090
FXUS61 KLWX 051305
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
905 AM EDT Wed Aug 5 2026

.WHAT HAS CHANGED...
Have dropped the Flood Watch from DC south and west as the
threat shifts off to the east and northeast. Expanded a new
segment of the watch to include the Baltimore/Annapolis area
through this afternoon.

&&

.KEY MESSAGES...
- 1) Localized urban flash flooding possible this morning as
  warm front lifts north.

- 2) Daily shower and thunderstorm chances are expected through
  early next week.

&&

.DISCUSSION...
KEY MESSAGE...Localized urban flash flooding possible this morning
as warm front lifts north.

A warm front is lifting across the Mid-Atlantic this morning.
12Z analysis shows a small meso-low feature near Madison VA, and
this feature will likely drift northeastward just northwest of
US-29 toward Baltimore`s northwest suburbs through midday.

On radar and satellite, this feature has the appearance of an
occluded low. The pseudo "triple point" east of DC toward
Annapolis is where convergence is strongest on the mesoscale,
outside of the low moving from near Madison to Culpeper.

The highest PW axis is overhead this morning, so anything that
develops as subtle daytime heating commences will be capable of
very heavy rainfall rates. Slow storm motions/training are
possible as this weak low moves overhead. Forcing for ascent via
moisture flux has ceased, so further development will rely on
subtle convergence axes and/or heating of an extremely humid
airmass through limited cloud breaks.

Have cancelled the watch as convergence continues to decrease
from DC south and west. Meanwhile, convergence and CAPE will
increase to the east and northeast of DC, in the Baltimore and
Annapolis area through this afternoon. The last few runs of the
HRRR have rather stubborn recurring activity in this area into
the afternoon, so the watch was expanded to include that area.


KEY MESSAGE 2...Daily shower and thunderstorm chances are expected
through early next week.

In the wake of what morning convection materializes, the models do
show a brief lull in the action. The northward pushing warm front
eventually stalls nearby before shearing out. Likewise, the upper
low across the Mid-South region begins to fill although the
reflection of this circulation still shows up across southern West
Virginia.

A deep southerly flow will continue around high pressure over the
Atlantic, ushering plenty of moisture. PWATS will be near or greater
than 2" in the valleys with 1-2" in the mountains, which is about 1-
2 SD above climo. A surface trough and shortwave energy will trigger
scattered showers/thunderstorms, but it should not be a washout
during the afternoon/evening. The main threat will be brief heavy
downpours and gusty winds. However, DCAPE and shear are on the lower
side, so the probability of severe storms is lower. If some storms
train over the same area, localized flash flooding can occur. The
pattern does favor the possibility for training convection (cloud
layer winds nearly parallel to low-level wind), but the coverage
should be isolated.

A similar pattern will hold on for Thursday and Friday while the
subtropical jet strengthens to the north and west. Therefore, more
showers and thunderstorms are likely along with the threat for
isolated instances of flash flooding and locally damaging wind
gusts. Hotter conditions may cause relatively steeper low-level
lapse rates and the wind field strengthens a bit (especially
Friday).

A quasi-zonal flow aloft will develop for the weekend into next
week, bringing more seasonably hot and humid conditions along with
daily chances for showers and thunderstorms.

&&

.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
MVFR to IFR CIGs are expected to persist this morning as a warm
front lifts north through the area. Heavy showers and a few
thunderstorms are possible at DCA and IAD, though all terminals
could get some rain this morning, with reduced VSBY possible.
Conditions do improve and return to VFR by mid afternoon, before
another round of thunderstorms could impact area terminals.
PROB30 groups in the TAFs have been adjusted earlier to capture
latest trends in highest TS probs.

Winds shift to mainly south to southwesterly for the foreseeable
future as a Bermuda high pressure system persists across the western
Atlantic. Daily convective chances each afternoon and evening will
support convective-driven restrictions. With little change in the
upcoming pattern, this sort of forecast will likely hold for the
next several days.

VFR conditions are expected most of the time Saturday and Sunday,
but a few showers and thunderstorms are possible, especially during
the afternoon and evening hours each day.

&&

.MARINE...
A warm front lifts north across the waters today, bringing a return
of southerly winds. Small Craft Advisories could be needed for parts
of the waters at times this week, mainly in the late afternoon to
evening. Otherwise, winds remain around 10 knots. Daily showers and
thunderstorms expected each afternoon this week. Special Marine
Warnings would accompany any of the stronger thunderstorms capable
of producing frequent lightning and wind gusts over 35 knots.

Winds may approach SCA criteria Saturday and Sunday as the gradient
strengthens a bit between high pressure over the Atlantic and lower
pressure to the the north. A few showers and thunderstorms are
possible each day, especially during the afternoon and evening
hours.

&&

.TIDES/COASTAL FLOODING...
Southerly winds return today behind a warm front that lifts north
through the area. Anomalies climb again mid to late week in response
to return southerly flow. Additional periods of coastal flooding are
possible at times of high tide at sensitive locations.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Flood Watch until 4 PM EDT this afternoon for MDZ011-014-508.
     Flood Watch until 11 AM EDT this morning for MDZ013.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 8 PM EDT this
     evening for ANZ533-534-543.

&&

$$

DISCUSSION...BJL/DHOF/KRR
AVIATION...BJL/DHOF/KRR
MARINE...BJL/DHOF/KRR

NWS LWX Office Area Forecast Discussion