039
FXUS61 KLWX 261923
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
323 PM EDT Sat Apr 26 2025

.SYNOPSIS...
As low pressure tracks across interior New England, a cold front
will move through the area by this evening. Canadian high
pressure will build into the area Sunday into Monday before
moving offshore. Another frontal system will waver across the
Mid Atlantic Wednesday and Thursday before a cold front sweeps
through on Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Low pressure is over northern Vermont this afternoon, with the
trailing cold front pushing east of the Blue Ridge. Stronger
trough axis/closed low lags behind over the Great Lakes,
although a subtle shortwave and height falls are coincident with
the front. Breaks in the clouds have allowed up to around 1000
J/kg of MLCAPE with effective shear around 30 kt. As the front
encounters this environment, convection has been steadily
blossoming. Modest lapse rates and DCAPE, combined with the
otherwise marginal environment will limit storm strength.
However, the strongest storms may produce isolated wind damage
as well as small hail. The front is progressing quickly, with
storms expected to depart by 8 PM, if not sooner. Very light
upslope rain showers or drizzle may linger through the evening
but end before subfreezing air arrives.

While gusty west winds immediately follow the front, a stronger
surge associated with pressure rises and stronger cold advection
will move across the area late this afternoon into this evening.
Gusts in the 30-40 mph range will be possible across the
northern half of the area. Winds may abate some the second half
of the night, especially in sheltered areas. Cold advection
brings lows into the upper 30s and 40s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A strong pressure gradient remains in place Sunday between low
pressure east of New England and strong high pressure over the
Great Lakes. After sunrise, winds will increase again with gusts
in the 25-35 mph range, perhaps locally higher. While winds may
not be quite as strong in the afternoon, gusts won`t diminish
until sunset, when they will do so quickly. While cooler, high
temperatures in the mid 60s to lower 70s are near to only a few
degrees below normal.

The center of the high will move overhead by Monday morning.
While clear skies will promote radiational cooling, a residual
northwesterly gradient may prevent temperatures from falling all
the way to dew points. Upper 30s to mid 40s will still be
common. The highest chance for frost concerns where the growing
season has started will be the central Shenandoah Valley. Dry
conditions, mainly clear skies, and moderating temperatures can
be expected Monday and Monday night as the surface high slides
southeast and upper ridging builds from the west.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Upper level ridge axis will be overhead Tue supporting highs well
into the 80s, while at the surface, high pressure will reside
offshore with southerly flow supporting a moist air mass. Low
pressure will be over southern Ontario/Quebec region Tue with a
trailing cold front extending southwest. The front will enter the
local area late Tue night/early Wed, then stall off across central
VA Wed afternoon. T-storm coverage Tue afternoon doesn`t look
particularly great due to strong ridging and lack of any appreciable
height falls. Best height falls will occur late at night when
instability is minimal. Wed looks more unsettled with a better risk
of showers and thunderstorms, closer to where the front actually
stalls off. The front will try to lift north through the area during
the second half of next week with the risk of showers or
thunderstorms tied to the exact position of the frontal zone. A
stronger low pressure may impact the area next Fri with a more
widespread threat of showers and thunderstorms.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
A cold front is pushing across the area this afternoon.
A broken line of showers and thunderstorms is impacting
MTN/BWI/DCA as this is written, with any threat of storms to the
east by 21Z, if not sooner. VFR conditions return for the
remainder of the TAF period.

Behind the front, west winds are gusting to around 25 kt.
However, a stronger surge of winds potentially gusting 30-35 kt
(except CHO) will push through this evening. A slight decrease
in gusts should occur the second half of the night.

Winds remain gusty Sunday while shifting from westerly to
northwesterly. Expect a quick increase after sunrise with gusts
to around 30 kt again. As Canadian high pressure moves in
Sunday evening into Monday morning, expect much lighter winds
over the area. As this ridge exits the Atlantic coast, winds
return to southerly by Monday afternoon.

Gusty S winds Tue afternoon up to 22 kt. Isold-sct showers and t-
storms expected Tue-Wed.

&&

.MARINE...
Localized advisory conditions continue in southerly flow ahead
of a cold front early this afternoon. As of 3 PM, the front and
a broken line of thunderstorms are entering the marine area.
The potential for strong wind gusts have prompted Special Marine
Warnings, and this threat will continue while sliding
southeastward through about 8 PM (though a faster departure is
not out of the question).

Behind the front, westerly winds will gust 20-25 kt. However, a
pressure surge will bring a stronger bout of winds this evening.
Gale Warnings have been expanded to all waters as forecast
sounding indicate 35-40 kt of wind in the boundary layer for
several hours. Winds will likely taper slightly the second half
of the night, especially on the narrower waterways.

Small Craft Advisories will likely be needed for Sunday as well.
However, as mixing increases after sunrise, there could be
another brief period of gale force gusts, especially across the
northern part of the bay. Winds will likely decrease quickly
Sunday evening as high pressure builds in, but northerly
channeling could linger for a while along the main channel of
the bay. Sub-advisory winds are expected on Monday, with winds
shifting to southerly in the afternoon as the high departs.

SCA conditions are likely Tue into Wed morning. South winds becoming
N Wed. Isold-sct afternoon and evening showers and thunderstorms
expected Tue-Wed.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 8 PM EDT this evening for MDZ008.
     Gale Warning from 8 PM this evening to 6 AM EDT Sunday for
     MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
     ANZ530>543.
     Gale Warning from 8 PM this evening to 6 AM EDT Sunday for
     ANZ530>543.

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...ADS
LONG TERM...LFR
AVIATION...ADS/LFR
MARINE...ADS/LFR