Colmar Manor Maryland Weather Forecast Discussion

193
FXUS61 KLWX 090758
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
358 AM EDT Thu Oct 9 2025
.SYNOPSIS...
High pressure will build to our north through Friday. A coastal
low will develop off the Southeast US coast and then track
northward up the Eastern Seaboard this weekend into early next
week.
&&
.NEAR TERM /THROUGH TONIGHT/...
High pressure will build to our north today. Northerly winds
will continue to transport cool air into the region, with
temperatures only expected to make it into the low to mid 60s
for most (50s mountains). Skies should remain sunny through the
duration of the day.
A surface ridge will build over the western half of the forecast
area tonight as high pressure becomes centered to our north.
This surface ridge will allow winds to go calm to the west of
the Blue Ridge and across far northern Maryland. Just enough of
a pressure gradient may persist to maintain very light
northerly flow further southeast. Skies will remain clear, so
the stage will be set for efficient radiational cooling across
much of the forecast area. The coldest night of the season thus
far is expected. Prior Freeze Watches have been upgraded to
Freeze Warnings for the Alleghenies, Potomac Highlands, and
portions of the Shenandoah Valley. Frost Advisories have been
issued just to the east of the Freeze Warning for northern
portions of the I-81 corridor(Hagerstown/Martinsburg/Winchester
vicinity), much of northern Maryland, as well as western
Loudoun, Fauquier, Culpeper, Rappahannock, and Madison Counties
in the Virginia Piedmont. Further east, winds remaining light
through much of the night and urban influences should act to
limit frost. However, some patchy frost can`t be completely
ruled out for other locations to the northwest of I-95. Low
temperatures will be in the 30s to the north and west of I-95,
and then in the low to mid 40s along and southeast of I-95.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure will build off the New England coastline tomorrow,
maintaining its influence across the region. Mostly sunny skies
are expected to the west of the Blue Ridge, with potentially a
few fair weather clouds developing to the east of I-95,
especially during the afternoon. Winds will turn out of the east
to southeast, but temperatures will remain below normal, with
highs in the mid 60s for most (mid 50s to near 60 in the
mountains).
A coastal low will deepen off the Southeast US coastline
Friday night into Saturday as a deep, closed upper low
simultaneously drifts southeastward across the Great Lakes.
Eventually these two systems will interact as the coastal low
feels the northward pull of the induced southerly winds ahead of
the upper low. This interaction will eventually draw the
coastal low northward toward the Mid-Atlantic, with most
guidance showing the coastal low tracking northward off the
Carolina coast Saturday into Saturday night. This interaction
between the closed upper low and the coastal low is a very
delicate one, and will be very difficult for forecast models to
get correct this far out in time. As a result, there is a much
higher than normal amount of uncertainty regarding the details
of the forecast this weekend. In terms of sensible weather,
chances for showers and also winds will be on the increase
locally Saturday afternoon, and especially Saturday night into
Sunday (covered below in the long term discussion). Just how
much rain we see and how strong the winds get will depend on the
ultimate track of the low, which remains uncertain at this time
horizon.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Surface high pressure will remain between the Great Lakes Region and
the Mid-Atlantic through the long term period as a coastal low
tracks north along the east coast. Aloft, a potent upper level
trough and cut-off low dig across the east coast through Tuesday as
upper level ridging builds in its wake. On Sunday morning, the
coastal low is forecast to be located off the coast of North
Carolina as surface high pressure remains to the northwest. As the
low tracks northward, there remains a good bit of uncertainty
surrounding the forecast as models vary on the timing and track
of the low.
Despite uncertainty in the forecast of the coastal low, a tight
pressure gradient between high pressure to the northwest and low
pressure to the southeast will result in gusty northwest winds
through the long term period. Strongest winds will be along and east
of the I-95 corridor, mainly over the waters, with winds gusting 20
to 30 mph. Persistent northwest flow will also result in below
average temperatures as highs stay in the 60s (50s mtns) Sunday and
Monday. Temperatures gradually warm with highs reaching the 60s to
low 70s Tuesday and Wednesday. Overnight low temperatures will be
in the 40s and 50s each night.
Precipitation chances linger Sunday and Monday as the coastal low
tracks northward. Conditions dry out and cloud cover decreases early
next week as the low moves away from the area.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
VFR conditions will persist at the terminals through Friday
night. Sub-VFR conditions may be possible at times Saturday into
Saturday night as a coastal low approaches from the south.
However, forecast uncertainty is high regarding the track of the
low and resultant impacts locally.
Winds will be out of the north today, either light out of the
northeast or calm tonight, turn out of the east to southeast
tomorrow, and then increase out of the east to northeast on
Saturday. Depending on the track of the low, winds may become
quite gusty by Saturday night.
Sub-VFR conditions are possible Sunday and Monday as a coastal low
brings gusty winds and precipitation to the forecast area.
Precipitation chances will be higher for the terminals along the
metros with strongest winds along and east of the I-95 corridor.
North/northwest winds are expected to blow around 10 knots in the
afternoon, gusting to 25 knots for IAD, DCA, BWI, and MTN. At MRB
and CHO, NNE winds blow 5 to 10 knots and gust up to 15 knots each
afternoon.
&&
.MARINE...
Low-end SCA level gusts will linger within northerly flow over
the waters this morning. These winds should become sub-SCA level
in nature by this afternoon. Winds will remain sub-SCA level
tonight through Friday night, turning out of the northeast
tonight, and then east to southeast tomorrow into tomorrow
night. Winds will increase out of the east on Saturday as a
coastal low approaches from the south. SCA level winds appear
likely within easterly flow Saturday into Saturday night, and
depending on the track of the low, gusts may reach Gale force by
late Saturday night. Gale Watches may need to be considered for
portions of the waters today.
A coastal low tracking up the east coast will bringing at least
SCA criteria winds across the waters Sunday and Monday. Gale
force winds may also be possible due to the tight pressure
gradient between high pressure to the northwest and low pressure
to the southeast. Winds are currently forecast to gust 20 to 30
knots over the Potomac and 30 to 40 knots over the Bay.
&&
.TIDES/COASTAL FLOODING...
Anomalies have begun to level out as flow turns northerly.
Anomalies will rapidly rebound later today into Friday as
northerly winds begin to decrease and turn easterly. Minor coastal
flooding appears likely Friday at Annapolis within onshore
flow, and may occur at other sites as well. Additional coastal
flooding appears likely this weekend as a coastal low develops
to our south and moves up the Eastern Seaboard. The worst of the
coastal flooding would likely occur on Sunday, which remains
just outside of our official forecast period. Depending on the
ultimate track of the low, potentially significant coastal
flooding could occur. However, forecast uncertainty remains
high this far out.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 1 PM EDT this afternoon for MDZ008.
     Frost Advisory from 2 AM to 9 AM EDT Friday for MDZ003>006-507.
     Frost Advisory until 9 AM EDT this morning for MDZ501-509-510.
     Freeze Warning from 2 AM to 9 AM EDT Friday for MDZ501-502-509-
     510.
VA...Frost Advisory from 2 AM to 9 AM EDT Friday for VAZ028-030-031-
     039-040-051-501-502-505.
     Frost Advisory until 9 AM EDT this morning for VAZ503-504.
     Freeze Warning from 2 AM to 9 AM EDT Friday for VAZ025>027-029-
     503-504.
WV...Frost Advisory from 2 AM to 9 AM EDT Friday for WVZ051>053.
     Frost Advisory until 9 AM EDT this morning for WVZ501>503-505-
     506.
     Freeze Warning from 2 AM to 9 AM EDT Friday for WVZ050-055-
     501>506.
MARINE...Small Craft Advisory until 1 PM EDT this afternoon for
     ANZ530>534-537>543.
&&
$$
SYNOPSIS...KJP
NEAR TERM...KJP
SHORT TERM...KJP
LONG TERM...AVS
AVIATION...AVS/KJP
MARINE...AVS/KJP
TIDES/COASTAL FLOODING...LWX

NWS LWX Office Area Forecast Discussion