575
FXUS61 KLWX 071743
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
143 PM EDT Mon Apr 7 2025

.SYNOPSIS...
A frontal boundary and wave of low pressure will pull away from the
area this evening. A secondary cold front will push through later
tonight, followed by a strong area of high pressure through the
middle of the week. An upper-level system may bring additional
rain to the area Thursday into Friday, then high pressure
returns for the weekend.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Steady rain is slowly moving off to the east of the FA as low
pressure moves eastward. Portions of southern Maryland may be
stuck in the rain for a few more hours this afternoon.
Elsewhere, sporadic light rain showers or areas of drizzle are
visible on radar. This is expected to continue through the
afternoon before drying out this evening. Areas in and near
terrain are experiencing reduced visibilities due to lowered
CIGs. This is expected to continue through the evening before
the next front comes through.

Tonight, a secondary cold front will move through. This will
bring upslope snow showers to the Alleghenies. From a snow
squall perspective, not that impressive, though there is a thin
ribbon of CAPE right along the front. Any snow that does fall may
accumulate on all surfaces given sfc temps in the low 20s. Snow
amounts generally light and perhaps less than an inch, though
some of the higher ridges above 4kft could get near two inches.
The front will also bring a significant wind shift into Tuesday
morning with up to 30 mph possible (35 to 40 mph on the
ridges).

Lows tonight will be well below average with lows in the 20s
and 30s. In terms of any frost/freeze headlines, none will be
issued for this event given growing season does not officially
start until April 11th for areas along and east of I-81.
However, a significant freeze is expected for some areas
tonight, and most areas Tuesday night. Now is the time to
protect and sensitive early season vegetation as lows Tuesday
night are forecast to be in the 20s for most. Have gone below
NBM guidance both nights, with a tad more Tuesday night given a
more favorable set up for radiational cooling.

Temperatures will only reach the mid to upper 40s Tuesday, and
with the wind it will actually feel more like the 30s. As high
pressure builds in behind this system Tuesday night into
Wednesday, a brief return to quiet weather is expected. Highs
return to the mid 50s Wednesday afternoon under mostly sunny
skies.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The upper-level pattern will become more amplified toward the end of
the week. The initial shortwave and associated low pressure system
will approach on Thursday. Rain chances will increase Thursday as
the warm front lifts into the area, then will continue into Friday
as the low begins to occlude and new low development possibly takes
place along the coast. By that time, another shortwave will have
deepened the upper trough, which will potentially close off into an
upper low nearby. As is often the case with amplified patterns,
there is considerable uncertainty with the progression of the trough
and to what extent the coastal low(s) could affect the area. The
current NBM carries lower rain chances for Saturday with a greater
consensus of moisture transport shifting east of the area and
focused on New England. Confidence increases further for Sunday that
the main trough axis will be positioned to the east, resulting in
lower rain chances (other than possible upslope precip). Regardless
of the evolution, the cold nature of the trough could support some
high elevation snow in the Alleghenies. In terms of rain amounts,
the NBM keeps the probability of 24 hour rainfall totals of greater
than an inch less than 30 percent, so the most likely outcome is
that any rainfall will be beneficial. High temperatures will likely
remain near to below normal each day. Low temperatures may run
slightly above normal owing to plentiful cloud cover.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
IFR to low end MVFR conditions continue across the terminals as
of 18Z. This will continue through the afternoon, then
conditions should gradually improve through the evening as a
slow-moving front pushes farther to the south. A secondary cold
front will cross the area Monday night, bringing an abrupt wind
shift out of the NW. Behind this secondary cold front,
northwest winds will gust 20 to 30 knots Monday night into
Tuesday. VFR conditions will evolve in the period as well.

High pressure returns late Tuesday into Wednesday, which should
keep winds light and conditions VFR.

Southerly winds may gust to around 20 kt Thursday. Sub-VFR
conditions due to low ceilings and rain are possible late Thursday
into Friday as the next low pressure system approaches.

&&

.MARINE...
After a brief lull, a secondary cold front will push through
tonight, resulting in a sharp increase in NW winds. This will
be a good setup for northerly channeling of winds, especially
along the open waters of the Chesapeake Bay. Brief gale-force
winds are possible Tuesday, but not enough confidence for a Gale
Warning at this time. This may be considered in the future, but
either way, this is expected to be at least a high-end SCA.

High pressure returns by Wednesday, with sub-SCA conditions
expected at this time.

SCA conditions are possible Thursday into Thursday night with
southerly flow. Winds are much more uncertain on Friday, with
dependencies on the timing of the passage of a cold or occluded
front and potential development of a coastal low thereafter.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 2 AM to 6 PM EDT Tuesday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 AM to 6 PM EDT Tuesday for
     ANZ530>543.

&&

$$

SYNOPSIS...DHOF/CPB
SHORT TERM...CPB
LONG TERM...DHOF
AVIATION...CPB/DHOF
MARINE...CPB/DHOF