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000
FXUS62 KRAH 201140
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
639 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 639 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS GEORGIA EARLY THIS
MORNING WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL SPREAD MOISTURE OVERHEAD
ALONG WITH LIFT TO PRODUCE PATCHES FO LIGHT RAIN...ESPECIALLY SOUTH
OF HIGHWAY 64. SOME OF THE LIGHT RAIN MAY MIX WITH A LITTLE SNOW
ALONG AND NORTH OF TEH I-40 CORRIDOR BETWEEN THE TRIAD AND KRDU
THROUGH 15Z. OTHERWISE EXPECT WIDESPREAD CEILINGS 5000-8000FT WITH
POCKETS OF MVFR CEILINGS (1500-2500FT) POSSIBLE. SURFACE WINDS WILL
BECOME NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY. DRY AIR ASSOCIATED WITH THE RIDGE SHOULD AID TO DIMINISH
SOME OF THE CLOUD COVERAGE LATER THIS EVENING INTO THE OVERNIGHT
HOURS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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





000
FXUS62 KRAH 201140
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
639 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 639 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS GEORGIA EARLY THIS
MORNING WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL SPREAD MOISTURE OVERHEAD
ALONG WITH LIFT TO PRODUCE PATCHES FO LIGHT RAIN...ESPECIALLY SOUTH
OF HIGHWAY 64. SOME OF THE LIGHT RAIN MAY MIX WITH A LITTLE SNOW
ALONG AND NORTH OF TEH I-40 CORRIDOR BETWEEN THE TRIAD AND KRDU
THROUGH 15Z. OTHERWISE EXPECT WIDESPREAD CEILINGS 5000-8000FT WITH
POCKETS OF MVFR CEILINGS (1500-2500FT) POSSIBLE. SURFACE WINDS WILL
BECOME NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY. DRY AIR ASSOCIATED WITH THE RIDGE SHOULD AID TO DIMINISH
SOME OF THE CLOUD COVERAGE LATER THIS EVENING INTO THE OVERNIGHT
HOURS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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




000
FXUS62 KRAH 200816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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




000
FXUS62 KRAH 200816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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





000
FXUS62 KRAH 200815
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
257 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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





000
FXUS62 KRAH 200815
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
257 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM SATURDAY...

TODAY...S/W EXITING THE DEEP SOUTH EARLY THIS MORNING
PROJECTED TO CROSS NEAR OR JUST SOUTH OF CENTRAL NC LATE THIS
MORNING-EARLY THIS AFTERNOON. THIS FEATURE APPEARS TO BE ADVANCING A
LITTLE FARTHER TO THE NORTH THAN WHAT PREVIOUS MODEL RUNS HAD
DEPICTED. STILL EXPECT BULK OF LIGHT PRECIPITATION ASSOCIATED WITH
THIS FEATURE TO AFFECT MAINLY OUR SOUTHERN COUNTIES.
HOWEVER...POTENTIAL FOR SPOTTY LIGHT PRECIP TO EXTEND AS FAR NORTH
AS THE I-40 CORRIDOR BETWEEN THE TRIAD AND THE TRIANGLE THIS
MORNING. THUS HAVE ADJUSTED POPS A LITTLE HIGHER ACROSS THE NORTHERN
PIEDMONT WHILE MAINTAINING LIKELY POPS ACROSS THE SOUTH.

BULK OF LIFT ASSOCIATED WITH THE S/W WILL BEGIN TO EXIT OUR REGION
BY MID DAY-EARLY AFTERNOON. THUS SHOULD SEE PRECIP COVERAGE DIMINISH
OVER MOST OF THE PIEDMONT BY EARLY AFTERNOON. DUE TO CLOSE PROXIMITY
OF THE S/W...PRECIP MAY PERSIST WELL INTO THE AFTERNOON ACROSS THE
SANDHILLS AND SOUTHERN COASTAL PLAIN.

PARTIAL THICKNESSES OFF THE LATEST MODEL GUIDANCE IN CONJUNCTION
WITH EVAPORATIVE COOLING SUGGEST DECENT PROBABILITY OF RAIN MIXED
WITH SNOW ACROSS THE NW PIEDMONT EARLY THIS MORNING.

HIGH TEMPS TODAY DEPENDENT ON EXTENT OF PRECIP. EXTENSIVE CLOUDINESS
WILL LIMIT INSOLATION. IF PRECIP MORE WIDESPREAD THAN ANTICIPATED
ACROSS THE PIEDMONT/NORTHERN COASTAL PLAIN...TEMPS MAY STRUGGLE TO
MAKE IT OUT OF THE 30S. OVERALL...TEMPS TODAY WILL BE A SOLID 7-10
DEGREES BELOW NORMAL. MAX TEMPS GENERALLY 40-45 DEGREES.

TONIGHT...WEAK SUBSIDENCE IN THE WAKE OF THE DEPARTING S/W AND SFC
RIDGE NOSING SWD INTO OUR REGION SHOULD AID TO DIMINISH THE CLOUD
COVERAGE OVER OUR REGION. MODELS DIFFER ON EXTENT OF CLEARING WITH
THE GFS A LITTLE MORE AGGRESSIVE THAN MOST. ANY PRECIP OCCURRING AT
SUNSET ACROSS THE FAR SE SHOULD DIMINISH/DISSIPATE BEFORE 10 PM.
STILL EXPECT SOME RESIDUAL CLOUDINESS OVERNIGHT. IF GFS VERIFIES
BEST...THEN MIN TEMPS TONIGHT MAY END UP BEING 2-4 DEGREES COLDER
THAN CURRENTLY FORECAST. MIN TEMPS UPPER 20S/AROUND 30 NORTH TO THE
LOWER 30S SOUTH.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...

SFC RIDGE EXTENDS SOUTH ACROSS THE AREA...AIDED ALOFT BY A
MINOR S/W RIDGE. THIS SHOULD PROVIDE PARTLY-MOSTLY SUNNY SKIES TO
START THE DAY. A S/W EXITING THE SOUTHERN PLAINS WILL BACK THE FLOW
ALOFT TO A SWLY FLOW AND BEGIN TO ADVANCE MID-HIGH LEVEL CLOUDINESS
FROM THE SOUTH LATE IN THE DAY. LOW LEVEL THICKNESSES IN THE 1315M-
1330M RANGE...SUPPORTIVE OF MAX TEMPS ABOUT A CATEGORY OR TWO BELOW
NORMAL. MAX TEMPS NEAR 50-LOWER 50S. IF CLOUDS ARE DELAYED ACROSS
THE SOUTH...MAX TEMPS MAY END UP BEING 2-3 DEGREES WARMER.

SUNDAY NIGHT...SOUTHERN STREAM S/W PROJECTED TO CROSS THE LOWER MS
VALLEY AND INDUCE WEAK SFC WAVE DEVELOPMENT OFF THE SC COAST BY
EARLY MONDAY. WHILE A DRY AIR SFC RIDGE WILL MAINTAIN A PRESENCE
OVER CENTRAL NC...DEVELOPING SLY FLOW A FEW THOUSAND FEET ALOFT WILL
INITIATE AN OVERRUNNING EVENT LEADING TO A CLASSICAL OR HYBRID COLD
AIR DAMMING EVENT. AS SLY FLOW STRENGTHENS TOWARD 06Z...EXPECT RAIN
TO OVERSPREAD THE REGION FROM THE SOUTH...LOCKING IN THE CAD AIR
MASS. WILL START OUT WITH CHANCE POPS ACROSS THE SOUTH IN THE
EVENING...RAMPING UP TO LIKELY POPS ACROSS THE SOUTH HALF AFTER
MIDNIGHT...AND CHANCE POPS ELSEWHERE. IF MODEL TRENDS CONTINUE IN
LATER MODEL RUNS...AN INCREASE IN POPS TO LIKELY NORTH AND
CATEGORICAL SOUTH WOULD BE WARRANTED. MIN TEMPS MAINLY 35-40 DEGREES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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




000
FXUS62 KRAH 200759
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
257 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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





000
FXUS62 KRAH 200759
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
257 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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




000
FXUS62 KRAH 200759
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
257 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

MONDAY THROUGH WEDNESDAY: A SOUTHERN STREAM S/W DISTURBANCE WILL
LIFT NORTHEASTWARD OUT FROM THE GULF COAST STATES ON SUNDAY NIGHT
INTO MONDAY MORNING... SPREADING WIDESPREAD RAIN ACROSS ALL OF
CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A 1030 MB SURFACE HIGH
STILL EXPECTED TO BE EXTENDING SOUTHWARD INTO OUR AREA (AS IT EVER
SO SLOWLY SHIFTS EASTWARD) EXPECT WE WILL SEE A PRONOUNCED DAMMING
EVENT DEVELOP.... WITH TEMPS FALLING INTO THE MID TO UPPER 30S
MONDAY MORNING ACROSS THE NORTHERN AND NORTHWEST PIEDMONT... WITH
TEMPS IN THE 40S ELSEWHERE. HOWEVER... BOTH THE GFS AND ECMWF
CONTINUE TO DEPICT AN ALL RAIN EVENT ACROSS THE AREA... WITH A
PRONOUNCED WARM NOES AT AROUND 4-5KFT COMBINED WITH SURFACE WETBULB
TEMPS IN THE MID 30S AT WORST WHEN THE PRECIP SPREADS INTO THE AREA.
THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END BY EARLY TO MID
AFTERNOON AS THE BEST MOIST ISENTROPIC UPGLIDE BEGINS TO WANE ALONG
WITH DRIER AIR ALOFT FILTERING INTO THE AREA. STILL WE SHOULD SEE
SOME LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING.

WITH A GOOD AREAWIDE QUARTER TO A HALF INCH OF RAIN EXPECTED WE
SHOULD BE ABLE TO LOCK IN THE DAMMING AIRMASS. THUS.. HAVE LOWERED
HIGH TEMPS... ESPECIALLY ACROSS THE EASTERN/SOUTHEASTERN PORTION OF
CENTRAL NC. EXPECT HIGH TEMPS TO RANGE FROM THE UPPER 30S N/NW TO
THE MID TO UPPER 40S E/SE. TEMPS MONDAY NIGHT/TUESDAY MORNING ARE
EXPECTED TO REMAIN NEAR STEADY OR EVEN SLOWLY BEGIN TO RISE A
LITTLE. THUS... WILL GO WITH LOWS RANGING FROM THE UPPER 30S TO MID
40S.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT (AND A POSSIBLE TRIPLE POINT LOW) MOVING ACROSS
CENTRAL NC ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT
STANDS NOW... STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO
WHERE A POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER
DETAILS LIKE THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE
FORECAST. HOWEVER... WITH THE POTENTIAL FOR A RETREATING CAD
BOUNDARY AND STRENGTHENING LOW LEVEL WIND FIELD... WE WILL NEED TO
KEEP AN EYE ON HOW THIS SYSTEM COMES TOGETHER. THIS WOULD BE A HSLC
TYPE OF SYSTEM. GIVEN THE TIME OF YEAR IT IS QUITE HARD TO GET THE
NEEDED INSTABILITY FOR POSSIBLE SEVERE STORMS THOUGH. AS THE
EFFECTIVE FRONT APPROACHES AND MOVES THROUGH THE AREA ON WEDNESDAY
MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF RAIN/SHOWERS
ALONG AND IN ADVANCE OF IT (WITH POSSIBLY A FEW THUNDERSTORMS)...
WITH THINGS DRYING OUT QUICKLY BEHIND THE EFFECTIVE FRONT ON
WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE UPPER 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE UPPER 40S NW TO MID 50S SE/E. TEMPS
ARE EXPECTED TO WARM WEDNESDAY AHEAD OF THE FRONT INTO THE UPPER 50S
NW TO THE UPPER 60S E.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING FOR THE REST OF THE WEEK... WITH A
RETURN TO QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN
THE 30S... WITH HIGHS THURSDAY AND FRIDAY AFTERNOONS IN THE 50S. WE
COULD BE A BIT BREEZE ON THURSDAY AS MODELS ARE SHOWING THE
POTENTIAL FOR SUSTAINED WINDS OUT OF THE WSW IN THE 14 TO 20 MPH
RANGE... WITH MAYBE SOME GUSTS OF UP TO 25 MPH.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

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




000
FXUS62 KRAH 200605
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
105 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...VINCENT
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...WSS




000
FXUS62 KRAH 200605
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
105 AM EST SAT DEC 20 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION TODAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NORTH
CAROLINA SUNDAY. ANOTHER DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL AFFECT OUR AREA SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM SATURDAY...

AN UPPER LEVEL DISTURBANCE ADVANCING EAST ACROSS THE
DEEP SOUTH WILL PASS SOUTH OF CENTRAL NC LATER THIS MORNING THROUGH
EARLY AFTERNOON. THIS WEATHER SYSTEM WILL INCREASE CLOUDINESS ALONG
WITH PATCHES OF LIGHT RAIN OVER OUR REGION BY DAYBREAK. EXPECT
CEILINGS TO LOWER TO THE 4000-6000FT LAYER WITH SCATTERED PATCHES OF
STRATOCU WITH CEILINGS 1500-2500FT POSSIBLE BY LATE MORNING THROUGH
THE AFTERNOON...MAINLY SOUTH OF HIGHWAY 64. THIS THREAT FOR LOWER
CEILINGS WILL AFFECT THE KFAY TERMINAL. SURFACE WINDS WILL BECOME
NELY WITH SUSTAINED WINDS AOB 10KTS.

WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NC FROM NORTH TONIGHT AND
SUNDAY...MAINTAINING MOSTLY VFR CONDITIONS.

A STRONGER UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM WILL BRING A HIGH PROBABILITY OF ADVERSE AVIATION
CONDITIONS TO CENTRAL NC SUNDAY NIGHT INTO MONDAY. WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN ARE EXPECTED. THESE CONDITIONS
WILL SPREAD NORTH INTO SOUTHERN SECTIONS OF CENTRAL NC SHORTLY AFTER
SUNSET SUNDAY THEN CONTINUE NORTHWARD SUNDAY NIGHT.

A DECENT TO HIGH THREAT FOR MVFR CEILINGS WILL LINGER MONDAY NIGHT
INTO TUESDAY AS THE LOW LEVEL AIR MASS REMAINS MOIST. A STRONG COLD
FRONT WILL APPROACH TUESDAY NIGHT AND CROSS THE REGION WEDNESDAY.
GUSTY SLY WINDS ARE EXPECTED AHEAD OF THE FRONT TUESDAY NIGHT ALONG
WITH HEAVY SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO. THE FRONT
WILL CROSS THE AREA WEDNESDAY WITH BLUSTERY WESTERLY WINDS EXPECTED
IN ITS WAKE.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...VINCENT
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...WSS





000
FXUS62 KRAH 200309
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1009 PM EST FRI DEC 19 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION ON SATURDAY BEFORE MOVING OFFSHORE SATURDAY NIGHT. A SERIES
OF UPPER LEVEL DISTURBANCES WILL TRACK NORTHEAST THROUGH THE
CAROLINAS SUNDAY INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 PM FRIDAY...

24 HOUR TAF PERIOD: HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST
TONIGHT/SATURDAY. MEANWHILE...A SHORT LIVED OVERRUNNING SCENARIO
WILL DEVELOP AS A COASTAL LOW PRESSURE AREA WILL DEVELOP WELL SOUTH
OF THE NORTH CAROLINA COAST EARLY SATURDAY. THIS LOW WILL STRENGTHEN
A BIT DURING THE DAY AS IT MOVES EAST AND FURTHER OFFSHORE. THE
UPSHOT...VFR CONDITIONS ARE EXPECTED AS HIGH CLOUDINESS CONTINUES TO
STREAM INTO THE AREA OVERNIGHT. EASTERLY LOW LEVEL FLOW WILL PUSH
MOISTURE INTO THE AREA...WITH SOME LOWERING OF THE CLOUDINESS
THROUGH THE DAY...WITH CEILINGS BY AFTERNOON IN THE 4-5KFT RANGE.
SOME LIGHT RAIN IS EXPECTED ACROSS THE SOUTHERN TIER...AND MAY
INDUCE OCCASIONAL MVFR CONDITIONS AT FAY BY MID DAY. ANY RAIN WILL
BE ENDING BY THE END OF THE TAF PERIOD WITH DEEP DRYING AS ABOVE-
SURFACE FLOW BECOMES WESTERLY.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...MLM





000
FXUS62 KRAH 200309
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1009 PM EST FRI DEC 19 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION ON SATURDAY BEFORE MOVING OFFSHORE SATURDAY NIGHT. A SERIES
OF UPPER LEVEL DISTURBANCES WILL TRACK NORTHEAST THROUGH THE
CAROLINAS SUNDAY INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 PM FRIDAY...

24 HOUR TAF PERIOD: HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST
TONIGHT/SATURDAY. MEANWHILE...A SHORT LIVED OVERRUNNING SCENARIO
WILL DEVELOP AS A COASTAL LOW PRESSURE AREA WILL DEVELOP WELL SOUTH
OF THE NORTH CAROLINA COAST EARLY SATURDAY. THIS LOW WILL STRENGTHEN
A BIT DURING THE DAY AS IT MOVES EAST AND FURTHER OFFSHORE. THE
UPSHOT...VFR CONDITIONS ARE EXPECTED AS HIGH CLOUDINESS CONTINUES TO
STREAM INTO THE AREA OVERNIGHT. EASTERLY LOW LEVEL FLOW WILL PUSH
MOISTURE INTO THE AREA...WITH SOME LOWERING OF THE CLOUDINESS
THROUGH THE DAY...WITH CEILINGS BY AFTERNOON IN THE 4-5KFT RANGE.
SOME LIGHT RAIN IS EXPECTED ACROSS THE SOUTHERN TIER...AND MAY
INDUCE OCCASIONAL MVFR CONDITIONS AT FAY BY MID DAY. ANY RAIN WILL
BE ENDING BY THE END OF THE TAF PERIOD WITH DEEP DRYING AS ABOVE-
SURFACE FLOW BECOMES WESTERLY.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...MLM




000
FXUS62 KRAH 200309
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1009 PM EST FRI DEC 19 2014

.SYNOPSIS...A FAST MOVING DISTURBANCE WILL TRACK EASTWARD ACROSS THE
REGION ON SATURDAY BEFORE MOVING OFFSHORE SATURDAY NIGHT. A SERIES
OF UPPER LEVEL DISTURBANCES WILL TRACK NORTHEAST THROUGH THE
CAROLINAS SUNDAY INTO MONDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1010 PM FRIDAY...

A SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTRAL AND LOWER MS
RIVER VALLEY THIS EVENING WILL TRACK E/ENE ACROSS THE TN VALLEY TO
THE SOUTHERN APPALACHIANS BY 12Z SAT...INDUCING WEAK CYCLOGENESIS
ALONG A BAROCLINIC ZONE OFFSHORE THE SOUTHEAST COAST AS HIGH
PRESSURE CONTINUES TO EXTEND SOUTH/SOUTHEASTWARD INTO THE CAROLINAS.

PRECIP: THE BEST UPPER LEVEL FORCING...DPVA ASSOC/W THE APPROACHING
SHORTWAVE...WILL LARGELY REMAIN WEST OF THE AREA THROUGH SUNRISE
SAT...THOUGH WEAK DPVA ATTENDANT SMALL AMPLITUDE DISTURBANCES OVER
THE DEEP SOUTH APPEAR LIKELY AS THEY TRACK ENE INTO THE CAROLINAS
BETWEEN 06-12Z. THOUGH LOWER-LEVEL FORCING IS ABSENT OVER CENTRAL NC
THIS EVENING...WEAK WARM ADVECTION WILL DEVELOP AFTER MIDNIGHT AS 10-
15 KT WESTERLY FLOW AT THE ~850 MB LEVEL BACKS TO THE SOUTHWEST IN
RESPONSE TO THE APPROACHING SHORTWAVE. GIVEN THAT THE APPROACHING
SHORTWAVE WILL REMAIN WEST OF THE APPALACHIANS THROUGH MOST OF THE
NIGHT...WARM ADVECTION WILL BE WEAK (SHORT-LIVED AS WELL)...AND THAT
THE 00Z GSO RAOB SHOWED A THOROUGHLY DRY AIRMASS IN PLACE ACROSS
CENTRAL NC THIS EVENING...IT SEEMS UNLIKELY THAT SUFFICIENT FORCING
AND/OR MOISTURE ADVECTION WILL OCCUR IN ORDER FOR MEASURABLE
PRECIPITATION TO DEVELOP PRIOR TO SUNRISE.

TEMPS: LOWS WILL RANGE FROM THE LOWER 30S IN THE NE COASTAL PLAIN TO
THE MID/UPPER 30S IN THE FAR SW PIEDMONT AS THICKENING MID-LEVEL
CLOUD COVER PROGRESSES INTO THE AREA FROM SW-NE.

THE RELATIVE BEST CHANCE FOR MEASURABLE PRECIP (PRIOR TO 12Z) WILL
BE IN THE WESTERN PIEDMONT. GIVEN THAT MEASURABLE PRECIP WILL
LARGELY DEPEND UPON THE MAGNITUDE/DURATION OF LOW-LEVEL WARM
ADVECTION...THE PRESENCE THEREOF (IN THIS CASE) WOULD IMPLY THERMAL
PROFILES EXCLUSIVELY SUPPORTIVE OF LIQUID. -VINCENT

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 PM FRIDAY...

24 HOUR TAF PERIOD: HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST
TONIGHT/SATURDAY. MEANWHILE...A SHORT LIVED OVERRUNNING SCENARIO
WILL DEVELOP AS A COASTAL LOW PRESSURE AREA WILL DEVELOP WELL SOUTH
OF THE NORTH CAROLINA COAST EARLY SATURDAY. THIS LOW WILL STRENGTHEN
A BIT DURING THE DAY AS IT MOVES EAST AND FURTHER OFFSHORE. THE
UPSHOT...VFR CONDITIONS ARE EXPECTED AS HIGH CLOUDINESS CONTINUES TO
STREAM INTO THE AREA OVERNIGHT. EASTERLY LOW LEVEL FLOW WILL PUSH
MOISTURE INTO THE AREA...WITH SOME LOWERING OF THE CLOUDINESS
THROUGH THE DAY...WITH CEILINGS BY AFTERNOON IN THE 4-5KFT RANGE.
SOME LIGHT RAIN IS EXPECTED ACROSS THE SOUTHERN TIER...AND MAY
INDUCE OCCASIONAL MVFR CONDITIONS AT FAY BY MID DAY. ANY RAIN WILL
BE ENDING BY THE END OF THE TAF PERIOD WITH DEEP DRYING AS ABOVE-
SURFACE FLOW BECOMES WESTERLY.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...MLM




000
FXUS62 KRAH 192351
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
640 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 PM FRIDAY...

24 HOUR TAF PERIOD: HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST
TONIGHT/SATURDAY. MEANWHILE...A SHORT LIVED OVERRUNNING SCENARIO
WILL DEVELOP AS A COASTAL LOW PRESSURE AREA WILL DEVELOP WELL SOUTH
OF THE NORTH CAROLINA COAST EARLY SATURDAY. THIS LOW WILL STRENGTHEN
A BIT DURING THE DAY AS IT MOVES EAST AND FURTHER OFFSHORE. THE
UPSHOT...VFR CONDITIONS ARE EXPECTED AS HIGH CLOUDINESS CONTINUES TO
STREAM INTO THE AREA OVERNIGHT. EASTERLY LOW LEVEL FLOW WILL PUSH
MOISTURE INTO THE AREA...WITH SOME LOWERING OF THE CLOUDINESS
THROUGH THE DAY...WITH CEILINGS BY AFTERNOON IN THE 4-5KFT RANGE.
SOME LIGHT RAIN IS EXPECTED ACROSS THE SOUTHERN TIER...AND MAY
INDUCE OCCASIONAL MVFR CONDITIONS AT FAY BY MID DAY. ANY RAIN WILL
BE ENDING BY THE END OF THE TAF PERIOD WITH DEEP DRYING AS ABOVE-
SURFACE FLOW BECOMES WESTERLY.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...MLM





000
FXUS62 KRAH 192351
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
640 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 PM FRIDAY...

24 HOUR TAF PERIOD: HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST
TONIGHT/SATURDAY. MEANWHILE...A SHORT LIVED OVERRUNNING SCENARIO
WILL DEVELOP AS A COASTAL LOW PRESSURE AREA WILL DEVELOP WELL SOUTH
OF THE NORTH CAROLINA COAST EARLY SATURDAY. THIS LOW WILL STRENGTHEN
A BIT DURING THE DAY AS IT MOVES EAST AND FURTHER OFFSHORE. THE
UPSHOT...VFR CONDITIONS ARE EXPECTED AS HIGH CLOUDINESS CONTINUES TO
STREAM INTO THE AREA OVERNIGHT. EASTERLY LOW LEVEL FLOW WILL PUSH
MOISTURE INTO THE AREA...WITH SOME LOWERING OF THE CLOUDINESS
THROUGH THE DAY...WITH CEILINGS BY AFTERNOON IN THE 4-5KFT RANGE.
SOME LIGHT RAIN IS EXPECTED ACROSS THE SOUTHERN TIER...AND MAY
INDUCE OCCASIONAL MVFR CONDITIONS AT FAY BY MID DAY. ANY RAIN WILL
BE ENDING BY THE END OF THE TAF PERIOD WITH DEEP DRYING AS ABOVE-
SURFACE FLOW BECOMES WESTERLY.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...MLM




000
FXUS62 KRAH 191959
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
259 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...ELLIS




000
FXUS62 KRAH 191959
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
259 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...ELLIS





000
FXUS62 KRAH 191959
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
259 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...ELLIS




000
FXUS62 KRAH 191959
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
259 PM EST FRI DEC 19 2014

.SYNOPSIS...A SHORTWAVE LOW PRESSURE SYSTEM WILL TRACK SOUTH OF THE
AREA ON SATURDAY...BRINGING SOME UNSETTLED WEATHER. OTHERWISE...
HIGH PRESSURE TO THE NORTH WILL CONTROL THE PATTERN UNTIL A STRONGER
LOW MOVES UP THE SOUTHEAST COAST FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...

FORECAST REMAINS ON TRACK FOR TODAY WITH MOSTLY CLEAR SKIES ASIDE
FROM A FEW HIGH LEVEL CLOUDS MAKING THEIR WAY IN FROM THE WEST.
MOSTLY NORTHWESTERLY WINDS IN THE WESTERN HALF OF THE CWA WITH SOME
NORTHEASTERLIES ALONG THE COAST AS A SURFACE HIGH OVER THE DELMARVA
PENINSULA EXTENDS SOUTHWARD ALONG THE CAROLINA COAST. OVERALL THE
TEMPERATURE FORECAST IS LOOKING VERY GOOD WITH MOST LOCATIONS IN THE
LOW TO MID 40S AS HEATING BEGINS TO WIND DOWN THIS AFTERNOON.
PERHAPS A FEW DEGREES TO WARM WITH FORECASTED MAX TEMPS IN THE
EXTREME NORTHEAST AS OBSERVED TEMPS ONLY IN THE MID TO UPPER 40S
THERE.

FOR TONIGHT EXPECT CLOUD COVER TO GRADUALLY INCREASE WITH SOME
CEILINGS FIRST APPEARING ABOVE 15 KFT BUT THEN GRADUALLY MAKING
THEIR WAY DOWN TO ABOUT 10 KFT OR JUST BELOW AROUND DAYBREAK ON
SATURDAY. DESPITE THE INCREASING CLOUD COVER...ANY PRECIPIATION IS
EXPECTED TO HOLD OFF AT LEAST UNTIL SATURDAY MORNING. AS FAR AS
TEMPERATURE DISTRIBUTION FOR THE LOW IS CONCERNED...CLOUDS WILL HOLD
OFF THE LONGEST IN THE NORTHEAST...AND THUS THE LOWEST TEMPERATURES
ARE EXPECT HERE WITH VALUES RIGHT AROUND OR JUST BELOW FREEZING
EXPECTED. FURTHER SOUTH AND WEST...TEMPERATURES WILL BOTTOM OUT IN
THE MID 30S WITH SOME COLDER POCKETS POSSIBLE IN THE RURAL AREAS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM FRIDAY...

A SOUTHERN STREAM SHORTWAVE IS EXPECTED TO ARRIVE FROM OUR SOUTHWEST
ON SATURDAY MORNING. THE LAST SEVERAL NUMERICAL MODEL RUNS HAVE ALL
TRENDED THIS SYSTEM TO BE DRIER...ESPECIALLY IN OUR NORTHERN
COUNTIES. BOTH THE GLOBAL AND THE HIGH RESOLUTION MODELS DO THIS AND
THEREFORE HAVE TRENDED BACK ON POPS AND QPF FORECASTS FOR SATURDAY
WITH MAINLY CHANCES WITH SOME BRIEF LIKELIES ACROSS THE EXTREME
SOUTHERN TIER DURING THE LATE MORNING/EARLY AFTERNOON. THIS ALSO
SEVERELY HANDICAPS ANY THREAT OF SNOW ACROSS THE TRIAD THAT WAS
POTENTIALLY BEING SHOWN BY PRIOR MODEL RUNS. FIRST...THERE MAY NOT
EVEN BE PRECIPIATION AT ALL IN THIS AREA. IF PRECIPIATION DOES IN
FACT OCCUR HERE...THE BEST OMEGA IS IN THE 700 MB LEVEL AND QUICKLY
DIMINISHES ABOVE THAT. THUS CURRENT MODELS...INCLUDING THE NAM WHICH
WAS THE MOST BULLISH ON THE SITUATION...NEARLY SATURATES IN THE 800-
600 MB LEVEL BUT LESS SO ABOVE THAT INTO THE SNOW GROWTH ZONE.
INCLUDE A WARM BOUNDARY LAYER INTO THE MIX AND CHANCES ARE HIGH THAT
ANY FALLING PRECIP WILL BE LIQUID.

THE CONCLUDING UPSHOT OF THE DAY WILL BE AN OVERCAST DAY WITH
TEMPERATURES IN THE MID 40S WITH BETTER CHANCES OF SOME VERY LIGHT
RAIN IN THE SOUTH. THE SYSTEM WILL MOVE OUT TO THE EAST OVERNIGHT
AND LOW TEMPERATURES ARE EXPECTED TO DROP IN TO THE LOW TO MID 30S
WITH THE COLDEST TEMPS IN THE NORTHWEST PIEDMONT.

SUNDAY WILL FEATURE HIGH PRESSURE BUILDING IN FROM THE NORTH AND
STARTING TO MOVE INTO POSITION TO EVENTUALLY FORM A CAD WEDGE BUT
INITIALLY WILL HELP AID SOME PARTIAL CLEARING EARLY SUNDAY BEFORE
INCREASING CLOUDS FROM THE SOUTH TAKE OVER BY AFTERNOON. IT SHOULD
BE A WARMER DAY THAN SATURDAY WITH TEMPS IN THE UPPER 40S NW TO
LOWER 50S SE. INCREASING MOISTURE FROM APPROACHING SOUTHERN LOW WILL
BRING DEWPOINTS UP NEAR 40 DEGREES BY THE END OF THE AFTERNOON BUT
THE SURFACE HIGH WILL KEEP ANY PRECIPIATION SOUTH OF THE AREA
THROUGH THE AFTERNOON.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...ELLIS





000
FXUS62 KRAH 191904
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
205 PM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL
BUILD SLOWLY INTO OUR REGION THROUGH SATURDAY... AS LOW PRESSURE
TRACKS JUST TO OUR SOUTH. THIS HIGH WILL SHIFT EAST OVER THE
CANADIAN MARITIMES THROUGH SUNDAY... WHILE EXTENDING SOUTHWARD INTO
NORTH CAROLINA. AN UPPER LEVEL DISTURBANCE WILL PASS OVERHEAD ON
MONDAY... WHILE A STRONG STORM SYSTEM STARTS TO TAKE SHAPE OVER THE
GULF COAST REGION. THIS SYSTEM WILL APPROACH OUR AREA FROM THE
SOUTHWEST LATE TUESDAY INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS/BSD
LONG TERM...HARTFIELD
AVIATION...ELLIS





000
FXUS62 KRAH 191904
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
205 PM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL
BUILD SLOWLY INTO OUR REGION THROUGH SATURDAY... AS LOW PRESSURE
TRACKS JUST TO OUR SOUTH. THIS HIGH WILL SHIFT EAST OVER THE
CANADIAN MARITIMES THROUGH SUNDAY... WHILE EXTENDING SOUTHWARD INTO
NORTH CAROLINA. AN UPPER LEVEL DISTURBANCE WILL PASS OVERHEAD ON
MONDAY... WHILE A STRONG STORM SYSTEM STARTS TO TAKE SHAPE OVER THE
GULF COAST REGION. THIS SYSTEM WILL APPROACH OUR AREA FROM THE
SOUTHWEST LATE TUESDAY INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 205 PM FRIDAY...

FOR SUN NIGHT THROUGH MON NIGHT: COOL SURFACE HIGH PRESSURE CENTERED
OVER FAR SERN CANADA WILL CONTINUE TO WEDGE SSW THROUGH CENTRAL NC
SUN NIGHT/MON. THE MID LEVEL WAVE NOW OFF THE PACIFIC COAST WILL
TRACK EAST AND DIG THROUGH THE SRN PLAINS SUN... THEN KICK NORTHEAST
THROUGH THE LOWER MISS VALLEY TOWARD THE OH VALLEY/MIDSOUTH/SRN APP
REGION... DAMPENING IN THE PROCESS AS NRN STREAM ENERGY BEGINS TO
DIG AND PHASE WITH A SRN STREAM WAVE OVER THE CENTRAL CONUS. THE
APPROACH OF THE INITIAL WEAKENING WAVE AND RESULTANT HEIGHT FALLS
HELP SATURATE THE MID-UPPER LEVELS FIRST SUN NIGHT... THEN AS THE
700-850 MB WARM FRONTAL ZONE APPROACHES FROM THE SOUTH WITH
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AROUND 290K-295K...
EXPECT PRECIP TO SPREAD INTO OUR AREA FROM THE SSW AS THE COLUMN
SATURATES. MODEL TIMING AND THEIR RECENT SLOWING TRENDS SUGGEST A
MID EVENING ONSET TIME IN THE SW... SPREADING NNE OVERNIGHT. EXPECT
THE BEST COVERAGE AND HIGHEST AMOUNTS WILL BE ALONG THE MORE STEEPLY
SLOPED PORTION OF THE COLD DOME SURFACE OVER THE PIEDMONT... AND
WILL RAISE POPS HERE TO LIKELY... AND IF TRENDS CONTINUE...
CATEGORICAL POPS MAY BE NEEDED STARTING OVERNIGHT SUN NIGHT. HIGH
COVERAGE (70-80%) OF RAIN SHOULD CONTINUE TO PUSH NORTHEAST THROUGH
CENTRAL NC MON MORNING... AND INTO NE NC IN THE AFTERNOON... WITH
PRECIP THEN TAPERING DOWN TO PATCHY DRIZZLE OR LESS OVER CENTRAL NC
FROM SW TO NE MON AFTERNOON AS THE DRY SLOT ARRIVES FROM THE SW
BEHIND THE RETREATING MID LEVEL WARM FRONTAL ZONE... RESULTING IN
TOP-DOWN DRYING. THIS IS VERY CLOSE TO THE PREVIOUS FORECAST TRENDS.
THE LOW LEVELS WILL REMAIN COOL/MOIST AND STABLE... AS THE DAMMING
WEDGE SHOULD HOLD FIRM... REINFORCED BY NE FLOW AROUND SURFACE LOW
PRESSURE OVER THE OUTER BANKS OR SOUNDS LATE MON. WILL RETAIN
OVERCAST SKIES (LOW CLOUDS PLUS SOME HIGH CLOUDINESS AS THE DIGGING
CENTRAL CONUS TROUGH YIELDS INCREASING SW MID LEVEL FLOW INTO NC)
AND LOW CHANCE POPS MON NIGHT WITH THE POTENTIAL FOR SOME DRIZZLE IN
THIS REGIME. THICKNESSES AND BUFR SOUNDINGS INDICATE ALL-LIQUID
PRECIP WITH THIS EVENT ACROSS CENTRAL NC. THE GFS/ECMWF HINT AT SOME
INLAND PROGRESSION OF THE ASSOCIATED WEDGE WARM FRONT INTO CENTRAL
NC... HOWEVER THIS LOOKS UNLIKELY TO MAKE MUCH HEADWAY GIVEN AN
EXPECTED STRONG COLD DOME... AND WILL NOT INDICATE A DRASTIC WARMUP
IN THE COASTAL PLAIN MON NIGHT... ALTHOUGH TEMPS ARE LIKELY TO BUDGE
LITTLE FROM MON TO MON NIGHT GIVEN THE WARMING ALOFT. LOWS SUN NIGHT
IN THE UPPER 30S TO MID 40S... AND HIGHS MON IN THE LOW 40S TO LOWER
50S (ALTHOUGH THIS DIURNAL RISE IN TEMPS MAY BE TOO LARGE IF WE SEE
STEADY PRECIP INTO THE WEDGE ALL DAY LONG). LOWS MON NIGHT FROM
AROUND 40 NW TO UPPER 40S SE.

FOR TUESDAY THROUGH FRIDAY: STILL LOOKS LIKE A STORMY PATTERN FOR
MID WEEK... ALTHOUGH SOME IMPROVEMENT TO QUIETER WEATHER APPEARS
PROBABLE FOR CHRISTMAS DAY AND FRIDAY.

WE`LL START THIS PERIOD WITH THE PARENT SURFACE HIGH OVER THE
CANADIAN MARITIMES SHIFTING EASTWARD YET STILL EXTENDING SE DOWN
THROUGH WRN/CENTRAL NC... WHILE THE COASTAL/WEDGE FRONTAL ZONE SITS
OVER COASTAL NC EXTENDING BACK THROUGH NRN GA TO A SURFACE LOW OVER
THE MIDWEST. MID LEVEL LOW PRESSURE CONTINUES TO DEEPEN OVER THE
CENTRAL CONUS TUE... THEN DRIFT NE AS ITS LONGWAVE TROUGH PIVOTS
EASTWARD INTO THE EASTERN STATES WED. THE GFS/ECMWF BRING THE WEDGE
FRONT WELL INLAND TUE EVENING/NIGHT... AS THE PRIMARY SURFACE LOW
MOVES OVER LAKE MICHIGAN AND A TRIPLE POINT LOW PUSHES INTO SW NC
(MORE PROMINENT ON THE ECMWF THAN THE GFS). TRYING TO TRACK THE
PROGRESSION OF WEDGE FRONTS ASSOCIATED WITH LATTER-STAGE DAMMING
EVENTS IS ALWAYS DIFFICULT... GIVEN THAT THE PARENT HIGH WILL BE
PUSHING OVER AND JUST OFF THE MARITIMES BUT MAINTAINING A CENTRAL
STRENGTH NEAR 1030 MB. WILL FOLLOW THE CLIMATOLOGICAL LEANINGS OF
SUCH EVENTS AND KEEP A COOL STABLE REGIME IN THE NW PIEDMONT... AS
IS TYPICAL WITH THESE EVENTS. WE SHOULD SEE THE RELATIVE LULL IN
PRECIP EXTEND INTO TUE... CONTINUED CLOUDY SKIES AND A CHANCE OF
LIGHT RAIN AS THE COLUMN REMAINS FAIRLY MOIST BUT WITH MARGINAL/WEAK
FORCING FEATURES. STRENGTHENING AND DEEPENING MOISTURE INFLUX AT
MULTIPLE LEVELS WILL OCCUR TUE NIGHT INTO WED... INCLUDING
STRENGTHENING LOW LEVEL MOIST ISENTROPIC UPGLIDE AND INCREASING
UPPER DIVERGENCE AS MID-UPPER LEVEL WINDS INCREASE JUST TO OUR SW.
WILL STICK WITH POPS INCREASING TO LIKELY FOR NOW. THE GFS/ECMWF
STILL INDICATE THE OCCLUDED/COLD FRONT SWEEPING ENE THROUGH THE
REGION SOMETIME WED (WITH THE ECMWF SLIGHTLY FASTER THAN THE GFS)...
AND DEPENDING ON THE LOCATION/TRACK OF VORTICITY CENTERS AND THE
TRIPLE POINT LOW... WE MAY STILL SEE A THREAT OF A FEW STRONG STORMS
LATE TUE NIGHT INTO WED IF WE ARE ABLE TO ACHIEVE ANY INSTABILITY...
AND WE WILL CONTINUE TO MONITOR FOR THIS POTENTIAL AS THIS TIME
FRAME APPROACHES. IMPROVING CONDITIONS ARE EXPECTED THE EVENING OF
CHRISTMAS EVE AS THE COLUMN DRIES OUT... ALTHOUGH WE SHOULD KEEP
SOME CLOUDS WITH THE TROUGH AXIS SWINGING THROUGH THE REGION. TEMPS
TUE/WED ARE TRICKY AND DON`T HAVE A LOT OF CONFIDENCE... AS A MINOR
SWING ONE WAY OR THE OTHER WITH THE WEDGE FRONT OR LOW TRACKS WILL
GREATLY ALTER TEMPS. WITH EXPECTATIONS OF SOME DAMMING AIR MASS
HOLDING IN THE NW CWA... EXPECT HIGHS TUE FROM 49 NW TO 61 SE.
MINIMAL DROP TUE NIGHT WITH STRENGTHENING LOW LEVEL WINDS AND
POSSIBLE ERODING WEDGE AIR MASS OVER MOST OF THE CWA... AND WILL GO
WITH LOWS OF 44-52. HIGHS 52 NW TO 61 SE WED WITH ALL BUT POSSIBLY
THE NW CWA IN THE WARM SECTOR. TEMPS SHOULD THEN FALL OFF WED
EVENING/NIGHT WITH RAPIDLY CLEARING AND COOL AIR ADVECTION... TO
LOWS OF 33-38. CHRISTMAS DAY AND FRI APPEAR FAIR WITH A WARMING
TREND AS SOUTHERN-STREAM HIGH PRESSURE BUILDS OVER THE GULF AND
SOUTHEAST STATES WITH DECREASING AMPLITUDE OF THE MID LEVEL FLOW.
HIGHS IN THE LOW 50S CHRISTMAS DAY (NEAR NORMAL) AND MID TO UPPER
50S FRI. LOWS IN THE 30S. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS/BSD
LONG TERM...HARTFIELD
AVIATION...ELLIS




000
FXUS62 KRAH 191758
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1258 PM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...ELLIS





000
FXUS62 KRAH 191758
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1258 PM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 100 PM FRIDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE IN VFR CONDITIONS
PERSISTING THROUGH THE TAF PERIOD. SKIES CONTINUE TO REMAIN MOSTLY
CLEAR THIS AFTERNOON WITH VARYING COMPONENTS OF NORTHERLY WIND AT
ROUGHLY 5 KTS. HIGH CLOUDS ARE EXPECTED TO FILTER IN OVERNIGHT
TONIGHT WITH CEILINGS STARTING OUT IN THE 10-15 KFT RANGE. NEAR
DAYBREAK THESE CEILINGS WILL BEGIN TO COME DOWN...MOST LIKELY INTO
THE 3-5 KFT RANGE BY EARLY AFTERNOON AS A SHORTWAVE PASSES TO OUR
SOUTH. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTHEAST WITH LITTLE
GUSTING. THERE IS A CHANCE OF SOME LIGHT RAIN IN THE SOUTH...MAINLY
AT KFAY BEGINNING LATE MORNING/EARLY AFTERNOON AND LASTING INTO THE
EARLY EVENING. ACCUMULATIONS SHOULD BE LIGHT AND VISIBILITIES SHOULD
NOT BE AFFECTED BY ANY PRECIPITATION. IF HEAVIER PRECIPITATION MOVES
IN WITH THE WAVE...CEILINGS COULD POTENTIALLY LOWER TO MVFR LEVELS
BUT THIS IS UNCERTAIN AT THIS TIME.

LONG TERM: BEYOND THE POTENTIAL RAIN ON SATURDAY INTO SATURDAY
EVENING...THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE ON MONDAY
WITH A COASTAL LOW AND SOME POTENTIAL COLD AIR DAMMING. AFTER THAT
THE PATTERN REMAINS UNSETTLED THROUGH MIDWEEK BEFORE CLEARING OUT
FOR CHRISTMAS EVE NIGHT AND INTO CHRISTMAS DAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...ELLIS




000
FXUS62 KRAH 191443
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
943 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 635 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC THROUGH EARLY THIS EVENING. PATCHES OF MID
LEVEL CLOUDS WITH BASES 6000-8000FT WILL CROSS THE REGION THROUGH
MID MORNING. OTHERWISE VFR CONDITIONS WILL PERSIST. FEWER CLOUDS
ANTICIPATED LATER THIS MORNING THROUGH THE AFTERNOON WITH LIGHT AND
VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS





000
FXUS62 KRAH 191443
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
943 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM FRIDAY...

TODAY...AS EXPECTED...EARLIER CLOUDINESS HAS DISSIPATED AND SKIES
HAVE CLEARED OUT NICELY OVER CENTRAL NC. EXPECT THIS TO CONTINUE FOR
THE NEXT SEVERAL HOURS BEFORE SOME HIGHER CLOUDS COULD BEGIN TO
CREEP IN LATER THIS AFTERNOON. PLUS OR MINUS 5 KT WINDS THIS MORNING
GENERALLY OUT OF THE NORTH NORTHWEST. THESE COULD VEER AROUND TO
NORTH OR NORTH NORTHEASTERLY AS THE MORNING PROGRESSES. OTHERWISE
COOL AIRMASS IN PLACE WILL KEEP TEMPERATURES DOWN A BIT BELOW
NORMAL WITH MAX TEMPS IN THE LOWER 50S NORTH TO MID 50S SOUTH. -ELLIS

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS. -WSS

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 635 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC THROUGH EARLY THIS EVENING. PATCHES OF MID
LEVEL CLOUDS WITH BASES 6000-8000FT WILL CROSS THE REGION THROUGH
MID MORNING. OTHERWISE VFR CONDITIONS WILL PERSIST. FEWER CLOUDS
ANTICIPATED LATER THIS MORNING THROUGH THE AFTERNOON WITH LIGHT AND
VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS




000
FXUS62 KRAH 191134
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
635 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 635 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC THROUGH EARLY THIS EVENING. PATCHES OF MID
LEVEL CLOUDS WITH BASES 6000-8000FT WILL CROSS THE REGION THROUGH
MID MORNING. OTHERWISE VFR CONDITIONS WILL PERSIST. FEWER CLOUDS
ANTICIPATED LATER THIS MORNING THROUGH THE AFTERNOON WITH LIGHT AND
VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

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




000
FXUS62 KRAH 190829
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
328 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

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





000
FXUS62 KRAH 190829
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
328 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...

SUNDAY: SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND SOUTHWARD INTO
THE AREA FROM NEW ENGLAND ON SUNDAY... WHILE BRIEF MID LEVEL S/W
RIDGING BUILDS ACROSS CENTRAL NC. HOWEVER... THE NEXT SOUTHERN
STREAM S/W DISTURBANCE WILL BEGIN TO SPREAD CLOUD COVER
NORTHEASTWARD FROM THE GULF OF MEXICO AND INTO OUR REGION. THIS WILL
YIELD PARTLY SUNNY SKIES DURING THE MID MORNING BECOMING MOSTLY
CLOUDY BY LATE DAY INTO THE EVENING. AFTERNOON LOW LEVEL THICKNESS
VALUES ARE EXPECTED TO BE NEAR NORMAL. THUS... GIVEN WE SHOULD SEE
SOME SUN ON SUNDAY EXPECT HIGH TEMPS WILL BE NEAR NORMAL... FROM
AROUND 50 N TO LOWER 50S SOUTH.

SUNDAY NIGHT THROUGH WEDNESDAY: THE AFOREMENTIONED SOUTHERN STREAM
S/W DISTURBANCE WILL LIFT NORTHEASTWARD OUT FROM THE GULF COAST
STATES ON SUNDAY NIGHT INTO MONDAY MORNING... SPREADING WIDESPREAD
RAIN ACROSS ALL OF CENTRAL NC AS ISENTROPIC LIFT RAMPS UP. WITH A
1030 MB SURFACE HIGH STILL EXTENDING SOUTHWARD INTO OUR AREA AS IT
EVER SO SLOWLY SHIFTS EASTWARD EXPECT WE WILL SEE A PRONOUNCED
DAMMING EVENT DEVELOP.... WITH TEMPS FALLING INTO THE UPPER 30S
MONDAY MORNING ACROSS THE NORTHWEST PIEDMONT AND HARDLY MOVING FOR
THE NEXT DAY OR SO. HOWEVER... BOTH THE GFS AND ECMWF CONTINUE TO
DEPICT AN ALL RAIN EVENT ACROSS THE AREA. WITH THE SURFACE LOW
EXPECTED TO LIFT NORTH-NORTHEASTWARD ALONG THE COAST ON MONDAY...
THINK WE COULD SEE OUR COASTAL PLAIN COUNTIES WARM UP A LITTLE BIT
MONDAY... BEFORE THE COLD AIR PUSHES FURTHER EAST AGAIN AS THE
SURFACE LOW MOVES TO THE NORTH AND EAST OF NC ON MONDAY NIGHT. AS
THIS HAPPENS THE MORE SUBSTANTIAL PRECIP WILL COME TO AN END... WITH
ONLY LINGERING AREAS OF LIGHT RAIN AND DRIZZLE REMAINING. LOWS
MONDAY MORNING ARE EXPECTED TO BE IN THE UPPER 30S NW TO LOWER 40S
SE. HIGHS MONDAY WILL BE TRICKY... FOR NOW WILL GO WITH HIGHS
RANGING FROM THE UPPER 30S/NEAR 40 NW TO THE MID 50S FAR E/SE.

A NORTHERN STREAM DISTURBANCE WILL HAVE FORMED A DEEP TROUGH BY
TUESDAY MORNING WITH STACKED LOW PRESSURE OVER THE UPPER MIDWEST.
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN SHOWING THE DEEP
ASSOCIATED TROUGH AXIS SHIFTING EASTWARD ON TUESDAY INTO WEDNESDAY
WHILE TAKING ON MORE OF A NEGATIVE TILT... WITH THE ASSOCIATED
SURFACE FRONT AND POSSIBLE TRIPLE POINT LOW MOVING ACROSS CENTRAL NC
ON WEDNESDAY MORNING INTO THE EARLY AFTERNOON (AS IT STANDS NOW...
STILL SEVERAL DAYS OUT THOUGH). QUESTIONS REMAIN AS TO WHERE A
POSSIBLE TRIPLE POINT LOW MAY FORM THOUGH... AS FINER DETAILS LIKE
THIS ARE HARD TO NAIL DOWN THIS FAR OUT IN THE FORECAST. HOWEVER...
WITH THE POTENTIAL FOR A RETREATING CAD BOUNDARY AND STRENGTHENING
LOW LEVEL WIND FIELD... WE WILL NEED TO KEEP AN EYE ON HOW THIS
SYSTEM DEVELOPS. THIS WOULD BE A HSLC TYPE OF SYSTEM. GIVEN THE TIME
OF YEAR IT IS QUITE HARD TO GET THE NEEDED INSTABILITY FOR POSSIBLE
SEVERE STORMS THOUGH. AS THE FRONT APPROACHES AND MOVES THROUGH THE
AREA ON WEDNESDAY MORNING INTO THE AFTERNOON WE SHOULD SEE A BAND OF
RAIN/SHOWERS ALONG AND IN ADVANCE OF IT... WITH THINGS DRYING OUT
QUICKLY BEHIND THE EFFECTIVE FRONT ON WEDNESDAY AFTERNOON.

HIGHS ON TUESDAY WILL BE TRICKY AND DEPEND ON HOW MUCH THE CAD
BOUNDARY RETREATS. FOR NOW WILL GO WITH HIGHS IN THE MID 40S NW TO
AROUND 60S SE. TEMPS BY WEDNESDAY MORNING WILL NOT FALL MUCH... WITH
LOWS WEDNESDAY MORNING IN THE MID 40S NW TO MID 50S SE/E. HIGHS
WEDNESDAY IN THE 50S TO AROUND 60.

WEDNESDAY NIGHT THROUGH THURSDAY: WE SHOULD SEE RAPID CLEARING ON
WEDNESDAY NIGHT AND CONTINUING INTO THURSDAY... WITH A RETURN TO
QUITE WEATHER. LOWS THURSDAY MORNING ARE EXPECTED TO BE IN THE
30S... WITH HIGHS THURSDAY AFTERNOON NEAR NORMAL IN THE UPPER 40S TO
LOWER 50S.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

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




000
FXUS62 KRAH 190816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BLAES
AVIATION...WSS




000
FXUS62 KRAH 190816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BLAES
AVIATION...WSS





000
FXUS62 KRAH 190816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BLAES
AVIATION...WSS





000
FXUS62 KRAH 190816
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM FRIDAY...

TODAY...MID LEVEL CLOUDS ASSOCIATED WITH WEAK WARM AIR ADVECTION
ALOFT WILL DECREASE/DIMINISH EARLY THIS MORNING AS A WEAK S/W RIDGE
AND ATTENDANT SFC RIDGE (FROM PARENT HIGH OVER THE MID MS VALLEY)
BUILDS INTO THE CAROLINAS. MINOR 850MB THERMAL TROUGH WITH WEAK CAA
WILL MAINTAIN A  CHILLY AIR MASS WITH HIGH TEMPS 4-5 DEGREES BELOW
NORMAL. MAX TEMPS UPPER 40S FAR NE TO THE MID 50S SOUTHERN THIRD.

TONIGHT...A S/W LIFTING E-NE FROM THE SOUTHERN PLAINS WILL ADVANCE
EAST ACROSS THE LOWER MS VALLEY TONIGHT. WARM AIR ADVECTION AHEAD OF
THIS SYSTEM WILL INCREASE MOISTURE ACROSS OUR REGION...RESULTING IN
THICKENING CLOUD COVERAGE FROM THE WEST-SW. MODEST ISENTROPIC
UPGLIDE MAY CAUSE PATCHES OF LIGHT RAIN TO DEVELOP OVER THE FAR
WESTERN-SOUTHERN PIEDMONT PRIOR TO DAYBREAK. MIN TEMPS GENERALLY IN
THE LOW-MID 30S THOUGH SOME PLACES IN THE WEST AND SOUTHWEST WILL
SEE MIN TEMPS OCCUR SHORTLY AFTER MIDNIGHT...WITH TEMPS HOLDING
STEADY THEREAFTER DUE TO THE THICKENING CLOUDS.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 AM FRIDAY...

S/W CROSSING THE DEEP SOUTH EARLY
SATURDAY WILL SPREAD MOISTURE INTO CENTRAL NC. BEST LIFT THROUGH THE
COLUMN ASSOCIATED WITH SPEED CONVERGENCE AT 700MB AND MODEST
HEIGHT FALLS IN THE MID LEVELS. THE MODEL GUIDANCE HAS BEEN
TRENDING DRIER COMPARED TO 48-72 HOURS AGO WITH SOME NEAR TERM MODELS
NOW SUGGESTING LITTLE IF ANY MEASURABLE PRECIP OVER THE NORTHERN
PIEDMONT. WILL NEED TO MONITOR THE DEVELOPING RAIN SHIELD OVER THE
LOWER MS VALLEY TODAY...AND THE TN VALLEY/DEEP SOUTH TONIGHT. PER
LATEST MOISTURE PROFILES AND LIFT...FELL THAT A FEW HUNDREDTHS
PROBABLE ACROSS THE PIEDMONT SATURDAY MORNING. THUS HAVE ADJUSTED
POPS BACK INTO THE LIKELY CATEGORY OVER THE NW PIEDMONT AND
MAINTAINED A LIKELY POPS IN THE SOUTH. FOR AREAS NORTH AND EAST OF
RDU..CONTINUED CHANCE POPS. AGAIN...WHAT PRECIP THAT OCCURS WILL BE
LIGHT WITH AMOUNTS VARYING BETWEEN A TRACE TO LESS THAN A TENTH OF
AN INCH.

NAM AND GFS BUFKIT SOUNDINGS SUGGEST A BRIEF OPPORTUNITY FOR MIXED
PRECIP IN THE NW PIEDMONT AROUND DAYBREAK...COINCIDING WITH THE BEST
LIFT. THE GFS AND NAM HAVE TRENDED SLIGHTLY COOLER WITH PARTIAL
THICKNESSES SUGGESTING A RAIN/SNOW MIX POSSIBLE IN THE TRIAD AND
POSSIBLY THE ROXBORO AREAS...MAINLY WHEN HEAVIER PRECIP INTENSITY IS
OCCURRING. WHILE BULK OF PRECIP WILL BE LIQUID...CANNOT RULE OUT THE
POSSIBILITY OF SOME SNOW MIXED IN AT TIMES NORTH OF TEH I-85/40
CORRIDOR IN THE TRIAD.

HIGH TEMPS SATURDAY DEPENDENT UPON EXTENT OF PRECIP SATURDAY AND
WHETHER PRECIP DOES DIMINISH SATURDAY AFTERNOON. HAVE ADJUSTED MAX
TEMPS UP A DEGREE OR TWO.

HAVE LEANED TOWARD A DRIER FORECAST FOR SATURDAY NIGHT AS SUBSIDENCE
IN THE WAKE OF THE DEPARTING S/W SHOULD END THE THREAT OF PRECIP
ACROSS THE REGION BY LATE SATURDAY...AND MORE SO SATURDAY EVENING
WITH SOME DECREASE IN CLOUDS POSSIBLE AFTER SUNSET. IF ENOUGH
CLEARING OCCURS...MAY SEE POCKETS OF FOG DEVELOP AFTER MIDNIGHT. IN
ANTICIPATION OF SOME PARTIAL CLEARING...HAVE LOWERED MIN TEMPS A FEW
DEGREES FROM THE PREVIOUS FORECAST (LOW-MID 30S).

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BLAES
AVIATION...WSS




000
FXUS62 KRAH 190557
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1255 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 PM THURSDAY...

SATELLITE AND MOST DATA CONFIRM PLENTY OF MID LEVEL MOISTURE WITH
MOSTLY CLOUDY SKIES LINGERING OVER TN/NC. THERE WERE SOME BREAKS IN
THE CLOUDS IN THE NW. SOME OF THIS DRIER AIR WILL FINALLY WORK INTO
THE REGION OVERNIGHT... MAINLY ACROSS THE NORTH. LOWS ARE ON TARGET
FOR 30-35 MOST AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...BADGETT
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...WSS





000
FXUS62 KRAH 190557
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1255 AM EST FRI DEC 19 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER
VALLEY WILL GRADUALLY EXTEND INTO THE CAROLINAS TODAY. A WEAK STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST TODAY... THEN TRACK
EASTWARD ACROSS THE SOUTHEAST STATES ON SATURDAY. WEAK HIGH PRESSURE
WILL BRIEFLY EXTEND ACROSS CENTRAL NC ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 PM THURSDAY...

SATELLITE AND MOST DATA CONFIRM PLENTY OF MID LEVEL MOISTURE WITH
MOSTLY CLOUDY SKIES LINGERING OVER TN/NC. THERE WERE SOME BREAKS IN
THE CLOUDS IN THE NW. SOME OF THIS DRIER AIR WILL FINALLY WORK INTO
THE REGION OVERNIGHT... MAINLY ACROSS THE NORTH. LOWS ARE ON TARGET
FOR 30-35 MOST AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM FRIDAY...

HIGH PRESSURE CENTERED OVER THE LOWER OH VALLEY WILL GRADUALLY
EXTEND INTO CENTRAL NC LATER TODAY AND EARLY THIS EVENING. WHILE
PATCHES OF MID LEVEL CLOUDS WILL CROSS THE REGION THROUGH 12Z...VFR
CONDITIONS WILL PERSIST. FEWER CLOUDS ANTICIPATED LATER THIS MORNING
THROUGH THE AFTERNOON WITH LIGHT AND VARIABLE SURFACE WINDS.

A LOW PRESSURE SYSTEM WILL ADVANCE TOWARD CENTRAL NC LATER TONIGHT
AND CROSS THE REGION SATURDAY. AREAS OF LIGHT RAIN WILL DEVELOP
TOWARD DAYBREAK SATURDAY AND CROSS CENTRAL NC SATURDAY MORNING
THROUGH EARLY AFTERNOON. THE LIGHT RAIN FALLING THROUGH THE LOWER
LEVELS OF THE ATMOSPHERE WILL AID TO MOISTEN THIS LEVEL...LEADING TO
THE POTENTIAL FOR PATCHES OF MVFR CEILINGS...MAINLY IN THE 14Z-20Z
SATURDAY TIME FRAME. WINDS EXPECTED TO REMAIN LIGHT AND VARIABLE.

VFR CONDITIONS EXPECTED SATURDAY NIGHT INTO SUNDAY AS WEAK HIGH
PRESSURE EXTENDS ACROSS THE AREA. ANOTHER LOW PRESSURE SYSTEM...THIS
ONE STRONGER THAN THE SATURDAY SYSTEM...WILL BEGIN TO AFFECT CENTRAL
NC SUNDAY NIGHT INTO SUNDAY...LEADING TO A PERIOD OF WIDESPREAD
MVFR/IFR CEILINGS AND AREAS OF RAIN. THE RAIN WILL DIMINISH ACROSS
THE REGION BY MONDAY NIGHT THOUGH MVFR/IFR CEILINGS WILL PERSIST
MONDAY NIGHT INTO TUESDAY.

&&

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

&&

$$

SYNOPSIS...WSS
NEAR TERM...BADGETT
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...WSS




000
FXUS62 KRAH 190328
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1020 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS THROUGH FRIDAY.
A WEAK LOW PRESSURE WILL TRACK SOUTH OF THE REGION SATURDAY AND
SATURDAY NIGHT. A STRONGER STORM MAY AFFECT THE REGION BY SUNDAY
NIGHT AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 PM THURSDAY...

SATELLITE AND MOST DATA CONFIRM PLENTY OF MID LEVEL MOISTURE WITH
MOSTLY CLOUDY SKIES LINGERING OVER TN/NC. THERE WERE SOME BREAKS IN
THE CLOUDS IN THE NW. SOME OF THIS DRIER AIR WILL FINALLY WORK INTO
THE REGION OVERNIGHT... MAINLY ACROSS THE NORTH. LOWS ARE ON TARGET
FOR 30-35 MOST AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 805 PM THURSDAY...

24-HR TAF PERIOD: VFR CONDITIONS AND LIGHT WINDS WILL RULE THROUGH
THE TAF PERIOD IN ASSOCIATION WITH DRY HIGH PRESSURE EXTENDING INTO
THE REGION FROM THE NORTHWEST. ASIDE FROM LINGERING 6-8 KFT CEILINGS
THIS EVENING...EXPECT CEILINGS TO REMAIN AT OR ABOVE 10 KFT.

LOOKING AHEAD: FORECAST CONFIDENCE DECREASES LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK. CEILINGS WILL REMAIN AT OR ABOVE 5 KFT AS A
FAST-MOVING UPPER LEVEL DISTURBANCE CROSSES THE REGION. CEILINGS
WILL LOWER DURING THE DAY SUNDAY AS A LOW PRESSURE SYSTEM DEVELOPS
ALONG THE GULF COAST...FALLING TO MVFR AND EVENTUALLY IFR/LIFR FROM
THE SOUTH SUNDAY NIGHT/MONDAY (LINGERING THROUGH TUESDAY) AS THE LOW
TRACKS NORTHEAST OFFSHORE THE CAROLINA COAST. SIGNIFICANT WEATHER IN
THE FORM OF LOW CEILINGS/VISBYS...HEAVY SHOWERS...AND STRONG WINDS
APPEAR LIKELY LATE TUE INTO WED AS A POWERFUL STORM SYSTEM DEVELOPS
OVER THE EASTERN CONUS. -VINCENT

&&

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

&&

$$

SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...VINCENT




000
FXUS62 KRAH 190328
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1020 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS THROUGH FRIDAY.
A WEAK LOW PRESSURE WILL TRACK SOUTH OF THE REGION SATURDAY AND
SATURDAY NIGHT. A STRONGER STORM MAY AFFECT THE REGION BY SUNDAY
NIGHT AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 PM THURSDAY...

SATELLITE AND MOST DATA CONFIRM PLENTY OF MID LEVEL MOISTURE WITH
MOSTLY CLOUDY SKIES LINGERING OVER TN/NC. THERE WERE SOME BREAKS IN
THE CLOUDS IN THE NW. SOME OF THIS DRIER AIR WILL FINALLY WORK INTO
THE REGION OVERNIGHT... MAINLY ACROSS THE NORTH. LOWS ARE ON TARGET
FOR 30-35 MOST AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 805 PM THURSDAY...

24-HR TAF PERIOD: VFR CONDITIONS AND LIGHT WINDS WILL RULE THROUGH
THE TAF PERIOD IN ASSOCIATION WITH DRY HIGH PRESSURE EXTENDING INTO
THE REGION FROM THE NORTHWEST. ASIDE FROM LINGERING 6-8 KFT CEILINGS
THIS EVENING...EXPECT CEILINGS TO REMAIN AT OR ABOVE 10 KFT.

LOOKING AHEAD: FORECAST CONFIDENCE DECREASES LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK. CEILINGS WILL REMAIN AT OR ABOVE 5 KFT AS A
FAST-MOVING UPPER LEVEL DISTURBANCE CROSSES THE REGION. CEILINGS
WILL LOWER DURING THE DAY SUNDAY AS A LOW PRESSURE SYSTEM DEVELOPS
ALONG THE GULF COAST...FALLING TO MVFR AND EVENTUALLY IFR/LIFR FROM
THE SOUTH SUNDAY NIGHT/MONDAY (LINGERING THROUGH TUESDAY) AS THE LOW
TRACKS NORTHEAST OFFSHORE THE CAROLINA COAST. SIGNIFICANT WEATHER IN
THE FORM OF LOW CEILINGS/VISBYS...HEAVY SHOWERS...AND STRONG WINDS
APPEAR LIKELY LATE TUE INTO WED AS A POWERFUL STORM SYSTEM DEVELOPS
OVER THE EASTERN CONUS. -VINCENT

&&

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

&&

$$

SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...VINCENT





000
FXUS62 KRAH 190104
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
804 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS THROUGH TONIGHT.
A LOW PRESSURE SYSTEM EXPECTED TO DEVELOP ALONG THE GULF COAST ON
FRIDAY WILL REMAIN SOUTH OF NORTH CAROLINA AS IT TRACKS OFFSHORE THE
SOUTHEAST COAST ON SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 805 PM THURSDAY...

24-HR TAF PERIOD: VFR CONDITIONS AND LIGHT WINDS WILL RULE THROUGH
THE TAF PERIOD IN ASSOCIATION WITH DRY HIGH PRESSURE EXTENDING INTO
THE REGION FROM THE NORTHWEST. ASIDE FROM LINGERING 6-8 KFT CEILINGS
THIS EVENING...EXPECT CEILINGS TO REMAIN AT OR ABOVE 10 KFT.

LOOKING AHEAD: FORECAST CONFIDENCE DECREASES LATE THIS WEEKEND
THROUGH EARLY NEXT WEEK. CEILINGS WILL REMAIN AT OR ABOVE 5 KFT AS A
FAST-MOVING UPPER LEVEL DISTURBANCE CROSSES THE REGION. CEILINGS
WILL LOWER DURING THE DAY SUNDAY AS A LOW PRESSURE SYSTEM DEVELOPS
ALONG THE GULF COAST...FALLING TO MVFR AND EVENTUALLY IFR/LIFR FROM
THE SOUTH SUNDAY NIGHT/MONDAY (LINGERING THROUGH TUESDAY) AS THE LOW
TRACKS NORTHEAST OFFSHORE THE CAROLINA COAST. SIGNIFICANT WEATHER IN
THE FORM OF LOW CEILINGS/VISBYS...HEAVY SHOWERS...AND STRONG WINDS
APPEAR LIKELY LATE TUE INTO WED AS A POWERFUL STORM SYSTEM DEVELOPS
OVER THE EASTERN CONUS. -VINCENT

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...VINCENT





000
FXUS62 KRAH 182028
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS




000
FXUS62 KRAH 182028
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDGING MOVES INTO THE CAROLINAS ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST...SPREADS
INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR MUCH OF MONDAY
MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM AND HAVE
INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S
ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S ELSEWHERE...THESE
TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND WET BULB ZERO
VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND PTYPE ISSUES.

A SURFACE LOW DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT WIDESPREAD CLOUDINESS AND SMALL RAIN CHANCES
WILL PERSIST AS A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE TROUGH DIVES INTO THE
MIDWEST ON TUESDAY AND TUESDAY NIGHT CARVING OUT A HIGH AMPLITUDE
LONG WAVE TROUGH DEVELOPS ACROSS THE MISSISSIPPI VALLEY TUESDAY
NIGHT AND BECOMES NEGATIVELY TILTED ON WEDNESDAY AS IT BROADENS AND
REACHES THE EAST COAST. BOTH THE DETERMINISTIC GFS AND ECMWF ARE
VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE...A STRONG SURFACE
CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO WEDNESDAY
WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE CAROLINA ON
TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL SUPPORT STRONG
AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT WITH A PERIOD OF
WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS ASSOCIATED WITH THE
FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE FRONT IS VERY STRONG
WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED AT 1 KFT NEAR RDU ON
WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS FORECAST AT RDU AT
1.5 KFT WEDNESDAY NIGHT. BOUNDARY LAYER INSTABILITY IS LIMITED BUT
BOTH THE GFS AND THE ECMWF SUGGEST A NARROW WINDOW FOR BOUNDARY
LAYER DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE WIND FIELD
COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS NOTED BY THE
GFS...LEADS TO AN ELEVATED SHERB VALUE THAT SUGGESTS SOME HIGHER
IMPACT HSLC CONVECTION IS POSSIBLE. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS





000
FXUS62 KRAH 182024
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

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

A WEAK SHORTWAVE OVER KENTUCKY/TENNESSEE WILL PASS TO OUR NORTH
THIS EVENING. A PATCH OF MID/HIGH CLOUDS RESULTING FROM SOME OF THE
ASSOCIATED MOISTURE IS CURRENTLY DRIFTING EAST ACROSS THE NORTHERN HALF
OF THE CWA.  WE WILL EVENTUALLY SEE SOME CLEARING FROM THE SOUTHWEST
LATER THIS EVENING AND OVERNIGHT.  THE PRESSURE GRADIENT WILL REMAIN
WEAK TONIGHT BEFORE HIGH PRESSURE BUILDS IN ON FRIDAY.  WITH LIGHT
WINDS AND CLEARING SKIES...LOWS SHOULD VARY FROM THE UPPER 20S IN
TYPICALLY COOLER RURAL AREAS TO LOW/MID 30S AROUND URBAN AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 315 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDING MOVES INTO THE REGION ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST ON SUNDAY
EVENING...SPREADS INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR
MUCH OF MONDAY MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM
AND HAVE INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO
THE MID 30S ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S
ELSEWHERE...THESE TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND
WET BULB ZERO VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND
PTYPE ISSUES.

A SURFACE DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE DIVES INTO THE MIDWEST ON
TUESDAY AND TUESDAY NIGHT AS A HIGH AMPLITUDE TROUGH DEVELOPS ACROSS
THE MISSISSIPPI VALLEY TUESDAY NIGHT AND BECOMES NEGATIVELY TILTED
ON WEDNESDAY AS IT REACHES THE EAST COAST. BOTH THE DETERMINISTIC
GFS AND ECMWF ARE VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE A
STRONG CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO
WEDNESDAY WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE
CAROLINA ON TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL
SUPPORT STRONG AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT
WITH A PERIOD OF WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS
ASSOCIATED WITH THE FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE
FRONT IS VERY STRONG WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED
AT 1KFT NEAR RDU ON WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS
FORECAST AT RDU AT 1.5KFT WEDNESDAY NIGHT. BOUNDARY LAYER
INSTABILITY IS LIMITED BUT BOTH THE GFS AND THE ECMWF SUGGEST A
NARROW WIND FOR DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE
WIND FIELD COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS
NOTED BY THE GFS LEADS TO AN ELEVATED SHERB VALUE THAT COULD SUPPORT
SOME HIGHER IMPACT HSLC CONVECTION. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS




000
FXUS62 KRAH 182024
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
320 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

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

A WEAK SHORTWAVE OVER KENTUCKY/TENNESSEE WILL PASS TO OUR NORTH
THIS EVENING. A PATCH OF MID/HIGH CLOUDS RESULTING FROM SOME OF THE
ASSOCIATED MOISTURE IS CURRENTLY DRIFTING EAST ACROSS THE NORTHERN HALF
OF THE CWA.  WE WILL EVENTUALLY SEE SOME CLEARING FROM THE SOUTHWEST
LATER THIS EVENING AND OVERNIGHT.  THE PRESSURE GRADIENT WILL REMAIN
WEAK TONIGHT BEFORE HIGH PRESSURE BUILDS IN ON FRIDAY.  WITH LIGHT
WINDS AND CLEARING SKIES...LOWS SHOULD VARY FROM THE UPPER 20S IN
TYPICALLY COOLER RURAL AREAS TO LOW/MID 30S AROUND URBAN AREAS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 315 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDING MOVES INTO THE REGION ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST ON SUNDAY
EVENING...SPREADS INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR
MUCH OF MONDAY MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM
AND HAVE INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO
THE MID 30S ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S
ELSEWHERE...THESE TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND
WET BULB ZERO VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND
PTYPE ISSUES.

A SURFACE DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE DIVES INTO THE MIDWEST ON
TUESDAY AND TUESDAY NIGHT AS A HIGH AMPLITUDE TROUGH DEVELOPS ACROSS
THE MISSISSIPPI VALLEY TUESDAY NIGHT AND BECOMES NEGATIVELY TILTED
ON WEDNESDAY AS IT REACHES THE EAST COAST. BOTH THE DETERMINISTIC
GFS AND ECMWF ARE VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE A
STRONG CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO
WEDNESDAY WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE
CAROLINA ON TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL
SUPPORT STRONG AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT
WITH A PERIOD OF WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS
ASSOCIATED WITH THE FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE
FRONT IS VERY STRONG WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED
AT 1KFT NEAR RDU ON WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS
FORECAST AT RDU AT 1.5KFT WEDNESDAY NIGHT. BOUNDARY LAYER
INSTABILITY IS LIMITED BUT BOTH THE GFS AND THE ECMWF SUGGEST A
NARROW WIND FOR DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE
WIND FIELD COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS
NOTED BY THE GFS LEADS TO AN ELEVATED SHERB VALUE THAT COULD SUPPORT
SOME HIGHER IMPACT HSLC CONVECTION. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS





000
FXUS62 KRAH 182017
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 315 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDING MOVES INTO THE REGION ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST ON SUNDAY
EVENING...SPREADS INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR
MUCH OF MONDAY MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM
AND HAVE INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO
THE MID 30S ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S
ELSEWHERE...THESE TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND
WET BULB ZERO VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND
PTYPE ISSUES.

A SURFACE DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE DIVES INTO THE MIDWEST ON
TUESDAY AND TUESDAY NIGHT AS A HIGH AMPLITUDE TROUGH DEVELOPS ACROSS
THE MISSISSIPPI VALLEY TUESDAY NIGHT AND BECOMES NEGATIVELY TILTED
ON WEDNESDAY AS IT REACHES THE EAST COAST. BOTH THE DETERMINISTIC
GFS AND ECMWF ARE VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE A
STRONG CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO
WEDNESDAY WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE
CAROLINA ON TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL
SUPPORT STRONG AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT
WITH A PERIOD OF WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS
ASSOCIATED WITH THE FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE
FRONT IS VERY STRONG WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED
AT 1KFT NEAR RDU ON WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS
FORECAST AT RDU AT 1.5KFT WEDNESDAY NIGHT. BOUNDARY LAYER
INSTABILITY IS LIMITED BUT BOTH THE GFS AND THE ECMWF SUGGEST A
NARROW WIND FOR DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE
WIND FIELD COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS
NOTED BY THE GFS LEADS TO AN ELEVATED SHERB VALUE THAT COULD SUPPORT
SOME HIGHER IMPACT HSLC CONVECTION. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS




000
FXUS62 KRAH 182017
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 315 PM WEDNESDAY...

...VERY ACTIVE PATTERN DEVELOPING OVER THE LONG TERM PERIOD...

BEHIND THE DEPARTING SOUTHERN STREAM SHORT WAVE TROUGH...SHORT WAVE
RIDING MOVES INTO THE REGION ON SUNDAY AS HIGH PRESSURE CENTERED
OVER THE EASTERN GREAT LAKES AND MID ATLANTIC EXTENDS INTO THE
REGION. THE NEXT SOUTHERN STREAM WAVE WHICH MOVES ONSHORE ACROSS CA
ON FRIDAY REACHES THE WESTERN GULF OF MEXICO ON SUNDAY NIGHT. LOOK
FOR INCREASING AND THICKENING CLOUDS ON SUNDAY WITH HIGHS IN THE
UPPER 40S TO LOWER 50S. PRONOUNCED ISENTROPIC LIFT WHICH DEVELOPS
AHEAD OF THIS SYSTEM SUNDAY EVENING ACROSS THE SOUTHEAST ON SUNDAY
EVENING...SPREADS INTO THE CAROLINAS AFTER MIDNIGHT AND PERSISTS FOR
MUCH OF MONDAY MORNING. EXPECT A BROAD AREA OF RAIN WITH THIS SYSTEM
AND HAVE INCREASED POPS. TEMPERATURES SUNDAY NIGHT WILL FALL INTO
THE MID 30S ACROSS THE NORTHERN PIEDMONT AND THE UPPER 30S
ELSEWHERE...THESE TEMPERATURES ALONG WITH A PRONOUNCED WARM NOSE AND
WET BULB ZERO VALUES HOLDING ABOVE FREEZING SHOULD PRECLUDE AND
PTYPE ISSUES.

A SURFACE DEVELOPING IN THE NORTHEAST GULF OF MEXICO WILL MOVE
NORTHEAST ALONG THE CAROLINA COAST MONDAY AFTERNOON AND FURTHER
OFFSHORE MONDAY NIGHT. PRECIPITATION SHOULD BECOME MUCH MORE
SCATTERED AND LIGHT MONDAY NIGHT INTO TUESDAY AS THE STRONGEST
FORCING ABATES BUT A MOIST AIR MASS LINGERS ACROSS THE AREA.

AN IMPRESSIVE NORTHERN STREAM SHORTWAVE DIVES INTO THE MIDWEST ON
TUESDAY AND TUESDAY NIGHT AS A HIGH AMPLITUDE TROUGH DEVELOPS ACROSS
THE MISSISSIPPI VALLEY TUESDAY NIGHT AND BECOMES NEGATIVELY TILTED
ON WEDNESDAY AS IT REACHES THE EAST COAST. BOTH THE DETERMINISTIC
GFS AND ECMWF ARE VERY SIMILAR WITH THIS PATTERN. AT THE SURFACE A
STRONG CYCLONE DEVELOPS ACROSS THE GREAT LAKES ON TUESDAY INTO
WEDNESDAY WITH A STRONG COLD FRONT PROGGED TO MOVE ACROSS THE
CAROLINA ON TUESDAY NIGHT AND EARLY WEDNESDAY. THIS PATTERN WILL
SUPPORT STRONG AND GUSTY WINDS AHEAD OF AND BEHIND THE COLD FRONT
WITH A PERIOD OF WIDESPREAD RAIN AND PERHAPS A FEW THUNDERSTORMS
ASSOCIATED WITH THE FRONT. THE DEEP LAYER FLOW ATTENDANT TO THE
FRONT IS VERY STRONG WITH A SOUTHWEST WIND OF AROUND 40KTS PROGGED
AT 1KFT NEAR RDU ON WEDNESDAY MORNING AND A WESTERLY WIND OF 40 KTS
FORECAST AT RDU AT 1.5KFT WEDNESDAY NIGHT. BOUNDARY LAYER
INSTABILITY IS LIMITED BUT BOTH THE GFS AND THE ECMWF SUGGEST A
NARROW WIND FOR DESTABILIZATION AHEAD OF THE FRONT. THE IMPRESSIVE
WIND FIELD COMBINED WITH 700-500 MB LAPSE RATES APPROACHING 7 AS
NOTED BY THE GFS LEADS TO AN ELEVATED SHERB VALUE THAT COULD SUPPORT
SOME HIGHER IMPACT HSLC CONVECTION. THE PRECIPITATION QUICKLY ENDS
BEHIND THE FRONT WEDNESDAY AFTERNOON WITH DRY WEATHER EXPECTED FOR
CHRISTMAS DAY. HIGHS ON TUESDAY WILL RANGE FROM THE LOWER 50S IN THE
TRIAD TO NEAR 60 ACROSS THE SOUTHERN COASTAL PLAIN. TEMPERATURES
SHOULDN`T FALL MUCH TUESDAY NIGHT WITH THE CLOUDS AND STRONG
SOUTHERLY FLOW. RAISED MINS ABOVE GUIDANCE TO THE MID 40S TO AROUND
50. HIGHS WEDNESDAY WILL RANGE FROM 50 IN THE TRIAD TO NEAR 60 IN
THE SOUTHEAST WITH CHILLIER MAXES IN THE MID 40S TO NEAR 50 EXPECTED
FOR CHRISTMAS DAY. -BLAES
&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...BLAES
AVIATION...BLS





000
FXUS62 KRAH 181955
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
255 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 255 PM THURSDAY...

FRIDAY AND FRIDAY NIGHT... HIGH PRESSURE OVER THE MIDWEST WILL
SLOWLY SETTLE EAST ACROSS THE CENTRAL APPALACHIANS AS THE PARENT
HIGH MOVES TOWARD EASTERN CANADA. WE SHOULD BE IN A RELATIVE MIN
BETWEEN MID/HIGH CLOUDS TODAY AND MOISTURE SPREADING IN AHEAD OF
SATURDAY`S SYSTEM. GUIDANCE SUGGESTS DEWPOINTS WILL FALL INTO THE
20S..THOUGH WOULDNT BE SURPRISED TO SEE SOME UPPER TEENS BASED ON
REGIONAL OBSERVATIONS.  THICKNESSES SUPPORT HIGHS IN THE LOW TO MID
50S.  LOWS FRIDAY NIGHT SHOULD BE ABLE TO FALL INTO THE LOW/MID 30S
(ESPECIALLY NORTHEAST) PRIOR TO THE ARRIVAL OF MORE ROBUST CLOUD
COVER.

SATURDAY... THE SHORTWAVE CURRENTLY OVER THE CALIFORNIA BAJA REGION
WILL LIFT NORTHEAST ACROSS THE SOUTHERN-CENTRAL US ON FRIDAY AND
THEN TOWARD OUR REGION ON FRIDAY NIGHT. MODELS CONTINUE TO TREND
TOWARD MORE DEAMPLIFICATION WITH THE WAVE BY THE TIME IT REACHES THE
SOUTHERN APPALACHIANS SATURDAY MORNING.  ACCORDINGLY...THE SURFACE
LOW EXPECTED TO DEVELOP ALONG THE GULF COAST IS MUCH WEAKER AND
ESSENTIALLY MOVES EAST OFF THE SOUTHEAST COAST. HIGH PRESSURE OVER
EASTERN CANADA WILL EXTEND DOWN THE EASTERN SEABOARD AND INTO
CENTRAL NC.  WHILE NOT OVERLY STRONG OR FAR ENOUGH SOUTH... THE HIGH
IS IN A MORE FAVORABLE POSITION TO SUPPLY DRY AIR INTO NC THAN
FORECAST A FEW DAYS AGO.  HOWEVER...WITH WEAKER DYNAMIC
FORCING...THE DRY AIR WILL ALSO LIMIT PRECIP...AND THE NAM/GFS/ECMWF
ARE ALL DRY OR NEARLY DRY.

CAN`T HELP BUT CONTINUE TO CUT BACK ON POPS BASED ON RECENT
GUIDANCE...BUT GIVEN THAT THE SHORTWAVE WILL BE INTERACTING WITH AN
ASSORTMENT OF NORTHERN STREAM WAVES OVER THE NORTHERN PLAINS...A
SMALL SHIFT BACK TO THE NORTH WILL BRING MEASURABLE PRECIP INTO
CENTRAL NC.  SHOULD NOTE THAT A SHIFT BACK TO THE NORTH COULD STILL
CREATE SOME PTYPE ISSUES AS PTYPE NOMOGRAMS HOVER AROUND THE WINTRY
MIX AND WETBULB PROFILES REMAIN CURIOUSLY CLOSE TO FREEZING IN THE
LOWEST 10K FT.  THIS IS A FINE LINE AS WELL...AS THE SHIFT WOULD
ALSO BRING SOME WARM AIR BACK NORTH.  WILL REDUCE POPS TO CHANCE
ACROSS THE NORTH AND LOW-END LIKELY (MAINLY BETWEEN 12Z AND 00Z)
NEAR THE SC BORDER...WHICH MAY STILL BE TOO HIGH BUT FOLLOWS A
CONSERVATIVE TREND.  WILL ALSO RAISE HIGHS A FEW DEGREES...THOUGH
NORTHEASTERLY FLOW AND THICK CLOUD COVER WOULD STILL KEEP TEMPS IN
THE UPPER 40S NORTHWEST TO NEAR 50 SOUTHEAST.

SATURDAY NIGHT....ALL ENERGY ASSOCIATED WITH THIS SYSTEM WILL DEPART
SATURDAY NIGHT...ALLOWING FOR SOME MID-LEVEL DRYING AND SCATTERING
OF CLOUDS.  HOWEVER...MODELS ARE QUICK TO BRING MOISTURE BACK TOWARD
THE REGION FROM THE SOUTH AS ANOTHER SYSTEM GETS GOING BY LATE
SUNDAY.  LOWS IN THE MID/UPPER 30S.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...



SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BLS
LONG TERM...WSS
AVIATION...BLS




000
FXUS62 KRAH 181744
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1240 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BLS




000
FXUS62 KRAH 181744
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1240 PM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM THURSDAY...

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON THROUGH THE END OF THE
TAF PERIOD.  A WEEK DISTURBANCE WILL CROSS VIRGINIA THIS
EVENING...BUT THE ONLY IMPACT OVER NC WILL BE INCREASING MID/HIGH
CLOUDS....MAINLY ACROSS THE NORTHERN HALF OF THE AREA. WINDS WILL BE
LIGHT OUR OF THE NORTH-NORTHWEST...INCREASING TO 4-6KT DURING THE
DAY FRIDAY.

OUTLOOK...A LOW PRESSURE SYSTEM MOVING FROM THE GULF COAST TO THE
CAROLINA COAST FRIDAY NIGHT AND SATURDAY WILL BRING A ROUND OF SUB-
VFR CONDITIONS TO CENTRAL NC ON SATURDAY AND SATURDAY NIGHT.
HOWEVER....THIS SYSTEM MAY NOT BE AS SIGNIFICANT AS ONCE EXPECTED.
VFR CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BLS





000
FXUS62 KRAH 181421
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
920 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 635 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
AND VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA FROM THE WEST. SCATTERED TO BROKEN
MID AND HIGH CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID
LEVEL DISTURBANCE APPROACHES THE REGION FROM THE WEST AND MOVES
ACROSS THE AREA TONIGHT. SKIES ARE EXPECTED TO CLEAR TONIGHT...
GENERALLY IN THE EARLY MORNING HOURS OF FRIDAY.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
MID TO LATE MORNING INTO THE AFTERNOON AS A STORM SYSTEM IS EXPECTED
TO FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
TRACKING EAST ACROSS THE SOUTHERN GULF STATES SATURDAY...TO ALONG OR
JUST OFF THE SOUTHEAST COAST SAT NIGHT AND SUN. AREAS OF RAIN WITH
SUB-VFR CONDITIONS APPEAR LIKELY FROM SATURDAY MID SATURDAY MORNING
THROUGH SATURDAY NIGHT. VFR CONDITIONS ARE EXPECTED TO BRIEFLY
RETURN FOR SUNDAY... BEFORE ANOTHER DISTURBANCE LIFTS NORTHEASTWARD
OUT OF THE GULF... SPREADING RAIN INTO CENTRAL NC SUNDAY NIGHT INTO
MONDAY... WITH SUB-VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC




000
FXUS62 KRAH 181421
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
920 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...

AN ALREADY LOW AMPLITUDE TROUGH ALOFT OVER THE MID-MISSISSIPPI RIVER
VALLEY THIS MORNING WILL CONTINUE TO DEAMPLIFY AS IT SKIRTS ACROSS
THE TENNESSEE VALLEY AND VIRGINIA THROUGH TONIGHT. AN AREA OF LIGHT
RAIN MOVING ACROSS EASTERN TENNESSEE...FOCUSED NEAR THE H925-H85
FRONTAL ZONE WHERE ISENTROPIC LIFT IS GREATEST...CONTINUES TO
GRADUALLY WEAKEN WITH EASTWARD EXTENT.  EXPECT THIS TREND TO THE
CONTINUE AS THE UPPER DISTURBANCE MOVES OFF TO THE EAST-NORTHEAST
AND THE FORCING DECOUPLES.  SO NO PRECIP IS EXPECTED OVER CENTRAL
NC.  EAST OF THE MOUNTAINS...THE AIRMASS REMAINS VERY DRY WITH ALL
MOISTURE ABOVE 12K FT.   WHILE THERE IS A FAIR AMOUNT OF HIGH LEVEL
MOISTURE UPSTREAM...GUIDANCE SUGGESTS  THERE WILL PERIODS OF SUN
MIXED IN WITH THE HIGH CLOUDS (POTENTIALLY OROGRAPHICALLY ENHANCED
AT TIMES THIS MORNING. TEMPS SHOULD GET TO WITHIN A COUPLE DEGREES
OF THE CURRENT FORECAST HIGHS OF 49-55.  IF ANYTHING...THEY WILL END
UP ON THE COOLER SIDE.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 635 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
AND VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA FROM THE WEST. SCATTERED TO BROKEN
MID AND HIGH CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID
LEVEL DISTURBANCE APPROACHES THE REGION FROM THE WEST AND MOVES
ACROSS THE AREA TONIGHT. SKIES ARE EXPECTED TO CLEAR TONIGHT...
GENERALLY IN THE EARLY MORNING HOURS OF FRIDAY.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
MID TO LATE MORNING INTO THE AFTERNOON AS A STORM SYSTEM IS EXPECTED
TO FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
TRACKING EAST ACROSS THE SOUTHERN GULF STATES SATURDAY...TO ALONG OR
JUST OFF THE SOUTHEAST COAST SAT NIGHT AND SUN. AREAS OF RAIN WITH
SUB-VFR CONDITIONS APPEAR LIKELY FROM SATURDAY MID SATURDAY MORNING
THROUGH SATURDAY NIGHT. VFR CONDITIONS ARE EXPECTED TO BRIEFLY
RETURN FOR SUNDAY... BEFORE ANOTHER DISTURBANCE LIFTS NORTHEASTWARD
OUT OF THE GULF... SPREADING RAIN INTO CENTRAL NC SUNDAY NIGHT INTO
MONDAY... WITH SUB-VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD/BLS
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC





000
FXUS62 KRAH 181138
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
638 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 635 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
AND VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA FROM THE WEST. SCATTERED TO BROKEN
MID AND HIGH CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID
LEVEL DISTURBANCE APPROACHES THE REGION FROM THE WEST AND MOVES
ACROSS THE AREA TONIGHT. SKIES ARE EXPECTED TO CLEAR TONIGHT...
GENERALLY IN THE EARLY MORNING HOURS OF FRIDAY.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
MID TO LATE MORNING INTO THE AFTERNOON AS A STORM SYSTEM IS EXPECTED
TO FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
TRACKING EAST ACROSS THE SOUTHERN GULF STATES SATURDAY...TO ALONG OR
JUST OFF THE SOUTHEAST COAST SAT NIGHT AND SUN. AREAS OF RAIN WITH
SUB-VFR CONDITIONS APPEAR LIKELY FROM SATURDAY MID SATURDAY MORNING
THROUGH SATURDAY NIGHT. VFR CONDITIONS ARE EXPECTED TO BRIEFLY
RETURN FOR SUNDAY... BEFORE ANOTHER DISTURBANCE LIFTS NORTHEASTWARD
OUT OF THE GULF... SPREADING RAIN INTO CENTRAL NC SUNDAY NIGHT INTO
MONDAY... WITH SUB-VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC





000
FXUS62 KRAH 181138
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
638 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 635 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
AND VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA FROM THE WEST. SCATTERED TO BROKEN
MID AND HIGH CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID
LEVEL DISTURBANCE APPROACHES THE REGION FROM THE WEST AND MOVES
ACROSS THE AREA TONIGHT. SKIES ARE EXPECTED TO CLEAR TONIGHT...
GENERALLY IN THE EARLY MORNING HOURS OF FRIDAY.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
MID TO LATE MORNING INTO THE AFTERNOON AS A STORM SYSTEM IS EXPECTED
TO FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
TRACKING EAST ACROSS THE SOUTHERN GULF STATES SATURDAY...TO ALONG OR
JUST OFF THE SOUTHEAST COAST SAT NIGHT AND SUN. AREAS OF RAIN WITH
SUB-VFR CONDITIONS APPEAR LIKELY FROM SATURDAY MID SATURDAY MORNING
THROUGH SATURDAY NIGHT. VFR CONDITIONS ARE EXPECTED TO BRIEFLY
RETURN FOR SUNDAY... BEFORE ANOTHER DISTURBANCE LIFTS NORTHEASTWARD
OUT OF THE GULF... SPREADING RAIN INTO CENTRAL NC SUNDAY NIGHT INTO
MONDAY... WITH SUB-VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC




000
FXUS62 KRAH 180847
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
347 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC




000
FXUS62 KRAH 180847
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
347 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC





000
FXUS62 KRAH 180847
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
347 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC




000
FXUS62 KRAH 180847
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
347 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 347 AM WEDNESDAY...

SATURDAY...WHILE A SFC DRY AIR RIDGE AND PARENT HIGH ARE STILL IN A
FAVORABLE LOCATION TO SUPPORT A COLD AIR DAMMING EVENT
SATURDAY...THE LATEST MODEL GUIDANCE HAS TAKEN THE MID LEVEL S/W ON
A MORE SLY TRAJECTORY THAN PREVIOUS MODEL RUNS AND PARENT HIGH A FEW
MILLIBARS WEAKER THAN PREVIOUS MODEL RUNS. THIS STILL YIELDS A
HYBRID DAMMING EVENT THOUGH PRECIP AMOUNTS APPEAR TO BE LIGHTER THAN
EARLIER FORECASTS. S/W HAS RECENTLY ENTERED THE UPPER AIR RAWINSONDE
NETWORK SO THE 12Z MODEL RUN SHOULD GIVE AN INDICATION OF EVENTUAL
STRENGTH/TRACK OF THIS SYSTEM  REGARDLESS...OVERCAST SKIES AND
AREAS/WIDESPREAD LIGHT RAIN WILL RESULT IN A COLD DAMP DAY. MOS
GUIDANCE APPEARS TOO WARM AND AM RELUCTANT TO RAISE MAX TEMPS
SATURDAY FROM CURRENT FORECAST (NEAR 40 NW TO UPPER 40S FAR SE). IF
RAIN COVERAGE ENDS UP BEING SPOTTY VERSUS WIDESPREAD...THEN COULD
SEE AN ADJUSTMENT IN MAX TEMPS TO VALUES COMPARABLE TO THE NAM MOS
(MID-UPPER 40S, NEAR 50 SE).

SATURDAY NIGHT...SUBSIDENCE BEHIND THE EXITING S/W SHOULD AID TO
DIMINISH LIGHT PRECIP WITH GREATEST THREAT FOR SPOTTY LIGHT PRECIP
OVER THE SANDHILLS/SOUTHERN COASTAL PLAIN (AGAIN DUE TO THE MORE SLY
TRACK OF THE S/W). OTHERWISE CONTINUED CONSIDERABLE CLOUDINESS WITH
PATCHY DRIZZLE AND/OR LIGHT FOG. MIN TEMPS MID-UPPER 30S.

SUNDAY THROUGH WEDNESDAY...A MAJOR STORM MAY AFFECT THE SE U.S. LATE
TUESDAY INTO WEDNESDAY (INCLUDING CENTRAL NC) WITH POTENTIAL IMPACT
ON TRAVEL DUE TO HEAVY RAIN AND STRONG GUSTY WINDS.

MODEL GUIDANCE FLIP-FLOPPED A BIT FOR SUNDAY INTO MONDAY WITH
GUIDANCE NOW INDICATING A NARROW DRY AIR SFC RIDGE ACROSS THE REGION
SUNDAY WITH ANOTHER S/W IN THE SOUTHERN STREAM INITIATING ANOTHER
AREA OF RAIN LATE SUNDAY INTO MONDAY. THIS SCENARIO HAS ALSO BEEN
PICKED-UP BY THE LATEST ECMWF. PARTIAL THICKNESSES SUPPORT ALL
LIQUID ACROSS THE PIEDMONT AT THIS TIME. DUE TO THE SHIFT...PLAN TO
CONFINE POPS TO JUST CHANCE AT THIS TIME LATE SUNDAY INTO MONDAY. IF
LATER MODEL RUNS MAINTAIN SOME CONSISTENCY...LIKELY POPS WARRANTED
FOR OVERNIGHT SUNDAY INTO MONDAY MORNING. WILL CONTINUE BELOW NORMAL
HIGH TEMPS SUNDAY INTO MONDAY...WITH MAX TEMPS MONDAY AS MUCH AS 7-8
DEGREES BELOW NORMAL IF RAIN MATERIALIZES.

TUESDAY INTO WEDNESDAY...AMPLIFYING L/W TROUGH IN THE NORTHERN
STREAM WILL TAP GULF MOISTURE AND STREAM IT NORTHWARD INTO THE
CAROLINAS TUESDAY INTO TUESDAY NIGHT. MODEL GUIDANCE INDICATE A
STRONG JET ROUNDING BASE OF TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING CAUSING THE TROUGH TO BECOME NEGATIVELY TILTED ACROSS THE SE
U.S. IF THIS HOLDS TOGETHER...COULD SEE A BAND OF HEAVY SHOWERS WITH
A FEW STORMS CROSS CENTRAL NC OVERNIGHT TUESDAY NIGHT INTO EARLY
WEDNESDAY. THE PARENT LOW DEEPENS SIGNIFICANTLY WEDNESDAY AND
WEDNESDAY NIGHT WITH THE POTENTIAL FOR STRONG GUSTY WINDS ACROSS
CENTRAL NC. A BRIEF BUMP UP IN TEMPS TUESDAY AHEAD OF THE STORM
SYSTEM TUESDAY FOLLOWED BY ANOTHER ROUND OF BELOW NORMAL MAX TEMPS
THOUGH TRULY FRIGID AIR NOT SEEN IN OUR REGION THROUGH CHRISTMAS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...WSS
AVIATION...BSD/KC





000
FXUS62 KRAH 180817
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...SEC
AVIATION...BSD/KC





000
FXUS62 KRAH 180817
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM THURSDAY...

BRIEF S/W RIDGING WILL BUILD ACROSS THE AREA THIS
MORNING INTO THE EARLY AFTERNOON... WITH A QUICK MOVING MID LEVEL
S/W APPROACHING THE AREA TODAY AND CROSSING THE REGION TONIGHT IN ITS
WAKE. THIS WILL ALLOW FOR AN INCREASE IN MID AND HIGH CLOUDS TODAY.
GIVEN THE LOW AMPLITUDE OF THIS DISTURBANCE AND DRY LOW LEVELS WE DO
NOT EXPECT ANY PRECIP FROM THE PASSING DISTURBANCE. HOWEVER... THE
CLOUDS WILL LIKELY HAVE SOME IMPACT ON HIGH TEMPS TODAY. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS
LOWER THAN ON WEDNESDAY. THUS... GIVEN THE EXPECTED CLOUD COVER AND
LOWER THICKNESS VALUES EXPECT WE SHOULD SEE HIGH TEMPS RUN A GOOD 6
TO 9 DEGREES COOLER TODAY. THIS YIELDS HIGH TEMPS RANGING FROM
AROUND 50 NORTH TO THE MID 50S SOUTH.

SKIES WILL BEGIN TO CLEAR OFF BY EARLY FRIDAY MORNING WITH THE
PASSAGE OF THE AFOREMENTIONED MID LEVEL TROUGH. GIVEN A RATHER WEAK
MSLP GRADIENT ACROSS THE AREA WITH SURFACE HIGH PRESSURE EXTENDING
INTO THE AREA FROM THE WEST... WE SHOULD SEE LIGHT AND VARIABLE TO
CALM WINDS OVERNIGHT. THIS COMBINED WITH CLEAR SKIES WILL ALLOW US
TO COOL QUITE NICELY TONIGHT. EXPECT LOW TEMPS WILL RANGE FROM THE
UPPER 20S TO AROUND 30 (WITH MAYBE EVEN A FEW MID 20S) IN THE USUAL
RURAL COLD LOCATIONS TO THE LOWER 30S ELSEWHERE.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 310 AM THURSDAY...

FRIDAY AND FRIDAY NIGHT: ANOTHER SOUTHERN STREAM DISTURBANCE IS
EXPECTED TO APPROACH THE AREA ON FRIDAY. S/W ENERGY IS EXPECTED TO
LIFT NORTHEASTWARD OUT OF THE SOUTHERN PLAINS ON FRIDAY. MEANWHILE
CENTRAL NC WILL EXPERIENCE BRIEF S/W RIDGING AGAIN ON FRIDAY IN
BETWEEN THE AFOREMENTIONED SYSTEM TONIGHT AND THE APPROACHING SYSTEM
ON FRIDAY. THIS WILL YIELD MOSTLY SUNNY SKIES... POSSIBLY BECOMING
PARTLY SUNNY BY LATE IN THE DAY AS HIGH LEVEL CLOUD COVER BEGINS TO
STREAM NORTH AND EASTWARD IN ADVANCE OF THE NEXT SYSTEM. AFTERNOON
LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE A BIT LOWER ON
FRIDAY... AROUND 5 METERS OR SO. HOWEVER... WITH MORE SUN EXPECTED
ON FRIDAY THINK WE WILL SEE SIMILAR HIGH TEMPS COMPARED TO TODAY.
THUS... EXPECT HIGH TO RANGE FROM 50 TO 55.

AS THE MID LEVEL DISTURBANCE SHIFTS NORTHEASTWARD TOWARDS OUR REGION
FROM THE LOWER MS RIVER VALLEY ON FRIDAY EVENING/EARLY SATURDAY
MORNING SURFACE LOW PRESSURE WILL DEVELOP ACROSS THE NORTHERN GULF
OF MEXICO AND BEGIN TRACKING EASTWARD. AS THE SYSTEM APPROACHES
MOISTURE WILL STREAM NORTHWARD ACROSS CENTRAL NC... WITH SHALLOW
ISENTROPIC LIFT BEGINNING TO INCREASE ACROSS THE WESTERN AND
SOUTHWESTERN PORTION OF THE CWA DURING THE EARLY MORNING HOURS OF
SATURDAY. AT THE ONSET OF LIGHT PRECIP SPREADING INTO NORTHWEST
PIEDMONT WE COULD SEE A BRIEF PERIOD OF SOME SLEET MIXED IN WITH THE
LIGHT RAIN. HOWEVER... TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT ON SATURDAY MORNING NO
IMPACTS ARE EXPECTED. IN FACT WILL KEEP ANY MENTION OF SLEET OUT OF
THE FORECAST FOR NOW.... AS ANY OCCURRENCE WOULD BE BRIEF AND OF NO
IMPACT. LOW TEMPS SATURDAY MORNING WILL RANGE FROM THE UPPER 30S
SOUTH/SOUTHWEST TO THE LOWER 30S NORTHEAST.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...BSD
SHORT TERM...BSD
LONG TERM...SEC
AVIATION...BSD/KC




000
FXUS62 KRAH 180542
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1240 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...BSD/KC




000
FXUS62 KRAH 180542
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1240 AM EST THU DEC 18 2014

.SYNOPSIS...HIGH PRESSURE OVER THE MISSISSIPPI RIVER VALLEY WILL
EXTEND EASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON THROUGH
FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE TEXAS COAST ON
FRIDAY AND TRACK EAST ALONG THE GULF COAST ON SATURDAY...THEN MOVE
OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1235 AM THURSDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE EXTENDS INTO THE AREA. SCATTERED TO BROKEN MID AND HIGH
CLOUDS WILL CONTINUE TO TRAVERSE THE AREA AS A MID LEVEL DISTURBANCE
APPROACHES THE REGION FROM THE WEST AND MOVES ACROSS THE AREA
TONIGHT.

LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE ON SATURDAY
AFTERNOON AS A STORM SYSTEM IS EXPECTED TO FORM OVER THE TEXAS GULF
COAST LATE FRIDAY...WITH LOW PRESSURE TRACKING EAST ACROSS THE
SOUTHERN GULF STATES SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST
COAST SAT NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS
APPEAR LIKELY FROM SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. VFR
CONDITIONS ARE EXPECTED TO BRIEFLY RETURN FOR SUNDAY... BEFORE
ANOTHER DISTURBANCE LIFTS NORTHEASTWARD OUT OF THE GULF... SPREADING
RAIN INTO CENTRAL NC SUNDAY NIGHT INTO MONDAY... WITH SUB-VFR
CONDITIONS.

&&

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

&&

$$

SYNOPSIS...BSD/VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...BSD/KC





000
FXUS62 KRAH 180348
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1048 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE OVER THE CENTRAL MISSISSIPPI RIVER VALLEY
WILL EXTEND SOUTHEASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE
TEXAS COAST ON FRIDAY AND TRACK EAST ALONG THE GULF COAST ON
SATURDAY...THEN MOVE OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT
INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD




000
FXUS62 KRAH 180348
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1048 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE OVER THE CENTRAL MISSISSIPPI RIVER VALLEY
WILL EXTEND SOUTHEASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE
TEXAS COAST ON FRIDAY AND TRACK EAST ALONG THE GULF COAST ON
SATURDAY...THEN MOVE OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT
INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD





000
FXUS62 KRAH 180348
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1048 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE OVER THE CENTRAL MISSISSIPPI RIVER VALLEY
WILL EXTEND SOUTHEASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE
TEXAS COAST ON FRIDAY AND TRACK EAST ALONG THE GULF COAST ON
SATURDAY...THEN MOVE OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT
INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD





000
FXUS62 KRAH 180348
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1048 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE OVER THE CENTRAL MISSISSIPPI RIVER VALLEY
WILL EXTEND SOUTHEASTWARD INTO THE MID ATLANTIC AND CAROLINAS ON
THURSDAY AND FRIDAY. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE
TEXAS COAST ON FRIDAY AND TRACK EAST ALONG THE GULF COAST ON
SATURDAY...THEN MOVE OFFSHORE THE SOUTHEAST COAST SATURDAY NIGHT
INTO SUNDAY.


&&

.NEAR TERM /OVERNIGHT/...
AS OF 1045 PM WEDNESDAY...

THE LATEST SATELLITE IMAGERY AND RAPID REFRESH MODEL DATA INDICATE
THAT SMALL AMPLITUDE WAVES EMBEDDED IN WESTERLY FLOW ALOFT (IN
CENTRAL/WESTERN TN AT 02Z) WILL TRAVERSE THE REGION OVERNIGHT.
MEANWHILE...A SFC-925 MB TROUGH EXTENDING SOUTHWESTWARD FROM THE MID-
ATLANTIC INTO THE CAROLINAS THIS EVENING WILL SHIFT OFFSHORE THE
SOUTHEAST COAST BY 12Z THU AS 1028 MB HIGH PRESSURE (CENTERED OVER
IL AT 02Z) EXTENDS EAST/SE THROUGH THE OH VALLEY INTO VA/NC. THOUGH
THE LOWER LEVELS WILL REMAIN DRY...MID/UPPER LEVEL MOISTENING (AS
EVIDENCED BY 12/00Z GSO RAOB DATA) WILL PERSIST OVERNIGHT AS
MOISTURE ADVECTS DOWNSTREAM OF PRECIP ASSOC/W A SHORTWAVE TRACKING
EASTWARD FROM THE CENTRAL PLAINS TO THE CENTRAL MS RIVER VALLEY.
THIS WILL DO LITTLE TO ALTER THE DRY/STABLE AIRMASS CURRENTLY IN
PLACE ACROSS THE CAROLINAS...HOWEVER...GIVEN THE DRY ANTECEDENT
AIRMASS CURRENTLY IN PLACE AND THE ABSENCE OF LOW-LEVEL WARM
ADVECTION.

WITH THE ABOVE IN MIND...EXPECT CONTINUED DRY CONDITIONS AND
ABSOLUTELY NO CHANCE FOR PRECIPITATION. GIVEN THE ONGOING/ CONTINUED
INFLUX OF CIRRUS (CEILINGS ~25 KFT) FROM THE WEST...THE PRIMARY
FORECAST CONCERN WILL BE THE `DEGREE` TO WHICH UPPER LEVEL CEILINGS
ATTENUATE RADIATIONAL COOLING...AND THE IMPACT THEREOF ON LOW
TEMPERATURES. WITH TEMPS RANGING FROM THE MID 30S TO LOWER 40S PER
02-03Z OBSERVATIONS...EXPECT OVERNIGHT LOWS IN THE 30S EVERYWHERE...
LOWER 30S WHERE CIRRUS IS LESS OPAQUE/THINNER AND MID 30S WHERE
CIRRUS IS THICKER. CIRRUS...LATIN FOR `CURL`...ARE HIGH ALTITUDE
CLOUDS COMPOSED ENTIRELY OF ICE CRYSTALS WHICH...WHEN PRESENT AT
NIGHT UNDER MOONLIGHT (OPTIMALLY A FULL MOON)...PLAY A KEY ROLE IN
THE FORMATION OF AN OPTICAL PHENOMENON KNOWN AS THE 22 DEGREE HALO
OR `MOON HALO`. MOON HALO ENTHUSIASTS MAY ULTIMATELY BE
DISAPPOINTED...HOWEVER...DUE TO AN ILL-FATED JUXTAPOSITION WITH THE
WANING CRESCENT PHASE IN WHICH <20% OF MOON LIGHT WILL BE PRESENT IN
COMPARISON WITH THAT OF A FULL MOON (CITATION NEEDED). -VINCENT

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD




000
FXUS62 KRAH 172317
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
617 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY
WILL GRADUALLY EXTEND INTO THE REGION TONIGHT AND FRIDAY. A STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN
STRENGTHEN AS IT TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO
SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM WEDNESDAY...

LATEST SURFACE ANALYSIS SHOWS A 1032MB SURFACE HIGH PRESSURE SYSTEM
CENTERED OVER THE UPPER MISSISSIPPI VALLEY THAT EXTENDED INTO MUCH
OF THE SOUTHEAST U.S.. A WEST TO NORTHWEST LOW/MID FLOW BEHIND THE
DEPARTING TROUGH HAS RESULTED IN A WEAK LEE TROUGH OVER THE
FOOTHILLS/WESTERN PIEDMONT OF THE CAROLINAS AND VIRGINIA. LARGE
SCALE SUBSIDENCE HAS RESULTED IN SUNNY SKIES EAST OF THE
MOUNTAINS WITH THE EXCEPTION OF A FEW THIN CIRRUS CLOUDS.

HIGH CLOUDS WILL INCREASE SOMEWHAT OVERNIGHT AS ENERGY LOCATED
ACROSS TX/OK THIS AFTERNOON BEGINS TO LIFT EAST AND SHEARS OUT. NOT
SURE HOW OPAQUE THE CLOUDINESS WILL BE BUT WE SHOULD BE ABLE TO SEE
THE WANING CRESCENT MOON FOR MOST OF THE OVERNIGHT WITH MAINLY
CLEAR SKIES. GUIDANCE TEMPS IN GOOD AGREEMENT AND WILL FORECAST LOWS
IN THE 31 TO 36 RANGE. -BLAES
&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD





000
FXUS62 KRAH 172317
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
617 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY
WILL GRADUALLY EXTEND INTO THE REGION TONIGHT AND FRIDAY. A STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN
STRENGTHEN AS IT TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO
SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM WEDNESDAY...

LATEST SURFACE ANALYSIS SHOWS A 1032MB SURFACE HIGH PRESSURE SYSTEM
CENTERED OVER THE UPPER MISSISSIPPI VALLEY THAT EXTENDED INTO MUCH
OF THE SOUTHEAST U.S.. A WEST TO NORTHWEST LOW/MID FLOW BEHIND THE
DEPARTING TROUGH HAS RESULTED IN A WEAK LEE TROUGH OVER THE
FOOTHILLS/WESTERN PIEDMONT OF THE CAROLINAS AND VIRGINIA. LARGE
SCALE SUBSIDENCE HAS RESULTED IN SUNNY SKIES EAST OF THE
MOUNTAINS WITH THE EXCEPTION OF A FEW THIN CIRRUS CLOUDS.

HIGH CLOUDS WILL INCREASE SOMEWHAT OVERNIGHT AS ENERGY LOCATED
ACROSS TX/OK THIS AFTERNOON BEGINS TO LIFT EAST AND SHEARS OUT. NOT
SURE HOW OPAQUE THE CLOUDINESS WILL BE BUT WE SHOULD BE ABLE TO SEE
THE WANING CRESCENT MOON FOR MOST OF THE OVERNIGHT WITH MAINLY
CLEAR SKIES. GUIDANCE TEMPS IN GOOD AGREEMENT AND WILL FORECAST LOWS
IN THE 31 TO 36 RANGE. -BLAES
&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 615 PM WEDNESDAY...

24-HOUR TAF PERIOD: HIGH CONFIDENCE THAT VFR CONDITIONS AND LIGHT
YET VARIABLE WINDS WILL DOMINATE THE 24 HOUR TAF PERIOD AS HIGH
PRESSURE RIDGES IN. SCATTERED TO BROKEN HIGH CLOUDS WILL CONTINUE TO
MOVE OVER THE AREA FROM THE WEST AND REMAIN IN PLACE THROUGH
THURSDAY. -KC

LOOKING AHEAD: VFR CONDITIONS WILL HOLD THROUGH FRI EVENING WITH
PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS...BUT POOR AVIATION
CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM SYSTEM WILL
FORM OVER THE TEXAS GULF COAST LATE FRIDAY...WITH LOW PRESSURE
STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF STATES
SATURDAY...TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT NIGHT AND
SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY FROM
EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT. RAIN
WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT LEAST
SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD HOLD
THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...KC/HARTFIELD




000
FXUS62 KRAH 171956
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
256 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY
WILL GRADUALLY EXTEND INTO THE REGION TONIGHT AND FRIDAY. A STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN
STRENGTHEN AS IT TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO
SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM WEDNESDAY...

LATEST SURFACE ANALYSIS SHOWS A 1032MB SURFACE HIGH PRESSURE SYSTEM
CENTERED OVER THE UPPER MISSISSIPPI VALLEY THAT EXTENDED INTO MUCH
OF THE SOUTHEAST U.S.. A WEST TO NORTHWEST LOW/MID FLOW BEHIND THE
DEPARTING TROUGH HAS RESULTED IN A WEAK LEE TROUGH OVER THE
FOOTHILLS/WESTERN PIEDMONT OF THE CAROLINAS AND VIRGINIA. LARGE
SCALE SUBSIDENCE HAS RESULTED IN SUNNY SKIES EAST OF THE
MOUNTAINS WITH THE EXCEPTION OF A FEW THIN CIRRUS CLOUDS.

HIGH CLOUDS WILL INCREASE SOMEWHAT OVERNIGHT AS ENERGY LOCATED
ACROSS TX/OK THIS AFTERNOON BEGINS TO LIFT EAST AND SHEARS OUT. NOT
SURE HOW OPAQUE THE CLOUDINESS WILL BE BUT WE SHOULD BE ABLE TO SEE
THE WANNING CRESCENT MOON FOR MOST OF THE OVERNIGHT WITH MAINLY
CLEAR SKIES. GUIDANCE TEMPS IN GOOD AGREEMENT AND WILL FORECAST LOWS
IN THE 31 TO 36 RANGE. -BLAES
&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...

HIGH CONFIDENCE IN FAVORABLE AVIATION CONDITIONS THROUGH THURSDAY...
WITH VFR CONDITIONS DOMINATING AND WEAK LOW LEVEL WINDS. HIGH THIN
CLOUDS NOW OVER THE AREA WILL SLOWLY THICKEN AND LOWER THROUGH
THURSDAY... AS MID LEVEL CLOUDS BEGIN TO SPREAD IN FROM THE WEST...
DUE TO STRONG UPPER LEVEL WINDS FROM NRN MEXICO ACROSS TX AND THE
GULF/SOUTHEAST STATES. BUT CIGS WILL REMAIN VFR THROUGH THE TAF
VALID PERIOD AS SURFACE HIGH PRESSURE EXTENDS OVER THE AREA.

LOOKING BEYOND 18Z THU... VFR CONDITIONS WILL HOLD THROUGH FRI
EVENING WITH PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS... BUT
POOR AVIATION CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM
SYSTEM WILL FORM OVER THE TX GULF COAST LATE FRI... WITH LOW
PRESSURE STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF
STATES SATURDAY... TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT
NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY
FROM EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT.
RAIN WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT
LEAST SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD
HOLD THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...HARTFIELD





000
FXUS62 KRAH 171956
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
256 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY
WILL GRADUALLY EXTEND INTO THE REGION TONIGHT AND FRIDAY. A STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN
STRENGTHEN AS IT TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO
SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM WEDNESDAY...

LATEST SURFACE ANALYSIS SHOWS A 1032MB SURFACE HIGH PRESSURE SYSTEM
CENTERED OVER THE UPPER MISSISSIPPI VALLEY THAT EXTENDED INTO MUCH
OF THE SOUTHEAST U.S.. A WEST TO NORTHWEST LOW/MID FLOW BEHIND THE
DEPARTING TROUGH HAS RESULTED IN A WEAK LEE TROUGH OVER THE
FOOTHILLS/WESTERN PIEDMONT OF THE CAROLINAS AND VIRGINIA. LARGE
SCALE SUBSIDENCE HAS RESULTED IN SUNNY SKIES EAST OF THE
MOUNTAINS WITH THE EXCEPTION OF A FEW THIN CIRRUS CLOUDS.

HIGH CLOUDS WILL INCREASE SOMEWHAT OVERNIGHT AS ENERGY LOCATED
ACROSS TX/OK THIS AFTERNOON BEGINS TO LIFT EAST AND SHEARS OUT. NOT
SURE HOW OPAQUE THE CLOUDINESS WILL BE BUT WE SHOULD BE ABLE TO SEE
THE WANNING CRESCENT MOON FOR MOST OF THE OVERNIGHT WITH MAINLY
CLEAR SKIES. GUIDANCE TEMPS IN GOOD AGREEMENT AND WILL FORECAST LOWS
IN THE 31 TO 36 RANGE. -BLAES
&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 254 PM WEDNESDAY...

SURFACE HIGH PRESSURE ACROSS THE GREAT LAKES WILL EXTEND IN TO THE
AREA... WHILE WE REMAIN UNDER CONFLUENT FLOW ALOFT. A SOUTHERN
STREAM SHORTWAVE OVER THE SOUTHERN PLAINS ON FRIDAY WILL LIFT
NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE NORTHERN GOM LATE FRIDAY.. AND MOVE OFF THE
SOUTHEAST COAST ON SUNDAY. THIS SYSTEM WILL BEGIN TO SPREAD RAIN IN
TO THE REGION BY DAYBREAK SATURDAY... AND RAIN WILL REMAIN ACROSS
THE AREA THROUGH THE EVENING BEFORE TAPERING OFF FROM WEST TO EAST
SUNDAY MORNING. RAIN STILL LOOKS TO BE THE MAIN PRECIP TYPE...
HOWEVER THERE CONTINUES BE THE POSSIBILITY OF FEW WET SNOWFLAKES
MIXING IN ACROSS THE TYPICAL NORTHWEST PIEDMONT AREA. TEMPERATURES
WILL BE BELOW NORMAL ON SATURDAY AND SUNDAY.

WEAK HIGH PRESSURE WILL CONTINUE TO WEDGE INTO THE AREA MONDAY...
AND CLOUDS AND BELOW NORMAL TEMPERATURES WILL CONTINUE WITH LOW
LEVEL NORTHEASTERLY FLOW. MODELS BRING A STRONG SHORTWAVE INTO THE
CENTRAL US ON TUESDAY... AND DIG A DEEP TROUGH ACROSS THE PLAINS AS
FLOW BECOMES HIGHLY AMPLIFIED. AS THIS SYSTEM MOVES EASTWARD...
UNSETTLED CONDITIONS LOOK LIKELY MIDWEEK.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...

HIGH CONFIDENCE IN FAVORABLE AVIATION CONDITIONS THROUGH THURSDAY...
WITH VFR CONDITIONS DOMINATING AND WEAK LOW LEVEL WINDS. HIGH THIN
CLOUDS NOW OVER THE AREA WILL SLOWLY THICKEN AND LOWER THROUGH
THURSDAY... AS MID LEVEL CLOUDS BEGIN TO SPREAD IN FROM THE WEST...
DUE TO STRONG UPPER LEVEL WINDS FROM NRN MEXICO ACROSS TX AND THE
GULF/SOUTHEAST STATES. BUT CIGS WILL REMAIN VFR THROUGH THE TAF
VALID PERIOD AS SURFACE HIGH PRESSURE EXTENDS OVER THE AREA.

LOOKING BEYOND 18Z THU... VFR CONDITIONS WILL HOLD THROUGH FRI
EVENING WITH PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS... BUT
POOR AVIATION CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM
SYSTEM WILL FORM OVER THE TX GULF COAST LATE FRI... WITH LOW
PRESSURE STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF
STATES SATURDAY... TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT
NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY
FROM EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT.
RAIN WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT
LEAST SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD
HOLD THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...SEC
AVIATION...HARTFIELD




000
FXUS62 KRAH 171917
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
215 PM EST WED DEC 17 2014

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY
WILL GRADUALLY EXTEND INTO THE REGION TONIGHT AND FRIDAY. A STORM
SYSTEM WILL DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN
STRENGTHEN AS IT TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO
SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 PM WEDNESDAY...

LATEST SURFACE ANALYSIS SHOWS A 1032MB SURFACE HIGH PRESSURE SYSTEM
CENTERED OVER THE UPPER MISSISSIPPI VALLEY THAT EXTENDED INTO MUCH
OF THE SOUTHEAST U.S.. A WEST TO NORTHWEST LOW/MID FLOW BEHIND THE
DEPARTING TROUGH HAS RESULTED IN A WEAK LEE TROUGH OVER THE
FOOTHILLS/WESTERN PIEDMONT OF THE CAROLINAS AND VIRGINIA. LARGE
SCALE SUBSIDENCE HAS RESULTED IN SUNNY SKIES EAST OF THE
MOUNTAINS WITH THE EXCEPTION OF A FEW THIN CIRRUS CLOUDS.

HIGH CLOUDS WILL INCREASE SOMEWHAT OVERNIGHT AS ENERGY LOCATED
ACROSS TX/OK THIS AFTERNOON BEGINS TO LIFT EAST AND SHEARS OUT. NOT
SURE HOW OPAQUE THE CLOUDINESS WILL BE BUT WE SHOULD BE ABLE TO SEE
THE WANNING CRESCENT MOON FOR MOST OF THE OVERNIGHT WITH MAINLY
CLEAR SKIES. GUIDANCE TEMPS IN GOOD AGREEMENT AND WILL FORECAST LOWS
IN THE 31 TO 36 RANGE. -BLAES
&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 215 PM WEDNESDAY...

MID LEVEL RIDGE AXIS APPROACHES EARLY ON THURSDAY AND GIVES WAY TO A
SOUTHERN STREAM SHORTWAVE TROUGH THAT SLIDES BY ACROSS THE OH VALLEY
AND THE MID ATLANTIC THURSDAY NIGHT. EXPECT FAIR WEATHER DURING THE
PERIOD WITH A FAIRLY THICK VEIL OF HIGH AND ESPECIALLY MID LEVEL
CLOUDINESS. GUIDANCE...ESPECIALLY THE GFS HAS BEEN HINTING AT SOME
LIGHT PRECIP MAKING IT ACROSS THE MOUNTAINS INTO THE WESTERN
PIEDMONT ON THURSDAY. RECENT RUNS HAVE BACKED OFF THIS AND WE EXPECT
A DRY PERIOD AND HAVE LOWERED POPS. WITH A GOOD DEAL OF CLOUD
COVER...HIGHS ON THURSDAY WILL SLOWLY REACH THE 48 TO 55 RANGE. LOOK
FOR LESS VARIABILITY IN LOWS ON THURSDAY NIGHT WITH LINGER MID AND
HIGH CLOUDS...LOWS SHOULD RANGE BETWEEN 32 AND 36 DEGREES. -BLAES
&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 AM WEDNESDAY...

FRIDAY...SFC RIDGE PROJECTED TO EXTEND NW-SE ACROSS THE REGION FROM
A PARENT HIGH (1025MB +/-) OVER THE LOWER OH VALLEY. MEANWHILE
ALOFT...WEAK S/W RIDGE WILL CROSS THE REGION. EXPECT THE DAY TO
START OUT SUNNY/MOSTLY SUNNY BUT SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDINESS LATE IN THE DAY...ESPECIALLY WESTERN PIEDMONT...IN
RESPONSE TO S/W TROUGH AND ATTENDANT SURFACE LOW DEVELOPING WELL TO
OUR SW. LOW LEVEL THICKNESSES CLOSE TO NORMAL WHICH SUGGEST HIGH
TEMPS AROUND 50 NORTH TO LOW-MID 50S SOUTH.

FRIDAY NIGHT...CLOUDS WILL CONTINUE TO THICKEN/LOWER THROUGH THE
NIGHT. ENOUGH ISENTROPIC UPGLIDE EXISTS SHORTLY BEFORE DAYBREAK TO
INCLUDE A MENTION OF SPOTTY LIGHT RAIN OVER THE SW TWO-THIRDS OF THE
CWA. PARTIAL THICKNESSES HOVERING IN VICINITY OF THE RAIN/FREEZING
SECTOR OF THE WINTER P-TYPE NOMOGRAM OVER THE NW PIEDMONT.
HOWEVER...MODEL GUIDANCE HAD BEEN TRENDING WARMER AND THE FREEZING
LEVEL FAIRLY ELEVATED (6000-8000FT). WHILE SATURATION AND
SIGNIFICANT LIFT NOTED IN THE FAVORED ICE NUCLEATION REGION OF THE
ATMOSPHERE...LOW LEVEL AIR MASS CURRENTLY APPEARS TOO WARM FOR ANY
WINTER P-TYPE AT THE ONSET OF THE PRECIP. WORSE CASE SCENARIO WOULD
BE SOME WET SNOWFLAKES MIXING WITH THE RAIN WHEN THE PRECIP RATES
ARE MODERATE/BRIEFLY HEAVY. MIN TEMPS GENERALLY MID 30S.

SATURDAY...SFC DRY AIR RIDGE AND PARENT HIGH IN FAVORABLE LOCATION
TO SUPPORT A COLD AIR DAMMING EVENT SATURDAY. THE NEAR SURFACE NE
FLOW WILL ADVECT A COOL AIR MASS INTO OUR REGION. MEANWHILE 850-
700MB FLOW WILL PULL WARM GULF MOISTURE OVER THE COOL STABLE NEAR
SURFACE AIR MASS RESULTING IN WIDESPREAD RAIN. LIFT APPEARS BEST IN
THE MORNING THROUGH EARLY AFTERNOON WITH LIFT WANING IN THE WEST BY
MID AFTERNOON. THE COOL SFC AIR MASS COMPOUNDED BY THE RAIN WILL
HOLD TEMPS AT OR BELOW 40 DEGREES ACROSS THE NW PIEDMONT...AND IN
THE 40S PRETTY MUCH ELSEWHERE.

SATURDAY NIGHT...AREAS OF RAIN WILL GRADUALLY TAPER TO SPOTTY LIGHT
RAIN WITH AREAS OF DRIZZLE AS MAIN LIFT MOVES AWAY FROM OUR REGION
AS S/W DAMPENS TO OUR EAST. LOW LEVEL AIR MASS EXPECTED TO REMAIN
NEARLY SATURATED SO WILL LIKELY KEEP LOW CLOUDS ALL NIGHT. MIN TEMPS
MID-UPPER 30S.

SUNDAY THROUGH TUESDAY...L/W TROUGH TO OUR WEST AMPLIFIES THIS
PERIOD AS A SUBSTANTIAL S/W DIGS ON THE BACK SIDE OF THE TROUGH.
THIS WILL MAINTAIN A SW FLOW ALOFT OVER CENTRAL NC. WITH A LACK OF A
MECHANISM TO SCOUR OUR THE CAD AIR MASS AND CONTINUED SW FLOW
ALOFT...COULD SEE A SET UP FOR A PERIOD OF CLOUDINESS SUNDAY THROUGH
TUESDAY ACROSS CENTRAL CN WITH PATCHES OF LIGHT RAIN AND/OR DRIZZLE
SUNDAY AND POSSIBLY INTO MONDAY. MAY SEE SOME IMPROVEMENT LATE
MONDAY INTO TUESDAY THOUGH MAY BE TRADING IN LOW CLOUDS FOR A DECK
OF MID-HIGH LEVEL CLOUDS. OVERALL EXPECT MORE CLOUDS THAN SUN THIS
PERIOD. HIGH TEMPS WILL AVERAGE 3-5 DEGREES BELOW NORMAL WHILE MIN
TEMPS WILL AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL (TYPICAL FOR CLOUDY
CONDITIONS).

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...

HIGH CONFIDENCE IN FAVORABLE AVIATION CONDITIONS THROUGH THURSDAY...
WITH VFR CONDITIONS DOMINATING AND WEAK LOW LEVEL WINDS. HIGH THIN
CLOUDS NOW OVER THE AREA WILL SLOWLY THICKEN AND LOWER THROUGH
THURSDAY... AS MID LEVEL CLOUDS BEGIN TO SPREAD IN FROM THE WEST...
DUE TO STRONG UPPER LEVEL WINDS FROM NRN MEXICO ACROSS TX AND THE
GULF/SOUTHEAST STATES. BUT CIGS WILL REMAIN VFR THROUGH THE TAF
VALID PERIOD AS SURFACE HIGH PRESSURE EXTENDS OVER THE AREA.

LOOKING BEYOND 18Z THU... VFR CONDITIONS WILL HOLD THROUGH FRI
EVENING WITH PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS... BUT
POOR AVIATION CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM
SYSTEM WILL FORM OVER THE TX GULF COAST LATE FRI... WITH LOW
PRESSURE STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF
STATES SATURDAY... TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT
NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY
FROM EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT.
RAIN WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT
LEAST SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD
HOLD THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...WSS
AVIATION...HARTFIELD




000
FXUS62 KRAH 171815
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
115 PM EST WED DEC 17 2014

.SYNOPSIS...WEAK HIGH PRESSURE WILL AND SETTLE OVER THE AREA FROM
THE WEST TONIGHT THROUGH FRIDAY. A STORM SYSTEM WILL DEVELOP OVER
THE TEXAS GULF COAST FRIDAY... THEN STRENGTHEN AS IT TRACKS ACROSS
THE SOUTHEAST STATES SATURDAY INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM WEDNESDAY...

GOING FORECAST IS IN GOOD SHAPE. LATEST SURFACE MAP SHOWS A CYCLONIC
FLOW AROUND A DOUBLE-BARREL LOW PRESSURE PAIR OVER THE NORTHEAST
STATES. OBSERVED SOUNDINGS EAST OF THE MOUNTAINS ARE FAIRLY DRY...
AS THE LOW LEVEL MOISTURE IS HELD BANKED-UP WEST OF THE MOUNTAINS...
ALTHOUGH WE WILL BE SEEING INCREASING THIN HIGH-LEVEL CLOUDINESS
THROUGH THE DAY... A FUNCTION OF A STRONG (130+ KT) SUBTROPICAL JET
OVER NRN MEXICO AND TX/OK/AR... YIELDING FAIR SKIES. TEMPERATURES
ARE PACING JUST SLIGHTLY WARMER THAN THE FORECAST PACE... SO HAVE
NUDGED HIGHS UP JUST A TAD... TO 55-60. -GIH

AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST US WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD WILL
SPREAD EAST INTO THE AREA THIS EVENING AND OVERNIGHT WHICH SHOULD
TEMPER MIN TEMPS A BIT. MOST AREA SHOULD BOTTOM OUT IN THE MID
30S...WITH SOME LOWER 30S IN SOME OUTLYING AREAS. -CBL

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 223 AM WEDNESDAY...

WEAK SHORTWAVE DISTURBANCES EMBEDDED IN THE VIGOROUS PACIFIC JET
BRANCH THAT EXTENDS ACROSS THE SOUTHERN CONUS WILL RESULT IN AN
EXTENSIVE CIRRUS SHIELD ACROSS THE AREA ON THURSDAY...AT LEAST
THROUGH THE FIRST HALF OF THE DAY. THE GFS OVER THE PAST COUPLE OF
DAYS HAS BEEN INSISTENT IN SPREADING A HUNDREDTH OR TWO OR QPF ACROSS
THE NORTH/NORTHWEST PIEDMONT IN PROXIMITY TO THE WEAK DPVA/UPPER
DIVERGENCE REGION...HOWEVER A DEEP DRY SUB-CLOUD LAYER ASSOCIATED
WITH THE DRY AIR SURFACE RIDGE EXTENDING INTO THE AREA FROM THE
NORTHWEST SHOULD PRECLUDE ANY SPRINKLES FROM REACHING THE GROUND AND
THUS WILL KEEP FORECAST DRY. TEMPERATURES WILL INITIALLY STRUGGLE TO
WARM UNDERNEATH THE MILKY SKIES...WITH A GOOD CHANCE THAT TEMPS MAY
NOT HAVE ENOUGH TIME TO FULLY RECOVER AS WE APPROACH THE SHORTEST
DAY OF THE YEAR(DEC 21). AS SUCH...HIGHS THURSDAY SEVERAL DEGREES
COOLER THAN TODAY...RANGING FROM UPPER 40S NORTH TO MID 50S SOUTH.
SKIES SHOULD REMAIN MOSTLY CLEAR THURSDAY NIGHT WITH LOWS IN THE
LOWER TO MID 30S.


&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 AM WEDNESDAY...

FRIDAY...SFC RIDGE PROJECTED TO EXTEND NW-SE ACROSS THE REGION FROM
A PARENT HIGH (1025MB +/-) OVER THE LOWER OH VALLEY. MEANWHILE
ALOFT...WEAK S/W RIDGE WILL CROSS THE REGION. EXPECT THE DAY TO
START OUT SUNNY/MOSTLY SUNNY BUT SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDINESS LATE IN THE DAY...ESPECIALLY WESTERN PIEDMONT...IN
RESPONSE TO S/W TROUGH AND ATTENDANT SURFACE LOW DEVELOPING WELL TO
OUR SW. LOW LEVEL THICKNESSES CLOSE TO NORMAL WHICH SUGGEST HIGH
TEMPS AROUND 50 NORTH TO LOW-MID 50S SOUTH.

FRIDAY NIGHT...CLOUDS WILL CONTINUE TO THICKEN/LOWER THROUGH THE
NIGHT. ENOUGH ISENTROPIC UPGLIDE EXISTS SHORTLY BEFORE DAYBREAK TO
INCLUDE A MENTION OF SPOTTY LIGHT RAIN OVER THE SW TWO-THIRDS OF THE
CWA. PARTIAL THICKNESSES HOVERING IN VICINITY OF THE RAIN/FREEZING
SECTOR OF THE WINTER P-TYPE NOMOGRAM OVER THE NW PIEDMONT.
HOWEVER...MODEL GUIDANCE HAD BEEN TRENDING WARMER AND THE FREEZING
LEVEL FAIRLY ELEVATED (6000-8000FT). WHILE SATURATION AND
SIGNIFICANT LIFT NOTED IN THE FAVORED ICE NUCLEATION REGION OF THE
ATMOSPHERE...LOW LEVEL AIR MASS CURRENTLY APPEARS TOO WARM FOR ANY
WINTER P-TYPE AT THE ONSET OF THE PRECIP. WORSE CASE SCENARIO WOULD
BE SOME WET SNOWFLAKES MIXING WITH THE RAIN WHEN THE PRECIP RATES
ARE MODERATE/BRIEFLY HEAVY. MIN TEMPS GENERALLY MID 30S.

SATURDAY...SFC DRY AIR RIDGE AND PARENT HIGH IN FAVORABLE LOCATION
TO SUPPORT A COLD AIR DAMMING EVENT SATURDAY. THE NEAR SURFACE NE
FLOW WILL ADVECT A COOL AIR MASS INTO OUR REGION. MEANWHILE 850-
700MB FLOW WILL PULL WARM GULF MOISTURE OVER THE COOL STABLE NEAR
SURFACE AIR MASS RESULTING IN WIDESPREAD RAIN. LIFT APPEARS BEST IN
THE MORNING THROUGH EARLY AFTERNOON WITH LIFT WANING IN THE WEST BY
MID AFTERNOON. THE COOL SFC AIR MASS COMPOUNDED BY THE RAIN WILL
HOLD TEMPS AT OR BELOW 40 DEGREES ACROSS THE NW PIEDMONT...AND IN
THE 40S PRETTY MUCH ELSEWHERE.

SATURDAY NIGHT...AREAS OF RAIN WILL GRADUALLY TAPER TO SPOTTY LIGHT
RAIN WITH AREAS OF DRIZZLE AS MAIN LIFT MOVES AWAY FROM OUR REGION
AS S/W DAMPENS TO OUR EAST. LOW LEVEL AIR MASS EXPECTED TO REMAIN
NEARLY SATURATED SO WILL LIKELY KEEP LOW CLOUDS ALL NIGHT. MIN TEMPS
MID-UPPER 30S.

SUNDAY THROUGH TUESDAY...L/W TROUGH TO OUR WEST AMPLIFIES THIS
PERIOD AS A SUBSTANTIAL S/W DIGS ON THE BACK SIDE OF THE TROUGH.
THIS WILL MAINTAIN A SW FLOW ALOFT OVER CENTRAL NC. WITH A LACK OF A
MECHANISM TO SCOUR OUR THE CAD AIR MASS AND CONTINUED SW FLOW
ALOFT...COULD SEE A SET UP FOR A PERIOD OF CLOUDINESS SUNDAY THROUGH
TUESDAY ACROSS CENTRAL CN WITH PATCHES OF LIGHT RAIN AND/OR DRIZZLE
SUNDAY AND POSSIBLY INTO MONDAY. MAY SEE SOME IMPROVEMENT LATE
MONDAY INTO TUESDAY THOUGH MAY BE TRADING IN LOW CLOUDS FOR A DECK
OF MID-HIGH LEVEL CLOUDS. OVERALL EXPECT MORE CLOUDS THAN SUN THIS
PERIOD. HIGH TEMPS WILL AVERAGE 3-5 DEGREES BELOW NORMAL WHILE MIN
TEMPS WILL AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL (TYPICAL FOR CLOUDY
CONDITIONS).

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...

HIGH CONFIDENCE IN FAVORABLE AVIATION CONDITIONS THROUGH THURSDAY...
WITH VFR CONDITIONS DOMINATING AND WEAK LOW LEVEL WINDS. HIGH THIN
CLOUDS NOW OVER THE AREA WILL SLOWLY THICKEN AND LOWER THROUGH
THURSDAY... AS MID LEVEL CLOUDS BEGIN TO SPREAD IN FROM THE WEST...
DUE TO STRONG UPPER LEVEL WINDS FROM NRN MEXICO ACROSS TX AND THE
GULF/SOUTHEAST STATES. BUT CIGS WILL REMAIN VFR THROUGH THE TAF
VALID PERIOD AS SURFACE HIGH PRESSURE EXTENDS OVER THE AREA.

LOOKING BEYOND 18Z THU... VFR CONDITIONS WILL HOLD THROUGH FRI
EVENING WITH PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS... BUT
POOR AVIATION CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM
SYSTEM WILL FORM OVER THE TX GULF COAST LATE FRI... WITH LOW
PRESSURE STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF
STATES SATURDAY... TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT
NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY
FROM EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT.
RAIN WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT
LEAST SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD
HOLD THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...WSS
AVIATION...HARTFIELD





000
FXUS62 KRAH 171815
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
115 PM EST WED DEC 17 2014

.SYNOPSIS...WEAK HIGH PRESSURE WILL AND SETTLE OVER THE AREA FROM
THE WEST TONIGHT THROUGH FRIDAY. A STORM SYSTEM WILL DEVELOP OVER
THE TEXAS GULF COAST FRIDAY... THEN STRENGTHEN AS IT TRACKS ACROSS
THE SOUTHEAST STATES SATURDAY INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM WEDNESDAY...

GOING FORECAST IS IN GOOD SHAPE. LATEST SURFACE MAP SHOWS A CYCLONIC
FLOW AROUND A DOUBLE-BARREL LOW PRESSURE PAIR OVER THE NORTHEAST
STATES. OBSERVED SOUNDINGS EAST OF THE MOUNTAINS ARE FAIRLY DRY...
AS THE LOW LEVEL MOISTURE IS HELD BANKED-UP WEST OF THE MOUNTAINS...
ALTHOUGH WE WILL BE SEEING INCREASING THIN HIGH-LEVEL CLOUDINESS
THROUGH THE DAY... A FUNCTION OF A STRONG (130+ KT) SUBTROPICAL JET
OVER NRN MEXICO AND TX/OK/AR... YIELDING FAIR SKIES. TEMPERATURES
ARE PACING JUST SLIGHTLY WARMER THAN THE FORECAST PACE... SO HAVE
NUDGED HIGHS UP JUST A TAD... TO 55-60. -GIH

AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST US WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD WILL
SPREAD EAST INTO THE AREA THIS EVENING AND OVERNIGHT WHICH SHOULD
TEMPER MIN TEMPS A BIT. MOST AREA SHOULD BOTTOM OUT IN THE MID
30S...WITH SOME LOWER 30S IN SOME OUTLYING AREAS. -CBL

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 223 AM WEDNESDAY...

WEAK SHORTWAVE DISTURBANCES EMBEDDED IN THE VIGOROUS PACIFIC JET
BRANCH THAT EXTENDS ACROSS THE SOUTHERN CONUS WILL RESULT IN AN
EXTENSIVE CIRRUS SHIELD ACROSS THE AREA ON THURSDAY...AT LEAST
THROUGH THE FIRST HALF OF THE DAY. THE GFS OVER THE PAST COUPLE OF
DAYS HAS BEEN INSISTENT IN SPREADING A HUNDREDTH OR TWO OR QPF ACROSS
THE NORTH/NORTHWEST PIEDMONT IN PROXIMITY TO THE WEAK DPVA/UPPER
DIVERGENCE REGION...HOWEVER A DEEP DRY SUB-CLOUD LAYER ASSOCIATED
WITH THE DRY AIR SURFACE RIDGE EXTENDING INTO THE AREA FROM THE
NORTHWEST SHOULD PRECLUDE ANY SPRINKLES FROM REACHING THE GROUND AND
THUS WILL KEEP FORECAST DRY. TEMPERATURES WILL INITIALLY STRUGGLE TO
WARM UNDERNEATH THE MILKY SKIES...WITH A GOOD CHANCE THAT TEMPS MAY
NOT HAVE ENOUGH TIME TO FULLY RECOVER AS WE APPROACH THE SHORTEST
DAY OF THE YEAR(DEC 21). AS SUCH...HIGHS THURSDAY SEVERAL DEGREES
COOLER THAN TODAY...RANGING FROM UPPER 40S NORTH TO MID 50S SOUTH.
SKIES SHOULD REMAIN MOSTLY CLEAR THURSDAY NIGHT WITH LOWS IN THE
LOWER TO MID 30S.


&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 AM WEDNESDAY...

FRIDAY...SFC RIDGE PROJECTED TO EXTEND NW-SE ACROSS THE REGION FROM
A PARENT HIGH (1025MB +/-) OVER THE LOWER OH VALLEY. MEANWHILE
ALOFT...WEAK S/W RIDGE WILL CROSS THE REGION. EXPECT THE DAY TO
START OUT SUNNY/MOSTLY SUNNY BUT SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDINESS LATE IN THE DAY...ESPECIALLY WESTERN PIEDMONT...IN
RESPONSE TO S/W TROUGH AND ATTENDANT SURFACE LOW DEVELOPING WELL TO
OUR SW. LOW LEVEL THICKNESSES CLOSE TO NORMAL WHICH SUGGEST HIGH
TEMPS AROUND 50 NORTH TO LOW-MID 50S SOUTH.

FRIDAY NIGHT...CLOUDS WILL CONTINUE TO THICKEN/LOWER THROUGH THE
NIGHT. ENOUGH ISENTROPIC UPGLIDE EXISTS SHORTLY BEFORE DAYBREAK TO
INCLUDE A MENTION OF SPOTTY LIGHT RAIN OVER THE SW TWO-THIRDS OF THE
CWA. PARTIAL THICKNESSES HOVERING IN VICINITY OF THE RAIN/FREEZING
SECTOR OF THE WINTER P-TYPE NOMOGRAM OVER THE NW PIEDMONT.
HOWEVER...MODEL GUIDANCE HAD BEEN TRENDING WARMER AND THE FREEZING
LEVEL FAIRLY ELEVATED (6000-8000FT). WHILE SATURATION AND
SIGNIFICANT LIFT NOTED IN THE FAVORED ICE NUCLEATION REGION OF THE
ATMOSPHERE...LOW LEVEL AIR MASS CURRENTLY APPEARS TOO WARM FOR ANY
WINTER P-TYPE AT THE ONSET OF THE PRECIP. WORSE CASE SCENARIO WOULD
BE SOME WET SNOWFLAKES MIXING WITH THE RAIN WHEN THE PRECIP RATES
ARE MODERATE/BRIEFLY HEAVY. MIN TEMPS GENERALLY MID 30S.

SATURDAY...SFC DRY AIR RIDGE AND PARENT HIGH IN FAVORABLE LOCATION
TO SUPPORT A COLD AIR DAMMING EVENT SATURDAY. THE NEAR SURFACE NE
FLOW WILL ADVECT A COOL AIR MASS INTO OUR REGION. MEANWHILE 850-
700MB FLOW WILL PULL WARM GULF MOISTURE OVER THE COOL STABLE NEAR
SURFACE AIR MASS RESULTING IN WIDESPREAD RAIN. LIFT APPEARS BEST IN
THE MORNING THROUGH EARLY AFTERNOON WITH LIFT WANING IN THE WEST BY
MID AFTERNOON. THE COOL SFC AIR MASS COMPOUNDED BY THE RAIN WILL
HOLD TEMPS AT OR BELOW 40 DEGREES ACROSS THE NW PIEDMONT...AND IN
THE 40S PRETTY MUCH ELSEWHERE.

SATURDAY NIGHT...AREAS OF RAIN WILL GRADUALLY TAPER TO SPOTTY LIGHT
RAIN WITH AREAS OF DRIZZLE AS MAIN LIFT MOVES AWAY FROM OUR REGION
AS S/W DAMPENS TO OUR EAST. LOW LEVEL AIR MASS EXPECTED TO REMAIN
NEARLY SATURATED SO WILL LIKELY KEEP LOW CLOUDS ALL NIGHT. MIN TEMPS
MID-UPPER 30S.

SUNDAY THROUGH TUESDAY...L/W TROUGH TO OUR WEST AMPLIFIES THIS
PERIOD AS A SUBSTANTIAL S/W DIGS ON THE BACK SIDE OF THE TROUGH.
THIS WILL MAINTAIN A SW FLOW ALOFT OVER CENTRAL NC. WITH A LACK OF A
MECHANISM TO SCOUR OUR THE CAD AIR MASS AND CONTINUED SW FLOW
ALOFT...COULD SEE A SET UP FOR A PERIOD OF CLOUDINESS SUNDAY THROUGH
TUESDAY ACROSS CENTRAL CN WITH PATCHES OF LIGHT RAIN AND/OR DRIZZLE
SUNDAY AND POSSIBLY INTO MONDAY. MAY SEE SOME IMPROVEMENT LATE
MONDAY INTO TUESDAY THOUGH MAY BE TRADING IN LOW CLOUDS FOR A DECK
OF MID-HIGH LEVEL CLOUDS. OVERALL EXPECT MORE CLOUDS THAN SUN THIS
PERIOD. HIGH TEMPS WILL AVERAGE 3-5 DEGREES BELOW NORMAL WHILE MIN
TEMPS WILL AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL (TYPICAL FOR CLOUDY
CONDITIONS).

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...

HIGH CONFIDENCE IN FAVORABLE AVIATION CONDITIONS THROUGH THURSDAY...
WITH VFR CONDITIONS DOMINATING AND WEAK LOW LEVEL WINDS. HIGH THIN
CLOUDS NOW OVER THE AREA WILL SLOWLY THICKEN AND LOWER THROUGH
THURSDAY... AS MID LEVEL CLOUDS BEGIN TO SPREAD IN FROM THE WEST...
DUE TO STRONG UPPER LEVEL WINDS FROM NRN MEXICO ACROSS TX AND THE
GULF/SOUTHEAST STATES. BUT CIGS WILL REMAIN VFR THROUGH THE TAF
VALID PERIOD AS SURFACE HIGH PRESSURE EXTENDS OVER THE AREA.

LOOKING BEYOND 18Z THU... VFR CONDITIONS WILL HOLD THROUGH FRI
EVENING WITH PERIODS OF MID AND HIGH CLOUDS AND VFR VSBYS... BUT
POOR AVIATION CONDITIONS ARE EXPECTED FROM SAT THROUGH MON. A STORM
SYSTEM WILL FORM OVER THE TX GULF COAST LATE FRI... WITH LOW
PRESSURE STRENGTHENING AS IT TRACKS EAST ACROSS THE SOUTHERN GULF
STATES SATURDAY... TO ALONG OR JUST OFF THE SOUTHEAST COAST SAT
NIGHT AND SUN. WIDESPREAD RAIN WITH SUB-VFR CONDITIONS APPEAR LIKELY
FROM EARLY SAT MORNING (POTENTIALLY BEFORE DAYBREAK) THROUGH SAT.
RAIN WILL TAPER TO PATCHY LIGHT DRIZZLE FOR SAT NIGHT THROUGH AT
LEAST SUN NIGHT WITH SUB-VFR CONDITIONS PERSISTING. LOW CIGS COULD
HOLD THROUGH MON AS WELL. -GIH

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...WSS
AVIATION...HARTFIELD




000
FXUS62 KRAH 171502
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1000 AM EST WED DEC 17 2014

.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...
AND SETTLE OVER THE AREA THURSDAY AND FRIDAY. A STORM SYSTEM WILL
DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN STRENGTHEN AS IT
TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM WEDNESDAY...

GOING FORECAST IS IN GOOD SHAPE. LATEST SURFACE MAP SHOWS A CYCLONIC
FLOW AROUND A DOUBLE-BARREL LOW PRESSURE PAIR OVER THE NORTHEAST
STATES. OBSERVED SOUNDINGS EAST OF THE MOUNTAINS ARE FAIRLY DRY...
AS THE LOW LEVEL MOISTURE IS HELD BANKED-UP WEST OF THE MOUNTAINS...
ALTHOUGH WE WILL BE SEEING INCREASING THIN HIGH-LEVEL CLOUDINESS
THROUGH THE DAY... A FUNCTION OF A STRONG (130+ KT) SUBTROPICAL JET
OVER NRN MEXICO AND TX/OK/AR... YIELDING FAIR SKIES. TEMPERATURES
ARE PACING JUST SLIGHTLY WARMER THAN THE FORECAST PACE... SO HAVE
NUDGED HIGHS UP JUST A TAD... TO 55-60. -GIH

AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST US WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD WILL
SPREAD EAST INTO THE AREA THIS EVENING AND OVERNIGHT WHICH SHOULD
TEMPER MIN TEMPS A BIT. MOST AREA SHOULD BOTTOM OUT IN THE MID
30S...WITH SOME LOWER 30S IN SOME OUTLYING AREAS. -CBL

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 223 AM WEDNESDAY...

WEAK SHORTWAVE DISTURBANCES EMBEDDED IN THE VIGOROUS PACIFIC JET
BRANCH THAT EXTENDS ACROSS THE SOUTHERN CONUS WILL RESULT IN AN
EXTENSIVE CIRRUS SHIELD ACROSS THE AREA ON THURSDAY...AT LEAST
THROUGH THE FIRST HALF OF THE DAY. THE GFS OVER THE PAST COUPLE OF
DAYS HAS BEEN INSISTENT IN SPREADING A HUNDREDTH OR TWO OR QPF ACROSS
THE NORTH/NORTHWEST PIEDMONT IN PROXIMITY TO THE WEAK DPVA/UPPER
DIVERGENCE REGION...HOWEVER A DEEP DRY SUB-CLOUD LAYER ASSOCIATED
WITH THE DRY AIR SURFACE RIDGE EXTENDING INTO THE AREA FROM THE
NORTHWEST SHOULD PRECLUDE ANY SPRINKLES FROM REACHING THE GROUND AND
THUS WILL KEEP FORECAST DRY. TEMPERATURES WILL INITIALLY STRUGGLE TO
WARM UNDERNEATH THE MILKY SKIES...WITH A GOOD CHANCE THAT TEMPS MAY
NOT HAVE ENOUGH TIME TO FULLY RECOVER AS WE APPROACH THE SHORTEST
DAY OF THE YEAR(DEC 21). AS SUCH...HIGHS THURSDAY SEVERAL DEGREES
COOLER THAN TODAY...RANGING FROM UPPER 40S NORTH TO MID 50S SOUTH.
SKIES SHOULD REMAIN MOSTLY CLEAR THURSDAY NIGHT WITH LOWS IN THE
LOWER TO MID 30S.


&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 AM WEDNESDAY...

FRIDAY...SFC RIDGE PROJECTED TO EXTEND NW-SE ACROSS THE REGION FROM
A PARENT HIGH (1025MB +/-) OVER THE LOWER OH VALLEY. MEANWHILE
ALOFT...WEAK S/W RIDGE WILL CROSS THE REGION. EXPECT THE DAY TO
START OUT SUNNY/MOSTLY SUNNY BUT SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDINESS LATE IN THE DAY...ESPECIALLY WESTERN PIEDMONT...IN
RESPONSE TO S/W TROUGH AND ATTENDANT SURFACE LOW DEVELOPING WELL TO
OUR SW. LOW LEVEL THICKNESSES CLOSE TO NORMAL WHICH SUGGEST HIGH
TEMPS AROUND 50 NORTH TO LOW-MID 50S SOUTH.

FRIDAY NIGHT...CLOUDS WILL CONTINUE TO THICKEN/LOWER THROUGH THE
NIGHT. ENOUGH ISENTROPIC UPGLIDE EXISTS SHORTLY BEFORE DAYBREAK TO
INCLUDE A MENTION OF SPOTTY LIGHT RAIN OVER THE SW TWO-THIRDS OF THE
CWA. PARTIAL THICKNESSES HOVERING IN VICINITY OF THE RAIN/FREEZING
SECTOR OF THE WINTER P-TYPE NOMOGRAM OVER THE NW PIEDMONT.
HOWEVER...MODEL GUIDANCE HAD BEEN TRENDING WARMER AND THE FREEZING
LEVEL FAIRLY ELEVATED (6000-8000FT). WHILE SATURATION AND
SIGNIFICANT LIFT NOTED IN THE FAVORED ICE NUCLEATION REGION OF THE
ATMOSPHERE...LOW LEVEL AIR MASS CURRENTLY APPEARS TOO WARM FOR ANY
WINTER P-TYPE AT THE ONSET OF THE PRECIP. WORSE CASE SCENARIO WOULD
BE SOME WET SNOWFLAKES MIXING WITH THE RAIN WHEN THE PRECIP RATES
ARE MODERATE/BRIEFLY HEAVY. MIN TEMPS GENERALLY MID 30S.

SATURDAY...SFC DRY AIR RIDGE AND PARENT HIGH IN FAVORABLE LOCATION
TO SUPPORT A COLD AIR DAMMING EVENT SATURDAY. THE NEAR SURFACE NE
FLOW WILL ADVECT A COOL AIR MASS INTO OUR REGION. MEANWHILE 850-
700MB FLOW WILL PULL WARM GULF MOISTURE OVER THE COOL STABLE NEAR
SURFACE AIR MASS RESULTING IN WIDESPREAD RAIN. LIFT APPEARS BEST IN
THE MORNING THROUGH EARLY AFTERNOON WITH LIFT WANING IN THE WEST BY
MID AFTERNOON. THE COOL SFC AIR MASS COMPOUNDED BY THE RAIN WILL
HOLD TEMPS AT OR BELOW 40 DEGREES ACROSS THE NW PIEDMONT...AND IN
THE 40S PRETTY MUCH ELSEWHERE.

SATURDAY NIGHT...AREAS OF RAIN WILL GRADUALLY TAPER TO SPOTTY LIGHT
RAIN WITH AREAS OF DRIZZLE AS MAIN LIFT MOVES AWAY FROM OUR REGION
AS S/W DAMPENS TO OUR EAST. LOW LEVEL AIR MASS EXPECTED TO REMAIN
NEARLY SATURATED SO WILL LIKELY KEEP LOW CLOUDS ALL NIGHT. MIN TEMPS
MID-UPPER 30S.

SUNDAY THROUGH TUESDAY...L/W TROUGH TO OUR WEST AMPLIFIES THIS
PERIOD AS A SUBSTANTIAL S/W DIGS ON THE BACK SIDE OF THE TROUGH.
THIS WILL MAINTAIN A SW FLOW ALOFT OVER CENTRAL NC. WITH A LACK OF A
MECHANISM TO SCOUR OUR THE CAD AIR MASS AND CONTINUED SW FLOW
ALOFT...COULD SEE A SET UP FOR A PERIOD OF CLOUDINESS SUNDAY THROUGH
TUESDAY ACROSS CENTRAL CN WITH PATCHES OF LIGHT RAIN AND/OR DRIZZLE
SUNDAY AND POSSIBLY INTO MONDAY. MAY SEE SOME IMPROVEMENT LATE
MONDAY INTO TUESDAY THOUGH MAY BE TRADING IN LOW CLOUDS FOR A DECK
OF MID-HIGH LEVEL CLOUDS. OVERALL EXPECT MORE CLOUDS THAN SUN THIS
PERIOD. HIGH TEMPS WILL AVERAGE 3-5 DEGREES BELOW NORMAL WHILE MIN
TEMPS WILL AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL (TYPICAL FOR CLOUDY
CONDITIONS).

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 610 AM WEDNESDAY...

24-HR TAF PERIOD: THERE IS HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE
24 TAF PERIOD AS WEAK HIGH PRESSURE EXTEND INTO THE AREA WITH
A LIGHT WEST-NORTHWEST BREEZE.


LOOKING AHEAD: SHORTWAVE DISTURBANCES EMBEDDED WITHIN THE VIGOROUS
PACIFIC JET THAT EXTENDS ACROSS THE SOUTHERN CONUS MAY RESULT IN
PERIODS OF BROKEN/OVERCAST MID/HIGH CLOUD DECK. OTHERWISE...A DRY
AIR SURFACE RIDGE EXTENDING INTO THE CAROLINAS FROM THE
NORTH/NORTHWEST WILL SECURE VFR CONDITIONS THROUGH 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...HARTFIELD
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...WSS
AVIATION...CBL





000
FXUS62 KRAH 171502
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1000 AM EST WED DEC 17 2014

.SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...
AND SETTLE OVER THE AREA THURSDAY AND FRIDAY. A STORM SYSTEM WILL
DEVELOP OVER THE TEXAS GULF COAST FRIDAY... THEN STRENGTHEN AS IT
TRACKS ACROSS THE SOUTHEAST STATES SATURDAY INTO SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM WEDNESDAY...

GOING FORECAST IS IN GOOD SHAPE. LATEST SURFACE MAP SHOWS A CYCLONIC
FLOW AROUND A DOUBLE-BARREL LOW PRESSURE PAIR OVER THE NORTHEAST
STATES. OBSERVED SOUNDINGS EAST OF THE MOUNTAINS ARE FAIRLY DRY...
AS THE LOW LEVEL MOISTURE IS HELD BANKED-UP WEST OF THE MOUNTAINS...
ALTHOUGH WE WILL BE SEEING INCREASING THIN HIGH-LEVEL CLOUDINESS
THROUGH THE DAY... A FUNCTION OF A STRONG (130+ KT) SUBTROPICAL JET
OVER NRN MEXICO AND TX/OK/AR... YIELDING FAIR SKIES. TEMPERATURES
ARE PACING JUST SLIGHTLY WARMER THAN THE FORECAST PACE... SO HAVE
NUDGED HIGHS UP JUST A TAD... TO 55-60. -GIH

AN ACTIVE PACIFIC WAVE TRAIN MOVING ONSHORE ACROSS CALIFORNIA AND
THEN THROUGH THE SOUTHWEST US WILL REINVIGORATE THE PACIFIC JET THAT
EXTENDS ACROSS THE SOUTHERN CONUS. AN OPAQUE CIRRUS SHIELD WILL
SPREAD EAST INTO THE AREA THIS EVENING AND OVERNIGHT WHICH SHOULD
TEMPER MIN TEMPS A BIT. MOST AREA SHOULD BOTTOM OUT IN THE MID
30S...WITH SOME LOWER 30S IN SOME OUTLYING AREAS. -CBL

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 223 AM WEDNESDAY...

WEAK SHORTWAVE DISTURBANCES EMBEDDED IN THE VIGOROUS PACIFIC JET
BRANCH THAT EXTENDS ACROSS THE SOUTHERN CONUS WILL RESULT IN AN
EXTENSIVE CIRRUS SHIELD ACROSS THE AREA ON THURSDAY...AT LEAST
THROUGH THE FIRST HALF OF THE DAY. THE GFS OVER THE PAST COUPLE OF
DAYS HAS BEEN INSISTENT IN SPREADING A HUNDREDTH OR TWO OR QPF ACROSS
THE NORTH/NORTHWEST PIEDMONT IN PROXIMITY TO THE WEAK DPVA/UPPER
DIVERGENCE REGION...HOWEVER A DEEP DRY SUB-CLOUD LAYER ASSOCIATED
WITH THE DRY AIR SURFACE RIDGE EXTENDING INTO THE AREA FROM THE
NORTHWEST SHOULD PRECLUDE ANY SPRINKLES FROM REACHING THE GROUND AND
THUS WILL KEEP FORECAST DRY. TEMPERATURES WILL INITIALLY STRUGGLE TO
WARM UNDERNEATH THE MILKY SKIES...WITH A GOOD CHANCE THAT TEMPS MAY
NOT HAVE ENOUGH TIME TO FULLY RECOVER AS WE APPROACH THE SHORTEST
DAY OF THE YEAR(DEC 21). AS SUCH...HIGHS THURSDAY SEVERAL DEGREES
COOLER THAN TODAY...RANGING FROM UPPER 40S NORTH TO MID 50S SOUTH.
SKIES SHOULD REMAIN MOSTLY CLEAR THURSDAY NIGHT WITH LOWS IN THE
LOWER TO MID 30S.


&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 AM WEDNESDAY...

FRIDAY...SFC RIDGE PROJECTED TO EXTEND NW-SE ACROSS THE REGION FROM
A PARENT HIGH (1025MB +/-) OVER THE LOWER OH VALLEY. MEANWHILE
ALOFT...WEAK S/W RIDGE WILL CROSS THE REGION. EXPECT THE DAY TO
START OUT SUNNY/MOSTLY SUNNY BUT SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDINESS LATE IN THE DAY...ESPECIALLY WESTERN PIEDMONT...IN
RESPONSE TO S/W TROUGH AND ATTENDANT SURFACE LOW DEVELOPING WELL TO
OUR SW. LOW LEVEL THICKNESSES CLOSE TO NORMAL WHICH SUGGEST HIGH
TEMPS AROUND 50 NORTH TO LOW-MID 50S SOUTH.

FRIDAY NIGHT...CLOUDS WILL CONTINUE TO THICKEN/LOWER THROUGH THE
NIGHT. ENOUGH ISENTROPIC UPGLIDE EXISTS SHORTLY BEFORE DAYBREAK TO
INCLUDE A MENTION OF SPOTTY LIGHT RAIN OVER THE SW TWO-THIRDS OF THE
CWA. PARTIAL THICKNESSES HOVERING IN VICINITY OF THE RAIN/FREEZING
SECTOR OF THE WINTER P-TYPE NOMOGRAM OVER THE NW PIEDMONT.
HOWEVER...MODEL GUIDANCE HAD BEEN TRENDING WARMER AND THE FREEZING
LEVEL FAIRLY ELEVATED (6000-8000FT). WHILE SATURATION AND
SIGNIFICANT LIFT NOTED IN THE FAVORED ICE NUCLEATION REGION OF THE
ATMOSPHERE...LOW LEVEL AIR MASS CURRENTLY APPEARS TOO WARM FOR ANY
WINTER P-TYPE AT THE ONSET OF THE PRECIP. WORSE CASE SCENARIO WOULD
BE SOME WET SNOWFLAKES MIXING WITH THE RAIN WHEN THE PRECIP RATES
ARE MODERATE/BRIEFLY HEAVY. MIN TEMPS GENERALLY MID 30S.

SATURDAY...SFC DRY AIR RIDGE AND PARENT HIGH IN FAVORABLE LOCATION
TO SUPPORT A COLD AIR DAMMING EVENT SATURDAY. THE NEAR SURFACE NE
FLOW WILL ADVECT A COOL AIR MASS INTO OUR REGION. MEANWHILE 850-
700MB FLOW WILL PULL WARM GULF MOISTURE OVER THE COOL STABLE NEAR
SURFACE AIR MASS RESULTING IN WIDESPREAD RAIN. LIFT APPEARS BEST IN
THE MORNING THROUGH EARLY AFTERNOON WITH LIFT WANING IN THE WEST BY
MID AFTERNOON. THE COOL SFC AIR MASS COMPOUNDED BY THE RAIN WILL
HOLD TEMPS AT OR BELOW 40 DEGREES ACROSS THE NW PIEDMONT...AND IN
THE 40S PRETTY MUCH ELSEWHERE.

SATURDAY NIGHT...AREAS OF RAIN WILL GRADUALLY TAPER TO SPOTTY LIGHT
RAIN WITH AREAS OF DRIZZLE AS MAIN LIFT MOVES AWAY FROM OUR REGION
AS S/W DAMPENS TO OUR EAST. LOW LEVEL AIR MASS EXPECTED TO REMAIN
NEARLY SATURATED SO WILL LIKELY KEEP LOW CLOUDS ALL NIGHT. MIN TEMPS
MID-UPPER 30S.

SUNDAY THROUGH TUESDAY...L/W TROUGH TO OUR WEST AMPLIFIES THIS
PERIOD AS A SUBSTANTIAL S/W DIGS ON THE BACK SIDE OF THE TROUGH.
THIS WILL MAINTAIN A SW FLOW ALOFT OVER CENTRAL NC. WITH A LACK OF A
MECHANISM TO SCOUR OUR THE CAD AIR MASS AND CONTINUED SW FLOW
ALOFT...COULD SEE A SET UP FOR A PERIOD OF CLOUDINESS SUNDAY THROUGH
TUESDAY ACROSS CENTRAL CN WITH PATCHES OF LIGHT RAIN AND/OR DRIZZLE
SUNDAY AND POSSIBLY INTO MONDAY. MAY SEE SOME IMPROVEMENT LATE
MONDAY INTO TUESDAY THOUGH MAY BE TRADING IN LOW CLOUDS FOR A DECK
OF MID-HIGH LEVEL CLOUDS. OVERALL EXPECT MORE CLOUDS THAN SUN THIS
PERIOD. HIGH TEMPS WILL AVERAGE 3-5 DEGREES BELOW NORMAL WHILE MIN
TEMPS WILL AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL (TYPICAL FOR CLOUDY
CONDITIONS).

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 610 AM WEDNESDAY...

24-HR TAF PERIOD: THERE IS HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THE
24 TAF PERIOD AS WEAK HIGH PRESSURE EXTEND INTO THE AREA WITH
A LIGHT WEST-NORTHWEST BREEZE.


LOOKING AHEAD: SHORTWAVE DISTURBANCES EMBEDDED WITHIN THE VIGOROUS
PACIFIC JET THAT EXTENDS ACROSS THE SOUTHERN CONUS MAY RESULT IN
PERIODS OF BROKEN/OVERCAST MID/HIGH CLOUD DECK. OTHERWISE...A DRY
AIR SURFACE RIDGE EXTENDING INTO THE CAROLINAS FROM THE
NORTH/NORTHWEST WILL SECURE VFR CONDITIONS THROUGH 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...HARTFIELD
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...WSS
AVIATION...CBL




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