617
FXUS61 KLWX 050145 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
845 PM EST Tue Feb 4 2025

.SYNOPSIS...
High pressure briefly builds to our north tonight, before an area of
low pressure approaches for late Wednesday into Thursday. Another
area of low pressure may potentially impact the area this
weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

High clouds should move in rapidly from the west in the next
several hours with a high dense overcast developing by 06Z.
Some guidance is indicating a band of very light snow across
northern MD. Specific humidity values suggest low-levels would
be too dry for any precip reach the ground. Low temps continue
to drop this evening with low temps likely in the mid to upper
20s.

Previous afd...

Dry conditions continue for most tonight as high pressure builds to
our north, though clouds will be on the increase ahead of the next
system approaching from the west. A stray snow shower cannot be
ruled out across northern Maryland toward daybreak. Overnight low
temperatures in the upper 20s and lower 30s for most.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
A favorable synoptic pattern sets up across the eastern CONUS that
will favor a potentially significant wintry mix event across our
area. Aloft, progressive zonal flow sets up mid week, stretching
from the Front Range of the Rockies toward the OH Valley/eastern
Great Lakes region. Within that flow, a progressive shortwave
traverses over our area tomorrow into Thursday, while a surface
high pressure is in place to our north by Wednesday morning.

High confidence in a strong CAD wedge developing over the area
by Wednesday afternoon. As a result, and with cloudy skies,
highs are only forecast to reach the mid to upper 30s Wednesday
afternoon.

Winds continue to veer southeast, then south Wednesday night as
the high pressure pulls away. The CAD is expected to persist for
most of the area, especially in the Potomac Highlands, northern
Shenandoah Valley, and north-central MD. As the upper-level
disturbance approaches, warm advection aloft ensues atop the
cold air at the surface - bringing a wintry mix of freezing rain
and sleet to most of the area.

The onset of precipitation will vary, though generally starting from
west to east. The earliest precip begins in Highland and Pendleton
Counties Wednesday morning, with likely a light freezing rain/sleet
mix. A light wintry mix begins in other areas along/west of the Blue
Ridge into central VA by evening.

Precipitation is expected to be fairly light, patchy, and
intermittent during the daytime hours Wednesday. Widespread wintry
precip develops across the area by late Wednesday afternoon into
Wednesday evening, with steady/heavy wintry precip Wednesday evening
into Wednesday night.

Ice Storm Warnings have been issued for portions of the Potomac
Highlands and Northern Shenandoah Valley, and Northern Virginia
Blue Ridge. Winter Weather Advisories have been issued for most
of the rest of the area. Those counties just east of the current
Advisory is where the edge of the CAD is likely to be, and given
marginal temperatures the falling sleet/freezing rain may not
have much impact.

Residents and visitors are urged to stay aware of the latest
forecast, and take all necessary actions to prepare for this
incoming winter storm.

The bulk of the ice will fall Wednesday night to just after
daybreak Thursday. Much of the freezing rain falls with temperatures
around 31F-32F, so while impacts are possible on area roadways, the
greatest ice accretions are likely to occur on elevated surfaces.

By late Thursday morning, all precipitation will have
transitioned to a cold rain that tapers off in the afternoon.
Temperatures are forecast to warm into the 40s to 50s, which
should allow for much of the ice/sleet to quickly melt in most
areas.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Friday is expected to be mostly dry with a large range of possible
temperatures from the 30s in the mountains to the 50s in the
Virginia Piedmont as CAA under NW flow moves in. Lows will be about
10 degrees cooler than the previous night, in the upper 20s to mid
30s.

Another overrunning CAD event arrives on Saturday, bringing another
round of mixed precip Saturday into Sunday. This trend of mixed
precip events every few days likely continues with our current
pattern of weak low pressure systems passing through. The next
system appears most likely in the Tue/Wed timeframe, but some
guidance brings a system into the region by late Monday night.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected through tonight. Winds abate this
evening and shift to north/northeast, then east by Wednesday morning.

Sub-VFR conditions are possible at times during the day Wednesday,
and likely Wednesday night through Thursday morning, in association
with wintry precipitation and low ceilings. Precipitation that falls
Wednesday into Wednesday night will mainly be freezing rain and/or
sleet, then rain mixes in Thursday morning before becoming all rain
by noon Thursday.

Winds out of the W/NW Friday could gust 15-20 kts in the morning and
afternoon before diminishing overnight. VFR conditions are expected
Friday, but conditions could begin to deteriorate late Friday with
the next approaching system, with sub-VFR conditions likely Saturday
with a mixed precip event. SE winds Saturday morning increase and
become SW by Saturday night.

&&

.MARINE...

Winds have dropped below SCA in all of the waters, except at the
usual suspect or elevated sites. Given recent obs and fcst
trends, we`ll likely be canceling all of the SCA at the top of
the hour.

Winds decrease below SCA levels Wednesday as winds shift to
northeast, then east. SCAs may be possible in channeled southerly
flow on Thursday.

Gusty NW winds could be around SCA criteria in the northern
Chesapeake Bay late Friday morning and into the afternoon, but are
expected to quickly diminish. SE winds Saturday turn SW and could
approach SCA criteria late Saturday night into Sunday morning.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Winter Weather Advisory from 9 PM Wednesday to 10 AM EST
     Thursday for DCZ001.
MD...Small Craft Advisory until 9 PM EST this evening for MDZ008.
     Winter Weather Advisory from 9 PM Wednesday to 10 AM EST
     Thursday for MDZ008-011-013-014-504-506-508.
     Ice Storm Warning from 7 PM Wednesday to noon EST Thursday for
     MDZ001-003-501-502.
     Winter Weather Advisory from 9 PM Wednesday to noon EST
     Thursday for MDZ004>006-503-505-507.
VA...Winter Weather Advisory from 9 PM Wednesday to 10 AM EST
     Thursday for VAZ038-039-050-051-053-054-502-527.
     Ice Storm Warning from 7 PM Wednesday to noon EST Thursday for
     VAZ028-031-507.
     Winter Weather Advisory from 9 PM Wednesday to noon EST
     Thursday for VAZ040-501-505-506-526.
     Winter Weather Advisory from 7 PM Wednesday to noon EST
     Thursday for VAZ025>027-029-030-508.
     Ice Storm Warning from 7 AM Wednesday to 7 AM EST Thursday for
     VAZ503.
     Winter Weather Advisory from 7 AM Wednesday to 7 AM EST
     Thursday for VAZ504.
WV...Ice Storm Warning from 7 PM Wednesday to noon EST Thursday for
     WVZ050>053-055-501>504.
     Ice Storm Warning from 7 AM Wednesday to 7 AM EST Thursday for
     WVZ505.
     Winter Weather Advisory from 7 AM Wednesday to 7 AM EST
     Thursday for WVZ506.
MARINE...Small Craft Advisory until 9 PM EST this evening for ANZ530-
     531-535-536-538-539.
     Winter Weather Advisory from 9 PM Wednesday to 10 AM EST
     Thursday for ANZ530.
     Small Craft Advisory until 6 AM EST Wednesday for ANZ532>534-
     537-540>543.

&&

$$

SYNOPSIS...KRR
NEAR TERM...LFR
SHORT TERM...KRR
LONG TERM...CAS
AVIATION...LFR/CAS
MARINE...LFR/CAS