919
FXUS61 KLWX 090753
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
353 AM EDT TUE SEP 9 2025
SYNOPSIS
HIGH PRESSURE WILL BUILD TO OUR NORTH THROUGH THE MIDDLE OF THE
WEEK. MEANWHILE, A WEAK WAVE OF LOW PRESSURE SLIDES UP THE EAST
COAST. A DRY COLD FRONT WILL CROSS THE REGION THURSDAY, FOLLOWED
BY ANOTHER CANADIAN HIGH PRESSURE SYSTEM AT THE END OF THE WEEK
INTO THIS WEEKEND.
NEAR TERM /THROUGH TONIGHT/
MODEL GUIDANCE CONTINUES TO BE IN PRETTY GOOD AGREEMENT
REGARDING THE DEVELOPMENT OF THE AREA OF LOW PRESSURE OFF THE
CAROLINA COAST ALONG THE COASTAL FRONT. WE WILL START TO SEE
SOME INCREASED CLOUDCOVER IN RESPONSE TO THIS FEATURE LATER
TODAY INTO THIS EVENING, MAINLY ALONG AND EAST OF THE I-95
CORRIDOR. OTHERWISE, HIGH PRESSURE TO THE NORTH WILL CONTINUE TO
FUNNEL IN COOLER THAN NORMAL AIR FOR THIS TIME OF YEAR, WHILE WE
WILL ALSO REMAIN DRY AREA-WIDE. HIGHS TODAY REACH THE MID 70S
ONCE AGAIN WITH THE MOUNTAINS IN THE 60S. NUDGED THE DEW POINTS
DOWN A BIT, THUS DECREASING THE RH IN THE FORECAST A BIT, IN
RESPONSE TO CONTINUED TREND OF DEW POINTS BEING LOWER THAN MOST
MODEL GUIDANCE. ALSO EXPECT AN UPTICK IN NORTHEASTERLY WINDS
GIVEN THE INCREASE IN LARGE-SCALE PRESSURE GRADIENTS. GUSTS UP
TO 15 TO 20 MPH ARE POSSIBLE DURING THE DAY, ESPECIALLY CLOSER
TO THE CHESAPEAKE BAY.
FOR TONIGHT, TEMPERATURES WILL BE ABOUT 5 DEGREES WARMER FOR
MOST, AND EVEN A BIT WARMER ALONG AND EAST OF I-95 WHERE
CLOUDCOVER WILL AID IN KEEPING LOW TEMPERATURES UP OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
SPARSE SHOWER CHANCES PERSIST INTO WEDNESDAY MORNING ALONG THE
CHESAPEAKE BAY SHORES. HOWEVER, IT IS MORE LIKELY THAT THESE
SHOWERS REMAIN OVER THE EASTERN SHORE AND POINTS EASTWARD. CLOUD
COVER REMAINS OVER AREAS EAST OF THE BLUE RIDGE, BUT THESE WILL
EDGE EASTWARD IN TIME. SOME LATE DAY SUNSHINE IS POSSIBLE
ACROSS THE I-95 CORRIDOR. HIGH TEMPERATURES ARE FORECAST TO
REMAIN IN THE LOW/MID 70S (60S IN THE MOUNTAINS). OVERNIGHT LOWS
DROP INTO THE 50S, WITH SOME MID/UPPER 40S POSSIBLE OVER THE
CENTRAL SHENANDOAH VALLEY BACK INTO THE POTOMAC HIGHLANDS.
HIGH PRESSURE RETURNS ON THURSDAY WITH MOSTLY SUNNY SKIES AND
TEMPERATURES ACTUALLY RETURNING CLOSER TO AVERAGE FOR THIS TIME
OF YEAR, WITH HIGHS IN THE 70S TO LOW 80S.
LONG TERM /FRIDAY THROUGH MONDAY/
ANOTHER AREA OF STRONG HIGH PRESSURE WILL DESCEND FROM CANADA INTO
NEW ENGLAND FRIDAY AND SATURDAY BENEATH LONGWAVE TROUGHING ALOFT. BY
SUNDAY, THE HIGH WILL BE SQUEEZED BETWEEN A LOW PRESSURE SYSTEM
APPROACHING THE GREAT LAKES AND A FRONTAL ZONE/POSSIBLE LOW OFF THE
SOUTHEAST COAST. MODELS DIVERGE ALOFT WITH HOW TO HANDLE A
TROUGH/CLOSED LOW DESCENDING SOUTHWARD FROM HUDSON BAY HEADING INTO
EARLY NEXT WEEK. WHILE THIS COULD LEND SOME UNCERTAINTY TO THE
FORECAST, THE APPROACHING FRONTAL ZONE APPEARS TO BE MOISTURE
STARVED. THEREFORE, DRY CONDITIONS AND SIMILAR TEMPERATURES (NEAR TO
SLIGHTLY BELOW NORMAL) PERSIST FOR THE FRIDAY THROUGH MONDAY
PERIOD.
AVIATION /08Z TUESDAY THROUGH SATURDAY/
WINDS WILL PICK UP AND SHIFT OUT OF THE NORTHEAST TODAY, WITH
HIGHEST GUSTS GENERALLY ALONG AND EAST OF I-95. GUSTS UP TO 15
TO 20 KNOTS ARE POSSIBLE AS GRADIENTS TIGHTEN BETWEEN HIGH
PRESSURE TO THE NORTH AND LOW PRESSURE PASSING BY TO OUR SOUTH
AND EAST. THIS WILL ESPECIALLY BE TRUE DURING THE AFTERNOON
HOURS.
SOME LOW CLOUDS WILL TRY TO PUSH AS FAR EAST AS THE BLUE RIDGE
OVERNIGHT INTO WEDNESDAY MORNING. SUB-VFR CONDITIONS ARE
POSSIBLE DURING THIS TIME AT IAD AND CHO, BUT SEEM MOST LIKELY
AT DCA, BWI, AND MTN.
WINDS RETURN TO NORTHERLY LATER WEDNESDAY AS THE COASTAL SYSTEM
PUSHES FURTHER OFFSHORE. SIGNIFICANT WEATHER IS UNLIKELY
THROUGH SATURDAY UNDER HIGH PRESSURE.
MARINE
THE COMBINATION OF CANADIAN HIGH PRESSURE TO THE NORTH AND LOW
PRESSURE MOVING ALONG A STALLED FRONTAL ZONE TO THE SOUTH WILL
AID IN ENHANCED NORTH TO NORTHEASTERLY WINDS THROUGH MID-WEEK.
EXPECT GUSTS UP TO AROUND 20 TO 25 KNOTS, PARTICULARLY OVER THE
MORE OPEN WATERS OF THE CHESAPEAKE BAY. SMALL CRAFT ADVISORIES
HAVE NOW BEEN EXTENDED THROUGH MUCH OF THE DAY ON WEDNESDAY
ACROSS VAST PORTIONS OF THE CHESAPEAKE BAY INTO THE LOWER TIDAL
POTOMAC. FOR NOW, THE UPPER/MIDDLE TIDAL POTOMAC SHOULD SEE
WINDS JUST SHORT OF ADVISORY CRITERIA.
WINDS FINALLY START TO DIMINISH WEDNESDAY EVENING AS THE
AFOREMENTIONED AREA OF LOW PRESSURE PUSHES AWAY FROM THE
REGION. SUB-SCA WINDS ARE EXPECTED TO CONTINUE THROUGH THURSDAY
AS WELL.
NORTHEAST TO EAST WINDS PREVAIL FRIDAY AND SATURDAY DUE TO HIGH
PRESSURE TO THE NORTH. WINDS ARE FORECAST TO REMAIN BELOW ADVISORY
LEVELS AT THIS TIME, BUT IT'S WORTH MONITORING THE POTENTIAL FOR LOW
PRESSURE TO FORM OFF THE SOUTHEAST COAST, WHICH COULD INCREASE THE
PRESSURE GRADIENT AND THUS WINDS.
TIDES/COASTAL FLOODING
DUE TO THE COMBINATION OF WINDS NOT QUITE ALIGNED TO PUSH WATER
SOUTH AND OUT OF THE BAY, AND THE RECENT FULL MOON, TIDES WILL BE
SOMEWHAT ELEVATED IN THE COMING DAYS. NE WINDS DURING THE MIDDLE OF
THE WEEK MAY ASSIST IN LOCKING IN HIGHER WATER LEVELS AND PUSHING
THE WATER TOWARD THE WESTERN SHORE. ANNAPOLIS IS MOST LIKELY TO
REACH MINOR FLOOD STAGE, BUT SOME OTHER LOCATIONS MAY BE CLOSE. THE
FIRST OPPORTUNITY FOR FLOODING WILL BE TUESDAY EVENING, AND THEN
COULD OCCASIONALLY BE AN ISSUE THROUGH THE END OF THE WEEK WITH NO
REAL PATTERN CHANGE IN SIGHT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR ANZ530-531-
538>540.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR ANZ532.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT WEDNESDAY FOR ANZ533-534-
537-541>543.
SYNOPSIS...CJL
NEAR TERM...CJL
SHORT TERM...BRO/CJL
LONG TERM...ADS
AVIATION...ADS/CJL
MARINE...ADS/CJL
TIDES/COASTAL FLOODING...CJL
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