Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 040602
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
202 AM EDT SAT JUL 4 2015

.SYNOPSIS...
A FRONTAL BOUNDARY WILL WORK SLOWLY NORTHEAST THROUGH THE AREA
TONIGHT INTO SATURDAY FOLLOWED BY A COLD FRONT. THE COLD FRONT
WILL HANG UP JUST SOUTH OF US SATURDAY NIGH INTO MONDAY. THIS WILL
KEEP OUR AREA IN AN UNSETTLED PATTERN THROUGH THE HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT FRIDAY...

RADAR SHOWED ANOTHER LARGE AREA OF MODERATE TO HEAVY SHOWERS
MOVING INTO SOUTHWEST VIRGINIA AND SOUTHEAST WEST VIRGINIA. HAVE
ADJUSTED PROBABILITY OF PRECIPITATION TO ACCOUNT FOR LATEST RADAR
TRENDS.

WARM FRONT EXTENDED FROM NEAR BLUEFIELD TO NEAR DANVILLE. NORTH
OF THE BOUNDARY WINDS WERE STILL OUT OF THE EAST TO NORTHEAST WITH
LOW CLOUDS AND DEW POINT DEPRESSION NEAR ZERO. LITTLE DROP IN
TEMPERATURE IS EXPECTED OVERNIGHT. HAVE ADDED PATCHY FOG IN THE
FORECAST TONIGHT FOR A LARGE PART OF THE COUNTY WARNING AREA. AS
THE FRONT DRIFTS NORTH CLOUDS AND FOG WILL LIFT...BUT IT MAY BE
MID MORNING BEFORE THE ALLEGHANY HIGHLANDS AND AREAS NORTH OF
ROUTE-460 GET OUT OF THE STRATUS AND FOG.

AS OF 300 PM EDT FRIDAY...

THE MODELS SEEM TO BE IN GENERAL AGREEMENT IN THE PATTERN TAKING
WAVY FRONT NORTH OF US SATURDAY MORNING. UNTIL THEN EXPECT SHOWERS
AND SOME THUNDERSTORMS THIS AFTERNOON INTO THE EVENING...WITH ONE
UPPER WAVE PASSING BY. A WINDOW OF SOMEWHAT DRY WX OCCURS
OVERNIGHT BEFORE THE ANOTHER WEAK WAVE MOVES ACROSS THE NC MTNS
OVERNIGHT INTO SATURDAY MORNING. THIS SECOND WAVE ONCE IT MOVES
EAST OF US MIDDAY SATURDAY WILL BE FOLLOWED BY A "COLD" FRONT
SATURDAY AFTERNOON.

THIS WILL BE THE FOCUS FOR MORE SHOWERS AND STORMS. GIVEN THE FLOW
TURNS MORE SW THEN WEST THE POPS WERE FOR MORE SCATTERED TO NUMEROUS
COVERAGE AND NOT EVERYONE WILL SEE RAIN SATURDAY BUT HALF TO 3/4 OF
YOU WILL AT LEAST FROM LATE MORNING INTO EARLY EVENING.

WITH CLOUDS AROUND TONIGHT...AND HIGH MOIST SFC CONDITIONS KEPT LOWS
AS WE HAVE HAD THEM THE PAST FEW NIGHTS LOWER TO MID 60S WEST TO
UPPER 60S/NEAR 70 EAST.

MAY SEE SOME SUNSHINE SATURDAY SO HIGHS WILL BE A FEW DEGREES WARMER
THAN TODAY RANGING FROM THE MID TO UPPER 70S WEST TO LOWER OR MID
80S EAST.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...

THE UNSETTLED WEATHER WILL CONTINUE INTO THE HOLIDAY WEEKEND.  A WAVE
OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY WILL LIFT NORTHEAST
SATURDAY EVENING INTO SATURDAY NIGHT. THIS WILL PUSH THE FRONT SOUTH
AS LOW CENTER MOVES AWAY FROM OUR AREA. LOW TEMPERATURES SATURDAY
NIGHT WILL RANGE FROM AROUND 60 DEGREES IN THE NORTHWEST MOUNTAINS
TO NEAR 70 DEGREES IN THE PIEDMONT.

THE FRONT GET HUNG UP ON SUNDAY ACROSS THE SOUTH AS CUTOFF LOW TAKES
SHAPE OVER NORTH CAROLINA. WIDESPREAD SHOWERS AND THUNDERSTORMS ARE
LIKELY...BUT THE EXTENSIVE CLOUD COVER WILL HINDER INSTABILITY.
LOCALIZED HEAVY RAINFALL WILL BE THE MAIN CONCERN...BUT GIVEN THAT
THE HEAVIEST RAINFALL SHOULD REMAIN MOSTLY EAST OF THE
MOUNTAINS...THIS FURTHER REDUCES CONCERNS OF FLOODING. WITH CLOUD
COVER AND RAIN...LEANED HIGHS TOWARDS THE COOLER MOS. HIGH
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS FROM AROUND
70 DEGREES IN THE MOUNTAINS TO THE LOWER 80S IN THE PIEDMONT.

THE BEST CHANCE OF CONVECTION SUNDAY WILL BE IN THE EAST. SCATTERED
SHOWERS WILL LINGER SUNDAY NIGHT. LOW TEMPERATURES SUNDAY NIGHT WILL
GENERALLY BE FROM AROUND 60 DEGREES TO THE UPPER 60S.

THE CLOUDY WET WEATHER CONTINUES MONDAY AS THE REMNANT UPPER LOW
DRIFTS INTO NORTHERN VA. THE BEST COVERAGE OF PRECIPITATION WILL BE
LOCATED ACROSS THE EASTERN SECTIONS...BUT DIFFERENTIAL HEATING
ACROSS THE MOUNTAINS SHOULD RESULT IN AN INCREASE OF AFTERNOON
CONVECTION COMPARED TO SUNDAY. WILL HOLD ON TO HIGH CHANCE TO LIKELY
POPS FOR MONDAY. INSTABILITY APPEARS MARGINAL AND THE MAIN CONCERN
WILL REMAIN THAT OF LOCALIZED HEAVY RAINFALL. HIGH TEMPERATURES
MONDAY WILL VARY FROM THE MID 70S IN THE MOUNTAINS TO THE MID 80S IN
THE PIEDMONT.

TAPER OF POPS MONDAY NIGHT INTO TUESDAY MORNING...AS SHOWN ON GFS
AND ECMWF. LOW TEMPERATURES MONDAY NIGHT WILL DROP INTO THE UPPER
50S IN THE NORTHWEST MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...

ON TUESDAY...SHORTWAVE ACROSS NORTHERN VIRGINIA WILL LIFT NORTHEAST
TOWARD NEW ENGLAND. AT THE SAME TIME...ANOTHER SHORTWAVE AND
ASSOCIATED FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY. HIGH
TEMPERATURES ON TUESDAY WILL WARM INTO THE LOWER 80S IN THE
MOUNTAINS T0 THE UPPER 80S IN THE PIEDMONT. COLD FRONT PUSHES
SOUTHEAST THROUGH THE OHIO VALLEY...WHILE SURFACE TROUGH WILL PUSH
EAST TO THE ATLANTIC TUESDAY NIGHT. LOWS TUESDAY NIGHT WILL
GENERALLY BE IN THE 60S.

THE FRONT DRIFTS SOUTH WEDNESDAY AND STALLS BY WEDNESDAY NIGHT.
HIGHS ON WEDNESDAY WILL AVERAGE FROM THE MID 70S IN THE MOUNTAINS TO
THE UPPER 80S IN THE PIEDMONT.  THIS BOUNDARY WILL REMAIN ACROSS OUR
REGION THURSDAY INTO FRIDAY NIGHT.

HOW FAR SOUTH THE BOUNDARY GOES IS DIFFERENT DEPENDING ON MODEL
CHOICE. THE ECMWF PUSHING THE COLD FRONT FARTHER SOUTH WITH SOME
SUPPORTIVE UPPER TROUGHINESS COMPARED TO GFS.

ONCE AGAIN WAVES OF LOW PRESSURE ARE EXPECTED TO FORM AND RIDE ALONG
THE FRONT KEEPING A GOOD CHANCES OF DIURNAL SHOWERS AND
THUNDERSTORMS ACROSS THE REGION. HIGH TEMPERATURES FOR THURSDAY AND
FRIDAY WILL MODERATE TO AROUND 80 DEGREES IN THE MOUNTAINS TO THE
MID TO UPPER 80S IN THE PIEDMONT. LOW TEMPERATURES WILL RANGE FROM
MID 60S IN THE MOUNTAINS TO AROUND 70 DEGREES IN THE PIEDMONT.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 200 AM EDT SATURDAY...

EXPECT VARIABLE CONDITIONS THROUGH THE TAF PERIOD.

LATEST RADAR LOOP SHOWS WIDELY SCATTERED LIGHT SHOWERS MOVING
ACROSS THE REGION FROM WEST TO EAST...AND CIGS/VSBYS ARE BOUNCING
AROUND A GOOD BIT. ANTICIPATING THE CIGS TO SETTLE DOWN INTO IFR
WITH VSBYS MVFR/IFR AND THIS IS INDICATED IN THE EARLY PORTION OF
THE TAFS. WILL NOT BE TOO QUICK TO AMEND UP IF VARIABLE CONDITIONS
PERSIST LONGER THAN EXPECTED.

ALL OF THIS WEATHER IS COURTESY OF THE PERSISTENT FRONTAL BOUNDARY
THAT HAS BEEN WAVERING ABOUT THE AREA FOR THE PAST SEVERAL DAYS.
THE LATEST ITERATION OF THIS SCENARIO HAS LOW PRESSURE MOVING TO
THE MID ATLANTIC REGION AND PUSHING THIS BOUNDARY BACK SOUTH AS A
COLD FRONT TODAY. AS THIS OCCURS AND WINDS COME AROUND TO THE
W/NW...CIGS/VSBYS WILL IMPROVE AND EXPECT VFR AT TAF SITES BY LATE
MORNING/EARLY AFTERNOON. MESO MODELS WANT TO REDEVELOP SHOWERS
WITH THE FRONT THIS AFTERNOON BUT EXPECT COVERAGE TO BE OF THE
SCATTERED VARIETY. WILL GO WITH VCSH AND ALLOW LATER PACKAGES TO
FINE TUNE TIMING/LOCATIONS OF ANY PRECIPITATION. INSTABILITY
CONTINUES TO BE LACKING SO EXPECT ONLY AN OUTSIDE CHANCE FOR TS.
LOW CLOUDS AND FOG WILL BE REDEVELOPING SATURDAY NIGHT BUT ANY
ADVERSE CONDITIONS LOOK LIKE THEY WILL BE SETTING IN AFTER THIS
VALID PERIOD.

EXTENDED AVIATION DISCUSSION...

POOR AVIATION CONDITIONS TO CONTINUE INTO NEXT WEEK...BUT WINDOWS
OF OPPORTUNITY FOR VFR CONDITIONS INCREASE INTO MON/TUE. UPPER
LOW/TROUGH WILL LINGER WEST OF THE VA/NC COASTAL PLAIN INTO THE
SOUTHEAST STATES THROUGH THE WEEKEND...THEN BEGIN TO DRIFT INTO
NORTHERN VA BY MON. MEANWHILE...A COLD FRONT WILL APPROACH FROM
THE OH VALLEY BY WED. THIS LEAVES A VERY UNSETTLED/WET PATTERN
ACROSS THE REGION THROUGH THE PERIOD.

EXPECT WIDESPREAD LATE NIGHT/EARLY MORNING LOW CLOUDS/FOG WITH
IFR-LIFR CIGS/VSBYS. OVERALL...CONDITIONS SHOULD IMPROVE TO MVFR-
VFR OUTSIDE SHRA/TSRA ACTIVITY DURING THE AFTERNOONS. AT THIS
POINT...TUESDAY APPEARS TO OFFER THE BEST OPPORTUNITY FOR MORE
WIDESPREAD VFR CONDITIONS.

&&

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

&&

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



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