Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 251847
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
247 PM EDT SAT OCT 25 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY. A REINFORCING COLD
FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO SUNDAY
BEFORE HIGH PRESSURE RETURNS FOR MONDAY. THE HIGH WILL MOVE OFF
THE COAST TUESDAY AND ANOTHER COLD FRONT WILL PASS THROUGH THE
AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
HIGH PRESSURE IS LOCATED ACROSS THE MID ATLANTIC THIS AFTERNOON
LEADING TO DRY CONDITIONS TODAY. DISSIPATING CLOUDS HAVE BEEN
APPROACHING THE ALLEGHENY FRONT IN RESPONSE TO A UPPER LEVEL JET
MOVING INTO THE NORTHEASTERN US. A SURGE OF W-NW WINDS AGANIST THE
MTNS MAY LEAD TO A FEW RAIN SHOWERS ALONG THE ALLEGHENY FRONT LATE TONIGHT.
ELSEWHERE...THESE CLOUDS MAY REACH THE POTOMAC HIGHLANDS BEFORE
DISSIPATING THIS EVENING. HIGH PRESSURE AT THE SFC HAS LED TO SW
WINDS USHERING IN HIGHER DEWPTS THAN FRIDAY. THE PRESSURE GRADIENT
HAS INCREASED THIS AFTERNOON AND SW WINDS HAVE INCRASED TO
15-20MPH WITH GUSTS UP TO 30MPH. THESE WINDS WILL DIMINISH THIS
EVENING BUT A LIGHT BREEZE WILL KEEP TEMPS IN THE 40S OVERNIGHT. THE
STRONG JET ACROSS THE GREAT LAKES REGION WILL DRIVE THE NEXT
CANADIAN LOW PRESSURE SYSTEM TOWARDS THE REGION TONIGHT. MOST OF
THE UPWARD LIFT AND MOISTURE OF THIS SYSTEM WILL STAY NORTH OF THE
MID- ATLANTIC AND A DRY COLD FRONT WILL CROSS BY SUNDAY MORNING.

THE COLD FRONT THAT IS CURRENTLY LOCATED ACROSS THE MID-WEST WILL
MOVE ACROSS THE MID-ATLANTIC LATE TONIGHT. THIS WILL CAUSE WINDS TO
BACK TO THE NW AGAIN AND USHER IN DRIER CONDITIONS FOR SUNDAY.
DEWPTS WILL DROP INTO THE 20S IN THE VA HIGHLANDS TO THE MID TO
UPPER 30S EAST OF THE BLUE RIDGE MAKING FOR A DRY DAY. NW WINDS
ARE EXPECTED TO BE 10-20MPH WITH GUSTS UP TO 30 MPH DURING THE
AFTERNOON. THESE CONDITIONS ARE FAVORABLE FOR THE SPREAD OF
WILDFIRES. PLEASE SEE FIRE WX SECTION BELOW. ANY CLOUDS IN
RESPONSE TO THE UPPER LEVEL LOW ACROSS NRN NEW ENGLAND SHOULD STAY
TO THE NORTH SUNDAY LEADING TO A SUNNY DAY WITH TEMPS REACHING THE
MID 60S TO NEAR 70.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL MOVE INTO THE MID ATLANTIC SUNDAY NIGHT AND
WILL PUSH THE PRESSURE GRADIENT OFF THE EAST COAST. WINDS SHOULD
SUBSIDE BY MONDAY MORNING. CALM AND CLEAR CONDITIONS WILL LEAD TO
RADIATIONAL COOLING OVERNIGHT. TEMPS ARE EXPECTED TO DROP INTO THE
MID 30S NORTH AND WEST OF THE I-95 CORRIDOR. PATCHY FROST IS
POSSIBLE ESPECIALLY IN SHELTERED VALLEYS WERE TEMPERATURES MAY REACH
FREEZING. THE HIGH WILL MOVE OFF THE COAST MONDAY AND SOUTHERLY
FLOW WILL USHER IN WARMER CONDITIONS. THIS WILL BE THE TREND FOR
THE START OF THE WORK WEEK.

SOUTHERLY FLOW CONTINUES TUESDAY AS A COLD FRONT APPROACHES FROM
THE MID-WEST. MOISTURE IS LAGGING WITH ONLY LIGHT WAA ALOFT.
MOSTLY SUNNY CONDITIONS ARE EXPECTED TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
STRONG SHORTWAVE/PVA CROSSING GREAT LAKES INTO QUEBEC TUESDAY NIGHT
INTO WEDNESDAY. ENERGY WITH THIS SYSTEM WILL STAY WELL NORTH OF CWA.
ADDITIONAL WEAKER SHORTWAVES WILL MOVE EASTWARD IN ECMWF 500MB
LONGWAVE TROUGH AND AFFECT THE CWA WEDNESDAY INTO THURSDAY. ANOTHER
STRONG SHORTWAVE WILL SLIDE DOWN TROUGH AND REACH THE EASTERN GULF
STATES BEFORE STALLING AT WEEKS END.

COLD FRONT FROM THE WEST WILL CROSS THE CWA TUESDAY NIGHT THROUGH
THURSDAY. WEAK SURFACE HIGH WILL BUILD INTO CWA FRIDAY WHILE A LOW
DEVELOPES OVER GEORGE IN RESPONSE TO THE SHORTWAVE. PATTERN
INDICATES THAT PRECIPITATION WITH THIS SYSTEM WILL NOT AFFECT THE
CWA UNTIL LATE IN THE PERIOD AND AMOUNTS WILL BE LIGHT.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT AS HIGH PRESSURE
CONTROLS THE MID-ATLANTIC REGION. SW WINDS WILL BECOME W-NW
OVERNIGHT AS A DRY COLD FRONT CROSSES THE TERMINALS. W-NW WINDS
15-20KTS WITH GUSTS UP TO 30 KTS EXPECTED. WINDS SHOULD SUBSIDE BY
SUNSET ON SUNDAY.

HIGH PRESSURE MOVES ACROSS THE REGION SUNDAY NIGHT THROUGH MONDAY.
VFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
SW WINDS WILL CONTINUE ON THE WATERS THIS AFTERNOON. A PRESSURE
SURGE HAS MOVED INTO THE NRN MARYLAND CHESAPEAKE BAY AND GUSTS OF
20KTS HAVE BEEN OBSERVED. A SCA IS IN EFFECT THROUGH EARLY
EVENING. A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT AND WINDS
WILL BECOME W-NW. SW WINDS AHEAD OF THE FRONT WILL INCREASE ACROSS
THE LOWER TIDAL POTOMAC AND MD BAY SOUTH OF DRUM PT LATE TONIGHT.
A SCA IS IN EFFECT FOR THIS AREA AND EXPANDS FOR ALL THE WATERS
SUNDAY. GUSTY WINDS UP TO 28KTS ARE POSSIBLE ON THE WATERS SUNDAY
AFTERNOON. A PRESSURE GRADIENT WILL MOVE OFF TO THE EAST SUNDAY
NIGHT AND WINDS WILL DIMINISH BY MONDAY MORNING.

HIGH PRESSURE OVER THE WATERS SUNDAY NIGHT WILL MOVE OFF THE COAST
MONDAY THROUGH TUESDAY. A SOUTHERLY FLOW WILL DEVELOP DURING THIS
TIME. A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY. A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS TUESDAY
AND WEDNESDAY. HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK.

&&

.FIRE WEATHER...
A DRY COLD FRONT WILL CROSS THE MID-ATLANTIC LATE TONIGHT AND
GUSTY WINDS AND DRY CONDITIONS ARE EXPECTED BEHIND IT. W-NE WINDS
10-20 MPH WITH GUSTS UP TO 30MPH AND DEWPTS ARE FCST TO DROP INTO
THE 20S AND 30S ACROSS THE MID ATLANTIC. THIS WILL LEAD TO DRY
CONDITIONS WITH RH VALUES AROUND 25-35% BY SUN AFTERNOON. LOW FUEL
MOISTURES HAVE BEEN OBSERVED ESPECIALLY IN THE BLUE RIDGE REGION
OF VA. THE COMBINATION OF GUSTY WINDS...LOW RH AND LOW FUEL
MOISTURES WILL LEAD TO THE ENHANCED THREAT OF WILDFIRES SUNDAY.

&&

.TIDES/COASTAL FLOODING...
DUE TO THE WESTERLY WINDS BECOMING SWLY BY AFTERNOON...CBOFS HAS
TIDAL ANOMALIES INCREASING THIS AFTERNOON. THE FCST IS FOR
ANNAPOLIS TO REACH MINOR FLOOD EARLY THIS EVENING BUT ANOMALIES
WOULD NEED TO REACH 0.8 FEET. AT THIS TIME ANOMALIES ARE AROUND A
HALF FOOT. ANOMALIES ARE NOT EXPECTED TO INCREASE THAT QUICKLY
THIS AFTERNOON AND THERFORE MINOR COASTAL FLOODING IS NOT
EXPECTED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ530>532-538>540.
     SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 2 AM EDT MONDAY FOR
     ANZ530>533-539>541.
     SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT SUNDAY FOR ANZ535-
     536-538-542.
     SMALL CRAFT ADVISORY FROM 2 AM SUNDAY TO 2 AM EDT MONDAY FOR
     ANZ534-537-543.

&&

$$
SYNOPSIS...HAS
NEAR TERM...HAS
SHORT TERM...HAS
LONG TERM...CEM
AVIATION...HAS
MARINE...HAS
FIRE WEATHER...HAS
TIDES/COASTAL FLOODING...HAS







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