Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 132328
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
728 PM EDT SUN APR 13 2014

.SYNOPSIS...
FRONTAL BOUNDARY FROM THE GREAT LAKES TO THE SOUTHERN PLAINS THIS
EVENING WILL TRACK EAST TO THE OHIO AND TENNESSEE VALLEYS BY
MONDAY EVENING...THEN ACROSS THE MID ATLANTIC REGION TUESDAY.
HIGH PRESSURE WILL BE OVER THE AREA WEDNESDAY...SHIFTING NORTHEAST
INTO FRIDAY.
&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 300 PM EDT SUNDAY...

OVERALL FORECAST DOES NOT CHANGE MUCH FROM THE PREVIOUS ONE. STILL
LOOKS LIKE GOOD SOUTHERLY FETCH OF MOISTURE WILL SLIDE NORTHWARD
ACROSS OUR AREA TONIGHT. MODELS SHOWING ENOUGH LOW LVL MOISTURE
AND UPSLOPE TO GENERATE SHOWERS ACROSS THE SOUTHERN BLUE RIDGE
LATE...WITH PATCHY DRIZZLE UP THE SPINE INTO THE ROANOKE AREA.

THE CORE OF THE LOW LEVEL JET SHIFTS FROM TN INTO THE OHIO VALLEY
BY MONDAY MORNING SO KEEPING THE HIGHER WINDS WEST OF US...BUT
WILL HAVE TO WATCH OUR FAR SW VA COUNTIES FOR GUSTS UP TO 40 MPH.

MONDAY MORNING THE MAIN STORM SYSTEM WILL STILL BE WELL WEST OF US
ACROSS THE MID MISSISSIPPI VALLEY INTO THE GREAT LAKES. ENOUGH JET
ENERGY AND SFC CONVERGENCE PUSHES INTO THE MOUNTAINS BY MIDDAY
WITH UPPER VORT MOVING ACROSS TO KEEP SHOWER CHANCES ABOVE 50
PERCENT...WITH LESS THREAT EAST OF LYH/DAN UNTIL AFTER 4 PM...WHEN
THE SHORTWAVE MOVES ACROSS. MODELS VARY ON TIMING OF INDIVIDUAL
WAVES...BUT IN THE BIGGER PICTURE ALL PAINT AN INCREASINGLY WET
MONDAY WITH HIGHS COOLER THAN TODAY...BUT STILL ABOVE NORMAL.

HIGHS WILL RANGE FROM THE LOWER 60S ACROSS THE MOUNTAINS OF NC
OVER TOWARD THE SRN BLUE RIDGE OF VA...TO UPPER 60S/NEAR 70 NEW
RIVER VALLEY...AND WILL SEE 70S BOTH OVER THE SE WV AREA AND
ALONG/EAST OF THE FOOTHILLS.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 205 PM EDT SUNDAY...

A COLD FRONT WILL APPROACH THE REGION FROM THE WEST MONDAY EVENING
AND WILL ENTER THE MOUNTAINS TUESDAY MORNING...SUPPORTED ALOFT BY A
STRONG UPPER LEVEL TROUGH. GUSTY WINDS...HEAVY RAINS AND FALLING
TEMPERATURES ASSOCIATED WITH THE FRONT AS IT PUSHES ACROSS OUR
REGION ARE THREE MAIN FORECASTING CONCERNS.

FIRST...THERE IS THE POTENTIAL FOR GUSTY WINDS WITH THE CONVECTION
ALONG THE FRONT...AS WELL AS THE GRADIENT WINDS BEHIND THE FRONT.
SEVERAL MODELS ARE IN GOOD AGREEMENT OF A 55+KT LOW LEVEL JET
DEVELOPING AHEAD OF THE FRONT...AND WHILE THUNDERSTORM ACTIVITY WILL
REMAIN LIMITED...EXPECT THAT THE STRONGER SHOWERS WILL BE CAPABLE OF
DRAWING THESE WINDS ALOFT DOWN TO THE SURFACE. THE SWODY3 PLACED THE
SLIGHT RISK OF SEVERE STORMS TO THE SOUTHEAST OF OUR AREA ACROSS
EASTERN NORTH CAROLINA.

6 HOUR PRESSURE RISES BEHIND THE COLD FRONT ARE QUITE IMPRESSIVE UP
TO 10 MB...WHICH WILL RESULT IN A PERIOD OF GUSTY NORTHWEST WINDS
FOR TUESDAY AFTERNOON INTO EARLY WEDNESDAY. WINDS SPEED ACROSS THE
HIGHEST TERRAIN WILL BE CLOSE TO WIND ADVISORY LEVELS.

SECOND...THERE IS THE POTENTIAL FOR HEAVY RAIN ALONG THE FRONTAL
BOUNDARY. A SOAKING INCH OF RAIN WILL BE COMMON FOR MOST OF THE
FORECAST ARE...WITH 1.5 TO 2 INCHES ALONG THE BLUE RIDGE AND HIGHER
RIDGES. A LONGER DURATION OF HEAVIER RAIN WOULD NOT BE A FLOODING
PROBLEM WITH SPRING PLANT DEVELOPMENT. HOWEVER...A SHORT PERIOD OF
HEAVY RAIN...MAY RESULTING IN LOCALIZED FLOODING ISSUES...SOMETHING
THAT WE WILL HAVE TO MONITOR CLOSELY.

LOW TEMPERATURES MONDAY NIGHT WILL DROP TO MID 40S IN THE NORTHWEST
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT. USED A NON-DIURNAL CURVE
WITH TEMPERATURES FALLING OFF QUICKLY WITH FRONTAL PASSAGE
TUESDAY...ON THE ORDER OF 5 TO 8 DEGREES PER HOUR FOR THE FIRST FEW
HOURS AFTER PASSAGE.

BY TUESDAY NIGHT...TEMPERATURES WILL DROP INTO THE LOWER 20S IN THE
MOUNTAINS TO THE MID 30S IN THE PIEDMONT. THERE MAY BE ENOUGH LINGER
MOISTURE TO ALLOW FOR RESIDUAL RAIN SHOWERS CHANGE OVER TO SNOW
SHOWERS BY SUNSET. ONLY LIGHT SNOW ACCUMULATION IS POSSIBLE WITH
WARM GROUND. SNOW SHOWERS OR FLURRIES WILL COME TO AN END EARLY
WEDNESDAY MORNING.

ON WEDNESDAY...HIGH PRESSURE WILL SLIDE EAST INTO NEW ENGLAND. THIS
WILL RESULT IN A COOL NORTHEAST FLOW WEDGING AGAINST THE
APPALACHIANS. HIGHS ON WEDNESDAY WILL RANGE FROM THE LOWER 40S IN
THE NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

IT WILL BE A COLD NIGHT WEDNESDAY NIGHT...WITH LOW TEMPERATURES IN
GENERALLY IN THE UPPER 20S TO MID 30S. THERE IS THE POTENTIAL FOR
PATCHY FROST OR A LIGHT FREEZE IN THE COLDER LOCATIONS.

&&

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

EXPECT HIGH PRESSURE TO CONTROL THE WEATHER PATTERN FOR THURSDAY
INTO FRIDAY. A COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT
INTO SATURDAY. GENERALLY FOLLOWED HPCGUIDE 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.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 700 PM EDT SUNDAY...

VFR CONDITIONS UNDER DIMINISHING SOUTHERLY WINDS WILL PREVAIL INTO
THIS EVENING. HOWEVER LOW LEVEL MOISTURE WILL BEGIN TO DEEPEN
LATER TONIGHT AS STRONGER SOUTH/SW FLOW ALOFT DEVELOPS WELL AHEAD
OF A COLD FRONT TO THE WEST. MOST GUIDANCE INDICATING THIS WILL
HAPPEN TO SOME DEGREE ESPCLY ALONG THE BLUE RIDGE AFTER MIDNIGHT
BUT DIFFER ON EXPANSE AND HOW FAR NORTH AND WEST TO TAKE LOWER
CIGS. LATEST NAM REMAINS THE MOST PESSIMISTIC IN BRINGING CLOUD
BASES DOWN TO IFR MOST SPOTS WHILE THE GFS AND ENSEMBLES MORE
MVFR TO VFR BY MORNING. THUS KEPT THE GOING TREND IN KEEPING CIGS
A BIT HIGHER BUT DID LOWER LATE TONIGHT WITH OVERALL MVFR CIGS AT
AT BCB/ROA/LYH/DAN WITH VFR TO THE WEST POTENTIAL FOR MVFR VSBYS
AND DRIZZLE EXISTS AS WELL ESPECIALLY AT BCB/ROA BUT CONFIDENCE
NOT HIGH ENOUGH TO INCLUDE ATTM GIVEN CURRENT DRYNESS.

CIGS ARE EXPECTED TO REMAIN VARIABLE IN THE HIGH END MVFR TO LOW
END VFR MOST SITES MONDAY MORNING BEFORE LOWERING AGAIN TO MVFR OVER
THE MOUNTAINS DURING THE AFTERNOON WHEN SHOWERS START TO INCREASE.
APPEARS THREAT OF SEEING A FEW BANDS OF SHRA OR ISOLD TSRA ENOUGH
TO INCLUDE A LATE DAY PREVAILING MENTION OF SHRA FROM ROA WEST
LATE MONDAY WHILE STAYING DRY OUT EAST.

LOOKS WET INTO TUESDAY WITH MOST STAYING BELOW VFR MONDAY NIGHT 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.
&&

.CLIMATE...
WARM SOUTHWEST FLOW BROUGHT RECORD HIGH TEMPERATURES THIS
AFTERNOON TO BOTH BLUEFIELD AND LEWISBURG WEST VA. SEE THE
WBCRERRNK PRODUCT FOR ADDITIONAL DETAILS.

&&

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

&&

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



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