287
FXUS61 KLWX 021914
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
314 PM EDT Tue Sep 2 2025

.SYNOPSIS...
High pressure will progress offshore on Wednesday. A cold front
will approach the area from the west on Thursday. A stronger
cold front will move through on Saturday. High pressure will
build back in early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Broad upper troughing remains in place across much of the
Eastern US. A more compact upper low centered to our north over
Lake Ontario is gradually weakening. A very weak upper
disturbance is rotating across the area today to the south of
the upper low. With high pressure in place at the surface, and
limited moisture available, only fair weather cumulus clouds are
developing across the bulk of the area. However, a few sprinkles
or very light showers may be possible near and/or west of the
Blue Ridge. Both temperatures and dewpoints will continue to be
well below normal, with highs in the 70s, and dewpoints in the
lower 50s.

Any showers should quickly dissipate after sunset, with any
fair weather cumulus also going away this evening. The
combination of clear skies, light to calm winds, and high
pressure nearby, will lead to ideal conditions for radiational
cooling, with low temperatures dropping back into the upper 40s
and 50s. Some patchy fog may be possible, especially in
sheltered mountain valleys.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Longwave troughing will remain in place across the Eastern US
through the short term period. The upper low centered to our
north today will shear out and lift off to our northeast
tomorrow. Meanwhile, a much stronger upper low will drop
southward into the western Great Lakes. We`ll be located between
these two disturbances tomorrow, and dry conditions are expected
for most as a result. The lone exception may be across far
southwestern portions of the forecast area, where a stray
afternoon shower may be possible as a weak shortwave approaches
from southwestern Virginia. Temperatures and dewpoints will both
remain below normal, with highs in the upper 70s/low 80s, and
dewpoints in the 50s.

The aforementioned upper low will drop southeastward across the
Great Lakes Thursday morning, before later turning northeastward
as it interacts with another potent disturbance dropping down
within northwesterly flow toward the base of the trough. This
will drive a cold front toward the area from the Ohio Valley on
Thursday. This front will then wash out overhead as it loses
upper level support (which will be moving off to our northeast).
Southerly flow ahead of the system will advect warmer and more
humid air into the area. When coupled with height falls aloft,
this will result in increasing instability. Flow aloft will also
be on the increase. Model soundings show around 500 J/kg of
MLCAPE and around 40 knots of shear. As a result, any
thunderstorms that form on Thursday should be well organized
(as either multicells or supercells), and a resultant threat for
strong to severe thunderstorms exists. This threat currently
looks to be greatest to the west of the Blue Ridge, where SPC
has a Marginal Risk for severe thunderstorms outlooked.
Temperatures will be warmer on Thursday, with highs making it
well into the 80s. It will also feel a bit more humid, with
dewpoints climbing back into the lower 60s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Upper level troughing pivoting over the eastern CONUS will push a
cold front through the forecast area early Friday ahead of a strong
cold front pushing through Saturday evening. Showers and
thunderstorms are possible Saturday afternoon and into the evening
as the cold front pushes through the forecast area. In the wake of
the cold front, surface high pressure builds over the Mid-
Atlantic from the west Sunday and into early next week.

Temperatures gradually warm Friday and Saturday ahead of a cold
front with high temperatures rising into the 80s for most of the
area. Those at higher elevations will stay in the upper 60s to 70s
both days. Overnight low temperatures on Friday will be in the 60s
for most with higher elevations dipping into the upper 50s. In the
wake of a cold front, low temperatures Saturday night will be in the
40s and 50s with only those near the metro areas staying in the low
60s. High temperatures Sunday and Monday will be in the 70s for most
with higher elevations staying in the 60s.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Prevailing VFR conditions are expected at the terminals through
Thursday. A thunderstorm could be possible Thursday afternoon or
evening as a decaying cold front approaches from the west. Winds
will be light out of the east this afternoon, before turning out
of the southeast this evening, and then south tomorrow. Stronger
southerly winds appear possible on Thursday, with gusts to
around 20 knots possible.

VFR conditions and southwest winds gusting around 15 knots are
expected on Friday. Showers and thunderstorms are possible across
the terminals on Saturday as a cold front pushes across the Mid-
Atlantic. Sub-VFR conditions are likely during showers and
thunderstorms. Southwest winds Saturday morning shift to
northwest in the wake of the cold front, gusting up to 15 knots
in the afternoon.

&&

.MARINE...
Sub-SCA level winds of varying directions are expected over the
waters today into tonight. Winds will become southerly
tomorrow and gradually pick up in magnitude through the day,
potentially nearing low-end SCA levels by tomorrow night. SCAs
appear likely within southerly flow on Thursday.

Small Craft Advisories are likely Friday through early Saturday
morning as winds gust 15 to 20 knots across the waters. Winds
diminish slightly on Saturday, will SCA criteria winds possible in
the afternoon.

&&

.TIDES/COASTAL FLOODING...
Water levels hold somewhat steady through tonight as northeast
winds remain in place. Annapolis will likely be the only
location that approaches minor flood stage tonight. A flip to
southerly flow Wednesday should allow for further rises in water
levels. Confidence in Annapolis reaching minor flood increases
Wednesday night. Peak water anomalies appear to occur Thursday
night ahead of a front in strong southerly flow. More locations
may reach minor flood, and some guidance has Annapolis
approaching moderate flood. Water levels should decrease
somewhat Friday as the front passes.

&&

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

&&

$$

SYNOPSIS...KJP
NEAR TERM...KJP
SHORT TERM...KJP
LONG TERM...AVS
AVIATION...AVS/KJP
MARINE...AVS/KJP
TIDES/COASTAL FLOODING...ADS