885
FXUS61 KLWX 071430
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1030 AM EDT SUN SEP 7 2025
SYNOPSIS
CANADIAN HIGH PRESSURE WILL BUILD IN FROM THE WEST THROUGH MONDAY,
THEN SETTLE TO THE NORTH OF THE AREA BY THE MIDDLE OF THE WEEK AS
A WAVE OF LOW PRESSURE PASSES OFFSHORE. AS A RESULT, EXPECT A
RETURN TO COOLER THAN NORMAL TEMPERATURES AND MAINLY DRY
CONDITIONS ACROSS THE REGION. A DRY COLD FRONT WILL CROSS THE
REGION THURSDAY REINFORCING BELOW NORMAL TEMPERATURES. HIGH
PRESSURE WILL RETURN FOR THE END OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
SHOWERS CONTINUE ALONG AND ON THE NORTHWEST SIDE OF A FRONT
ACROSS SOUTHERN MARYLAND AND THE CHESAPEAKE BAY. OTHERWISE,
PARTIAL AND GRADUALLY CLEARING IS ANTICIPATED ELSEWHERE. A
NORTHWEST DOWNSLOPING BREEZE OF 10 TO 15 MPH WILL HELP PUSH
TEMPERATURES INTO THE 70S FOR THIS AFTERNOON (60S FOR THE
MOUNTAINS).
A MAINLY CLEAR SKY AND LIGHT NORTH WIND WILL ALLOW TEMPERATURES
TO DROP INTO THE 40S AND 50S BY DAYBREAK MONDAY. IT IS POSSIBLE
THAT, GIVEN THE DRY AIRMASS AND LIGHT WINDS, SOME OF THE HIGH
ELEVATION VALLEYS COULD DROP INTO THE 30S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
PREVIOUS DISCUSSION...
HIGH PRESSURE WILL BUILD TO THE NORTH OF THE MID- ATLANTIC
MONDAY INTO TUESDAY, WITH A SURFACE RIDGE AXIS WEDGING DOWN THE
EASTERN SIDE OF THE APPALACHIANS AS A WAVE OF LOW PRESSURE
DEVELOPS OFFSHORE BY TUESDAY. THIS WILL RESULT IN NORTH TO
NORTHEASTERLY BREEZES AND A CONTINUATION OF BELOW NORMAL
TEMPERATURES.
AS LOW PRESSURE PASSES OFFSHORE, CLOUDS WILL INCREASE EAST OF
THE BLUE RIDGE MOUNTAINS TUESDAY. SOME GUIDANCE DRAWS A COASTAL
FRONT CLOSE ENOUGH TO THE AREA TO BRING SOME RAIN SHOWERS ACROSS
THE CHESAPEAKE BAY TO THE I-95 CORRIDOR TUESDAY NIGHT, BUT IT
IS MORE LIKELY THAT THE DRY SURFACE WEDGE WINS OUT FOR MUCH OF
THE REGION. ANY SHIFTS COULD BRING RAIN INTO THE METROS BY
DAYBREAK WEDNESDAY, BUT FOR NOW HAVE LEFT THE FORECAST DRY
OUTSIDE OF THE CHESAPEAKE BAY TO SOUTHERN MARYLAND.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
PREVIOUS DISCUSSION...
TRANQUIL WEATHER CONDITIONS ARE EXPECTED THROUGHOUT THE
EXTENDED PERIOD. COOLER THAN NORMAL TEMPERATURES LOOK TO
CONTINUE AS ONE AREA OF CANADIAN HIGH PRESSURE SHIFTS OFF THE
NORTHERN NEW ENGLAND COAST BEFORE BEING REPLACED BY ANOTHER FOR
THE UPCOMING WEEKEND.
LONGWAVE TROUGHING WILL RESIDE OVER THE EASTERN CONUS TO START THE
PERIOD WITH EMBEDDED SHORTWAVES RIDING A STALLED BOUNDARY DRAPED
ACROSS THE CAROLINA/SOUTHEAST U.S. COAST. THIS FRONTAL BOUNDARY
WILL AID IN EXTRA CLOUD COVER FOR AREAS EAST OF BLUE RIDGE
WEDNESDAY ALONG WITH A LOW END SHOWER CHANCE (15-20 PERCENT)
FOR PORTIONS OF SOUTHERN MD AND THE NORTHERN NECK OF VA
WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON. THE CLOUD COVER WILL
BE SHORT LIVED AS EMBEDDED SHORTWAVE LOW PRESSURE QUICKLY LIFTS
OUT TO SEA FROM THE DELMARVA COAST WEDNESDAY EVENING. BY
THURSDAY, A DECAYING COLD FRONT WILL APPROACH THE REGION. THE
FRONT IS EXPECTED TO CROSS THURSDAY INTO FRIDAY WITH LIMITED TO
NO PRECIPITATION EXPECTED. BROAD CANADIAN HIGH PRESSURE RETURNS
IN THE WAKE OF THE FRONT FRIDAY INTO THE UPCOMING WEEKEND.
IT WILL BE A TRUE TASTE OF EARLY FALL AROUND HERE FOR THE REMAINDER
OF THE WORKWEEK AND UPCOMING WEEKEND. DAILY HIGH TEMPERATURES WILL
MAINLY BE IN THE LOW/MID 70S WEDNESDAY BEFORE A DOWNSLOPING
NORTHWESTERLY WIND RETURNS READINGS TO THE LOW 80S ON THURSDAY.
THEREAFTER, TEMPERATURES RETURN BACK INTO THE MID 70S INTO THE
FIRST HALF OF NEXT WEEKEND INTO EARLY NEXT WEEK. HIGHER
ELEVATIONS CAN EXPECT TEMPERATURES AROUND 10 TO 15 DEGREES
COOLER THAN THE REST OF THE AREA. AT NIGHT, AMPLE RADIATIONAL
COOLING WILL MAKE FOR SOME CHILLY NIGHTS DURING THE PERIOD WITH
SOME AREAS DROPPING INTO THE MID/UPPER 40S. HIGH MOUNTAIN VALLEY
LOCATIONS OF THE ALLEGHENIES COULD SEE LOWS IN THE 30S.
AVIATION /15Z SUNDAY THROUGH THURSDAY/
A SHOWER OR SOME PATCHY DRIZZLE NEAR CHO, DCA, BWI AND MTN
THROUGH MID-AFTERNOON. OTHERWISE, DRYING AND PARTIAL CLEARING
SKIES. NW BREEZES AROUND 10 KTS OR SO (A FEW GUSTS AROUND 15
KTS ARE POSSIBLE). VFR WILL THEN PREVAIL THROUGH TUESDAY AS
WINDS SHIFT AROUND TO THE NORTH AND NORTHEAST. CLOUDS WILL
INCREASE, WITH LOWER CIGS POSSIBLE IN ONSHORE FLOW TUESDAY NIGHT
CLOSER TO THE CHESAPEAKE BAY AS AN AREA OF LOW PRESSURE PASSES
OFFSHORE.
VFR CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY. EXPECT
INCREASED CLOUD COVER EAST OF THE BLUE RIDGE AS A WEAK
DISTURBANCE RIDES ALONG A STALLED BOUNDARY OFFSHORE. HIGH
PRESSURE WILL DOMINATE THE FORECAST OTHERWISE WITH MULTIPLE WIND
SHIFTS EXPECTED THROUGH THE PERIOD. NORTHERLY WINDS WEDNESDAY
WILL TURN NORTH-NORTHEASTERLY THURSDAY.
MARINE
RAIN SHOULD DEPART BY MID AFTERNOON IN THE WAKE OF A DEPARTING
COLD FRONT. NORTH TO NORTHWEST WINDS WILL INCREASE IN THE WAKE
OF THE FRONT, GUSTING 15-20 KNOTS THROUGH MID AFTERNOON. WINDS
WILL SUBSIDE A BIT HEADING INTO THIS EVENING BEFORE A SECONDARY
PUSH CHANNELS NORTH TO SOUTH DOWN THE CHESAPEAKE BAY LATER TONIGHT
INTO EARLY MONDAY; THIS PROMPTED ADDITIONAL SCAS. WINDS SHIFT TO NE
MONDAY NIGHT INTO TUESDAY WITH ADDITIONAL SCAS POSSIBLE DEPENDING ON
THE STRENGTH OF THE GRADIENT BETWEEN HIGH PRESSURE TO THE NORTH AND
LOW PRESSURE OFFSHORE.
NEAR SCA LEVEL WINDS COULD LINGER INTO WEDNESDAY WITH AN AREA OF LOW
PRESSURE PUSHING OFF THE DELMARVA COAST AND INCOMING HIGH PRESSURE
BUILDING FROM THE OHIO RIVER VALLEY. SUB-SCA LEVEL WINDS ARE
EXPECTED WEDNESDAY EVENING THROUGH THURSDAY.
TIDES/COASTAL FLOODING
ONSHORE FLOW WILL INCREASE BY TUESDAY AS THE GRADIENT BETWEEN
HIGH PRESSURE TO THE NORTH AND LOW PRESSURE OFFSHORE STRENGTHENS.
THE TRAJECTORY OF THE FLOW MAY CAUSE WATER TO GET BOTTLED UP
NEAR THE MOUTH OF THE CHESAPEAKE BAY, WHICH WOULD PUSH WATER
LEVELS UP HEADING INTO MIDWEEK. THE STRENGTH OF THE GRADIENT AND
EXACT WIND DIRECTION WILL BE CRITICAL IN DETERMINING JUST HOW
MUCH EXCESS WATER SWELLS UP THE BAY, BUT AT LEAST NEAR MINOR
FLOODING SEEMS PLAUSIBLE ALONG VULNERABLE SHORELINE AS EARLY AS
LATE TUESDAY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530-535-536.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ531>533-538>542.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EDT MONDAY
FOR ANZ531-538-540.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EDT MONDAY
FOR ANZ532>534-537-541>543.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ534-
537-543.
SYNOPSIS...DHOF
NEAR TERM...KLW/DHOF
SHORT TERM...DHOF
LONG TERM...EST
AVIATION...KLW/DHOF/EST
MARINE...KLW/DHOF/EST
TIDES/COASTAL FLOODING...KLW
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