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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 131518
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1118 AM EDT THU MAR 13 2014

.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY
ALLOWING FOR DRIER BUT CONTINUED BLUSTERY AND COLD CONDITIONS. THE
HIGH WILL PASS ACROSS THE REGION TONIGHT...WITH WARMING
TEMPERATURES FOR LATE WEEK INTO THE WEEKEND AS THE HIGH SLIDES
OFFSHORE.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 1045 AM EDT WEDNESDAY...

SURFACE OBSERVATIONS INDICATE THAT WIND SPEEDS ARE GRADUALLY
DECREASING ACROSS THE REGION...WHILE TEMPERATURES SLOWLY WARM WITH
DAYTIME HEATING. THEREFORE...THE HIGH WIND WARNING AND THE WIND
ADVISORY...AS WELL AS THE WIND CHILL ADVISORY...HAVE BEEN
CANCELLED. THAT STATED...WINDS WILL STILL REMAIN SOMEWHAT GUSTY
TODAY AND...DESPITE THE ABUNDANT SUNSHINE...AFTERNOON TEMPERATURES
WILL REMAIN CHILLY...WELL BELOW AVERAGE FOR MARCH. APPROPRIATE
WINTER CLOTHES SHOULD STILL BE WORN THROUGH THE DAY TO PROTECT
AGAINST THE WIND AND THE COLD.

THE ONLY OTHER CONCERN GOING INTO THE AFTERNOON WILL BE THE
REMAINING SNOW STREAMERS PUSHING OFF THE WESTERN RIDGES TOWARD THE
BLUE RIDGE. MOST OF THESE STREAMERS HAVE DIMINISHED SINCE
SUNRISE...HOWEVER A FEW REMAIN ACROSS MERCER AND BLAND COUNTIES...
AND MAY RESULT IN SUDDEN DROPS IN VISIBILITY AS TRAVELERS
ENCOUNTER THEM. REMAINING SNOWFALL WILL END DURING THE EARLY
AFTERNOON...WITH REMAINING CLOUDS CLEARING BY EARLY EVENING.

SURFACE HIGH PRESSURE WILL PASS ALONG THE GULF COAST THIS EVENING
AND OVERNIGHT...ALLOWING THE PRESSURE GRADIENT TO RELAX AND
MAKING FOR LIGHTER WINDS BY SUNSET. THE LIGHT WINDS AND CLEAR
SKIES WILL ALLOW FOR STRONG RADIATIONAL COOLING CONDITIONS...WITH
LOWS MAINLY IN THE TEENS TO MID 20S. AS THE CENTER OF THE HIGH
PRESSURE PASSES ACROSS FLORIDA AFTER MIDNIGHT...EXPECT TO SEE
TEMPERATURES ALONG THE RIDGES START TO RISE DURING EARLY FRIDAY
MORNING AS WINDS BECOME MORE SOUTHWESTERLY.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 345 AM EDT THURSDAY...

VERY QUICK REBOUND...WITH MID MARCH SUNSHINE AND VERY DRY AIR...HIGH
TEMPS SHOULD CROSS 60F EAST OF THE BLUE RIDGE FRIDAY. DIURNAL RANGE
MAY BE CLOSE TO 40F. FAVORED THE DRIER DEWPOINTS...AS THE MET MOS
SEEMED TO BE ON AN ISLAND COMPARED TO ALL OTHER DATA SETS. STILL
HOLDING ONTO A DOWNSLOPING WIND TOO...AND THERE MAY BE SOME 25 KT
GUSTS FRIDAY AFTERNOON...WHICH EXACERBATE CONDITIONS. MAY ONCE AGAIN
APPROACH RED FLAG...OR AT THE VERY LEAST NEED A FIRE WX SPS FOR NC
COUNTIES...WITH RH EASILY IN THE 20 PERCENT RANGE. WIND CRITERIA
PROBABLY WON`T BE MET FOR VIRGINIA...BUT ANOTHER DRY AND BREEZY DAY
IS EXPECTED.

ALTHOUGH DEWPOINT DEPRESSIONS WILL BE LARGE...EXPECTING A BIG
DIFFERENCE BETWEEN VALLEY AND HILL TOP LOW TEMPS FRIDAY NIGHT...WITH
WINDS AND HIGH CLOUDS. AS THE SURFACE HIGH MOVES OFF THE COAST INTO
SATURDAY...A WEAK BOUNDARY WILL SINK THROUGH WEST VA...SHOVING MORE
CLOUDS AND POSSIBLY A FEW SHOWERS MOSTLY WEST OF THE BLUE RIDGE
DURING THE SECOND HALF OF SATURDAY. ACTUALLY THERE IS A RIBBON OF
WEAK CAPE THAT STRETCHES INTO EXTREME SW VA...SO THE SHOWERS WILL BE
GENERATED THANKS TO A TOUCH OF INSTABILITY AND MORE NUMEROUS IN THE
BLF/JFZ CORRIDOR. A FEW OF THE SHOWERS MAY SNEAK INTO THE NEW RIVER
VALLEY LATE DAY. STOUT...ALTHOUGH DISORGANIZED UPPER DISTURBANCE
DIVES OUT OF THE ROCKIES INTO THE SOUTH CENTRAL CONUS LATE SATURDAY.
AND SO MATERIALIZES THE NEXT POTENTIAL WINTER THREAT ACROSS OUR
REGION SUNDAY INTO MONDAY.

A CONSENSUS MAY BE FORMING BETWEEN THE ECMWF/ECMWF ENSEMBLE/GFS
ENSEMBLE. THE OP GFS IS MUCH FURTHER EAST THAN ANYTHING ELSE IN THE
MODEL SUITE AND SEEMS TO BE AN OUTLIER. ROUGHLY FOLLOWED THE MORE
CONSISTENT ECMWF WITH REGARDS TO THIS SYSTEM. IT HAS A LOW TRACK
CLOSER TO THE COAST...BUT WHAT`S IMPORTANT IS THE NORTHERN EXTENT OF
THE PRECIP SHIELD...AND HOW QUICKLY ARCTIC HIGH PRESSURE WILL ALLOW
COLD AIR TO SEEP SOUTH AND MEET UP WITH THE PRECIP. THERE IS STRONG
CONFLUENT FLOW OVER NEW ENGLAND SUNDAY AFTERNOON...AND FORECASTED
DEWPOINTS WITH THE 1036MB SURFACE HIGH ARE NEAR ZERO ALONG IT`S
TRACK THROUGH THE MIDWEST AND THE OHIO VALLEY. THERE`S NO QUESTION
THAT THIS ARCTIC HIGH WILL BE COLD ENOUGH TO SUPPLY THE REGION WITH
AN AIRMASS THAT WILL SUPPORT WINTRY PRECIP...IT`S ARRIVAL TIME IS
THE BIG QUESTION. ALTHOUGH CONFIDENCE IS ABOVE AVERAGE REGARDING
MEASURABLE PRECIP...CONFIDENCE IS MUCH LOWER WITH REGARDS TO IF IT
WILL BE RAIN OR SNOW. THE COASTAL SYSTEM DOES SEEM SUPPRESSED BY
THIS SURFACE HIGH AND THUS TAKES MORE OF A WSW-ENE TRACK INSTEAD OF
DIRECTLY UP THE COAST. EASTERLY SURFACE WINDS ARE IN PLACE SUNDAY
MORNING...AND WITH PRECIP APPROACHING...CAN SEE MAX TEMPS THIS DAY
COMING IN WELL BELOW GUIDANCE WITH INITIALLY AN IN SITU WEDGE
FORMING SUNDAY MORNING. BUT IT DOESN`T APPEAR AS THOUGH THAT COLDER
SOLUTION WILL BE ENOUGH TO SUPPORT SNOW UNTIL SUNDAY NIGHT. IT NEEDS
TO BE STATED THAT MODELS ARE TYPICALLY TOO WARM AT THIS TIMEFRAME
WITH THIS TYPE OF SETUP. GFS ENSEMBLE MEAN H85 TEMPS ARE COLDER BY A
FEW DEGREES THAN THE OP ECMWF. THUS...MAYBE SNOW/SLEET GETS UNDERWAY
A LITTLE EARLIER THAN MODELS SUGGEST ACROSS THE SOUTHERN SHENANDOAH
AND GREENBRIER VALLEY SUNDAY AFTERNOON. SUNDAY NIGHT...THE SURFACE
HIGH IS IN BETTER POSITION OVER NEW ENGLAND FOR WEDGING TO
OCCUR...AND IF THERE IS QPF LEFT...WILL CHANGE MUCH OF THE REGION
OVER TO SNOW. BOTH THE ECMWF AND GFS ENSEMBLE SUGGEST THERE WILL BE
ADDITIONAL PRECIP SUNDAY NIGHT...BUT REMAIN SKEPTICAL AS TO HOW MUCH
OF IT WILL SURVIVE THE COLD YET DRY DOME OF HIGH PRESSURE IN PLACE.
CHILLY AIR AND WEDGE ARE HERE TO STAY INTO MONDAY ALTHOUGH PRECIP
WILL BE ENDING.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 320 PM EDT WEDNESDAY...

COULD THURSDAY BE THE LAST ATTACK OF WINTER WEATHER FOR THE SEASON?
MARCH INTO APRIL IS A TRANSITION TIME WHERE WE COULD HAVE WARM
TEMPERATURES FOR A FEW DAYS...THEN COLD AGAIN FOR A DAY OR TWO.
THE GOOD NEWS IS THAT WITH THE HIGHER SUN ANGLE AND WARMER AIR
ADVANCING FARTHER NORTH...THE DURATION OF COLD SPELLS WILL BE
SHORTER. THE CHANCES FOR WINTRY PRECIPITATION ALSO EXIST...BUT
THE ODDS OF A SIGNIFICANT SNOW OR ICE EVENT ARE ON THE DECLINE.

WITH THAT SAID...HIGH PRESSURE WILL WEDGE DOWN THE EAST COAST
INTO MONDAY. MODELS DO LOOK SIMILAR TO LAST WEEKS MARCH 6-7 2014
SYSTEM. AT THIS TIME...THERMAL PROFILES SUPPORT MAINLY SNOW IN THE
NORTHERN HALF WITH A WINTRY MIX OVER THE SOUTHEASTERN HALF. WILL
TREND TEMPERATURES COLDER. OUTSIDE OF THE SUNDAY- MONDAY
EVENT...THE WEATHER PATTERN IS QUIET WITH NEAR NORMAL
TEMPERATURES.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 700 AM EDT THURSDAY...

BANDS OF SNOW WILL CONTINUE TO PERSIST ACROSS THE MOUNTAINS EARLY
THIS MORNING WITH MVFR AND OCNL IFR IN HEAVIER SNOW SHOWERS
ESPCLY IN THE AREA BETWEEN KLWB-KBLF TO KBCB. EXPECT MOISTURE TO
SLOWLY DECREASE WITH SNOW SHOWERS SLOWLY TAPERING AND CIGS LIFTING
OR SCATTERING BY 14Z/10AM. SOME SPILLOVER OF LOWER CIGS LIKELY
INTO KROA BUT THINKING THEY WILL STAY WITH AN VFR CIG AND ONLY A
FEW FLURRIES OR LIGHT SNOW SHOWERS AT BEST EARLY. ELSW CONTINUED
VFR UNDER MAINLY CLEAR SKIES WITH ALL SITES BECOMING CLEAR THIS
AFTERNOON.

OTRW WINDS WILL CONTINUE TO BE THE AVIATION ISSUE EARLY THIS
MORNING WITH GUSTS TOPPING 40 KTS AT TIMES ESPCLY AROUND
KBCB/KROA WITH 25-30 KTS COMMON ELSW DURING THE DAY.

WINDS WILL START TO WIND DOWN LATE THURSDAY AFTERNOON AND BECOME
LIGHT INTO THURSDAY EVENING.

.EXTENDED AVIATION...

THURSDAY NIGHT...HIGH PRESSURE WILL SETTLE OVER THE AREA AND
BRING A DECREASE IN WIND SPEED AND A RETURN TO VFR CONDITIONS FOR
THE ENTIRE AREA. ANOTHER WEAK COLD FRONT WILL DROP THROUGH THE
REGION DURING THE WEEKEND WITH SUB-VFR POSSIBLE OVER THE SOUTH AND
WEST AS DEEPER MOISTURE WITH YET ANOTHER LOW PRESSURE SYSTEM
SPREADS EAST ALONG THE FRONT BY SUNDAY. THIS SYSTEM HAS THE
POTENTIAL FOR EXTENDED PERIOD OF SUB VFR INTO MONDAY AS THE LOW
DEEPENS OFF THE COAST.

&&

.FIRE WEATHER...
VERY DRY AIR WILL CONTINUE TO PUSH INTO THE AREA TODAY ON GUSTY
NORTHWEST WINDS. THIS COMBINED WITH HEATING AND DOWNSLOPE WILL
CAUSE HUMIDITY LEVELS TO DROP BELOW 20 PERCENT THIS AFTERNOON.
ALTHOUGH SOME AREAS SAW LIGHT RAINFALL ON WEDNESDAY...THE VERY DRY
AIR WILL CAUSE THE FINER FUELS TO DRY QUICKLY DESPITE THE COOL
TEMPERATURES. IN ADDITION...WINDY AND GUSTY CONDITIONS WILL
REMAIN THROUGH THE DAY AND GREATLY ENHANCE FIRE DANGER. THUS WENT
AHEAD AND UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING
FOR AREAS EAST OF THE BLUE RIDGE IN VIRGINIA AND NORTH CAROLINA
TODAY.

FIRE WX CONCERNS SHOULD CONTINUE INTO FRIDAY. ALTHOUGH WIND
CRITERIA MAY NOT BE MET...A FIRE WX SPS MAY BE NECESSARY ACROSS THE
ENTIRE REGION...WITH BREEZY CONDITIONS AND WIND GUSTS TO 25 MPH.
CONTINUED DOWNSLOPE FLOW MAY DROP RH VALUES BELOW 20 PERCENT
ACROSS THE NORTH CAROLINA PIEDMONT AND SOUTHSIDE VIRGINIA WITH
DEEP MIXING EXPECTED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
VA...RED FLAG WARNING UNTIL 6 PM EDT THIS EVENING FOR VAZ032>035-
     043>047-058-059.
NC...RED FLAG WARNING UNTIL 6 PM EDT THIS EVENING FOR NCZ003>006-
     019-020.
WV...NONE.
-- End Changed Discussion --

&&

$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...KM
LONG TERM...RCS
AVIATION...JH/NF/WP
FIRE WEATHER...JH/KM