479
FXUS61 KLWX 181932
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
332 PM EDT MON AUG 18 2025
SYNOPSIS
A FRONTAL BOUNDARY WILL REMAINED STALLED TO OUR SOUTH THROUGH
THE MIDDLE OF THE WEEK, BEFORE EVENTUALLY DISSIPATING. AN AREA
OF LOW PRESSURE WILL TRACK TOWARD HUDSON BAY THIS WEEKEND, AND
AN ASSOCIATED COLD FRONT WILL MOVE THROUGH EARLY NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
HIGH PRESSURE CONTINUES TO BUILD TO OUR NORTH ACROSS QUEBEC THIS
AFTERNOON. CONDITIONS REMAIN CLOUDY, COOL, AND BREEZY LOCALLY
WITH A COLD AIR DAMMING WEDGE ENTRENCHED ACROSS THE FORECAST
AREA. TEMPERATURES ARE WELL BELOW NORMAL, WITH HIGH TEMPERATURES
ONLY IN THE LOW TO MID 70S FOR MOST. TEMPERATURES HAVE EVEN
DROPPED INTO THE UPPER 60S ACROSS NORTHEAST MARYLAND. SPC
MESOANALYSIS SHOWS A WEAK CONVERGENCE AXIS AT 850 HPA ALONG THE
I-95 CORRIDOR. A FEW SHOWERS HAVE STARTED TO FORM IN THAT AREA.
SHOWERS WILL CONTINUE TO BE POSSIBLE NEAR/SOUTHEAST OF I-95 ON
AND OFF THROUGH THE NIGHT. SOME CAMS ALSO SUGGEST THAT A MESOLOW
MAY TRY TO FORM ACROSS SOUTHERN MARYLAND LATER TONIGHT,
POTENTIALLY LEADING TO SOME STEADIER RAINFALL IN THE VICINITY OF
ST. MARY'S COUNTY. MAINLY DRY CONDITIONS ARE EXPECTED TO THE
NORTH AND WEST OF I-95. OVERNIGHT LOWS WILL BE IN THE 60S FOR
MOST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
THE COLD AIR DAMMING WEDGE IS EXPECTED TO REMAIN IN PLACE
THROUGH THE DAY TOMORROW WITH HIGH PRESSURE CENTERED OVER NEW
ENGLAND. LOW CLOUDS, EASTERLY WINDS, AND WELL BELOW NORMAL
TEMPERATURES ARE EXPECTED THROUGH THE DAY. ON AND OFF SHOWERS
WILL ALSO BE POSSIBLE ALONG AND SOUTHEAST OF I-95. TEMPERATURES
WILL STRUGGLE TO GET OUT OF THE LOW TO MID 70S.
THE CAD WEDGE WILL FINALLY BREAK UP ON WEDNESDAY AS HIGH
PRESSURE PROGRESSES OFFSHORE. THIS WILL ALLOW THE LOW CLOUDS TO
FINALLY START TO BREAK UP, RESULTING IN SOME BREAKS OF SUNSHINE
BY WEDNESDAY AFTERNOON. THIS WILL ENABLE TEMPERATURES TO CLIMB
BACK INTO THE UPPER 70S AND LOWER 80S. MEANWHILE, A SHORTWAVE
TROUGH WILL DESCEND DOWN IN NORTHWESTERLY FLOW FROM THE GREAT
LAKES. THIS DISTURBANCE COULD POTENTIALLY SPARK THE DEVELOPMENT
OF A FEW SHOWERS OR STORMS WEDNESDAY AFTERNOON, WITH THE
GREATEST COVERAGE EXPECTED TO THE WEST OF THE BLUE RIDGE.
LONG TERM /THURSDAY THROUGH MONDAY/
THE NATIONAL HURRICANE CENTER FORECAST SHOWS ERIN TRACKING EAST OF
THE MID ATLANTIC COAST THURSDAY. THE SHORTWAVE TROUGH RESPONSIBLE
FOR STEERING THE STORM NORTHWARD WILL ALSO HELP PUSH THE STALLED
FRONTAL ZONE TO THE SOUTH. THOSE SYNOPTIC SCALE FEATURES WILL KEEP A
CHANCE OF SHOWERS IN THE FORECAST, MAINLY OVER THE MOUNTAINS. THE
TIGHTENING PRESSURE GRADIENT DUE TO ERIN WILL RESULT IN AN UPTICK OF
WINDS, ESPECIALLY ALONG THE CHESAPEAKE BAY WHERE 20-30 MPH GUSTS ARE
POSSIBLE. TEMPERATURES LIKELY REMAIN SLIGHTLY BELOW NORMAL DUE TO
THE NORTHEASTERLY WIND DIRECTION.
HIGH PRESSURE TO THE NORTHEAST WILL BUILD INTO THE AREA FRIDAY, AND
A SHORTWAVE RIDGE WILL QUICKLY PASS ACROSS THE AREA ALOFT. THIS
SHOULD KEEP CONDITIONS DRY, ALTHOUGH SOME RESIDUAL MOISTURE MAY
LINGER ACROSS THE SOUTHWESTERN PART OF THE CWA. THE HIGH WILL MOVE
FARTHER TO THE EAST ON SATURDAY, ALLOWING SOUTHERLY FLOW TAKING OVER
WHICH WILL WARM TEMPERATURES BACK CLOSER TO NORMAL (THOUGH LIKELY
REMAINING BELOW 90F FOR MOST AREAS). A POTENT SHORTWAVE TROUGH WILL
ALSO BE DIGGING THROUGH THE GREAT LAKES OVER THE WEEKEND. THERE IS
SOME UNCERTAINTY WITH HOW MUCH FORCING WILL REACH THE AREA SATURDAY,
AS WELL AS THE TIMING OF THE ASSOCIATED COLD FRONT SUNDAY INTO
MONDAY. THE FORECAST HAS A CHANCE OF SHOWERS AND THUNDERSTORMS EACH
DAY DURING THIS PERIOD ALONG WITH SEASONABLE TEMPERATURES. WILL HAVE
TO KEEP AN EYE ON POTENTIAL FOR STRONGER THUNDERSTORMS GIVEN
INCREASING WIND FIELDS ALOFT, BUT WEAK INSTABILITY WILL LIKELY BE A
LIMITING FACTOR.
AVIATION /18Z MONDAY THROUGH SATURDAY/
CEILINGS ARE CURRENTLY MVFR AT MOST TERMINALS, AND ARE EXPECTED
TO DROP TO IFR TONIGHT. IFR CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MOST, IF NOT ALL, OF THE DAY TOMORROW. A FEW TERMINALS
MAY HAVE A COUPLE HOURS OF LOW-END MVFR DURING PEAK HEATING. IFR
CONDITIONS WILL CONTINUE THROUGH TOMORROW NIGHT. IMPROVEMENT
BACK TO VFR CONDITIONS IS EXPECTED BY WEDNESDAY AFTERNOON. A FEW
SHOWERS MAY BE POSSIBLE THIS AFTERNOON THROUGH TOMORROW
AFTERNOON, BUT THE VAST MAJORITY OF THE TIME SHOULD REMAIN DRY.
A FEW SHOWERS OR STORMS MAY ALSO BE POSSIBLE WEDNESDAY
AFTERNOON. WINDS WILL BE OUT OF THE NORTHEAST TODAY, BEFORE
BECOMING EASTERLY FOR TUESDAY AND WEDNESDAY.
SOME SUB-VFR CEILINGS MAY START THURSDAY. WITH HURRICANE ERIN
OFFSHORE, THE INCREASED PRESSURE GRADIENT WILL RESULT IN GUSTY
NORTHEAST WINDS DURING THE DAY, ESPECIALLY BWI/DCA/MTN WHERE SOME
GUSTS OF 20-25 KT ARE POSSIBLE. MORE TRANQUIL WEATHER IS EXPECTED
FRIDAY. A THUNDERSTORM IS POSSIBLE AT MRB SATURDAY AFTERNOON OR
EVENING AS THE NEXT FRONTAL SYSTEM BEGINS TO APPROACH.
MARINE
SCA CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON WITHIN
NORTHEASTERLY FLOW. WINDS WILL DECREASE SLIGHTLY FROM NORTH TO
SOUTH OVERNIGHT. SCA CONDITIONS APPEAR POSSIBLE IN EASTERLY FLOW
TOMORROW. EASTERLY WINDS WILL CONTINUE ON WEDNESDAY, AND COULD
REACH SCA MAGNITUDE LATER WEDNESDAY AFTERNOON INTO WEDNESDAY
NIGHT.
SCA CONDITIONS ARE LIKELY TO CONTINUE THURSDAY INTO THURSDAY NIGHT
DUE TO THE TIGHTENED PRESSURE GRADIENT WITH ERIN OFFSHORE. SOME
GUSTS TO AROUND 30 KT ARE POSSIBLE ON THE WIDER WATERS OF THE MIDDLE
BAY. HIGH PRESSURE BUILDING NORTH OF THE AREA WILL TURN WINDS TO THE
EAST FRIDAY AND SOUTH FRIDAY NIGHT AND SATURDAY, LIKELY BELOW
ADVISORY LEVELS. SOUTHERLY CHANNELING MAY INCREASE WINDS TO NEAR
ADVISORY CRITERIA SATURDAY EVENING.
TIDES/COASTAL FLOODING
ANOMALIES WILL REMAIN ELEVATED WITHIN EASTERLY FLOW THROUGH MUCH
OF THE WEEK. THE GREATEST CHANCE FOR COASTAL FLOODING LOOKS TO
BE TUESDAY NIGHT, WHEN MORE SENSITIVE SITES SUCH AS ANNAPOLIS
MAY APPROACH MODERATE FLOOD STAGE. ADDITIONAL COASTAL FLOODING
MAY BE POSSIBLE ON THURSDAY AS HURRICANE ERIN PROGRESSES
OFFSHORE.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ530>533-
539>541.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ534-537-543.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ535-
536-538-542.
SYNOPSIS...KJP
NEAR TERM...KJP
SHORT TERM...KJP
LONG TERM...ADS
AVIATION...ADS/KJP
MARINE...ADS/KJP
TIDES/COASTAL FLOODING...KJP
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