Areal Flood Warning 2, NWS Blacksburg, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
642 AM EDT FRI SEP 14 2007

.SYNOPSIS...
HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL CONTINUE TO PULL OUT
OF THE REGION TODAY. LOW PRESSURE COMING THROUGH THE TENNESSEE
VALLEY WILL BE THE TRIGGER FOR WIDESPREAD RAIN TODAY AND TONIGHT.
A STRONG COLD FRONT WILL CROSS THROUGH THE AREA LATE
TONIGHT...LEADING IN DRIER AND MUCH COOLER AIR FOR EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CEILINGS ARE LOWERING AND RADAR IS INDICATING SHOWERS JUST
APPROACHING THE FAR SOUTHWEST COUNTIES OF THE FORECAST AREA.
PRECIPITABLE WATER WILL CONTINUE TO INCREASE TODAY...TO OVER 1.5
INCHES BY TONIGHT. COMBINATION OF GOOD INFLOW OFF THE ATLANTIC AND
UPSLOPE ON THE EAST SIDE OF THE BLUE RIDGE AS WELL AS WARM AIR
ADVECTION AND ISENTROPIC LIFT WILL RESULT IN WIDESPREAD RAIN
ACROSS THE REGION. INITIALLY THE FOCUS WILL BE IN THE NORTHWEST
NORTH CAROLINA MOUNTAINS AND ALONG THE BLUE RIDGE SOUTH OF
ROANOKE. THEN BY 18Z THE AIRMASS IN THE NORTHEAST COUNTY WARNING
AREA WILL BE SATURATED AND THE BEST UPSLOPE AND INFLOW SHIFTS
NORTH OF ROANOKE.

MODELS HOLD STABLE AIR IN OVER THE FORECAST AREA
TODAY...ESPECIALLY IN THE EAST. LEFT SCATTERED THUNDERSTORMS IN
THE FAR WEST AND SOUTH...OTHERWISE PRECIPITATION WILL BE
STRATIFORM.

GUIDANCE FOR TEMPERATURES TODAY HAD ANYWHERE FROM A 3 TO 10 DEGREE
RISE FROM MORNING LOWS. FOLLOWED THIS TREND FOR MAXIMUM
TEMPERATURES SINCE THERE WILL BE LITTLE HEATING WITH ALL THE
CLOUDS AND RAIN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TIMING OF THE COLD FRONT HAS NOT CHANGED...STILL EXPECTING IT TO
BE THROUGH THE FORECAST AREA BY 12Z SATURDAY. NO MAJOR CHANGES
NEEDED TO TIMING OF THE BACK EDGE OF THE PRECIPITATION. CUT BACK
ON WESTERN UPSLOPE SHOWERS FOR LATE FRIDAY NIGHT AND SATURDAY
MORNING.

LOWERED DEW POINTS A LITTLE BASED ON CURRENT GUIDANCE AND LOOKING
THE AIRMASS NOW WITH THE LARGE HIGH IN SOUTHWEST CANADA. THIS HIGH
WILL BE CENTERED IN PENNSYLVANIA SUNDAY MORNING. SO CONDITIONS
WILL BE FAVORABLE FOR THE VALLEYS IN SOUTHEAST WEST VIRGINIA AND
IN THE ALLEGHANY HIGHLANDS TO DROP INTO THE UPPER 30S TO LOWER
40S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
FOLLOWED HPCGUIDE WHICH LEANED EXTENDED RANGE TOWARDS 00Z ECMWF.
SURFACE HIGH PRESSURE TRAVELS TOWARD THE NORTHEAST EARLY NEXT WEEK
AS UPPER RIDGE REBUILDS OVER THE EAST. NORTHWEST FLOW EXPECTED
ALONG THE EASTERN SEABOARD AND A POSSIBLE WEAKNESS ALONG THE
SOUTHEAST COAST. NEAR SEASONABLE TEMPERATURES ANTICIPATED THRU
WEDNESDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CEILINGS ARE GRADUALLY LOWERING AND WILL BE DOWN TO MVFR LEVELS AT
DAN...ROA...BLF BY 18Z AS RAIN SPREADS AROSS THE FORECAST AREA
FROM THE SOUTHWEST. THE BEST LIFT AND EASTERLY UPSLOPE WILL BE
FROM 18-00Z. AFTER 00Z THE RAIN WILL BEGIN TO MOVE OUT TO THE
NORTHEAST. CEILINGS WILL BE IFR IN THE LARGE AREA OF RAIN WITH
VISIBILITIES AT MVFR LEVELS. LOW CLOUDS WILL REMAIN OVER THE AREA
UNTIL THE FRONT COMES THROUGH EARLY SATURDAY MORNING. CONDITIONS
WILL QUICKLY IMPROVE TO VFR AT ROA...LYH AND DAN SATURDAY
MORNING. MVFR CLOUDS WILL HOLD IN AT BLF AND LWB A LITTLE LONGER
BUT WILL STILL BE GONE BY 18Z SATURDAY.

BEHIND THE FRONT...A LARGE HIGH PRESSURE SYSTEM WILL MOVE FROM THE
OHIO VALLEY ACROSS PENNSYLVANIA AND NEW YORK THROUGH EARLY NEXT
WEEK. THIS WILL RESULT IN DRY WEATHER AND VFR CONDITIONS THROUGH
TUESDAY.

&&

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

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
500 AM EDT FRI SEP 14 2007

NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-
WVZ042>045-150900-
ASHE-ALLEGHANY NC-SURRY-STOKES-ROCKINGHAM-CASWELL-WATAUGA-WILKES-
YADKIN-TAZEWELL-SMYTH-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY-GRAYSON-
CARROLL-FLOYD-CRAIG-ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-
PATRICK-FRANKLIN-BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-
APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-MERCER-SUMMERS-MONROE-
GREENBRIER-
500 AM EDT FRI SEP 14 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...CENTRAL VIRGINIA...SOUTH
CENTRAL VIRGINIA...SOUTHWEST VIRGINIA...WEST CENTRAL VIRGINIA AND
SOUTHEAST WEST VIRGINIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
953 AM EDT FRI SEP 14 2007

NCZ003-019-VAZ016-032-141600-
SURRY-WILKES-CARROLL-PATRICK-
INCLUDING THE CITIES OF...DOBSON...WILKESBORO...GALAX...STUART
953 AM EDT FRI SEP 14 2007

...AREAS OF HEAVY RAIN PERSISTING ALONG THE BLUE RIDGE...

WIDESPREAD RAINFALL HAS MOVED UP THE EASTERN SLOPES OF THE BLUE
RIDGE OF NORTH CAROLINA AND VIRGINIA THIS MORNING...WITH SOME
AREAS OF EMBEDDED HEAVY RAIN. TOTAL RAINFALL AMOUNTS WERE
APPROACHING 2 INCHES IN SOME AREAS. WITH MORE RAINFALL EXPECTED
IN THESE AREAS OVER THE NEXT SEVERAL HOURS...MINOR FLOODING OF
POOR DRAINAGE AREAS IS LIKELY. FLOODING OF URBAN ROADWAYS WILL
CREATE HAZARDOUS TRAVEL CONDITIONS IN SOME AREAS.