289
FXUS61 KLWX 170125
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
925 PM EDT Sun Aug 16 2026

.WHAT HAS CHANGED...
A Flood Watch had been issued and remains in effect for
portions of central and southern Maryland, Washington D.C.,
northeastern and eastern Virginia until 3am tonight. Garrett
County also remains in a Flood Watch that had been issued
earlier today. A Severe Thunderstorm Watch had been issued and
is in effect for parts of northeastern Virginia, Washington D.C.
and parts of southern Maryland.

&&

.KEY MESSAGES...
- 1) Severe weather continues and flash flooding is possible
  through tonight.

- 2) Thunderstorm chances return Wednesday night into Thursday.

&&

.DISCUSSION...
KEY MESSAGE 1...Severe weather continues and flash flooding is
possible through tonight.

As of 9pm, radar indicates a band of showers and embedded strong
to severe thunderstorms extending from Baltimore County to
Charles County and further south into southeastern Virginia. One
severe thunderstorm in particular has prompted a Tornado Warning
for parts of Charles and Prince Georges Counties in Maryland.
Main threats are isolated tornado, frequent and dangerous
lightning, and severe wind gusts.

Scattered showers across western and southern Pennsylvania show
a movement into Maryland over the next few hours and possibly
into the Virginias. Another more defined area of heavy showers
and intense thunderstorms cover much of West Virginia to the
westward side of the Appalachians. This activity could move into
our western zones over the next 3 to 5 hours with an emphasis on
damaging wind gusts and isolated tornadoes. It is this activity
that formed over the central and eastern Ohio Valley with
another strong mid-level disturbance. There is plenty of low
level moisture available as dewpoint temperatures are in the
upper 60s to middle 70s widespread.

A Flood Watch remains in effect for Garrett County, as well as a
new Flood Watch issued this past afternoon for the Washington DC
metro areas and parts of eastern Virginia and central and
southern Maryland.

Storms are expected to clear the area by around 2 or 3 AM, with
dry conditions later tonight. Additional thunderstorms may be
possible tomorrow afternoon, but coverage of storms is expected
to be much lower, and the threat for both severe thunderstorms
and flash flooding is expected to be much lower, if not zero.


KEY MESSAGE 2...Thunderstorm chances return Wednesday night into
Thursday.

Surface high pressure will build from the Ohio Valley into the Mid
Atlantic Tuesday and Wednesday, providing dry conditions and
slightly lower humidity. Temperatures may cool off a few degrees
Tuesday but overall remain seasonable.

The next cold front will approach from the northwest Wednesday
night, perhaps bringing some showers and thunderstorms depending on
its timing. The front will slowly drift south through the area
Thursday, which will result in the greatest chance of showers and
thunderstorms. At this time, it`s not certain if there will be
enough instability, and enough overlap with higher shear values, to
present a severe weather threat. It`s possible the front will stall
or only move just south of the area, which will play a role in
precipitation chances Friday. On Saturday, a shortwave trough may
cause low pressure to develop along the front, which could bring
more rain, even if we are north of its track. The next cold front
could approach from the Great Lakes next Sunday.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR conditions expected to develop or continue through the
middle of the night for the terminals. CHO could encounter
another round of showers and thunderstorms around midnight or
shortly thereafter as another disturbance moves into the area.
VFR conditions are expected through the day Tuesday. A brief
thunderstorm also can`t be ruled out Monday afternoon, but
coverage of storms is expected to be much less than today. Winds
will be out of the south today, northwest tomorrow, and then
north on Tuesday.

Prevailing VFR conditions are anticipated Tuesday through Wednesday
with high pressure. Potential showers and thunderstorms re-enter the
forecast Thursday and Friday.

&&

.MARINE...
SCAs will continue into tonight. SMWs may be needed within the
hour as the severe thunderstorms over southern Maryland make a
progress toward the southeast into the waters. Sub-SCA levels
anticipated into Tuesday after the brief bout of convection
overnight and again Monday afternoon.

North to northwest winds continue for Tuesday but likely remain
below SCA levels. As high pressure departs, winds turn southerly by
late Wednesday, and channeling may bring marginal SCA conditions
along the bay during the evening/overnight. A cold front may bring
some thunderstorms on Thursday as winds shift back to the north.

&&

.TIDES/COASTAL FLOODING...
Water levels continue to rise along the Bay within southerly
flow. A Coastal Flood Advisory remains for Annapolis for the
high tide cycle. Havre de Grace and Baltimore will also come
very close to Minor Flood Stage. Water levels will decrease
tomorrow as winds shift to out of the northwest.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch until 3 AM EDT Monday for DCZ001.
MD...Small Craft Advisory until 6 AM EDT Monday for MDZ008.
     Flood Watch until 3 AM EDT Monday for MDZ013-016-504.
     Coastal Flood Advisory until midnight EDT tonight for MDZ014.
     Flood Watch until midnight EDT tonight for MDZ509-510.
VA...Flood Watch until 3 AM EDT Monday for VAZ053>057-506-526-527.
WV...None.
MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ530>534-
     537>543.

&&

$$

DISCUSSION...ADS/KLW/KJP
AVIATION...ADS/KLW/KJP
MARINE...ADS/KLW/KJP