National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 250131
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
832 PM EST SAT JAN 24 2015

.SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT
THROUGH SUNDAY... PASSING SOUTH OF NORTH CAROLINA. AN UPPER LEVEL
DISTURBANCE WILL CROSS THE REGION FROM THE NORTHWEST SUNDAY NIGHT
AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 832 PM SATURDAY...


STRONG SUBSIDENCE IN THE WAKE OF THE PRIMARY S/W TROUGH LIFTING UP
THE MID-ATLANTIC COAST WILL QUICKLY COME TO AN END THIS EVENING AS
THE NEXT SHORTWAVE TROUGH WILL TRAVERSE THE AREA OVER THE NEXT
SEVERAL HOURS. MOISTURE IS LIMITED WITH THE WAVE...SO EXPECT ONLY
SOME THIN HIGH CLOUDS TO SKIRT MOSTLY NORTHERN PORTIONS OF THE
FORECAST AREA. LOW-LEVEL DRIER AIR FEED FROM THE WEST SHOULD
PRECLUDE FOG DEVELOPMENT OVERNIGHT WITH SFC DEWPOINT DEPRESSIONS
~5F DEGREES. LOWS IN THE UPPER 20S TO LOWER 30S.
-- End Changed Discussion --


&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 235 PM SATURDAY...

SUNDAY... AN INCREASING SOUTHWESTERLY FLOW AT ALL LEVELS OF THE
ATMOSPHERE SUNDAY WILL LEAD TO A VERY MILD AFTERNOON. MOSTLY SUNNY
SKIES ARE EXPECTED UNTIL MID TO LATE AFTERNOON. THIS IS WHEN HIGH
LEVEL MOISTURE IS EXPECTED TO BEGIN OVERSPREADING OUR REGION. A
RAPID INCREASE IN HIGH CLOUDINESS IS EXPECTED DUE TO THE APPROACHING
MID/UPPER TROUGH THAT WILL BE DIVING SOUTHEAST FROM THE MID
MISSISSIPPI VALLEY TOWARD THE CENTRAL APPALACHIANS DURING THE
AFTERNOON. HIGHS SHOULD REACH INTO THE 50S THROUGHOUT CENTRAL NORTH
CAROLINA... COOLEST IN THE NW WHERE CLOUDS WILL INCREASE EARLIER.

SUNDAY NIGHT... THE OPERATIONAL MODELS HAVE TRENDED A BIT SOUTHWARD
WITH THE TRACK OF THE MID/UPPER LEVEL VORTICITY MAXIMUM DIVING
SOUTHEAST IN THE "ALBERTA CLIPPER" FASHION. USING THE ENSEMBLE
APPROACH GIVEN SOME 50-100 MILE DIFFERENCES IN THE FORECAST TRACK
WITHIN THE MODEL SUITE... A TRACK NEARLY BISECTING NORTH CAROLINA
FROM NW TO SE WOULD BE AN AVERAGE RESULT. THE LATEST OPERATIONAL
EUROPEAN IS A GOOD REPRESENTATIVE TO START WITH. THIS WOULD SUGGEST
A SURFACE WAVE TRACK SOUTHEAST FROM SOUTHERN KENTUCKY INTO NC LATE
SUNDAY NIGHT... WITH REDEVELOPMENT OFFSHORE OF CAPE HATTERAS MONDAY.
FOR A WINTER P-TYPE THREAT... THE TYPICAL "CLIPPER LOW" TRACK WOULD
MOST LIKELY HAVE TO TRACK 50-100 MILES TO THE SOUTH OF THE CURRENT
FORECAST TRACK.

THEREFORE... SUNDAY NIGHT... ANY LIGHT PRECIPITATION THAT DEVELOPS
OVER OUR REGION IS EXPECTED TO BE LIQUID WITH HIGH CONFIDENCE.

WE WILL STILL BE IN THE WARM SECTOR THROUGH SUNDAY NIGHT WHICH ALSO
MEANS THAT TEMPERATURES TYPICALLY ARE A FEW DEGREES WARMER THAN
FORECAST MOS GUIDANCE WITH PRE-FRONTAL WARM SECTOR EVENTS.

EXPECT TO SEE THICKENING CLOUDINESS SUNDAY EVENING LEADING TO A
CHANCE OF RAIN SHOWERS IN THE NORTHERN SECTIONS LATE SUNDAY NIGHT.
LOWS ARE EXPECTED TO REMAIN WELL ABOVE FREEZING (IN THE 37-42 RANGE
NW TO SE). WE WILL CARRY LOW END "CHANCE" POP IN THE NORTH FOR NOW
WHICH IS 25-30 PERCENT FOR MEASURABLE RAIN (0.01). ANYTHING THAT
FALLS THROUGH 12Z/MON WOULD BE RAIN AND WOULD BE LIGHT AND IN THE NW
ZONES.

MONDAY... THERE IS GOOD MODEL CONSENSUS ON THE TIMING OF THIS SHORT
WAVE CLIPPER SYSTEM PIVOTING ACROSS THE AREA ON MONDAY. MOISTURE AND
LIFT WILL BE QUITE LIMITED AND SUPPORTIVE OF ONLY LIGHT RAIN
SHOWERS... AND MAINLY ACROSS THE NORTHERN TIER OF CENTRAL NC.

RAINFALL AMOUNTS WILL BE LESS THAN A TENTH OF AN INCH. HIGHS SUNDAY
WILL NOT SHOW MUCH INCLINATION TO RISE ACROSS THE NORTHERN TIER DUE
TO CLOUDINESS AND LIGHT PRECIP...BUT SHOULD STILL REACH THE MID 40S
DUE TO THE MILD...MID 30S...START TO THE DAY. HIGHS ACROSS THE SOUTH
MAY REACH THE MID 50S WITH A SHORT PERIOD OF SOUTHWEST FLOW AND WARM
AIR ADVECTION AHEAD OF THE SURFACE REFLECTION OF THE UPPER
SHORTWAVE.

THE COLD AIR SURGE BEHIND THE SYSTEM AS IT LIFTS NORTHEAST EARLY
MONDAY NIGHT WILL OCCUR AFTER DEEPER MOISTURE HAS PULLED OUT...AND
MODEL SOUNDINGS SHOW ONLY A COUPLE OF HOURS OF POTENTIAL SNOW
SHOWERS MIXING WITH THE DEPARTING RAIN AS LEVELS ABOVE -12 DRY OUT.
PRECIP WILL BE ENDING AROUND MIDNIGHT...WITH LOWS FALLING TO THE
UPPER 20S NORTH TO AROUND FREEZING SOUTH. CLOUDINESS SHOULD REMAIN
WIDESPREAD OVERNIGHT WITH THE APPROACH OF ANOTHER SHORT WAVE WITH
LAGGING MID LEVEL MOISTURE IN THE FAST UPPER NORTHWEST FLOW.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...

A SECOND SHORT WAVE WILL DIVE SOUTHEAST ACROSS THE AREA ON
TUESDAY...BUT MOISTURE WILL BE EVEN MORE LIMITED WITH THIS
SYSTEM...AND WILL CONTINUE A DRY FORECAST. COLD AIR WILL BE SETTLED
IN ALONG WITH WHAT COULD BE A NEAR CONTINUOUS STREAM OF MID TO HIGH
CLOUDINESS IN NORTHWEST FLOW. HIGHS WILL STRUGGLE TO REACH 40 ACROSS
THE NORTH...WITH SOME MID 40S SOUTH. THE UPPER TROF WILL SHIFT
FURTHER OFFSHORE TUESDAY NIGHT...WITH MOSTLY SUNNY SKIES FAILING TO
WARM UP THE COLD AIRMASS...HIGHS WILL BE MOSTLY IN THE MID 40S ON
WEDNESDAY AFTER MORNING LOWS IN THE MID 20S.

SURFACE HIGH PRESSURE WILL BE MIGRATING OVERHEAD LATE WEDNESDAY...
WITH A MILD WARMUP ON TAP FOR LATE WEEK IN RETURN FLOW. SKIES WILL
BE SUNNY THURSDAY WITH HIGHS AROUND 50...WHILE SOUTHWEST WIND AHEAD
OF A COLD FRONT WHICH WILL BE MOVING THROUGH OVERNIGHT WILL PRODUCE
MILDER MINS...MAINLY MID 30S. CLOUDS WILL BE DECREASING FRIDAY WITH
HIGHS NEAR 50...BUT COOLER AIR SETTLES IN BEHIND THE FRONT WITH LOWS
IN THE 20S FRIDAY NIGHT AND HIGHS IN THE MID 40S SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 640 PM SATURDAY...

VFR CONDITIONS WILL PREVAIL THROUGH THE CURRENT TAF PERIOD AS HIGH
PRESSURE BUILDS ACROSS THE SOUTHEAST US...EXTENDING INTO AND
DOMINATING THE WEATHER ACROSS CENTRAL NC. LIGHT WESTERLY WINDS
OVERNIGHT WILL GRADUALLY BECOME SOUTHWESTERLY ON SUNDAY AS OUR NEXT
SYSTEM APPROACHES. MID/HIGH CLOUDS WILL BE ON THE INCREASE BY THE
END OF THE TAF PERIOD.

OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED TO DOMINATE THROUGH
THURSDAY. HOWEVER...ONE EXCEPTION MAY BE WHEN A CLIPPER SYSTEM
PASSES THROUGH THE AREA SUNDAY NIGHT INTO MONDAY...WHICH COULD
RESULT IN A FEW PERIODS OF MVFR CIGS AND POSSIBLY A LIGHT SHOWER OR
TWO ACROSS MAINLY NORTHERN NC.

&&

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

&&

$$

SYNOPSIS...BADGETT
NEAR TERM...CBL
SHORT TERM...BADGETT/MLM
LONG TERM...MLM
AVIATION...KRD/BADGETT