Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

671
FXUS61 KLWX 291908
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
308 PM EDT Wed Apr 29 2026

.WHAT HAS CHANGED...
Substantially reduced thunder risk out of the forecast for areas
generally east of US-15, at least until the main front comes
through later this evening. Also, severe threat seems to be
dwindling, given that we are approaching peak heating with
little/no sign of destabilization. Also, changed Key Messages 2
and 3, so note those changes below.

&&

.KEY MESSAGES...
1) Showers and thunderstorms will accompany a strong frontal
system through this evening.

2) Below normal temperatures are expected Thursday
through Sunday night, with frost and/or freezing temperatures
possible especially west of the Blue Ridge Mountains.

3) Showers remain possible at times early next week as
temperatures gradually climb.

&&

.DISCUSSION...
KEY MESSAGE 1...Showers and thunderstorms will accompany a
strong frontal system through this evening.

The current surface analysis differs very little from what was
observed 6 hours ago, with a warm front lingering across
eaastern WV and down along eastern VA into eastern NC. With very
little eastward progression today, showers have very gradually
moved across the region as a result. This will continue to
hinder our ability to destabilize ahead of the approaching
strong cold front. Off to our west, over central/eastern WV,
there are a few breaks in the cloudcover, so a little more
instability is developing there, with some convection occurring
as a result. However, none has grown severe yet.

Looking towards southwestern WV, there are some more breaks in
the clouds, with better instability. Maybe this works its way
into our western areas later this afternoon/evening. If this
does occur, perhaps convection could start to grow stronger
than we are seeing currently as the powerful cold front
approaches from the west. If we can get into this area of subtle
clearing ahead of the frontal passage, perhaps a discrete cell
or two could form. The magnitude of deep-layer shear (40 to 50
knots) could make up for lower CAPE, but there still needs to be
at least some destabilization compared to what we are seeing
now. If we do achieve that, an isolated tornado cannot be ruled
out. However, still have this as a very low likelihood
scenario, as I am just not condient in the environment being
able to rebound before peak heating ends.

On the rainfall side of the equation, a broad axis of 0.50 to
0.75 inches of rain is expected. This should prove to be more
beneficial in nature given the longstanding rainfall deficit.

Showers finally exit into the Eastern Shore overnight. Drier
conditions ensue along with a shift to northwesterly winds. Low
temperatures tonight should fall into the 40s to low 50s, with
spotty upper 30s along the Allegheny Front.


KEY MESSAGE 2: Below normal temperatures are expected Thursday
through Sunday night, with frost and/or freezing temperatures
possible especially west of the Blue Ridge Mountains.

A closed upper low will persist to our north from Thursday into next
week. It will gradually retreat northward with time, but some
reinforcing troughs will sweep across the eastern US at times. The
net effect will be below normal temperatures and occasional shower
chances. Unfortunately for the drought, a widespread soaking is not
anticipated.

The main hazard through this period will be the potential for
frost/freeze conditions, with the greatest threat west of the Blue
Ridge Mountains. Thursday night into Friday morning will offer the
first opportunity as gusty northwest winds subside after sunset.
While still chilly, clouds may mitigate the threat somewhat Friday
night. While Saturday night is forecast to be the coldest of the
stretch, elevated northwest winds may limit the frost threat.
However, the higher elevations in particular will likely drop below
freezing. The airmass will start to moderate Sunday night into
Monday morning. However, residual sub-freezing dew points west of
the Blue Ridge could lead to at least a localized frost threat.

Subtle perturbations in the cyclonic flow will result in mainly
daytime shower chances Thursday and Friday. This threat may be
relegated to the Alleghenies Thursday, with greater coverage
expected on Friday. The deepest trough will approach on Saturday,
likely leading to an area of low pressure developing along the
Carolina coast. Some rain could spread into southeastern portions of
the forecast area, but the northwest edge of precipitation shield
remains uncertain. At a minimum, clouds will be more prevalent.
Overall precipitation type should be rain, especially considering
the highest chances are during the daytime periods. However, can`t
totally rule out some snow flakes or graupel pellets on the higher
ridges on days with convective showers. Surface high pressure will
cross the area Sunday with the upper level pattern flattening,
leading to the driest day of the forecast.


KEY MESSAGE 3: Showers remain possible at times early next week as
temperatures gradually climb.

Shortwave troughs will continue to drive relatively weak frontal
systems toward the area next week. Depending on the timing of these
systems, there will be shower chances each day. However, these
chances may eventually consolidate as timing agreement increases. A
few thunderstorms could also be in the mix, although severe weather
probabilities appear low. With the main upper level gyre well to the
north and surface high pressure setting up off the east coast, there
will be a gradual warming trend in temperatures through mid week,
reaching near to above normal values.


&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Abundent showers are now being observed for most of the
terminals along the warm front. This is resulting in VSBY
restrictions intermittently. This is paired with MVFR CIGs that
have been around all day, which won`t be going away until after
the frontal passage later this evening. Could see some gusty
winds in showers/storms along the front when it comes through
this evening. However, most terminals may be east of the warm
front and remain stable enough to mitigate this threat. May have
to do some nowcasting later on as the line moves through to
truly assess the thunder threat, as well as stronger wind gusts.

Any convective threat winds down by late this evening while
winds shift to northwesterly overnight behind the cold front.
VFR conditions return into the night.

For Thursday and Friday, expect mainly VFR conditions. Breezy
northwesterlies are likely to start off with afternoon gusts to
around 20 to 25 knots. Any shower chances are likely relegated
to the Allegheny Front. An upper low to the north will bring a
better shot of isolated/scattered showers on Friday. These could
support a few brief restrictions and some locally gusty
downdraft winds. Otherwise, the overall winds will remain out of
the west.

VFR conditions are expected at the terminals this weekend. Winds are
forecast to be out of the northwest on Saturday, and then west on
Sunday.

&&

.MARINE...
Small Craft Advisories remain in effect for all waters until
early Thursday morning as winds shift to northwesterly behind
tonight`s cold front. Additionally, this front will pose a risk
of some stronger storms which may require some evening Special
Marine Warnings. However, that threat is uncertain, as it may be
too stable to get stronger winds down to the surface. Such
storms push into the Eastern Shore by after midnight. There may
be a brief overnight "lull" in winds, falling below SCA criteria
for a few hours, but expect those to increase Thursday morning
yet again.

Breezy northwesterly winds are expected on Thursday with Small
Craft Advisories likely needed through much of the day. Winds
begin to decrease into Thursday night as well as Friday with a
shift to westerlies. An upper low will aid in some shower
development on Friday, many of which will be high based. Some of
these could produce locally gusty winds so Marine Weather
Statements may be needed at times.

Sub-SCA level northwesterly winds are expected over the waters on
Saturday. Westerly gusts may reach low-end SCA levels on Sunday.

&&

.TIDES/COASTAL FLOODING...
Southeasterly flow continues to keep anomalies elevated at most
of the tidal sites. Many locations will reach Action Stage
during high tide through tonight, with Minor tidal flooding
expected at Annapolis. While it will come close this afternoon
as well, it being the lower of the high tide cycles should keep
it just below minor flood stage. A few other tidal sites like
Alexandria, Dahlgren, and Havre de Grace could get close during
the higher of the two astronomical high tides this evening as
well. There are no advisories out yet, as there is still at
least some uncertainty with the frontal passage maybe coming
through just before high tide. Once we are more confident on
exact timing of the wind shift, a final decision can be made.

Water levels begin to drop off tonight into Thursday as winds
shift to northwesterly.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 7 PM EDT Thursday for ANZ530>543.

&&

$$

DISCUSSION...ADS/BRO/CJL
AVIATION...ADS/BRO/CJL
MARINE...ADS/BRO/CJL