-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 290506
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
106 AM EDT TUE JUL 29 2014

.SYNOPSIS...
AN UPPER TROUGH OF LOW PRESSURE WILL REMAIN CENTERED OVER THE EAST
COAST THROUGH THE MIDDLE OF THE WEEK. LIKEWISE...COOL HIGH
PRESSURE WILL SETTLE OVER THE REGION THROUGH WEDNESDAY. DURING THE
LATTER HALF OF THE WEEK AND HEADING INTO THE WEEKEND...THE UPPER
TROUGH WILL RETROGRADE WESTWARD...AND ALLOW FOR AN INCREASE IN
MOISTURE...MODERATING TEMPERATURES...AND POTENTIAL FOR SHOWERS
AND STORMS.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM EDT TUESDAY...

STILL A FEW SHOWERS ACROSS THE AREA THIS MORNING...WITH ONE BAND
MAKING OVER THE NEW RIVER VALLEY FROM SOUTHEAST WEST VIRGINIA.
RAPID UPDATE MODELS INDICATING THAT A FEW SPRINKLES WILL LINGER
THROUGH THE NIGHT HERE AND THERE...NOT DOING MUCH MORE THAN
WETTING THE SURFACE. REGARDLESS...WILL EXTEND SLIGHT RAIN CHANCES
THROUGH AROUND DAYBREAK. WINDS HAVE CALMED IN THE VALLEYS...SO
PATCHY FOG MAY FORM IN TYPICAL LOCATIONS AROUND RIVERS/LAKES BY
DAWN WITH COOLER AIR RUSHING IN. SKIES WILL REMAIN SOMEWHAT CLOUDY
OVER THE UPSLOPE REGIONS OF SOUTHEAST WEST VIRGINIA OVERNIGHT BUT
SCATTERED OUT TO THE EAST. FORECAST LOWS APPEAR ON TRACK...FROM
THE LOWER 50S ACROSS THE MTNS TO AROUND 60 OUT EAST.

LATER TODAY...OUR COOL PATTERN WILL CONTINUE WITH THE AXIS OF THE
UPPER TROUGH STILL OVER OUR REGION...AND THE CENTER OF SURFACE
HIGH PRESSURE WILL APPROACH FROM THE WEST. EMBEDDED WITH THE MAIN
UPPER TROUGH PATTERN...MODEL GUIDANCE OFFER A SOLUTION WITH A WEAK
DISTURBANCE WITHIN THE MAIN FLOW CROSSING MAINLY THE SOUTHERN HALF
OF THE AREA ON TUESDAY. WILL CONTINUE TO ALLOW FOR ISOLATED
SHOWERS IN THE FORECAST ACROSS THE SOUTHWESTERN PART OF THE
AREA...IN THE PATH OF THE DISTURBANCE AND WITHIN A ZONE OF WEAK
UPSLOPE 850 MB FLOW. HIGH ON TUESDAY ARE EXPECTED TO AVERAGE
AROUND FIVE DEGREES COOLER THAN THOSE REALIZED TODAY. LOW TO MID
70S ARE FORECAST ACROSS THE MOUNTAINS WITH UPPER 70S TO NEAR 80
ACROSS THE PIEDMONT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
AS OF 345 PM EDT MONDAY...

BY WEDNESDAY MORNING SURFACE HIGH PRESSURE IS CENTERED OVER THE
FORECAST AREA. A VERY WEAK PRESSURE GRADIENT REMAINS IN PLACE
THROUGH THURSDAY. PRECIPITABLE WATER VALUES GRADUALLY INCREASE BACK
UP INTO THE 1.0 TO 1.5 INCH RANGE BY LATE THURSDAY.

BUFKIT FORECAST SOUNDINGS FOR WEDNESDAY SHOW ENOUGH MIXING TO BRING
DEW POINTS DOWN INTO THE 40S FOR MUCH OF THE AREA DURING THE
AFTERNOON. WILL STAY CLOSE TO COOLER GUIDANCE FOR LOWS ON BOTH
TUESDAY NIGHT AND WEDNESDAY NIGHT. RECORD LOWS ARE STILL POSSIBLE
TUESDAY NIGHT WITH LOWS 5 TO 15 DEGREES BELOW NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 345 PM EDT MONDAY...

UPPER 500 MB TROF OVER THE NORTHEAST UNITED STATES AMPLIFIES ON
FRIDAY AND SATURDAY WITH A SIGNIFICANT SHORT WAVE OVER THE OHIO
VALLEY. MODELS SIMILAR IN SHOWING HEIGHT FALLS ON THE SOUTHERN END
OF THE TROF AND WHAT MAY EVENTUALLY BE A CUT OFF LOW OVER THE LOWER
MISSISSIPPI VALLEY OR SOUTHEAST UNITED STATES MONDAY.

MOISTURE BEGINS TO INCREASE ACROSS THE AREA ON FRIDAY BUT LITTLE IN
THE WAY OF ANY ORGANIZED LIFT TO TRIGGER ANY PRECIPITATION ASIDE
FROM DAILY THREAT OF AIRMASS TYPE SHOWERS AND THUNDERSTORMS. WITH
LITTLE CHANGE IN THE AIR MASS THERE WILL BE MINIMAL CHANGES IN HIGH
AND LOW TEMPERATURES EACH DAY. TEMPERATURES WILL BE NEAR NORMAL. NOT
ANTICIPATING ANY EXTREMES.

&&

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
AS OF 730 PM EDT MONDAY...

INCLINED TO KEEP THE NW FLOW SC IN THE WEST THROUGH MOST OF THE
EVENING...WITH MODELS SHOWING DOWNWARD TREND IN CIGS AT LWB/BLF
AND POSSIBLY BCB OVERNIGHT WITH MVFR/IFR CIGS. IN ADDITION FOG
WILL BE AN ISSUE...IF ANY CLEARING TAKES PLACE DESPITE THE DRY
AIRMASS...DUE TO WARM WATERS/COOLER AIR...AT LWB/BCB AND PERHAPS
BLF. BLF WILL BE MORE DUE TO LOWER CLOUDS IN THE MTNS THAN
RADIATION FOG AS WINDS STAY UP THERE.

FURTHER EAST VFR EXPECTED.

ANY SUB-VFR CONDITIONS WILL RAPIDLY IMPROVE TO VFR TUESDAY
MORNING.

EXTENDED AVIATION DISCUSSION...

PERSISTENT TROUGH PATTERN IN THE EAST WILL GRADUALLY RETROGRADE
WEST BY THE END OF THE WEEK. MAINLY VFR CONDITIONS ARE EXPECTED
THROUGH AT LEAST THURSDAY SAVE FOR SOME LATE NIGHT/EARLY MORNING
PATCHY MVFR FOG IN THE MOUNTAIN AND RIVER VALLEYS. AFTER
THURSDAY...WITH THE TROUGH AXIS FARTHER WEST...THIS WILL ALLOW FOR
A RETURN OF ATLANTIC MOISTURE AND A GREATER ABUNDANCE OF
SHOWERS...AND POTENTIALLY STORMS...IN THE FORECAST HEADING INTO
THE WEEKEND. THIS ALSO WILL ALLOW FOR INCREASED CHANCES OF SUB-VFR
CONDITIONS WITHIN THE AREA OF THE SHOWERS...AND THEN AGAIN
OVERNIGHT IN THE FORM OF LIGHT FOG OR STRATUS AS BOUNDARY MOISTURE
GETS TRAPPED UNDER THE NOCTURNAL INVERSION.

&&

.CLIMATE...
JULY 29TH RECORD LOWS:

ROANOKE......52...1925
BLUEFIELD....55...2013
DANVILLE.....58...1968
LEWISBURG....46...2013
LYNCHBURG....53...1920
BLACKSBURG...50...1983


JULY 30TH RECORD LOWS:

ROANOKE......54...1997
BLUEFIELD....50...1981
DANVILLE.....60...1972/81/83/2013
LEWISBURG....46...2013
LYNCHBURG....52...1997
BLACKSBURG...50...1973/81


JULY 31ST RECORD LOWS:

ROANOKE......49...1914
BLUEFIELD....49...1997
DANVILLE.....55...1966
LEWISBURG....48...1997
LYNCHBURG....49...1997
BLACKSBURG...44...1997

&&

.EQUIPMENT...
THE NOAA WEATHER RADIO AT WYTHEVILLE VA...WZ2500...BROADCASTING
ON A FREQUENCY OF 162.450 MHZ...IS OFF THE AIR...DUE TO PHONE LINE
ISSUES. PHONE COMPANY IS WORKING ON IT. NO ESTIMATED TIME FOR
RETURN TO SERVICE.

&&

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

&&

$$
SYNOPSIS...DS
NEAR TERM...DS/NF/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...DS/WP
CLIMATE...DS/PH
EQUIPMENT...DS