Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 211743
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1243 PM EST FRI NOV 21 2014

.SYNOPSIS...
YET ANOTHER ARCTIC HIGH WILL SETTLE OVER THE REGION TODAY...THEN
MOVE OFF TO THE EAST SATURDAY ALLOWING TEMPERATURES TO RETURN TO
MORE SEASONAL LEVELS FOR SATURDAY. A STRONG UPPER-LEVEL
DISTURBANCE WILL APPROACH THE REGION FROM THE SOUTHWEST
SUNDAY...MOVING THROUGH THE REGION SUNDAY NIGHT AND EARLY MONDAY
BRINGING WIDESPREAD RAIN TO THE REGION. UNSEASONABLY WARM
CONDITIONS ARE EXPECTED MONDAY IN THE WAKE OF THIS SYSTEM BEFORE A
COLD FRONT MOVES THROUGH TUESDAY AND RETURNS TEMPERATURES TO NEAR
OR SLIGHTLY BELOW NORMAL LEVELS FOR THE REMAINDER OF THE
THANKSGIVING WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS 933 AM EST FRIDAY...

MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES AND CLOUD COVER
FOR THIS MORNING INTO THIS AFTERNOON. HIGH PRESSURE SETTLES OVER
OUR REGION TODAY INTO TONIGHT. HAVE A GOOD AFTERNOON!

AS OF 330 AM EST FRIDAY...

THE FINAL IN THE SERIES OF FOUR ARCTIC HIGHS WILL SETTLE OVER THE
REGION TODAY. GUSTY NW WINDS WILL CONTINUE THROUGH THE
MORNING...THEN DIMINISH RAPIDLY AS THE CENTER OF THE HIGH DRIFTS
OVER THE REGION TONIGHT. UPSLOPE CLOUDS AND ISOLATED -SHSN OR
FLURRIES WILL LINGER ACROSS THE WESTERN SLOPES OF THE ALLEGHANYS
AND SOME OF THESE CLOUDS WILL BRIEFLY SPILL OVER TOWARD THE
MOUNTAINS ALONG THE MONROE/CRAIG MONROE/GILES COUNTY LINES IN SW
VA THROUGH 13/14Z. ALL MODELS INDICATE THAT VERY DRY AIR WILL
ADVECT OVER THE REGION THROUGH ALL LEVELS OF THE ATMOSPHERE BY
MID-DAY...SO WILL TREND TOWARD SKC BY AFTERNOON AND OVERNIGHT.
WELL BELOW NORMAL TEMPERATURES ARE EXPECTED AGAIN TODAY WITH MAX
TEMPS REMAINING BELOW FREEZING...UPPER 20S TO LOWER 30S ACROSS THE
ALLEGHANYS TO THE LOW AND MID 40S ACROSS THE PIEDMONT.
OVERNIGHT...RAPID WAA IS EXPECTED AT 850MB WITH WELL BELOW 0C
850MB TEMPS THROUGH MID-DAY TRANSITION CWA-WIDE BY 12Z SAT INTO
THE +4-+5C RANGE. THUS...THE COOLEST AREAS SAT MORNING WILL BE THE
DEEPER VALUES AND PIEDMONT CLOSER TO THE REMNANT ARCTIC HIGH. NEAR
IDEAL RADIATIONAL COOLING CONDITIONS OVERNIGHT UNDER THE ARCTIC
HIGH WITH CLEAR SKIES AND CALM WINDS. MANY HIGHER ELEVATIONS WILL
SEE WARMING OVERNIGHT AND MAY BE WARMER BY 12Z SAT THAN AT 00Z
THIS EVENING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WE WILL SQUEEZE OUT ONE MORE NICE DAY ON SATURDAY AS HIGH PRESSURE
SLIDES OF TO OUR EAST. THINGS WILL START GOING DOWNHILL SUNDAY NIGHT
AS LOW PRESSURE STARTS TO WIND UP OVER THE LOWER MISSISSIPPI VALLEY
AND A WARM FRONT APPROACHES FROM THE SOUTH. LIKE THE NAM IDEA OF
BRINGING POPS IN ALONG THE RIDGES A BIT FASTER AS FLOW WILL BECOME
MORE SELY AND FAVOR UPSLOPE...BUT THE BULK OF PRECIPITATION WILL
ARRIVES SUNDAY AFTERNOON AND CONTINUES INTO SUNDAY NIGHT. GRIDS SHOW
A FEW PIXELS OF WINTRY PTYPE AS THE ONSET OF PCPN ALONG THE RIDGES
EARLY SUNDAY MORNING...BUT WITH TEMP PROFILES DO NOT ANTICIPATE ANY
ISSUES AS WE SHOULD BE ALL LIQUID BY DAYBREAK SUNDAY.

THE BEST ENERGY WITH THIS SYSTEM SLIDES BY TO OUR NORTHWEST CLOSER
TO THE PARENT LOW AS IF MOVES NORTH INTO THE GREAT LAKES...AND WITH
SECOND LOW LEVEL JET MAX MORE TOWARD THE COASTAL PLANE. CURRENTLY
BELIEVE QPF DISTRIBUTION WILL BE HIGHEST EAST OF THE BLUE RIDGE FROM
THE NC FOOTHILLS UP THROUGH SOUTHSIDE VA WHERE VALUES OF ROUGHLY ONE
HALF TO THREE QUARTERS OF AN INCH CAN BE EXPECTED...WITH LESSER
AMOUNTS FURTHER NORTH AND WEST.

LOW LEVEL WINDS WILL BE HOWLING BUT MODEL SOUNDINGS DO NOT SHOW GOOD
MOMENTUM TRANSFER TO THE SURFACE. HOWEVER THE HIGHER RIDGES ARE A
CONCERN FOR WIND SUNDAY AFTERNOON INTO SUNDAY NIGHT AND WILL
CONTINUE TO MENTION IN THE HWO.

THE LOW BOMBS OUT AS IT CONTINUES TO MORE NORTHWARD THROUGH THE
GREAT LAKES AND INTO CANADA. THIS WILL PUT US IN A DRY SLOT ON
MONDAY AHEAD OF THE COLD FRONT. WITH ALL OF THE ENERGY SHEARING OFF
TO OUR NORTHWEST...PRECIPITATION CHANCES WILL DECREASE CONSIDERABLY
FOR MONDAY AS TEMPS WARM WELL INTO THE 60S.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 1230 PM EST THURSDAY...

FRONT CROSSES THE REGION MONDAY NIGHT INTO TUESDAY WITH A FEW
SHOWERS POSSIBLE WHILE MUCH OF THE COLD AIR LAGS THE BOUNDARY
GIVEN THE STRONG SW FLOW ALOFT. AGAIN MAY BE VOID OF MUCH SHRA BUT
LEAVING IN A LOW POP TO COVER ISOLATED COVERAGE BUT DECREASING BY
TUESDAY AFTERNOON BEHIND THE BOUNDARY. SHOULD AGAIN BE PRETTY MILD
MONDAY NIGHT PER LOWS IN THE 40S AND MOSTLY 50S TO AROUND 60 SE
TUESDAY IF NOT WARMER ESPCLY IF THE FRONT SLOWS.

COOLER AIR SHOULD FINALLY MAKE SOME INROADS WEDNESDAY INTO THURSDAY BUT
TO WHAT DEGREE REMAINS IN QUESTION GIVEN QUITE DIFFERENT SCENARIOS IN
DAYS 6-7 IN LATEST MODELS. COLDER GFS MORE PRONOUNCED IN DIGGING A DEEP
5H TROUGH OVER THE EAST WHILE THE ECMWF MORE ZONAL WITH MORE ENERGY
SPILLING OVER THE RIDGE FARTHER TO THE WEST AND THE CMC IN BETWEEN.
THIS SPELLS DIFFERENCES IN TEMPS BY 10-15 DEGREES INTO THANKSGIVING
ALONG WITH ADDED UPSLOPE PRECIP VS JUST DRY WITH SEASONAL TEMPS. GIVEN
TRENDS WITH MORE TROUGHING OVER THE EAST...GOING COOLER BUT A BIT ABOVE
THE GFS WHILE KEEPING THINGS DRY BUT A GOOD 5-10 DEGREES BELOW NORMAL.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1242 PM EST FRIDAY...

HIGH PRESSURE WILL PROVIDE OUR REGION WITH VFR CONDITIONS THIS
AFTERNOON INTO TONIGHT. NORTHWEST WINDS AROUND 10 MPH WITH GUSTS
UP TO 20 MPH ACROSS THE RIDGES WILL DIMINISH THIS EVENING INTO
TONIGHT AS THE HIGH CENTER DRIFTS EAST OVER THE REGION TONIGHT.
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT INTO SATURDAY.

HIGH PRESSURE WILL CONTINUE TO BRING VFR CONDITIONS TO TAF SITES
THROUGH SATURDAY. THE HIGH CENTER WILL PUSH OFF THE COAST SATURDAY
NIGHT INTO SUNDAY.

HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS THROUGH THE
TAF VALID PERIOD.

EXTENDED DISCUSSION...

THE NEXT SIGNIFICANT WEATHER MAKER WILL ARRIVE ON SUNDAY WITH
POOR AVIATION CONDITIONS IN PRECIPITATION AND MVFR OR LOWER
CIGS...ESPECIALLY SUNDAY AFTERNOON/NIGHT. ALSO...STRENGTHENING
LOW LEVEL WINDS LATER ON SUNDAY MAY LEAD TO LLWS
CONDITIONS...ESPECIALLY THE BLF AREA. A BRIEF RETURN TO VFR DURING
MONDAY OUTSIDE OF THE MOUNTAINS AS A DRY SLOT DEVELOPS BETWEEN THE
EXITING FRONT FROM SUNDAY AND THE NEXT UPSTREAM COLD FRONT. FOR
THE REMAINDER OF NEXT WEEK...EXPECT PERIODS OF MVFR CIGS ACROSS
EASTERN WV/FAR SW VA...BUT MOSTLY VFR ELSEWHERE WITH A COLDER NW
FLOW.

&&

.EQUIPMENT...
AS OF 245 PM EST THURSDAY...

THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.

&&

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

&&

$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...MBS
LONG TERM...JH
AVIATION...KK/MBS/RAB
EQUIPMENT...RAB


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