493
FXUS61 KLWX 191358 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
958 AM EDT SAT SEP 19 2026
WHAT HAS CHANGED
NOTHING.
KEY MESSAGES
- 1) SLIGHTLY COOLER AND DRIER CONDITIONS ARE FORECAST FOR
TODAY, BEFORE SHOWERS AND THUNDERSTORMS RETURN SUNDAY.
- 2) DAILY CHANCES FOR SHOWERS PERSIST INTO NEXT WEEK ALONG
WITH COOLER TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...SLIGHTLY COOLER AND DRIER CONDITIONS ARE
FORECAST FOR TODAY, BEFORE SHOWERS AND THUNDERSTORMS RETURN
SUNDAY.
HIGH PRESSURE CURRENTLY CENTERED ACROSS SOUTHERN QUEBEC WILL
CONTINUE TO BUILD SOUTHEASTWARD OVER THE COURSE OF THE DAY
TODAY, EVENTUALLY REACHING THE GULF OF MAINE BY THIS EVENING.
AS THE HIGH SHIFTS FURTHER EAST, WINDS WILL GRADUALLY SHIFT FROM
OUT OF THE NORTH/NORTHEAST THIS MORNING TO OUT OF THE EAST AND
THEN SOUTHEAST THIS AFTERNOON. PERSISTENT COOL/DRY ADVECTION HAS
ENABLED DEWPOINTS TO DROP INTO THE UPPER 50S TO MID 60S AS OF
EARLY THIS MORNING. WITH THIS SOMEWHAT DRIER AIRMASS IN PLACE,
ZONAL FLOW ALOFT, AND THE INFLUENCE OF THE HIGH BUILDING TO OUR
NORTH, CONDITIONS ARE EXPECTED TO REMAIN DRY THROUGH THE DAY
TODAY. TEMPERATURES ARE FORECAST TO CLIMB INTO THE 70S TO NEAR
80 BENEATH MOSTLY CLOUDY SKIES.
HIGH PRESSURE WILL SHIFT FURTHER OFFSHORE TOMORROW WHILE A
SHORTWAVE DISTURBANCE TRACKS EASTWARD ACROSS SOUTHERN ONTARIO
AND QUEBEC. WINDS AT THE SURFACE WILL TURN SOUTHERLY IN RESPONSE
TO THE HIGH MOVING FURTHER OFFSHORE, WHILE WINDS ALOFT TURN
WESTERLY IN RESPONSE TO THE SHORTWAVE PASSING TO OUR NORTH. THE
NET EFFECT OF THESE WIND SHIFTS WILL BE TO DRAW A WARMER, MORE
HUMID AIRMASS BACK INTO THE AREA FROM THE SOUTH AND WEST.
TEMPERATURES ARE FORECAST TO CLIMB WELL INTO THE 80S WITH
DEWPOINTS JUMPING BACK INTO THE LOWER 70S. MODEL GUIDANCE
SUGGESTS THAT CHANCES FOR SHOWERS AND POTENTIALLY A FEW
THUNDERSTORMS WILL INCREASE TOMORROW AFTERNOON INTO TOMORROW
NIGHT AS A COLD FRONT APPROACHES FROM THE NORTH, MOVING INTO THE
WARM AND HUMID AIRMASS. THIS COLD FRONT WILL EVENTUALLY MOVE
THROUGH THE AREA SUNDAY NIGHT, CAUSING WINDS TO SHIFT TO OUT OF
THE NORTH TO NORTHEAST.
KEY MESSAGE 2...DAILY CHANCES FOR SHOWERS PERSIST INTO NEXT
WEEK ALONG WITH COOLER TEMPERATURES.
UPPER-LEVEL RIDGING BREAKS DOWN EARLY NEXT WEEK, WITH MULTIPLE
SHORTWAVE DISTURBANCES MOVING ACROSS THE MID-ATLANTIC IN THE DAYS
FOLLOWING. MID-LEVEL MOISTURE BROUGHT IN FROM THE SOUTH WILL
OVERRUN MOIST NORTHEASTERLY FLOW OFF THE ATLANTIC, LEADING TO
DAILY CHANCES FOR SHOWERS. TEMPERATURES REMAIN SOMEWHAT UNCERTAIN
DUE TO MODEL DISCREPANCY IN CLOUD COVER, BUT THEY CONTINUE TO
FAVOR THE COOLER SIDE OF GUIDANCE GIVEN A POSSIBLE COLD AIR
DAMMING SURFACE PATTERN.
WELL BELOW AVERAGE TEMPERATURES COULD LAST THROUGH MIDWEEK AS NEARBY
DISTURBANCES CONTINUE TO BRING RAIN AND SHOWERS TO THE AREA. TOWARDS
THE BAY AND COASTLINES, WIND GUSTS COULD REMAIN ELEVATED THROUGH
LATE NEXT WEEK AS THESE DISTURBANCES SHIFT OFFSHORE. OVERALL,
COASTAL FLOODING COULD BECOME SOMETHING TO WATCH OUT FOR NEXT
WEEK. SEE THE COASTAL FLOODING SECTION BELOW FOR MORE DETAILS.
AVIATION /13Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS ARE EXPECTED THROUGH THE DAY TODAY AS WINDS
GRADUALLY SHIFT FROM THE NORTHEAST TO THE SOUTHEAST. MVFR
CEILINGS MAY BE POSSIBLE LATER TONIGHT, WITH GRADUAL IMPROVEMENT
BACK TO VFR TOMORROW MORNING. WINDS WILL BE OUT OF THE SOUTH
TOMORROW, AND A FEW SHOWERS AND THUNDERSTORMS MAY BE POSSIBLE
TOMORROW AFTERNOON INTO TOMORROW NIGHT AS A COLD FRONT
APPROACHES FROM THE NORTH. WINDS EVENTUALLY SHIFT TO OUT OF THE
NORTH LATER SUNDAY NIGHT AS THE FRONT MOVES THROUGH. SUB-VFR
CEILINGS APPEAR LIKELY BEHIND THE FRONT IN NORTHEASTERLY FLOW ON
MONDAY.
SUB-VFR CEILINGS LIKELY CONTINUE ON TUESDAY AND WEDNESDAY, ALONG
WITH SHOWERS AND GUSTY NORTHEASTERLY WINDS.
MARINE
WINDS ARE EXPECTED TO GRADUALLY SHIFT AROUND TO OUT OF THE
EAST. WINDS PICK UP OUT OF THE EAST TO SOUTHEAST TONIGHT, WITH
SCA CONDITIONS POSSIBLE. LOW-END SCA LEVEL WINDS MAY LINGER INTO
SUNDAY WITHIN SOUTHERLY FLOW ACROSS THE WIDER WATERS OF THE
BAY. A COLD FRONT WILL MOVE OVER THE WATERS SUNDAY NIGHT,
CAUSING WINDS TO SHIFT TO OUT OF THE NORTH. SCA CONDITIONS MAY
BE POSSIBLE IN THE SURGE OF NORTHERLY WINDS BEHIND THE FRONT
SUNDAY NIGHT. SCA CONDITIONS WILL LIKELY CONTINUE WITHIN
NORTHEASTERLY FLOW ON MONDAY, AND THEN EASTERLY FLOW MONDAY
NIGHT.
HEADING INTO THE MIDDLE OF NEXT WEEK, WINDS COULD APPROACH GALE
CONDITIONS BETWEEN TUESDAY AND WEDNESDAY WITHIN NORTHEASTERLY
FLOW AS A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR NORTH.
TIDES/COASTAL FLOODING
TIDAL ANOMALIES WILL GRADUALLY INCREASE AS WINDS SHIFT FROM THE
NORTHEAST THIS MORNING TO EAST THIS AFTERNOON, SOUTHEAST
TONIGHT, AND THEN SOUTH TOMORROW. ANNAPOLIS COULD COME CLOSE TO
MINOR FLOODING TOMORROW, BUT FOR NOW THE FORECAST HAS THEM JUST
BELOW IN ACTION STAGE. AFTER A BRIEF DROP IN ANOMALIES BEHIND A
COLD FRONT SUNDAY NIGHT, ANOMALIES SHOULD GRADUALLY INCREASE
ONCE AGAIN NEXT WEEK WITHIN ONSHORE FLOW. AT LEAST MINOR
FLOODING APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK, AND
MODERATE FLOODING CAN'T BE COMPLETELY RULED OUT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
ANZ530>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 1 AM EDT
SUNDAY FOR ANZ534-537-543.
DISCUSSION...LFR/KJP/KVH
AVIATION...LFR/KJP/KVH
MARINE...LFR/KJP/KVH
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