253
FXUS61 KLWX 140133
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
933 PM EDT Fri Jun 13 2025

.SYNOPSIS...
A cold front is expected to stall across the region over the
weekend. Multiple rounds of convection will accompany the front
during the period. This front will move to the north as a warm
front on Tuesday. High pressure over the Atlantic will bring
hotter conditions for the middle portion of next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
Current (as of 930 PM) radar imagery shows an arc of heavy
rainfall and thunderstorms extending southwestward from Charles
County into the Central Virginia Piedmont. This activity is
slowly progressing off toward the east. Further north, activity
is more isolated to scattered to the north of I-66, and also
slowly progressing off toward the east.

The environment this evening is very conducive for heavy
rainfall in any thunderstorms, with around 1000-2000 J/kg of
MLCAPE, very moist profiles through a deep layer, high freezing
levels, and precipitable water values near 2 inches. Rainfall
rates as high as 2 inches in 20 minutes were observed with
thunderstorms as they moved through Fairfax County earlier.
Isolated to scattered instances of flash flooding will continue
to be possible over the next few hours, especially to the south
and east of the earlier mentioned convective line (Central
Virginia Piedmont to southern Maryland). A Flash Flood Watch
remains in effect for much of the area through 2 AM. Portions of
this Watch may be able to be canceled early.

While heavier rain and thunderstorms should wind down over the
next few hours, showers and/or drizzle may linger on and off
through the night. Temperatures will remain mild overnight, with
lows in the mid 60s to lower 70s.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
A cold front will stall across the central zones of our region
through the day Saturday. An upper level low will move closer to
the area from the west. A lull in shower and any thunderstorm
activity more likely through Saturday morning with and
thereafter the fog. Another heavy round of showers and
thunderstorms is expected Saturday afternoon and evening. There
is still some uncertainty as to exactly where this will setup,
but latest guidance continues to suggest areas south and west of
the Potomac River as the areas most likely to get the strongest
convection. All the ingredients are there for a flash flood
threat. Will continue to monitor, because the position of the
front will be vitally important as to exactly where the
strongest convection will be. For areas to the northeast of the
boundary. A few showers and a thunderstorm are still possible,
especially late in the day into the evening as stronger
convection upstream propagates into the area.

The upper level low will shear apart as it moves into the area
Sunday, but latest guidance shows the boundary pushing a little
farther south and west. This is most likely in response to
subsidence associated with a departing jetmax in the northern
stream, causing high pressure to strengthen off the New England
Coast. The threat for heavy rain is most likely across central
Virginia into the Allegheny Highlands, but that can change if
the location of the front is off. Will continue to monitor.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
The stalled front will remain nearby in our region through the
day on Monday with cool marine air remaining in place for most
areas. The boundary will dissipate and move north Tuesday as a
warm front and high pressure over the Atlantic will likely
control the weather pattern for the middle of next week with a
return of hotter and humid conditions. Unsettled conditions will
likely persist during this time with chances for showers and
thunderstorms. Perhaps the best chance for stronger storms will
be Thursday as a cold front approaches from the west.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Thunderstorms are progressing through the area this evening. As
of 930 PM, storms have moved off to the south and east of IAD,
DCA, MRB, and CHO, with showers still in the vicinity of BWI and
MTN. Chances for showers and storms should continue to wind down
through the remainder of the evening.

Low clouds and areas of fog/drizzle are likely to develop late
tonight behind a stalling front that moves into the area. There
is still some uncertainty as to exactly where the boundary will
set up, but latest indications are that most areas will end up
in the marine air for Saturday through Monday. This means that
low clouds and subVFR conditions are likely most of the time
with IFR/subIFR conditions possible, especially at night into
the morning hours each day. Unsettled conditions will continue
with the likelihood for showers and perhaps a few storms. The
best chance for storms will be around KCHO, KMRB and KIAD
Saturday afternoon and evening and KCHO for Sunday afternoon and
evening. However, storms are possible everywhere.

More low clouds and fog will likely hang around through Tuesday
morning, but cigs/vsbys should improve as the backdoor boundary
dissipates and moves northward.

&&

.MARINE...
A southerly flow will increase into this evening, but winds
should remain below SCA criteria. Thunderstorm coverage will
increase through this evening. Gusty winds associated with
storms may warrant Special Marine Warnings.

A stalling front will slide across the central areas for later
Saturday through Monday night. An easterly flow will bring low
clouds and areas of fog, and the likelihood for showers and
perhaps a thunderstorm will persist. Winds should be below SCA
criteria. The boundary will dissipate Tuesday and a southerly
flow will develop for the middle portion of next week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch until 2 AM EDT Saturday for DCZ001.
MD...Flood Watch until 2 AM EDT Saturday for MDZ013-016-017-504.
VA...Flood Watch until 2 AM EDT Saturday for VAZ037>039-050-051-
     053>057-502-527.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...BJL
NEAR TERM...KJP
SHORT TERM...KLW
LONG TERM...BJL
AVIATION...BJL/KLW/KJP
MARINE...BJL/KLW