIST THROUGH THE OVERNIGHT HOURS BEFORE
DETERIORATING DURING THE MORNING HOURS ON FRIDAY AS A QUICK MOVING
LOW PRESSURE SYSTEM IMPACTS THE AREA. CLOUDS WILL INCREASE FROM THE
SOUTHWEST...INITIALLY WITH CIGS AROUND 5 KFT BUT THEN DROPPING INTO
THE MVFR RANGE AS PRECIPITATION BEGINS. PRECIPITATION IS EXPECTED TO
BEGIN SHORTLY AFTER SUNRISE AT KFAY AND THEN OVERSPREAD INTO KRDU
AND KRWI. PRECIPITATION TYPE FOR KFAY IS EXPECTED TO BE A WINTRY MIX
WITH SNOW...SLEET AND FREEZING RAIN POSSIBLE...WITH A CHANGEOVER TO
ALL RAIN DURING THE AFTERNOON HOURS. FURTHER NORTH...THE PRIMARY
PRECIP TYPE IS EXPECTED TO BE SNOW...WITH SOME SLEET POTENTIALLY
MIXED IN. GIVEN THAT THE LOW PRESSURE SYSTEM WILL TRACK JUST
OFFSHORE...THE MAJORITY OF THE PRECIP IS EXPECTED TO REMAIN ACROSS
THE EASTERN HALF OF THE FORECAST AREA. THEREFORE...KGSO AND KINT
SHOULD REMAIN LARGELY PRECIP FREE...ALTHOUGH THERE COULD BE A SHORT
PERIOD OF A FLURRIES DURING THE LATE MORNING TIME FRAME. PRECIP
SHOULD PULL OUT OF THE AREA DURING THE LATE AFTERNOON/EARLY EVENING
HOURS...WITH A CLEARING TREND THROUGH THE OVERNIGHT HOURS.

OUTLOOK...VFR CONDITIONS WILL RETURN FOR THE WEEKEND AS HIGH
PRESSURE BUILDS TOWARDS AND EVENTUALLY OVER THE AREA. THE NEXT
CHANCE FOR ADVERSE AVIATION CONDITIONS WILL COME MONDAY INTO TUESDAY
AS ANOTHER LOW PRESSURE SYSTEM IMPACTS THE AREA.

&&

.CLIMATE...

HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT
FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY:


       REC    YR     REC    YR
       LOW         LOW MAX
----------------------------------------------
GSO:
02/13   11   1955     31   1986
02/14    6   1905     22   1914

RDU:
02/13    4   1899     10   1899
02/14   -2   1899     27   1916

FAY:
02/13   14   1973     32   1955
02/14   12   1968     33   1916

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST TODAY FOR
NCZ010-011-026>028-041>043-077-078-085-086-088-089.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...KRD


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