372
FXUS61 KLWX 111425
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1025 AM EDT Tue Aug 11 2026

.WHAT HAS CHANGED...
Monitoring the evolution of upstream thunderstorm clusters and
how the environment recovers today. May need to lower
temperatures a bit today if cloud cover remains thick.

&&

.KEY MESSAGES...
- 1) Severe thunderstorms possible again today with a focus south
and west of the I-95 metros. Damaging winds are the main threat.

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

&&

.DISCUSSION...
KEY MESSAGE 1...Severe thunderstorms possible again today with a
focus south and west of the I-95 metros. Damaging winds are the main
threat.

Multiple clusters of showers and thunderstorms exist at mid
morning, ranging from stratified rain in the southern Shenandoah
Valley, to a decaying cluster in SW PA, to more potent storms in
Ohio. There is new development in northern IN, and another
cluster in NW IL, both of which will be fed by a rich theta-e
airmass and could potentially grow upscale. Locally, we are in a
stable environment thanks to earlier decaying thunderstorms.
Anvil level winds will likely keep sending debris cloudiness
into the area, and if low level winds remain west or
northwesterly, it may be difficult to advect richer moisture
back into the area. Therefore, the thunderstorm clusters to the
west may tend to either propagate southeastward along the
instability gradient or weaken with eastward extent.
Southwestern portions of the CWA may remain closest to this
storm track. Any MCSes which approach from the activity farther
to the west likely wouldn`t reach the area until later this
evening or overnight. Thus their maintenance remains in
question.

A Flood Watch remains in effect through tonight for Garrett
County due to the combination of ongoing flooding and expected
additional rainfall (possibly multiple rounds).

Previous discussion:
Hi-res guidance is all over the place when it comes to how
upstream convection will evolve and impact our region in regards
to both timing and coverage of storms based upon the convective
debris this morning. Some of the guidance has a linear feature
working across central WV into southwest VA perhaps grazing the
southern Shenandoah Valley while other pieces of guidance have a
cluster of storms working across the entirety of the forecast
area between 19z-23z/3-7pm. Additionally a secondary batch of
showers and thunderstorms may come through during the overnight
period into early Wednesday morning similar to what we are
seeing now. SPC maintains a Slight Risk (Level 2 out of 5) for
eastern WV/far western MD and the Shenandoah Valley. A Marginal
Risk (Level 1 out 5) has been outlooked elsewhere across the
region for through tonight. Damaging winds will once again be
the main threat along with isolated instances of flash flooding.


Beyond today, timing, coverage, and locations of storms remains
uncertain despite strong mid level flow and increased height
falls across the region. Shortwave disturbances will continue to
pulse through although more cloud cover may be noted which
could dampen the threat. Machine learning probabilities for
severe weather have decreased to around 5-20 percent with a
focus further south. These probabilities taper even more late
week as the front finally drops into the region. Once again
damaging winds will be the main threat with storms along with
isolated instances of flash flooding.


KEY MESSAGE 2...Showers and thunderstorms remain possible at
times Wednesday through Friday, 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 /14Z TUESDAY THROUGH SATURDAY/...
VFR conditions will likely prevail outside of thunderstorms and
small potential for morning fog.

Stable conditions may limit thunderstorm development or
maintenance across much of the area through this afternoon,
although some guidance still pops a few showers and
thunderstorms this afternoon. Locations further south toward
CHO may have a better bet at seeing organized convection later
this afternoon and evening between 19-23z/3-7pm as activity in
the Ohio Valley dives southeastward. Additional showers and
thunderstorms are modeled during the evening or overnight period
although confidence is low given what may happen earlier in the
day and dependent on evolution of storms over IN and IL. Gusty
winds, frequent lightning, and locally heavy rainfall as the
primary concerns.

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. Outside of the thunderstorms expect
patchy fog between the terminals each morning through Thursday.
Winds will remain light out of the west and southwest at less than
15 kts.

VFR conditions are more likely Friday and Saturday as high pressure
builds into the region. Isolated showers and thunderstorms return
Sunday into early next week as the front tries to lift back into the
region.

&&

.MARINE...
Overall sub-SCA level winds are expected through Thursday. 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...Flood Watch through late tonight for MDZ509-510.
VA...None.
WV...None.
MARINE...None.

&&

$$

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

NWS LWX Office Area Forecast Discussion