-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 151800
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
200 PM EDT TUE APR 15 2014

.SYNOPSIS...
FRONT NOW LOCATED JUST EAST OF THE BLUE RIDGE WILL SLIDE OUT OF
THE AREA BY LATE AFTERNOON. COLDER AIR BUILDS IN BEHIND THE FRONT. HIGH
PRESSURE WILL BUILD ACROSS THE AREA WEDNESDAY AND REMAIN IN
CONTROL OF THE AREAS WEATHER THROUGH FRIDAY WITH MODERATING
TEMPERATURES. A WEAK DISTURBANCE MOVING TOWARD THE REGION FROM THE
NORTHWEST MAY BRING THE NEXT CHANCE OF SHOWERS TO THE REGION FOR
THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1145 AM EDT TUESDAY...

NARROW BAND OF MODERATE TO HEAVY SHOWERS FORMING ALONG THE FRONT
STRETCHED FROM AMHERST AND ROCKBRIDGE SOUTH TOWARD THE NC/VA LINE
JUST ALONG AND EAST OF THE BLUE RIDGE. THE LATEST RAP/RUC SHOWS
THIS AREA SHIFT EAST THRU THE AFTERNOON. INSTABILITY REMAINS
LIMITED BUT ENOUGH TO ADD TO ISOLATED THUNDER EAST OF A LYH/DAN
LINE EARLY THIS AFTERNOON. FRONT SHOULD CLEAR THE EASTERN CWA BY
19-20Z. COLDER AIR WORKING IN BEHIND IT TO BRING SNOW SHOWERS TO
THE HIGHER ELEVATIONS THIS AFTERNOON. BROAD AREA OF PRECIP FROM
ERN TN INTO WRN WV SHOULD START TO EDGE INTO THE MOUNTAINS OF WRN
NC/SW VA/NW NC...BUT MODELS WEAKEN IT THRU THIS TIME WHERE AMOUNTS
OF ANY SNOW WILL BE LIGHT AROUND 1-2 INCHES AT MOST BY THIS
EVENING OVER THE HIGHEST RIDGES...DUE TO WARM GROUND. TEMPS SHOULD
BE IN THE 30S ACROSS THE WEST BY DUSK AND INTO THE 40S AROUND
ROANOKE/FOOTHILLS AND LOWER 50S EAST.

STILL LOOKS LIKE CLEARING TO THE EAST OF THE MOUNTAINS WILL BE
AFTER 5 PM...AND THAT SHOULD BE THE TIME THE HIGHER WIND GUSTS
START TO ROLL IN.


PREVIOUS VALID DISCUSSION...

VERY TIGHT PRESSURE GRADIENT WILL DEVELOP QUICKLY ALONG WITH
STRONG CAA. STRONGEST WINDS WILL BE ALONG THE BLUE RIDGE AS
TYPICAL FOR THIS TYPE OF PATTERN. HOWEVER...WINDS DO NOT MEET HIGH
WIND WARNING CRITERIA...SO HAVE ISSUED A WIND ADVISORY FROM
WATAUGA NORTHEASTWARD TO ROANOKE FROM 2 PM TO MIDNIGHT. THE TIME
FRAME OF THE VERY STRONG WINDS WILL BE A NARROW WINDOW...AND
MOSTLY FOCUSED WITHIN A FEW HOURS OF FRONTAL PASSAGE.

STRONG CAA WILL QUICKLY NET WINTERLIKE TEMPERATURES JUST A FEW
HOURS AFTER FRONTAL PASSAGE. LOW-LEVEL THICKNESS VALUES QUICKLY
DROP TO CRITICAL SNOW LEVELS WITHIN A FEW HOURS ACROSS THE
MOUNTAINS AS 850MB TEMPS PLUNGE TOWARD -12C IN EASTERN WV BY 06Z
WED. HAVE CONTINUED MENTION OF -SHSN THROUGH THE MOUNTAINS OF
EASTERN WV...SOUTHWEST VA...NORTHWEST NC AS TEMPERATURES DROP.
ACCUMULATIONS UP TO AN INCH APPEAR POSSIBLE...MAINLY AFTER 00Z
WHEN SFC TEMPS FALL BELOW FREEZING IN THOSE AREAS.

WILL START THE EVENING OFF WITH NORTHWEST WINDS HOLDING STRONG
ACROSS THE MOUNTAINS...WITH 45 TO 55 MPH GUSTS AT SPOTS ALONG THE
BLUE RIDGE SOUTH OF ROANOKE. TEMPERATURES BY SUNSET WILL BE COLD
ENOUGH THAT RAIN SHOWERS WILL HAVE ALREADY CHANGED TO SNOW ALONG
OUR WESTERN RIDGELINES...WITH AN ADDITIONAL HALF INCH OF SNOW
POSSIBLE THROUGH MIDNIGHT ACROSS WESTERN GREENBRIER COUNTY.

WIND SPEEDS AND SNOW SHOWERS WILL GRADUALLY DIMINISH THROUGH THE
NIGHT AS COLD HIGH PRESSURE MOVES UP THE OHIO RIVER VALLEY. ALL
MODELS ARE IN GOOD AGREEMENT THAT TEMPERATURES WILL FALL BELOW
FREEZING AREAWIDE BY SUNRISE WEDNESDAY...WITH WIND SPEEDS
DIMINISHING ENOUGH ACROSS THE PIEDMONT FOR A FEW PATCHES OF FROST TO
POSSIBLY DEVELOP. A FREEZE WARNING WILL BE IN EFFECT FOR COUNTIES
EAST OF THE BLUE RIDGE FOR TUESDAY NIGHT...MEANING THAT ANY
VEGETATION SENSITIVE TO FREEZING TEMPERATURES MAY BE KILLED IF NOT
PROTECTED. ALTHOUGH WE DO NOT BEGIN ISSUING FREEZE WARNINGS FOR THE
MOUNTAINS UNTIL BEGINNING APRIL 30TH...WE SHOULD BE MINDFUL THAT THE
RECENT WARM WEATHER MAY HAVE CAUSED SENSITIVE VEGETATION TO BEGIN
GROWING THERE AS WELL...WHICH WOULD ALSO BE AFFECTED BY THE COLD.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT TUESDAY...


AT ANY RATE...HIGH PRESSURE WILL BUILD SOUTHWARD TO HUG THE EASTERN
FACE OF THE APPALACHIANS ON WEDNESDAY...ALLOWING WINDS TO SHIFT
INCREASINGLY NORTHEASTERLY. CAN EXPECT ANOTHER ROUND OF FREEZING
OVERNIGHT LOWS FOR WEDNESDAY NIGHT AREAWIDE...THIS TIME WITH A MUCH
BETTER CHANCE FOR AREAS OF FROST TO DEVELOP DUE TO THE LIGHT WIND
SPEEDS AND CLEAR SKIES. AS SUCH...EXPECT WE WILL NEED ANOTHER FREEZE
WARNING FOR WEDNESDAY NIGHT EAST OF THE BLUE RIDGE.

LOOK FOR A SLIGHT WARMING TREND AS WE HEAD INTO THE FINAL DAYS OF
THE WORKWEEK AS WINDS ALOFT SHIFT SOUTHWESTERLY AHEAD OF ANOTHER
APPROACHING TROUGH. AT THE SURFACE...BELIEVE MODELS ARE TRYING TO
ERODE THE COLD HIGH PRESSURE WEDGED AGAINST THE APPALACHIANS TOO
QUICKLY...AND THEREFORE HAVE UNDERCUT MODEL GUIDANCE BY A FEW
DEGREES FOR THURSDAY AND FRIDAY TEMPERATURES. THAT STATED...BELIEVE
THURSDAY NIGHT LOWS WILL BE A FEW DEGREES WARMER...WITH THE
POTENTIAL FOR FREEZING TEMPERATURES LIMITED TO THE SHENANDOAH VALLEY
AND THE MOUNTAINS.

THE HIGH PRESSURE WEDGE WILL FINALLY BEGIN TO BREAK FRIDAY EVENING
AS ANOTHER LOW PRESSURE SYSTEM MOVES ACROSS THE GREAT LAKES...
DRAGGING A COLD FRONT TOWARD OUR AREA. EXPECT A FEW SHOWERS ACROSS
THE MOUNTAINS AS THE FRONT PASSES...BUT WITH NO RETURN FLOW OF
MOISTURE FROM THE GULF OR ATLANTIC AHEAD OF THE BOUNDARY...
PRECIPITATION IS EXPECTED TO BE LIGHT.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 355 PM EDT MONDAY...

WEAK TROUGH THROUGH THE MIDWEST EVENTUALLY PUSHES EAST...AND
WEDGING HIGH PRESSURE EVENTUALLY DEPARTS THIS WEEKEND. WITH A
RATHER DRY ANTECEDENT AIRMASS...QUESTIONABLE IF THIS MIDWEST
TROUGH PRODUCES ANY PRECIP ONCE IT ARRIVES ACROSS THE OHIO VALLEY
AND MIDDLE ATLANTIC THIS WEEKEND. OP GFS IS FAR MORE WET THAN THE
ECMWF. THUS...POPS WERE KEPT RATHER LOW. A ZONAL UPPER FLOW TAKES
SHAPE BY LATE WEEKEND INTO EARLY NEXT WEEK...WITH UNEVENTFUL AND
DRY WEATHER CONTINUING ACROSS THE REGION.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
AS OF 145 PM EDT TUESDAY...

DEALING WITH RAIN SHOWERS AND VARIABLE CIGS/VSBYS. COLDER AIR WILL
TRANSITION RAIN TO SNOW IN THE BLF/LWB SOON. SHOULD SEE CIGS LIFT
TO MVFR/VFR THROUGH THE AFTERNOON WITH DOWNSLOPE WINDS CLEARING
THINGS OUT THIS EVENING EAST OF THE MTNS. WINDS WILL BE GUSTY IN
THE 19-04Z TIME FRAME LEADING TO SVR TURBULENCE PER MOUNTAIN WAVE
ACTION.

ANY CIGS WILL BE GONE AT BLF/LWB AROUND 06Z TONIGHT. HIGH PRESSURE
ENTERS THE AREA WEDNESDAY WITH VFR THROUGH FRIDAY.

THE NEXT COLD FRONT APPROACHES FROM THE WEST FRIDAY BUT APPEARS
SLOW AND WEAK ENOUGH TO MAINTAIN VFR DURING THE DAY FOR NOW. THIS
SYSTEM MAY BRING MVFR CIGS TO THE MOUNTAINS SATURDAY ALONG WITH A
FEW SHOWERS OTRW VFR ELSW TO START THE WEEKEND.
-- End Changed Discussion --

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ022>024-
     032>035-043>047-058-059.
     WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VAZ014>017-022.
NC...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR NCZ003>006-
     019-020.
     WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001-002-018.
WV...NONE.

&&

$$
SYNOPSIS...RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...JH/RAB/WP