-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 140855
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
455 AM EDT MON APR 14 2014

.SYNOPSIS...
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LOW PRESSURE WAS OVER ILLINOIS WITH A COLD FRONT TRAILING FROM
THE LOW INTO TEXAS. THIS FRONT WILL MOVE EAST TODAY AND TONIGHT
AND WILL CROSS THE MID ATLANTIC REGION ON TUESDAY. BEHIND THE
FRONT HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY THROUGH FRIDAY.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
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AS OF 415 AM EDT MONDAY...

WATER VAPOR LOOP SHOWED A WELL DEFINED SHORT WAVE CROSSING THROUGH
THE TENNESSE VALLEY. THICK CLOUD COVER WAS ALREADY SPREADING INTO
THE COUNTY WARNING AREA FROM THE WEST. SHORT RANGE MODELS
INCLUDING THE LATEST RUC/WRF AND HRRR BRING THE PRECIPITATION
ASSOCIATED WITH THIS WAVE INTO THE WESTERN COUNTY WARNING AREA
BETWEEN 15Z/11AM AND 18Z/2PM.

WITH ALL THE CLOUD COVER DO NOT EXPECT MUCH INSTABILITY. BUFKIT
OFF THE NAM AND GFS SHOWED LOW CAPE VALUES TODAY. HELD PROBABILITY
OF THUNDER TO SLIGHT CHANCE. DO EXPECT ISOLATED TO SCATTERED
SHOWERS AHEAD OF THE TENNESSEE VALLEY SHORT WAVE...WITH THE BETTER
AREAL COVERAGE IN THE MOUNTAINS THROUGH NOON. HIGH TODAY WILL
STILL BE ABOVE NORMAL BUT ONLY A SMALL RISE FROM THE CURRENT MILD
TEMPERATURES.

MUCH BETTER SYNOPTIC SCALE LIFT AFTER 00Z/8PM THIS EVENING. AS THE
COLD FRONT APPROACHES LATE TONIGHT...SURFACE AND LOW LEVEL WINDS
BACK...ADDING THE SOUTHEAST UPSLOPE COMPONENT TO THE STRONG
FORCING. LARGEST PRECIPITATION AMOUNTS WILL BE AFTER MIDNIGHT.
FRONT DOES NOT REACH THE FAR WESTERN PART OF THE FORECAST AREA
BEFORE 12Z/8AM. STAYED CLOSER TO THE WARMER GUIDANCE FOR OVERNIGHT
LOWS. THE LOW LEVEL JET INCREASES OVERNIGHT. HIGHER ELEVATIONS
MAY HAVE GUSTS OF 25 TO 30 MPH.
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&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
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AS OF 400 AM EDT MONDAY...

A STRONG COLD FRONT WILL MAKE ITS WAY ACROSS THE FORECAST AREA
BEGINNING TUESDAY MORNING...AND THEREFORE WILL HAVE SEVERAL THINGS
TO KEEP AN EYE. MODELS CONTINUE TO INDICATE A SOUTHWESTERLY 55KT LOW
LEVEL JET DEVELOPING AHEAD OF THE FRONT. INSTABILITY AHEAD OF THE
FRONT WILL BE MARGINAL...RESULTING IN MAINLY HEAVY SHOWER ACTIVITY
WITH ONLY ISOLATED THUNDER AS THE FRONT PASSES. HOWEVER...WITH THE
JET BLOWING JUST OFF THE SURFACE OVER THE MOUNTAINS...WOULD NOT BE
SURPRISED TO SEE SOME OF THE MORE INTENSE SHOWER ACTIVITY DRAW THE
STRONGER WINDS DOWN TO THE GROUND LEVEL.

HIGH PRESSURE WILL BUILD IN QUICKLY AFTER THE COLD FRONT PASSES...
RESULTING IN A ROUGHLY 10MB PRESSURE GRADIENT ACROSS THE FORECAST
AREA FROM MID AFTERNOON THROUGH ALMOST MIDNIGHT. EXPECT STRONG
NORTHWEST WINDS WITH 40 TO 50 MPH GUSTS ACROSS THE MOUNTAINS...WITH
THE STRONGEST GUSTS FOUND ALONG THE BLUE RIDGE PARKWAY SOUTH OF
ROANOKE. THESE GUSTS...WHEN COMBINED WITH PROLONGED RAINFALL...WILL
LIKELY BE ENOUGH TO BRING DOWN A FEW TREES...AND RESULT IN LOCALIZED
POWER OUTAGES.

RAINFALL WILL BE WIDESPREAD AND HEAVY AT TIMES...WITH A STORM TOTAL
AMOUNT OF OVER AN INCH FOR THE ENTIRE FORECAST AREA...WITH AROUND 2
INCHES EXPECTED ALONG THE BLUE RIDGE. MAY SEE LOCALIZED MINOR
FLOODING ISSUES DEVELOP WHERE BANDS OF HEAVY RAIN PASS REPEATEDLY
OVER THE SAME LOCATIONS. RAINFALL MAY ALSO PUSH SOME RIVERS TO
BANKFULL OR MINOR FLOOD LATER IN THE WEEK.

FOR THE FIRST FEW HOURS AFTER FRONTAL PASSAGE...TEMPERATURES WILL
PLUMMET AT A RATE OF 6 TO 9 DEGREES PER HOUR. EXPECT TEMPERATURES TO
APPROACH FREEZING FROM SOUTHEAST WEST VIRGINIA THROUGH THE NORTH
CAROLINA MOUNTAINS BY EARLY EVENING...ALLOWING RAIN SHOWERS TO
CHANGE OVER TO SNOW. WHILE WARM GROUND TEMPERATURES WILL CAUSE SNOW
TO MELT ON CONTACT ACROSS MANY AREAS...MAY SEE UP TO A HALF INCH OF
SNOW ACCUMULATE ALONG OUR MORE PROMINENT WEST FACING SLOPES BEFORE
SNOW SHOWERS END OFF SHORTLY AFTER MIDNIGHT WEDNESDAY.

NEXT WE GET TO DEAL WITH SUB FREEZING TEMPERATURES AREAWIDE BY
SUNRISE WEDNESDAY. EXPECT OVERNIGHT LOWS TO RANGE FROM THE MID 20S
ACROSS SOUTHEAST WEST VIRGINIA TO THE LOW 30S ACROSS THE SOUTHSIDE.
PRECAUTIONS SHOULD BE TAKEN TO PROTECT ANY PLANTS THAT MAY BE KILLED
BY FREEZING TEMPERATURES.

HIGH PRESSURE WILL PASS FROM THE GREAT LAKES TO NEW ENGLAND ON
WEDNESDAY...AND WILL BUILD SOUTHWARD ALONG THE EASTERN FACE OF THE
APPALACHIANS. THE NORTHEASTERLY WIND FLOW AROUND THE HIGH WILL KEEP
COOL CONDITIONS IN PLACE HEADING INTO THE SECOND HALF OF THE
WORKWEEK...WITH FREEZING TEMPERATURES LIKELY AGAIN WEDNESDAY NIGHT.
A GRADUAL WARM UP WILL TAKE PLACE THURSDAY AS WINDS ALOFT BEGIN TO
SHIFT SOUTHWESTERLY AGAIN.
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&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
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AS OF 200 PM EDT SATURDAY...

EXPECT HIGH PRESSURE TO REMAIN IN CONTROL OF THE WEATHER PATTERN FOR
FRIDAY. A COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT INTO
SATURDAY. GENERALLY FOLLOWED WPCGUIDE FOR POPS. STILL LOOKS LIKE
THE BEST CHANCE FOR WIDESPREAD RAIN WILL OCCUR ON FRIDAY NIGHT
INTO SATURDAY. LEANED TOWARDS THE ECENS MEAN WITH HANDLING THE
SOUTHERN STREAM SYSTEM AND ITS MOISTURE. TEMPERATURES MODERATE
TOWARD NEXT WEEKEND CLOSER TO NORMAL.
-- End Changed Discussion --

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 130 AM EDT MONDAY...

CEILINGS WILL GRADUALLY LOWER THIS MORNING. MVFR CLOUDS WILL FORM
ALONG THE BLUE RIDGE AND IN THE FOOTHILLS BEFORE 12Z. THERE IS
A LOW POSSIBILITY THAT CEILINGS WILL EVEN DROP TO IFR AT KBCB
BEFORE 12Z.

MODELS BRING THE SHORT WAVE ENTERING THE TENNESSEE VALLEY ACROSS
THE REGION MAINLY BETWEEN 15Z/11AM AND 21Z/5PM. WITH ALL THE
CLOUD COVER DURING THE DAY...THERE WILL BE ONLY A LIMITED THREAT
OF ANY THUNDER. MODERATE CONFIDENCE THAT VISIBILITIES WILL REMAIN
VFR AND NOT LOWER AS THE SHOWERS MOVE THROUGH.

THE STRONG COLD FRONT WILL ARRIVE IN THE MOUNTAINS BY 12Z/8AM
TUESDAY. WILL HOLD OFF ADDING ANOTHER PERIOD OF RAINFALL IN UNTIL
AFTER THE END OF THE 06Z TAFS.

LOOKS WET TUESDAY THRU TUESDAY NIGHT. STRONG GUSTY NW WINDS ARE
LIKELY BEHIND THE FRONT TUESDAY AFTERNOON AND NIGHT. DRIER AIR
WORKS IN BEHIND THE SYSTEM FOR WEDNESDAY ALTHOUGH RESIDUAL
MOISTURE AND COLD AIR ALOFT MAY ACT TO KEEP MVFR CIGS OVER THE
MOUNTAINS ON TUESDAY NIGHT. VFR THEN EXPECTED THURSDAY WITH HIGH
PRESSURE RIDGING IN FROM OFF NEW ENGLAND BETWEEN THE EXITING FRONT
OFFSHORE AND THE NEXT COLD FRONT TO THE NW. NEXT COLD FRONT
APPROACHES FROM THE WEST FRIDAY BUT APPEARS SLOW ENOUGH TO
MAINTAIN VFR DURING THE DAY FOR NOW.

&&

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

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/JH