Montgomery Village, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

501
FXUS61 KLWX 150808
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
408 AM EDT Thu May 15 2025

.SYNOPSIS...
Low pressure will drift toward the northeast today while a warm
front approaches from the west by tonight. Low pressure will
move into the Great Lakes Region Friday, with a trailing cold
front pushing through the area Saturday. High pressure will
build in from the north Sunday and Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Trough axis/remnant closed low is centered across the forecast
area this morning. A weak surface low is noted near southern
Maryland. Most of the showers have turned more drizzly in nature
at this early hour, although some more notable showers are
moving up the Chesapeake Bay that weren`t well modeled. The end
outcome should be the same, that rain chances will consolidate
northeast of the Potomac River through the morning hours. Low
clouds and fog will start the morning across much of the area.
Locally dense fog is possible, but at this time doesn`t appear
like it will become widespread.

Clouds may take well into the afternoon to break up northeast of
the Potomac, while more sun is expected to the southwest. A few
showers may regenerate near the trough axis in northeast
Maryland in the afternoon, but southwestern areas will be the
place to watch for more impactful thunderstorms. Forcing is
somewhat nebulous besides terrain lift and the leading edge of
warm advection...as otherwise heights will be rising. However,
most models show scattered storms developing near the central
Appalachians to Blue Ridge vicinity this afternoon before
progressing southeast by this evening. CAPE of 1000-2000 J/kg
and shear up to 40 kt could support severe storms with a large
hail and damaging wind threat. SPC has added a slight risk for
severe storms. The storms should have decent motion...however
with this area being hydrologically sensitive with many streams
running high, can`t rule out an isolated flood issue. WPC
expanded a marginal risk for excessive rainfall across the
region for this reason. Most 00Z guidance keeps these stronger
storms south of I-66 (if not much farther south).

Locations that see appreciable sun today should approach/exceed
80, while locations to the northeast stay in the mid 70s.

After storms move to the southeast during the evening there
should be a quiet period as temperatures fall back to the 60s.
Some patchy fog or low clouds could develop, with the best
signal across northern Maryland. See short term section for
discussion about additional thunderstorm chances.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
From late Thursday night through Saturday, much uncertainty
exists around thunderstorm chance...with a high dependence on
what happens upstream, both in terms of advection, and how the
local environment may be modified. Current guidance favors
several periods, but this could obviously change: First is
convection that forms along the warm front upstream which could
move into the area any time from around/just after midnight
tonight through 8 AM Friday morning. Most guidance shows this
activity weakening, but at least some storms may be supported by
elevated instability and shear. Second is something originating
from the southwest into Friday afternoon, though this carries
the most uncertainty. If no forcing can move into the area
Friday, it could turn out pretty dry, as forecast soundings
exhibit a fairly strong cap. Third will be upstream convection
that may arrive late Friday night into Saturday morning. The
question is whether this survives in tact or regenerates during
the day Saturday along its outflow. Throughout the period, CAPE
and shear would be supportive of severe thunderstorms,
especially any that are previously organized and/or develop
locally during peak heating. Storms should generally be
progressive, but will have to monitor the flooding threat as
well. Hopefully details can be refined moving forward.

Assuming early clouds/rain are not too widespread, Friday will
turn out rather hot and humid with highs well into the 80s. Some
locations could have heat indices in the lower 90s. The same can
be said for Saturday after a very mild start. It`s possible the
cold front clears the area Saturday morning, with
clearing/drying and breezy conditions in the afternoon however.
The secondary cold front may bring some upslope showers Saturday
night. Otherwise temperatures will start cooling off.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
An upper low/trough is progged to be pivoting by to the north to
start the second half of the weekend. This trough slowly departs
toward the Canadian Maritimes and into the North Atlantic Monday
into Tuesday. At the surface, a cold front will move offshore as
high pressure builds well to the north near James Bay. The result
locally should be a period of cooler and drier weather with NW winds.

A sharp but narrow ridge crests over the eastern CONUS Tuesday into
Wednesday before another trough approaches the Great Lakes inducing
height falls along the East Coast mid next week. This should offer
the next appreciable chance of showers and thunderstorms.

Temperatures look to be near to below normal through the
extended.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Remaining showers have become very light, although some
additional showers could affect BWI/MTN through mid morning.
Otherwise the story is IFR to LIFR conditions in low ceilings
and reduced visibility. Can`t rule out some patchy dense fog,
but doesn`t look widespread.

Conditions gradually improve to VFR later this morning, at
least for everyone except BWI and MTN. The highest chance for an
afternoon/evening thunderstorm appears to be at CHO, but far
from definite. By the afternoon, even BWI and MTN should try to
clear out. At this time, it appears any storms will stay south
of the metros, so have removed that mention from the TAF.

Sub-VFR conditions (ceilings or fog) may return to mainly
MRB/BWI/MTN tonight into early Friday. There is also potential
for one or more rounds of showers and thunderstorms late
tonight through Friday afternoon, but details remain very
uncertain at this time. Otherwise VFR conditions should prevail.
Another round of thunderstorms could arrive late Friday night
or Saturday morning. A cold front will push through Saturday
with gusty winds in its wake.

VFR in NW flow Sunday-Monday as a cold front pushes offshore.

&&

.MARINE...
Sub-SCA conditions should prevail through Friday night with
winds becoming southerly today and southwesterly Friday. Strong
to severe thunderstorms are possible across mainly the southern
Maryland waters this afternoon and evening. Additional strong
thunderstorms could affect the waters at times through Saturday,
although timing and coverage remain uncertain. A cold front will
push through Saturday, with SCA conditions likely in its wake.

NW winds may gust 20-25 kts Sunday before becoming lighter Sunday
night into Monday.

&&

.TIDES/COASTAL FLOODING...
Georgetown will have some freshwater related flooding by
this morning, and a Coastal Flood Warning is in effect for this
threat. Current forecast brings Georgetown to Moderate for much
of the day on Thursday as a result of the freshwater influence
flowing down from the west. Water should recede Friday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Warning from 7 AM this morning to 4 PM EDT
     Friday for DCZ001.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

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