631
FXUS61 KLWX 101943
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
343 PM EDT Mon Aug 10 2026

.WHAT HAS CHANGED...
A Severe Thunderstorm Watch has been issued for much of the area
through 9 PM.

&&

.KEY MESSAGES...
- 1) Severe thunderstorms are possible today and Tuesday amongst
  hot and humid conditions.

- 2) Showers and thunderstorms remain possible at times through
  the end of the week, with a cooling trend expected toward the
  weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...Severe thunderstorms are possible today and
Tuesday amongst hot and humid conditions.

A Severe Thunderstorm Watch is in effect until 9 PM for much of
the area, although it will likely be able to be cancelled early
once storms push through. Previous clusters and their outflows
from our northwest have congealed. While there was some
weakening over/downslope of the Alleghenies, the cold pool is
starting to organize again as it encounters MLCAPE over 2000
J/kg with 30-35 kt shear. The main question is whether the line
will remain in balance or if outflows eventually outpace it as
it encounters higher DCAPE. Isolated storms/some supercells have
also fired ahead of the main line which also pose a severe risk.
Overall, the risk for damaging winds will continue as the line
pushes east. Some locally considerable damage is possible. A few
instances of large hail could occur, mainly in more singular
cells. A tornado also can`t be ruled out, although low level
shear is not overly favorable.

Some guidance shows some more showers and thunderstorms moving
through the area overnight or into Tuesday morning, though this
will be dependent on what develops upstream. It`s unlikely any
of this activity would be severe.

Prospects for thunderstorm continue Tuesday but confidence in
the details is lower. There is some signal in the models that
instability will be lower over much of the forecast area since
the atmosphere might be a bit overturned and there could be
debris cloudiness around. Severe weather probabilities are
highest across southwestern portions of the CWA, which may be in
closer proximity to the MCS track coming out of the Ohio Valley.
Some models do still show thunderstorms farther north in the
area as well, though. Damaging winds will again be the primary
threat.

The risk for isolated flash flooding could occur anywhere on
either day if a merging or backbuilding storm were to occur
over a susceptible area. Accumulatively, however, the risk of
flooding is greatest near and west of the Appalachians where
several rounds of heavy thunderstorms may occur through mid week.

Today might be the hottest day of the week as heat index values
are locally peaking over 100. While the humidity sticks around
Tuesday, temperatures may be slightly lower.


KEY MESSAGE 2...Showers and thunderstorms remain possible at
times through the end of the week, with a cooling trend
expected toward the weekend.

Daily storm chances look to continue through at least Friday as a
cold front gradually drifts south. Ahead of that front will be
several fast moving shortwave disturbances which will help aid
in shower and thunderstorm development during the diurnal
periods. The southward progress of the cold front is uncertain
however, and could be modulated by various convective complexes
and a potential wave of low pressure tracking along it Thursday
or Friday. Both physics-based and AI guidance show lower severe
weather chances Wednesday through Friday with declining
instability. Showers and thunderstorms could remain possible
though with the front nearby. Thursday may be relatively the
hottest day as heights briefly rise.

For Saturday in particular, there may be a better chance of
drying out as high pressure builds to the north. This will also
bring a corresponding cool down in temperatures (potentially a
bit below normal) along with lower humidity. The front won`t be
too far to the south however, and will likely attempt to lift
north later this weekend or early next week as a low pressure
system moves into the Great Lakes. Thus, some low end PoPs
remain in the forecast each day through the end of the forecast
period.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR conditions look to prevail across the terminals through
Friday, although there will be daily chances for showers and
thunderstorms.

A line of thunderstorms has developed this afternoon and will
continue eastward across the metro areas through 22-23Z. A few
thunderstorms have been developing ahead of the line as well. The
leading edge will bring strong to severe winds and heavy
rainfall. However, there is currently a lot of lightning in the
trailing stratiform region, so some impacts may linger for an
hour or so afterward.

Some models show more showers and thunderstorms later tonight or
Tuesday morning, but this will depend on what develops upstream
and its ultimate evolution, so confidence is too low to include
any mentions in the TAFs. There will likely be a wind shift to
the west or northwest tonight, with that direction prevailing
through Tuesday and perhaps through the end of the week.

Coverage of thunderstorms is much more uncertain by Tuesday
afternoon, so have only included PROB30 groups for now. The risk
may be relatively higher at CHO. Guidance has a slightly greater
signal for some patchy fog Tuesday night.

Showers and thunderstorms remain possible Wednesday through
Friday but will depend on the position of an approaching cold
front and the timing of any disturbances.

VFR conditions and dry conditions are more likely Saturday as
high pressure builds to the north.

&&

.MARINE...
A brief period of southerly channeling may return to the middle and
open waters of the Chesapeake Bay this afternoon/evening, but
the duration may be brief or disrupted by approaching
thunderstorms. Overall sub-SCA level winds are expected through
much of the week, though wind direction is a bit uncertain as a
cold front slowly approaches and various disturbances/thunderstorm
clusters pass through. There could be an enhanced northwesterly
surge once the front does push through Friday or Saturday.

Outside of the background winds, expect daily shower and
thunderstorm chances each afternoon and evening through
upcoming Friday (though can`t rule out storms overnight and in
the mornings as well). Special Marine Warnings may be needed to
encompass any stronger thunderstorms that may form especially
today (especially as an organized line approaches) and
Wednesday. Strong to severe wind gusts and frequent lightning
will be the main threats.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...ADS/EST
AVIATION...ADS/EST
MARINE...ADS/EST

NWS LWX Office Area Forecast Discussion