Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 280129
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
929 PM EDT SAT JUN 27 2015

.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM EXTENDING FROM THE GREAT LAKES TO
THE MID ATLANTIC WILL LIFT TOWARDS NEW ENGLAND OVERNIGHT.  HIGH
PRESSURE WILL BUILD INTO THE REGION SUNDAY...REMAINING IN PLACE
THROUGH TUESDAY BEFORE A WEAK COLD FRONT PASSES TUESDAY NIGHT.
LOW PRESSURE IS EXPECTED TO CROSS THE REGION FRIDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...

AT 01Z...REGIONAL RADAR MOSAIC SHOWS SHOWERS SCATTERED ABOUT THE
REGION. SOME TSTMS CROSSING SOUTH CENTRAL VIRGINIA...BUT I AM NOT
EXPECTING ANYTHING MORE THAN A STRAY RUMBLE OF THUNDER IN OUR CWA.
PER THE HRRR...ALL SHOWER ACTIVITY SHOULD BE EAST OF THE
CHESAPEAKE BY 06Z WHEN THE FRONT WILL HAVE PASSED THROUGH THE
REGION AND WE START DRYING OUT. SOME PATCHY FOG WILL BE WITH US
THROUGH DAWN...ESP EAST OF I-95.

SUNDAY WILL START OUT SUNNY BUT QUICKLY BY LATE MORNING DEVELOP A
CUMULUS DECK ALONG WITH A GUSTY WEST WIND OF 20-30 MPH. SCATTERED
SHOWERS WILL EXIST WEST OF I-81 IN THE HIGHER TERRAIN DURING MAX
DAYTIME HEATING.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
ANY WRAP-AROUND/ UPSLOPE RAIN SHOWERS IN THE POTOMAC HIGHLANDS WILL
END EARLY SUNDAY EVENING AS STRONG LOW PRESSURE SYSTEM PULLS AWAY
FROM NEW ENGLAND. A MUCH COOLER AND DRIER AIRMASS WILL BE FOUND IN
ITS WAKE...WHICH WILL ALLOW TEMPERATURES TO DROP INTO THE 50S EXCEPT
IN THE URBAN AREAS AND COASTAL PLAIN. DUE TO THE EXTENT OF THE P-
GRAD...WL STILL HV A GOOD WIND FIELD INTO THE EVENING HRS BEFORE
SUBSIDENCE AND DIURNAL TRENDS RESULT IN SLACKENING WINDS.

MONDAY WILL BE A DRY DAY AS SHORTWAVE RIDGING QUICKLY SLIDES ACROSS
THE AREA. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL. KEPT SKIES
MOSUN DUE TO THE DRY AMS AND SUBSIDENCE.

NEXT SHORTWAVE TROUGH WILL BE MOVING INTO THE GREAT LAKES MONDAY
NIGHT...LEADING TO AT THE VERY LEAST INCREASING CLOUDS. AT THIS
POINT...MADE NO CHGS TO POP FCST...WHICH HAS CONFINED POPS WEST OF I-
81 OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
WARM FRONT AND SFC LOW MOVES OVER THE CWA TUES AND SLOWLY MOVES
AWAY EARLY ON WED. A COLD FRONT APPROACHES ON WED EVE AND PUSHES
SOUTH OF THE CWA WED NIGHT. THE FRONT WILL STALL SOUTH ON THURS
AND LIFT ON FRI. SURFACE TROUGH MAY IMPACT THE REGION SAT. SHOWERS
AND AFTERNOON TSTMS ARE PSBL AS THESE SYSTEMS IMPACT THE REGION
THROUGH THE WEEK. LOOKS LIKE THE DRIEST DAYS WILL BE WED AND SAT.
THURS PRECIP IS UNCERTAIN DUE TO THE EXACT LOCATION OF THE FRONT.
MAX TEMPS WILL BE IN THE MID TO UPR 80S AND LOW TEMPS IN THE 60S
TO LOW 70S.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
RESIDUAL SHOWERS AND LOW CIGS GIVING MVFR CONDITIONS AT ALL TERMS
THROUGH 06Z. CIGS IMPROVE TO VFR AFTER 06Z SUN AFTER A COLD FRONT
SHIFTS WIND WEST.

WEST WIND GUSTS 20 TO 25 KT SUNDAY IN VFR CONDS. WINDS WILL LINGER
INTO SUN EVE.

VFR CONDITIONS EXPECTED SUNDAY NIGHT THROUGH MONDAY NIGHT. SUB-
VFR DUE TO PSBL SHOWERS AND TSTMS...MAINLY ON TUES.

&&

.MARINE...
WINDS ON TIDAL POTOMAC AND CHESAPEAKE BAY WILL BECOME GUSTY
THROUGH SUN NIGHT.

WINDS WILL DIMINISH ON MONDAY AS HIGH PRESSURE QUICKLY PASSES BY.
SOUTHERLY FLOW WILL BECOME ESTABLISHED MONDAY NIGHT...AND
CHANNELING OVER THE BAY IS POSSIBLE.

SCA CONDITIONS PSBL TUES DUE TO SHOWERS AND TSTMS ACROSS THE
WATERS. WED MOSTLY SUB-SCA CONDITIONS WITH SOME PSBL AFTERNOON
TSTMS.

&&

.TIDES/COASTAL FLOODING...
WIDESPREAD MINOR COASTAL FLOODING EXPECTED TONIGHT ON THE
PREFERRED HIGH TIDE.

SELY FLOW 15 TO 25 KT HAS RAISED WATER DEPARTURES TO AROUND 1.5
FT ON THE BAY AND 2 FT IN THE UPPER TIDAL POTOMAC. WATER LEVELS
WILL CONTINUE TO RISE THROUGH THIS EVENING AHEAD OF A COLD FRONT.
AFTERNOON HIGH TIDE WILL SEE MINOR COASTAL FLOODING AT THE
PARTICULARLY SENSITIVE SITE OF DC/ALEXANDRIA AND ANNAPOLIS WHERE
AN ADVISORY IS IN EFFECT. WIDESPREAD MINOR COASTAL FLOODING
TONIGHT ON THE PREFERRED HIGH TIDE. CURRENT ADVISORY FOR WRN SHORE
OF THE BAY AND DC/ALEXANDRIA FOR THE PREFERRED HIGH TIDE TONIGHT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 9 AM EDT SUNDAY FOR DCZ001.
MD...COASTAL FLOOD ADVISORY FROM 2 AM TO 10 AM EDT SUNDAY FOR
     MDZ011-508.
     COASTAL FLOOD ADVISORY UNTIL 4 AM EDT SUNDAY FOR MDZ017-018.
     COASTAL FLOOD ADVISORY UNTIL 7 AM EDT SUNDAY FOR MDZ014.
VA...COASTAL FLOOD ADVISORY UNTIL 9 AM EDT SUNDAY FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ530>534-
     537>543.
     COASTAL FLOOD ADVISORY FROM 2 AM TO 10 AM EDT SUNDAY FOR
     ANZ538.
     COASTAL FLOOD ADVISORY UNTIL 4 AM EDT SUNDAY FOR ANZ542.
     SMALL CRAFT ADVISORY UNTIL 9 PM EDT SUNDAY FOR ANZ535-536.
     COASTAL FLOOD ADVISORY UNTIL 9 AM EDT SUNDAY FOR ANZ535.

&&

$$
SYNOPSIS...LEE
NEAR TERM...LEE
SHORT TERM...HTS
LONG TERM...ADS/IMR
AVIATION...LEE/ADS/IMR
MARINE...LEE/ADS/IMR
TIDES/COASTAL FLOODING...BAJ/ADS/IMR


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