Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 242350
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
750 PM EDT FRI OCT 24 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD THROUGH SATURDAY. A REINFORCING
COLD FRONT WILL PASS THROUGH THE REGION LATE SATURDAY NIGHT INTO
SUNDAY BEFORE HIGH PRESSURE RETURNS FOR MONDAY. THE HIGH WILL MOVE
OFF THE COAST DURING THE MIDDLE PORTION OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
A SHORTWAVE TROUGH WILL ROUND THE BASE OF AN UPPER LEVEL TROUGH AND
MOVE ACROSS THE SE US TODAY. HIGH PRESSURE WILL CONTINUE TO MOVE
INTO THE APPALACHIAN REGION OF THE MID-ATLANTIC WHILE LOW PRESSURE
ACROSS THE NRN ATLANTIC MOVES AWAY.

NW WINDS 15-20 MPH WITH GUSTS UP TO 25 MPH ARE EXPECTED THIS
AFTERNOON MAINLY EAST OF THE BLUE RIDGE WHERE A PRESSURE GRADIENT STILL
EXISTS BETWEEN THE TWO SFC FEATURES. THIS GRADIENT WILL MOVE
EASTWARD TONIGHT AND WINDS ARE EXPECTED TO DIMINISH. ONLY MID-HIGH
LEVEL CLOUDS EXPECTED TODAY AHEAD OF THE APPROACHING SHORTWAVE
TROUGH. FCST MIN TEMPS AROUND 40 DEG ARE EXPECTED.

HIGH PRESSURE WILL MOVE FURTHER INTO THE MID-ATLANTIC SATURDAY WHILE
THE SHORTWAVE TROUGH MOVES OFF THE SC/GA COAST. MOSTLY SUNNY
CONDITIONS ARE EXPECTED SATURDAY WITH W-SW WINDS AROUND 10 MPH. A
DRY COLD FRONT WILL APPROACH THE ALLEGHENY FRONT SATURDAY
AFTERNOON AND OVC CONDTIONS ARE EXPECTED IN UPSLOPE LOCATIONS. FCST MAX
TEMPS WILL BE SLIGHTLY WARMER THAN TODAY...FRIDAY...MID TO UPPER
60S EXPECTED.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
VERTICALLY STACKED LOW PRESSURE WILL TRAVEL ACROSS SOUTHERN QUEBEC
SATURDAY NIGHT...WITH A TRAILING COLD FRONT CROSSING THE LOCAL AREA.
THIS FRONT WILL BE VERY WEAK IN NATURE AS THE MOISTURE AND FORCING
WITH THIS SYSTEM WILL BE WELL TO OUR NORTH. CONDITIONS MAY BE
FAVORABLE FOR UPSLOPE SHOWERS OR SPRINKLES...BUT GIVEN THE SHALLOW
NATURE OF THE MOISTURE...WOULD EXPECT ANY AMOUNTS TO BE VERY LIGHT.
ANY PRECIPITATION THAT DOES FALL SHOULD BE IN LIQUID FORM AS
OVERNIGHT LOWS WILL BE NEAR 40 IN THE HIGHER ELEVATIONS. MUCH IN THE
WAY OF CLOUD COVER MAY BE DIFFICULT TO COME BY WITH THE FRONTAL
PASSAGE EAST OF THE MOUNTAINS WITH LOWS IN THE UPPER 40S TO LOW 50S.

PRESSURE GRADIENT FROM SYSTEM TO THE NORTHEAST WILL RESULT IN A
BREEZY SUNDAY WITH GOOD MIXING. MINIMAL THERMAL DIFFERENCES BEHIND
THE FRONT...PLENTIFUL SUN AND A DOWNSLOPE FLOW WILL RESULT IN HIGH
TEMPERATURES SIMILAR TO SATURDAY ACROSS MOST OF THE AREA...NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS. HIGH PRESSURE WILL BUILD INTO THE
CENTRAL APPALACHIANS SUNDAY NIGHT AND WITH A DRY ATMOSPHERE...
FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP. HAVE
MID-UPPER 30S WEST OF THE METROS BUT FEEL THESE AREAS COULD SNEAK A
FEW DEGREES COOLER. MENTION OF PATCHY FROST HAS BEEN MAINTAINED IN
THESE AREAS. MID 40S CAN BE EXPECTED IN THE METROS. THE HIGH WILL
SLIDE TOWARD THE CAROLINA COAST ON MONDAY WITH MID/UPPER LEVEL
RIDGING EXPANDING TOWARD THE EAST COAST. MANY LOCATIONS WILL SEE
HIGHS NEAR OR ABOVE 70.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ECMWF INDICATES THAT A SHORTWAVE FROM NORTHERN PLAINS CROSSING GREAT
LAKES BY LATE TUESDAY. 500MB TROUGH AND WEAK PVA CROSSING CWA
WEDNESDAY. NEXT SHORTWAVE TO CROSS CWA FRIDAY THROUGH SATURDAY.
SURFACE FRONT FROM WEST WILL CROSS THE CWA TUESDAY NIGHT INTO
THURSDAY MORNING. ANOTHER FRONT FROM THE WEST WILL AFFECT THE CWA
FROM LATE THURSDAY INTO FRIDAY AFTERNOON. CERTAINTY REMAINS LOW THIS
FAR OUT IN THE FORECAST PERIOD. ALTHOUGH ECMWF TIMING SEEMS TO TRACK
FAIRLY WELL WITH HPC ENSEMBLE HPC INDICATES THAT PATTERN WILL
PRODUCE LESS PRECIPITATION THAN ECMWF.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
CI DECK CROSSING THE TERMINALS THIS EVNG. WNDS SUBSIDING...AND HV
ACTUALLY DCPLD AT SVRL SITES. VFR CONDITIONS EXPECTED TONIGHT AND
SATURDAY AS HIGH PRESSURE MOVES OVER THE REGION.

CLOUDS WILL INCREASE FROM THE NORTHWEST SAT NIGHT INTO SUNDAY. VFR
CONDITIONS EXPECTED. GUSTY NW WINDS ARE EXPECTED SUNDAY.

&&

.MARINE...
WINDS HV SUBSIDED ACRS THE ENTIRE MARINE AREA. ALLOWED THE SCA FOR
MOST OF THE WATERS TO EXPIRE AT 6PM...AND HV CANCELLED THE REST.

HIGH PRESSURE MOVES NEAR THE WATERS TONIGHT AND SATURDAY. W-NW
WINDS ARE EXPECTED BUT WILL STAY BELOW SCA CRITERIA.

A DRY COLD FRONT WILL MOVE OVER THE WATERS BY SUNDAY AND NW WINDS
WILL INCREASE ACROSS THE WATERS. A SCA IS LIKELY SUNDAY AND SUNDAY
NIGHT.

HIGH PRESSURE WILL BUILD OVERHEAD LATE SUNDAY NIGHT INTO MONDAY
BEFORE MOVING OFF THE COAST LATER MONDAY THROUGH THE MIDDLE
PORTION OF NEXT WEEK. A SOUTHERLY FLOW WILL INCREASE DURING THIS
TIME. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE
WATERS TUESDAY AND WEDNESDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...HAS
NEAR TERM...HAS
SHORT TERM...ADS
LONG TERM...CEM
AVIATION...HTS/HAS
MARINE...HTS/HAS







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