Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 270034
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
734 PM EST MON JAN 26 2015

.SYNOPSIS...
LOW PRESSURE OVER VIRGINIA WILL DEVELOP INTO A MAJOR WINTER STORM
AS IT MOVES NORTHEAST ALONG THE NEW ENGLAND COAST TONIGHT AND
TUESDAY. THIS STORM WILL INFLUENCE OUR WEATHER THROUGH TUESDAY
WITH MOUNTAIN SNOW SHOWERS AND GUSTY NORTHWEST WINDS.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 715 PM EST MONDAY...

NO CHANGES PLANNED TO CURRENT WINTER WEATHER ADVISORIES.

AREA RADARS SHOWING SCATTERED SHOWERS MOVING THROUGH THE REGION
ALONG A COLD FRONT BEING ENHANCED A BIT BY A WEAK UPPER LEVEL
SHORT WAVE. MESO MODELS SEEM TO HAVE BEEN HANDLING THE EVOLUTION
OF THIS WELL AND INDICATE IT WILL CONTINUE TO DISSIPATE AS IT
MOVES INTO THE PIEDMONT. THEREFORE WILL BE LOWERING POPS OUT EAST.
EXPECT THE UPSLOPE SNOW SHOWERS TO CONTINUE IN THE BLUSTERY NW
FLOW BEHIND THE FRONT FOR THE FAR WESTERN SLOPES OF THE BLUE
RIDGE...AND A MORE VIGOROUS SHORT WAVE DIVING DOWN THE BACKSIDE OF
THE UPPER TROF SHOULD ENERGIZE THE ACTIVITY FROM THE NORTH
CAROLINA MTNS UP INTO THE GRAYSON HIGHLANDS WHERE THE WINTER
WEATHER ADVISORY CONTINUES THROUGH NOON TOMORROW.

PREVIOUS AFD...

LOW PRESSURE IS CURRENTLY PASSING OVER CENTRAL VIRGINIA WITH
UPPER TROF AXIS AND COLDER AIR SPILLING OVER THE APPALACHIAN
MOUNTAINS. TEMPERATURES ARE FALLING ACROSS THE MOUNTAINS...AND
THIS COLD AIR ADVECTION WILL CAUSE FALLING TEMPERATURES FARTHER
EAST AS WE PROGRESS THROUGH THE EVENING. TEMPERATURES HAVE ALREADY
DROPPED INTO THE 20S IN THE MOUNTAINS. READINGS IN THE 40S WERE
FOUND OVER THE PIEDMONT OF NC AND INTO SOUTHSIDE VA...BUT THESE
NUMBERS WILL TAKE A TUMBLE TONIGHT.

THROUGH 4PM TODAY...LITTLE OR NO SNOW HAD ACCUMULATED ANYWHERE
WITHING THE CWA...WITH MAINLY A MIX OF RAIN/SNOW OVER THE
MOUNTAINS AND RAIN EAST OF THE BLUE RIDGE. AS TEMPERATURES FALL
THIS EVENING...ANY LINGERING RAIN WILL CHANGE TO SNOW. THE
DEFORMATION ZONE ON THE NORTHWEST SIDE OF THE LOW IS EXPECTED TO
PRODUCE A PERIOD OF SNOW OVER THE MOUNTAINS THIS EVENING. HIGHEST
ACCUMULATIONS THIS EVENING ARE EXPECTED TO BE IN THE WV HIGHLANDS
WHERE 1 TO 3 INCHES OF ACCUMULATION IS ANTICIPATED BEFORE
MIDNIGHT. LATER TONIGHT THERE WILL BE A SECONDARY SURGE OF
MOISTURE ASSOCIATED WITH AN UPPER LEVEL SHORT WAVE CROSSING THE
NORTH CAROLINA MOUNTAINS. THIS WILL LIKELY RESULT IN ACCUMULATING
SNOW FOR THE NORTH CAROLINA HIGH COUNTRY AND MOUNT ROGERS IN
VIRGINIA. SNOW TO LIQUID RATIOS WILL ALSO BEGIN TO COME INTO PLAY
LATE TONIGHT AS TEMPERATURES DIP BELOW 20 DEG F...WILDING 2 TO 1.
AS SUCH...THINK IT IS FEASIBLE TO SEE 2 TO 4 INCHES OF SNOW OVER
THE NC HIGH COUNTRY...POSSIBLY MORE AT ELEVATIONS ABOVE 4000 FT.

OVERALL THIS IS NOT EXPECTED TO BE A BIG SNOW PRODUCER FOR
THE CENTRAL APPALACHIANS. THE MAIN MEDIA FOCUS WILL BE ON COASTAL
NEW ENGLAND WHERE THIS AREA OF LOW PRESSURE WILL WRAP UP INTO A
MAJOR WINTER STORM. FOR THE CENTRAL APPALACHIANS...WE GET TO DEAL
WITH THE BACKLASH WINDS AND MOUNTAIN SNOW SHOWERS. THEIR IS SOME
POTENTIAL FOR WRAP AROUND MOISTURE FROM THE COASTAL STORM TO
PENETRATE AS FAR SOUTH AS OUR NORTHEASTERN CWA LATE TONIGHT...SO
WILL HAVE TO MONITOR THIS CLOSELY AS THERE MAY BE A NEED FOR
WINTER WEATHER HEADLINES FOR AREAS NORTHEAST OF LYNCHBURG...
SPECIFICALLY APPOMATTOX...BUCKINGHAM AND POINTS NORTH AND EAST.

EVEN THOUGH WE ARE NOT ADVERTISING MUCH PRECIP WITHIN OUR LOCAL
FORECAST AREA...THIS WEATHER SYSTEM IS VERY DYNAMIC...LOTS OF
ENERGY ALOFT THAT WILL CAUSE THIS STORM TO DEEPEN QUICKLY AS IT
MOVES UP THE EAST COAST. HAVE EVEN SEEN A FEW LIGHTNING STRIKES
WITHIN THE SHOWERS OVER THE NORTH CAROLINA PIEDMONT TODAY WHICH IS
AN INDICATOR OF HOW UNSTABLE THIS ATMOSPHERE IS BECOMING AND THE
POTENTIAL ENERGY THAT IS BUILDING UP FOR THIS THING TO FEED OFF OF
ONCE IT GETS EAST OF OUR FORECAST AREA AND CERTAINLY SETTING THE
STAGE FOR COASTAL BOMBOGENESIS TONIGHT. MODELS HAVE BEEN
STRUGGLING WITH QPF...AND IT WAS A BIT INTERESTING TO SEE ALL THE
QPF THE GFS MODEL PAINTING OVER OUR CWA THIS MORNING...YET NOT
MUCH WAS OCCURRING...CONVECTIVE FEEDBACK IN THE MODEL. WHAT REALLY
MADE IT HUMOROUS WAS THE MODEL THEN TOOK THE 4-6 TENTHS OF AN INCH
OF QPF AND CONVERTED IT TO ALL SNOW. ANYONE ISSUING FORECASTS AND
BLINDLY FOLLOWING GUIDANCE THIS MORNING WOULD HAVE THEN
EXPERIENCED A GOOD TASTE OF METEOROLOGICAL/MODEL CANCER...A
GARBAGE IN...GARBAGE OUT SORT OF FORECAST.

QPF ISSUES ASIDE...THE IMPACT FROM THIS STORM FOR OUR LOCAL AREA
WILL BE MINOR COMPARED TO OUR NEIGHBORS TO THE NORTH. I.E. NOTHING
WE HAVN`T SEE BEFORE. IN SUMMARY...A PERIOD OF SNOW IS LIKELY FOR
OUR MOUNTAINS TONIGHT WITH FLURRIES AND SCATTERED SNOW SHOWERS
LINGERING INTO TUESDAY. IT WILL BECOME BLUSTERY WITH NORTHWEST
WINDS OF 10 TO 20MPH...AND GUSTS OF 25 TO 30 MPH. A 40 MPH GUST
OVER THE NC/VA/WV HIGHLANDS IS CERTAINLY POSSIBLE. COLDER AIR
SPILLING INTO THE AREA TONIGHT WILL PUSH TEMPERATURES INTO THE
TEENS ACROSS THE HIGHLANDS...TO NEAR 30 IN THE PIEDMONT.
TEMPERATURES WILL MOVE VERY LITTLE ON TUESDAY...REMAINING IN THE
20S MOUNTAINS...AND 30S TO NO MORE THAN 40 EAST OF THE BLUE RIDGE.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 400 PM EST MONDAY...

TUESDAY NIGHT OUR REGION WILL CONTINUE TO BE WITHIN A NORTHWEST FLOW
REGIME ON THE BACKSIDE OF THE DEEPENING LOW PRESSURE SYSTEM OFF THE
NEW ENGLAND COAST. NORTHWEST FLOW...WITH A ORIGIN ACROSS LAKE
ERIE...WILL BRING MOISTURE UPSLOPE ACROSS THE SOUTHEAST WEST
VIRGINIA MOUNTAINS...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH
CAROLINA. ANTICIPATE LIGHT ACCUMULATIONS OF SNOW ALONG THE PREFERRED
WESTERN SLOPES. AMOUNTS WILL BE GREATEST IN WESTERN GREENBRIER
COUNTY WHERE LESS THAN INCH OF NEW MEASURABLE SNOW IS EXPECTED.
ELSEWHERE...THE SNOW WILL LIKELY BE IN THE FORM OF FLURRIES...OR
ACCUMULATING SNOW THAT PRODUCES A DUSTING ON SURFACES. WINDS WILL
GUST ACROSS THE MOUNTAINS IN THE 20 TO 30 MPH RANGE WITH LESSER
MAGNITUDES ACROSS THE PIEDMONT.

BY WEDNESDAY...HIGH PRESSURE WILL BE BUILDING INTO THE AREA AND LOW
LEVEL WINDS WILL WEAKEN AND VEER MORE NORTHERLY...THUS TURNING OFF
THE UPSLOPE SNOW MACHINE. ANTICIPATE A TREND TOWARD LITTLE OR NO
CLOUD COVER AND WEAKENING WINDS.

WEDNESDAY NIGHT INTO THURSDAY...THE CENTER OF THE SURFACE HIGH WILL
SHIFT EAST OF THE REGION WHILE OUR NEXT CLIPPER SYSTEM HEADS
SOUTHEAST THROUGH THE GREAT LAKES REGION. LOOK FOR WINDS TO BACK
SOUTHWEST AND INCREASE THROUGH THIS TIME PERIOD...ALONG WITH AN
ONSET OF WARM AIR ADVECTION. CLOUD COVER WILL START TO INCREASE FROM
WEST TO EAST WEDNESDAY NIGHT SO THAT BY DAYBREAK THURSDAY MOSTLY
CLOUDY TO CLOUDY CONDITIONS ARE EXPECTED ACROSS THE ENTIRE FORECAST
REGION. OUR NEXT CHANCE OF PRECIPITATION WILL ARRIVE IN THE WEST BY
MIDDAY THURSDAY AS THE CLIPPER SYSTEM HEADS INTO THE OHIO VALLEY.
THE ONSET OF PRECIPITATION LOOKS AT THIS TIME TO BE A RAIN/SNOW MIX
IN THE WEST. AS PRECIPITATION SPREADS EAST DURING THE...MILDER AIR
WILL ALLOW FOR THE VAST MAJORITY OF THE PRECIPITATION TO TRANSITION
TO PLAIN RAIN.

TEMPERATURES WILL MODERATE DURING THIS TIME PERIOD...ESPECIALLY
ACROSS WESTERN PARTS OF THE AREA ONCE WARM AIR ADVECTION STARTS
WEDNESDAY NIGHT INTO THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 PM EST MONDAY...

BELOW NORMAL TEMPERATURES TRENDING TO MUCH BELOW THROUGH THE
EXTENDED...ALONG WITH STRONG NORTHWEST WINDS THURSDAY NIGHT/FRIDAY
AND AGAIN SUNDAY NIGHT/MONDAY.

UPPER LEVELS WILL BE EVOLVING TO MORE OF A DOMINANT NORTHERN STREAM.
THE LATEST INDICATIONS POINT TO A COLDER MORE AMPLIFIED EASTERN TROF
DEVELOPING AS PER THE ECMWF...AND SPLIT FLOW OUT WEST WITH A RIDGE
FOR THE PACIFIC NW AND A CUTOFF LOW REGENERATING OVER THE BAJA
PENINSULA.

THURSDAY NIGHT STARTS OUT WITH A COLD FRONT PUSHING THROUGH FOLLOWED
BY UPSLOPE SNOW SHOWERS FOR THE WESTERN SLOPES OF THE APPALACHIANS
WITH BLUSTERY NORTHWEST WINDS. THE SNOW SHOWERS AND BLUSTERY
CONDITIONS WILL CONTINUE INTO FRIDAY. HIGH PRESSURE THEN BUILDS IN
WITH FAIR WEATHER AND COLD TEMPERATURES FOR THE START OF THE
WEEKEND.

IT NOW APPEARS THAT A COLD FRONT WILL BE APPROACHING FROM THE WEST
ON SUNDAY...BRINGING A GOOD CHANCE OF PRECIPITATION TO THE REGION.
THE FRONT WILL PUSH THROUGH SUNDAY NIGHT...ALLOWING VERY STRONG
NORTHWEST WINDS TO USHER IN A SHOT OF ARCTIC AIR AND COLD
TEMPERATURES FOR THE START OF NEXT WEEK. THE ECMWF HAS BEEN
CONSISTENT WITH THIS MESSAGE AND NAEFS ANOMALIES NOW SUPPORT THE GFS
TREND TOWARD THIS SOLUTION SO CONFIDENCE IS GROWING IN THIS COLD
OUTBREAK.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
DEEP COASTAL LOW PRESSURE AREA THE MAIN FOCUS FOR THIS TAF VALID
CYCLE. THE MAIN EFFECTS OF THIS STORM WILL BE FOR THE BIG CITIES
IN THE NORTHEAST. FOR US...WE WILL DEAL WITH A COUPLE OF BANDS OF
SNOW...ONE ASSOCIATED WITH THE FRONT...AND PERHAPS THE DEFORMATION
ZONE ACROSS THE PIEDMONT...WHILE IN THE WEST IS A STRONG UPPER-
LEVEL DISTURBANCE TRACKING SSE FROM THE OH/TN VALLEY TOWARD
GA/SC...THAT WILL MAINLY IMPACT EASTERN TN/FAR SOUTHWEST
VA/NORTHWEST NC OVERNIGHT/EARLY TUE. THIS WOULD PRINCIPALLY IMPACT
TNB...BUT COULD IMPACT LWB/BLF/BCB TO SOME EXTENT...SO HAVE
INCLUDED -SN WITH IFR-LIFR CIGS AND MVFR-IFR VSBYS WITH THIS
ACTIVITY. SOME -SN MAY ALSO IMPACT LYH LATER ON AS THE COASTAL LOW
INTENSIFIES OFF THE DELMARVA. CIGS WEST OF THE BLUE RIDGE WILL
REMAIN MVFR-IFR MUCH OF THE TAF VALID PERIOD...ESPECIALLY ALONG
AND WEST OF THE ALLEGHANY FRONT...INCLUDING BLF/LWB. BCB WILL
LIKELY REMAIN MVFR MUCH OF THE NIGHT. EAST OF THE BLUE
RIDGE...CIGS WILL GENERALLY BE MVFR OVERNIGHT...BECOMING VFR BY
DAYBREAK TUE. IFR CIGS MAY PERSIST LYH-DAN UNTIL THE COLD FRONT
REACHES THAT AREA BY 02Z. A FEW -SHRA MAY ALSO OCCUR IN THE WARMER
AIR EAST OF THE BLUE RIDGE THROUGH 02Z...BUT THIS WILL NOT IMPACT
CIGS/VSBYS. WINDS...NNE EAST OF THE BLUE RIDGE TO NW WEST OF THE
BLUE RIDGE THROUGH 04Z...BECOMING NW ALL AREAS BY OR AFTER 04Z.
SPEEDS 8-12KTS WITH GUSTS 15-20KTS INCREASING OVERNIGHT TO 9-13KTS
WITH GUSTS 17-25KTS.

MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH 14Z...THEN MEDIUM TO
HIGH CONFIDENCE IN CIGS AND VSBYS.

MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.

EXTENDED DISCUSSION...
HIGH PRESSURE ON WEDNESDAY WILL PROVIDE A QUIET DAY WITH VFR
CONDITIONS ACROSS ALL TAF LOCATIONS. ANOTHER CLIPPER SYSTEM
ARRIVES ON THURSDAY...BRINGING A CHANCE OF SUB-VFR CIGS AND
VSBYS...WITH A CHANCE FOR -SHRA...-SHSN IN THE MOUNTAINS.

&&

.EQUIPMENT...
HINTON ALL HAZARDS RADIO...162.425MHZ WAS OFF THE AIR THIS
MORNING. TECHNICIANS INDICATE THERE IS QUITE A BIT OF TREE DAMAGE
FROM ICE IN THE AREA AND THE RADIO WILL CONTINUE EXPERIENCE
INTERMITTENT OUTAGES DUE TO POWER INTERRUPTIONS IN THE AREA.

THE ROANOKE TRANSMITTER...POOR MOUNTAIN 162.475 MHZ...IS ALSO
EXPERIENCING PROBLEMS WITH INTERMITTENT OUTAGES. SIMILAR
CONDITIONS EXIST ON POOR MOUNTAIN WITH THE POWER BEING INTERRUPTED
BY TREE DAMAGE FROM ICE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ019-020.
     WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ015.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ507-508.

&&

$$
SYNOPSIS...PM
NEAR TERM...MBS/PM
SHORT TERM...DS
LONG TERM...MBS
AVIATION...PM/RAB
EQUIPMENT...PM


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