Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 281735
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1235 PM EST WED JAN 28 2015

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY THIS MORNING WILL
BUILD EAST ACROSS THE APPALACHIANS THIS AFTERNOON. MEANWHILE...AN
AREA OF LOW PRESSURE OVER THE NORTHERN ROCKIES WILL MOVE EAST
ACROSS THE NORTHERN PLAINS TODAY. THIS FAST MOVING CLIPPER LIKE
SYSTEM WILL MOVE INTO THE GREAT LAKES BY THURSDAY. A COLD FRONT
TRAILING SOUTH FROM THE LOW WILL CROSS THE APPALACHIANS THURSDAY
AFTERNOON. HIGH PRESSURE SHOULD AGAIN FOLLOW THIS SYSTEM WITH
ANOTHER ROUND OF COLDER AIR INCLUDING STRONG NORTHWEST WINDS AND
MOUNTAIN SNOW SHOWERS OR FLURRIES FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EST WEDNESDAY...

A COLD START TO THE DAY WITH TEMPERATURES IN THE TEENS MOUNTAINS
AND 20S PIEDMONT. ADD IN A 10 MPH NORTHWEST WIND AND THE WIND
CHILLS RANGE FROM THE SINGLE DIGITS IN THE MOUNTAINS TO THE TEENS
ACROSS THE PIEDMONT. LINGERING LOW LEVEL MOISTURE WAS STILL
RESULTING IN SCATTERED FLURRIES ACROSS THE MOUNTAINS...BUT LITTLE
OR NO ACCUMULATION.

OUR FORECAST AREA REMAINS ON THE SOUTHWEST PERIPHERY OF THE NEW
ENGLAND UPPER LEVEL LONG WAVE TROUGH AND COASTAL WINTER STORM. THE
ONLY REMNANT EFFECT IS THE WIND AND SOME FLURRIES...WHICH WILL GO
AWAY TODAY AS HEIGHTS RISE AND HIGH PRESSURE BUILDS ACROSS THE
AREA. AS OF DAYBREAK THIS MORNING...A 1026 MB SURFACE HIGH
WAS CENTERED OVER THE OHIO VALLEY AND GREAT LAKES. THIS HIGH IS
FORECAST TO MOVE EAST AND STRENGTHEN TO AROUND 1030 MB AS IT
PASSES OVERHEAD THIS EVENING. NET RESULT SHOULD BE DIMINISHING
WINDS AND CLEAR SKIES...TEMPERATURES CLIMBING INTO THE 30S IN THE
MOUNTAINS AND LOWER 40S PIEDMONT.

MEANWHILE...WELL UPSTREAM OF THE FORECAST AREA...AN AREA OF LOW
PRESSURE WILL EXIT THE NORTHERN ROCKIES TODAY CROSSING THE
NORTHERN PLAINS. THIS CLIPPER LIKE STORM IS PROGGED BY ALL MODELS
TO REMAIN NORTH OF OUR REGION AS IT ENTERS THE GREAT LAKES TONIGHT
AND THURSDAY. A COLD FRONT WILL TRAIL SOUTH FROM THE
LOW...SWEEPING ACROSS THE UPPER MIDWEST AND INTO THE OHIO VALLEY
TONIGHT. AS THE FRONT APPROACHES OUR AREA LATE TONIGHT...WIND FLOW
WILL BECOME SOUTHWESTERLY ALOFT PROMOTING WARMING TEMPERATURES
IN ADDITION TO SOME INCREASING MID/UPPER LEVEL CLOUDINESS.
TEMPERATURES ACROSS OUR FORECAST AREA TONIGHT WILL LIKELY BOTTOM
OUT EARLY PRIOR TO THE ARRIVAL OF ANY CLOUD COVER...LOWS IN THE
20S. IF CLOUDS ARE DELAYED...THEN WE COULD SEE TEMPERATURES DIP
BACK INTO THE TEENS AS INDICATED BY SOME OF THE MODELS. FOR NOW
WILL GO WITH A MODEL BLEND SINCE NOT OVERLY CONFIDENT ON THE CLOUD
COVER TIMING.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EST WEDNESDAY...

1028 MB SFC HIGH PRESSURE IN EASTERN NORTH CAROLINA THURSDAY MORNING
WILL SLIDE EAST INTO THE ATLANTIC COAST...AS CLIPPER APPROACHING
FROM THE UPPER MIDWEST. THE LOW CENTER WILL CONTINUE TO MOVE EAST
AND IS PROGGED TO PASS WELL TO THE NORTH LATER THURSDAY...WHILE
SWINGING ASSOCIATED COLD FRONT INTO THE REGION THURSDAY AFTERNOON.

KEPT THE HIGHEST POPS IN THE MOUNTAINS WITH BEST DYNAMICS AND LIFT
HEADING BY TO THE NORTH. A BAND OF SNOW/RAIN WILL ARRIVE OVER THE
FAR WEST BY MIDDAY AND ATTEMPT TO CROSS THE RIDGES UNDER A QUICKLY
VEERING WESTERLY FLOW. PTYPE LIKELY TO START AS LIGHT SNOW MOUNTAINS
BEFORE SWITCHING TO MORE LIQUID NATURE AS BOTH 85H AND BOUNDARY
LAYER WARMING TAKE OVER. DURING THE DAY...SNOWFALL AMOUNTS OF
PERHAPS AN INCH OR SO IN WESTERN GREENBRIER WITH OVERALL QPF OF LESS
THAN A TENTH OF AN INCH...MAINLY WEST.

HIGH TEMPERATURES THURSDAY WILL RANGE FROM THE MID 30S IN THE
NORTHWEST TO AROUND 50 DEGREES IN THE PIEDMONT. MAXIMUM TEMPERATURES
ARE A CHALLENGE WITH CLOUDS AND PRECIPITATION.

TIMING OF THE COLD FRONT WAS SIMILAR ON BOTH THE ECMWF AND GFS AND
FAIRLY CONSISTENT. THE COLD FRONT WILL MOVE EAST THROUGH OUR REGION
THURSDAY EVENING OR EARLY THURSDAY NIGHT...USHERING IN MUCH COLDER
AIR. IN THE WAKE OF THE FRONT...NORTHWEST UPSLOPE SNOW SHOWERS AND
SNOW FLURRIES ARE EXPECTED WEST OF THE BLUE RIDGE. A WINTER WEATHER
ADVISORY MAY BE NEEDED FOR WESTERN GREENBRIER THURSDAY NIGHT INTO
FRIDAY MORNING. BUT...IT IS TOO EARLY FOR ANY HEADLINES. WILL
MENTION SNOW POTENTIAL IN THE HWO. SNOW ACCUMULATIONS FOR THE FAR
WESTERN SLOPES SHOULD BE AN INCH OR TWO...BUT WESTERN GREENBRIER
COUNTY SHOULD PICK UP A TOTAL OF AROUND 5 INCHES BEFORE THINGS START
TO WIND DOWN FRIDAY MORNING INTO FRIDAY AFTERNOON. LOW TEMPERATURES
THURSDAY NIGHT WILL VARY FROM THE UPPER TEENS IN THE NORTHWEST
MOUNTAINS TO AROUND FREEZING MARK IN THE SOUTHEAST.  HIGH
TEMPERATURES FRIDAY WILL REMAIN COLD WITH READINGS FROM THE UPPER
TEENS IN THE NORTHWEST TO THE LOWER 40S IN THE SOUTHEAST.

ANOTHER ISSUE TO WATCH OUT FOR THURSDAY NIGHT INTO FRIDAY IS VERY
STRONG WINDS. BOTH THE GFS AND NAM SHOWED A 50 KNOT LOW LEVEL JET
WHICH COULD MIX DOWN LATE THURSDAY NIGHT INTO FRIDAY MORNING. LEANED
TOWARDS HPCGUIDE FOR LOWS FRIDAY NIGHT FROM THE SINGLE DIGITS TO THE
LOWER 20S. WITH THE COMBINED WIND AND COLD...WIND CHILL VALUES MAY
BE AS COLD AS ZERO TO TEENS WEST OF THE BLUE RIDGE TO THE 20S IN THE
EAST.

HIGH PRESSURE WILL BUILD EAST ACROSS OUR AREA SATURDAY INTO SATURDAY
NIGHT. HIGHS SATURDAY WILL VARY FROM THE MID 20S IN THE NORTHWEST TO
THE LOWER 40S IN THE SOUTHEAST. UNDER INCREASING CLOUDS SATURDAY
NIGHT...LOWS WILL GENERALLY BE FROM THE TEENS IN THE MOUNTAINS TO
AROUND 30 DEGREES ALONG THE SOUTHERN BLUE RIDGE.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 400 AM EST WEDNESDAY...

BELOW NORMAL TEMPERATURES TRENDING TO MUCH BELOW THROUGH THE
EXTENDED...ALONG WITH POSSIBILITY OF MORE STRONG NORTHWEST WINDS
SUNDAY NIGHT THROUGH MONDAY.

UPPER LEVEL PATTERN FOR THE EXTENDED WILL BE SPLIT FLOW WITH A
DOMINANT NORTHERN STREAM TROF IN THE EAST AND RIDGE FOR THE PAC NW.
THERE IS ENOUGH GENERAL AGREEMENT BETWEEN THE GFS AND ECMWF
MEMBERS...WHICH ARE SUPPORTED BY NAEFS ANOMALIES...TO LEAN TO THE
COLD SOLUTION.

THE UPPER TROF IN THE CENTRAL US WILL SLIDE EAST SUNDAY. LOW
PRESSURE WHICH DEVELOPS TO OUR WEST AND TRACKS INTO NEW ENGLAND WITH
A TRAILING COLD FRONT SWEEPING THROUGH THE REGION SUNDAY NIGHT. WILL
NOT SPLIT HAIRS ABOUT PTYPE THIS FAR OUT BUT THE GENERAL TRACK TO
OUR WEST AND NORTH WILL KEEP US ON THE WARM SIDE OF THE STORM.
POSSIBLE HYBRID WEDGE IN PLACE AT THE ONSET MAY HELP COOL THINGS FOR
WINTRY MIX AT ONSET GOING TO RAIN FOR THE BULK OF SUNDAY THEN BACK
TO WINTRY AS PCPN TAPERS OFF...THOUGH TYPICAL NW FLOW UPSLOPE SNOW
SHOWERS WEST OF THE BLUE RIDGE BECOME ESTABLISHED IN THE COLD AIR
BEHIND THE COLD FRONT. MAY ALSO BE LOOKING AT ANOTHER STRONG NW WIND
EVENT AS WE GO THROUGH SUNDAY NIGHT AND INTO MONDAY BUT THERE IS
PLENTY OF TIME TO WATCH THIS AND SEE HOW LATER MODEL RUNS HANDLE THE
EVOLUTION OF LOW LEVEL WINDS. HIGH PRESSURE WILL PROVIDE DRY WEATHER
TUESDAY...BEFORE MOISTURE TRYS TO RETURN FROM THE SOUTHWEST
WEDNESDAY.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1235 PM EST WEDNESDAY...

SURFACE HIGH PRESSURE WAS OVER THE OHIO VALLEY THIS AFTERNOON AND
WILL MOVE ACROSS THE AREA TONIGHT. WINDS WILL BECOME LIGHT AND
VARIABLE THIS EVENING. THE SMALL PATCH OF IFR CLOUDS OVER
SOUTHEAST WEST VIRGINIA THIS MORNING HAD NEARLY DISSIPATED. HIGH
CONFIDENCE CONDITIONS WILL BE VFR ACROSS MUCH OF THE MID ATLANTIC
THROUGH THURSDAY MORNING.

BY THURSDAY AFTERNOON...A CLIPPER WHICH WILL MOVE ACROSS THE
GREAT LAKES FROM WEST TO EAST. THE ASSOCIATED SURFACE FRONT WILL
SWEEP SOUTHEAST ACROSS THE OHIO VALLEY...PASSING OVER THE CENTRAL
APPALACHIANS LATE IN THE AFTERNOON...BRINGING A CHANCE OF SUB-VFR
CIGS AND VSBYS...WITH A CHANCE FOR -SHRA...-SHSN IN THE MOUNTAINS.

EXTENDED DISCUSSION...

BEHIND THE COLD FRONT...MVFR CIGS LIKELY TO LINGER OVER THE
MOUNTAINS INTO FRIDAY WITH STRONG NW WINDS ALSO PERSISTING INTO
FRIDAY EVENING. GUSTS UP TO 40 KNOTS ARE POSSIBLE IN THE HIGHER
ELEVATIONS. CLOUDS WILL BEGIN TO CLEAR OUT EAST OF THE BLUE RIDGE
ON FRIDAY MORNING...SO KLYH AND KDAN WILL IMPROVE BACK UP TO VFR.

ANOTHER AREA OF HIGH PRESSURE SHIFTS EAST INTO THE AREA SATURDAY
WITH VFR EXPECTED FOR BOTH SATURDAY AND SATURDAY NIGHT. THE NEXT
LOW PRESSURE SYSTEM HEADING OUT OF THE SW STATES WILL BRING A
RETURN OF CLOUDS AND SOME PRECIPITATION ON SUNDAY AND MONDAY WITH
WIDESPREAD MVFR TO IFR LIKELY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...KK
LONG TERM...MBS
AVIATION...AMS/PM



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