Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS61 KRNK 071153
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
653 AM EST SUN FEB 7 2016

.SYNOPSIS...
LOW PRESSURE ALONG THE SOUTHEAST ATLANTIC COAST WILL SLOWLY MOVE
NORTHEAST TODAY...PRECIPITATION ASSOCIATED WITH THIS FEATURE
REMAINING EAST OF OUR FORECAST AREA. A SECOND AREA OF LOW
PRESSURE WILL MOVE SOUTHEAST ACROSS THE UPPER MIDWEST AND INTO THE
GREAT LAKES. THE ARCTIC FRONT ASSOCIATED WITH THIS FEATURE WILL
CROSS OUR FORECAST AREA ON MONDAY. FOR TODAY AND TONIGHT WE WILL
REMAIN SANDWICHED BETWEEN THE TWO SYSTEMS WITH FAIR/DRY WEATHER.
PASSAGE OF THE ARCTIC FRONT ON MONDAY WILL BRING ONSET OF MUCH
COLDER TEMPERATURES AND MOUNTAIN SNOW SHOWERS. THE BITTER COLD
WILL LAST THROUGH MID WEEK WITH A MULTIDAY SNOW EVENT FOR THE
MOUNTAINS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 515 AM EST SUNDAY...

DEVELOPING STORM ALONG THE SOUTHEAST U.S. COASTLINE WILL BRING
RAIN TO THE COAST AND A MIX OF RAIN AND SNOW TO PORTIONS OF THE
EASTERN CAROLINAS. PRECIPITATION IS NOT EXPECTED TO REACH INTO
OUR FORECAST AREA PER VERY DRY AIRMASS...WHICH EXTENDS FROM THE
SURFACE UP THROUGH ABOUT 700 MB...AWAITING TO SWALLOW ANYTHING
THAT TRIES TO REACH THIS FAR NORTHWEST. ALL FORECAST MODELS HAVE
THIS SYSTEM UNDERGOING RAPID INTENSIFICATION AS IT MOVES
NORTHEAST...DEEPENING TO A 980 MB LOW AS IT PASSES WELL OFF THE VA
COAST MONDAY MORNING...A WINTERCANE IN THE MAKING.

PART OF THE REASON WHY THE COASTAL SYSTEM IS NOT GOING ANY
FARTHER INLAND IS THE RESULT OF A KICKER TROUGH WHICH IS RAPIDLY
MOVING SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER
MIDWEST. THE POSITIVE TILT TO THE UPPER TROUGH IS GIVING THE
COASTAL SYSTEM A BOOT TO THE EAST. THAT SAID...MOST OF OUR
FORECAST FOR THE UPCOMING WEEK WILL HINGE ON IMPACT FROM THE
APPROACHING UPPER MIDWEST TROUGH AND THE ARCTIC INTERLUDE THAT IT
BRINGS WITH IT BEGINNING MONDAY.

UNTIL THE THE ARRIVAL OF MONDAYS ARCTIC FRONT OUR FORECAST AREA
WILL REMAIN SANDWICHED BETWEEN THE TWO AREAS OF LOW PRESSURE...
SUBSIDENCE BETWEEN THE TWO SYSTEMS KEEPING OUR FORECAST FAIR/DRY
THROUGH 12Z/7AM MONDAY. THERE WILL BE A VEIL OF MID/UPPER LEVEL
CLOUDINESS WHICH WILL PERSIST OVER THE EASTERN 2/3RDS OF THE CWA
TODAY ASSOCIATED WITH THE COASTAL SYSTEM. BIGGEST IMPACT WILL BE
TO KEEP TEMPERATURES DOWN. FOR AREAS EAST OF HIGHWAY 29 SHAVED AT
LEAST 5 DEGREES OFF OF MAV MOS WITH THE THINKING THAT TEMPERATURES
WILL STRUGGLE WHERE THE THICKER CLOUDS PERSIST. WEST OF THE BLUE
RIDGE THERE SHOULD BE MORE SUN AND AN OPPORTUNITY TO REACH FULL
INSOLATION THIS AFTERNOON.

FOR TONIGHT...CLOUDS WILL EXIT THE EAST...BUT THEN BEGIN TO
INCREASE IN THE WEST PER THE APPROACH OF THE UPPER MIDWEST TROUGH.
NO PRECIPITATION IS EXPECTED ANYWHERE IN THE FORECAST AREA
TONIGHT WITH A DRY FORECAST BEING MAINTAINED THROUGH 0700 MONDAY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 400 AM EST SUNDAY...

LOW PRESSURE OFF THE VIRGINIA COAST MONDAY MORNING WILL INTENSIFY AS
IT LIFTS NORTHEAST ALONG THE EAST COAST MONDAY AFTERNOON INTO MONDAY
NIGHT. AS THE COASTAL LOW EXITS TO THE NORTHEAST ON MONDAY...A BROAD
UPPER LEVEL TROUGH IN THE NORTHERN STREAM WILL DIG SOUTHWARD FROM
THE GREAT LAKES TOWARD THE MID ATLANTIC REGION. A STRONG CLIPPER
SYSTEM ALONG THE LEADING EDGE OF THIS TROUGH WILL PROVIDE LIFT TO
GENERATE LIGHT SNOW WEST OF THE BLUE RIDGE DURING MONDAY. THE
NAM...GFS AND ECMWF HAVE ALL SLOWED THE ARRIVAL OF THE MOISTURE ON
MONDAY. DECREASED POPS FOR THE MONDAY MORNING IN THE EAST AND SPREAD
MOISTURE ACROSS FORECAST AREA MONDAY AFTERNOON.  PRECIPITATION TYPE
IS ALSO PROBLEMATIC WITH MORE SNOW IN WEST AND RAIN IN THE EAST. FOR
EXAMPLE...LOCATIONS IN THE PIEDMONT MIGHT START AS SNOW FLURRIES
MONDAY MORNING BEFORE CHANGING TO RAIN WITH TEMPERATURES RISING INTO
THE 40S. THE RAIN WOULD CHANGE BACK TO SNOW FLURRIES BY MONDAY
EVENING INTO MONDAY NIGHT AS TEMPERATURES DROP. USED A MIXTURE OF
RAIN AND SNOW FOR MONDAY...THEN TRANSITION TO SNOW SHOWERS FOR
MONDAY NIGHT. THE SLOWER ARRIVAL...MIXTURE OF RAIN AND SNOW...AND
TEMPERATURES WILL HINDER SNOW ACCUMULATIONS ON MONDAY. HIGH
TEMPERATURES MONDAY WILL RANGE FROM THE LOWER 30S IN THE NORTHWEST
MOUNTAINS TO THE MID 40S IN THE PIEDMONT.

THE BROAD UPPER LEVEL TROUGH WILL BE OVERHEAD BY MONDAY NIGHT...AS A
DEEP ARCTIC AIR MASS SPILLS OVER THE FORECAST AREA. WITH THE COLD
AIR COMING IN...SNOW SHOWERS AND SNOW FLURRIES WILL KICK IN
ESPECIALLY ALONG THE WESTERN SLOPES. LOW TEMPERATURES MONDAY NIGHT
WILL VARY FROM THE TEENS IN THE MOUNTAINS TO THE MID 20S IN THE
PIEDMONT. THE COMBINATION OF WIND AND TEMPERATURES MAY PRODUCE WIND
CHILLS MONDAY NIGHT INTO TUESDAY MORNING INTO THE SINGLE DIGITS AND
TEENS IN THE MOUNTAINS. A FEW OF THE HIGHEST ELEVATIONS IN NORTHWEST
NORTH CAROLINA MAY APPROACH WIND CHILL ADVISORY LEVELS. SNOW
ACCUMULATIONS ON MONDAY COULD RANGE FROM A COATING TO AROUND 5
INCHES IN NORTHWEST GREENBRIER COUNTY. WITH A LATER ONSET TIME...AND
COORDINATION WITH SURROUNDING WFOS DECIDED TO HOLD OFF ON ANY SNOW
ADVISORIES AT THIS TIME WITH THE PROLONG NORTHWEST SNOW EVENT.  WILL
MENTION THE POTENTIAL FOR WINTER WEATHER HEADLINES FOR MONDAY
AFTERNOON/EVENING INTO TUESDAY...IN THE HWO.

ENERGY FROM THE GREAT LAKES LOW PRESSURE SYSTEM WILL TRANSFER TO
COASTAL LOW OFF THE NORTH CAROLINA COAST TUESDAY. SNOW ACCUMULATIONS
OF ONE TO THERE INCHES MAY BE POSSIBLE ON TUESDAY INTO TUESDAY NIGHT
IN THE WEST MOUNTAINS WITH LIGHT AMOUNTS TO THE EAST. HIGH
TEMPERATURES TUESDAY WILL VARY GREATLY FROM THE LOWER 20S IN THE
NORTHWEST MOUNTAINS TO THE LOWER 40S IN THE PIEDMONT. LOW
TEMPERATURES TUESDAY NIGHT INTO WEDNESDAY MORNING WILL DROP INTO THE
TEENS TO THE MID 20S IN THE SOUTHEAST. WIND CHILL READINGS ON
TUESDAY NIGHT INTO WEDNESDAY MORNING... MAY BE AS COLD AS THE SINGLE
DIGITS WEST OF THE BLUE RIDGE BY DAWN...AND POSSIBLY HIT ZERO ALONG
THE WESTERN SLOPES. WILL INCLUDE MENTION OF SNOW AND WIND CHILLS IN
THE HWO.

&&

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

A DEEP ARCTIC AIR MASS SHOULD REMAIN ENTRENCHED OVER THE MID
ATLANTIC DURING WEDNESDAY AND THURSDAY. PERSISTENT NORTHWEST FLOW
SHOULD KEEP THE UPSLOPE SNOW MACHINE IN ACTION THROUGH WEDNESDAY
ALONG THE WESTERN SLOPES...BUT THE PIEDMONT SHOULD STAY DRY FROM THE
DOWNSLOPE FLOW. ALTHOUGH THE SNOWFALL THREAT WILL DECREASE LATER IN
THE WORK WEEK...THE THREAT FOR LOW WIND CHILL VALUES WILL INCREASE.
THE LONG RANGE MODELS PROJECT THAT THE WIND CHILL VALUES SHOULD
APPROACH WIND CHILL ADVISORY CRITERIA OF -5 F IN THE WESTERN
MOUNTAINS ON EARLY WEDNESDAY MORNING...AND EVEN LOWER TO -10 F BY
THURSDAY MORNING. WITH LOW TEMPERATURES DIVING INTO THE TEENS AND
UPPER SINGLE DIGITS AND A DECENT NORTHWEST BREEZE...THE WIND CHILL
THREAT IS WORTHY ENOUGH TO NOTE IN THE HWO.

TEMPERATURES SHOULD MODERATE A LITTLE BY FRIDAY AS THE UPPER LEVEL
TROUGH PUSHES EASTWARD. THE TROUGH AXIS LINGERS INTO THE WEEKEND.
THE ECMWF AND GFS SIGNIFICANTLY DIVERGE BEYOND FRIDAY INTO EARLY
NEXT WEEK. THE TIMING AND PLACEMENT OF SEVERAL SHORTWAVE ROTATING
AROUND THE UPPER TROUGH ARE DIFFERENT. THE PLACEMENT OF THE MOISTURE
AND POTENTIAL DEVELOPMENT OF ANOTHER COASTAL LOW BY SATURDAY REMAIN
IN QUESTION. IN GENERAL...TEMPERATURES WILL REMAIN BELOW NORMAL
DURING THE MEDIUM RANGE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM EST SUNDAY...

VFR CONDITIONS ARE EXPECTED THROUGH 12Z/7AM MONDAY FOR THE CENTRAL
APPALACHIANS.

OVER THE NEXT 24 HOURS...ENDING 12Z/7AM MONDAY...THE RNK FORECAST
AREA WILL BE SANDWICHED BETWEEN STRONG COASTAL CYCLONE NEAR THE
MID ATLANTIC COAST...AND AN UPPER LEVEL LOW OVER THE UPPER
MIDWEST AND WESTERN GREAT LAKES. IN SPITE OF THE POOR FLYING
CONDITIONS NEAR THE COAST...STRONG SUBSIDENCE ON THE WEST SIDE OF
THE STORM WILL RESULT IN SINKING MOTION OVER THE MOUNTAINS WITH
LITTLE OR NO CLOUD COVER BLO 10KFT. AREAS WEST OF KDAN/DANVILLE
WILL EXPERIENCE VFR CONDITIONS TODAY. FROM KDAN/DANVILLE EAST
THERE WILL BE A SOLID LAYER OF CLOUD ABOVE 10KFT WITH THREAT FOR
PRECIPITATION...LOWER CLOUD BASES AND VISIBILITY RESTRICTIONS EAST
OF INTERSTATE 95. WINDS TODAY WILL BE OUT OF THE NORTH...AND GUSTY
ACROSS THE PIEDMONT THE CLOSER YOU GET TO THE COASTAL STORM.


EXTENDED DISCUSSION...

FOR MONDAY INTO MID WEEK...A STRONG UPPER LEVEL LOW PRESSURE
SYSTEM WILL SINK SOUTHWARD FROM THE GREAT LAKES AND UPPER MIDWEST.
AN ASSOCIATED COLD FRONT WILL CROSS THE REGION MONDAY FOLLOWED BY
A SECOND SURGE OF ARCTIC AIR TUESDAY. NORTHWEST WINDS WILL
INCREASE WITH AN INFLUX OF VERY COLD AIR AND DEEP UPSLOPE
MOISTURE. SNOW SHOWERS WILL BEGIN MONDAY AND CONTINUE THROUGH
WEDNESDAY EVENING RESULTING IN VISIBILITY RESTRICTIONS ACROSS THE
MOUNTAINS IN ADDITION TO LOW CIGS. THIS SHOULD RESULT IN A
PROLONGED PERIOD OF MVFR TO IFR AT KBLF/KLWB AND POTENTIAL PERIODS
OF MVFR AT KBCB/KROA. ACCUMULATING SNOW IS LIKELY IN THE MOUNTAINS
WEST OF THE BLUE RIDGE. FLURRIES MAY OCCUR AS FAR EAST AS THE
PIEDMONT WHERE INTERVALS OF VFR TO MVFR CIGS WILL ALSO OCCUR.

CONDITIONS SHOULD BRIEFLY RETURN TO MAINLY VFR LATER WEDNESDAY
NIGHT INTO THURSDAY BEFORE POSSIBLY RETURNING TO SUB-VFR AGAIN
OVER THE MOUNTAINS FRIDAY ASSOCIATED WITH THE PASSAGE OF AN UPPER
LEVEL DISTURBANCE.

&&

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

&&

$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...KK
LONG TERM...KK/PW
AVIATION...PM


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.