232
FXUS61 KLWX 140106
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
906 PM EDT Sun Jul 13 2025

.SYNOPSIS...
High pressure will remain in place offshore over the course of
the week. A weakening cold front will approach from the
northwest tomorrow, before ultimately stalling out and
dissipating overhead by mid-week.

&&

.NEAR TERM /THROUGH MONDAY/...
Most of the organized convection earlier this afternoon has now
dissipated, with remnant heavy showers and a few thunderstorms
lingering. Will watch that complex across south-central PA,
though it also looks to be weakening this evening. The Flood
Watch has been dropped for the southern half of the area, and
kept up along the Alleghenies, northern Shenandoah Valley, and
northern Maryland until 1 AM. It is possible we can cancel the
watch before that as convection continues to dissipate.

Given the soupy tropical environment, popup showers and a few
thunderstorms will be possible across the area tonight. Some of
these will produce heavy downpours, though the flood threat
looks to be minimal. Overnight low temperatures settle in the
upper 60s to low 70s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
Another active day is expected tomorrow as a shortwave and
associated cold front approach from the northwest. Differential
cyclonic vorticity advection ahead of the aforementioned
shortwave will provide synoptic scale forcing that has been
lacking on previous days, within what will be a very similar
thermodynamic environment. A much higher areal coverage of
storms is expected as a result. With the increased organization
and slightly stronger mid-level flow (around 15 knots), storms
may be be slightly more progressive compared to preceding days,
but will likely pose an even greater threat for flash flooding,
given the higher areal coverage and a thermodynamic environment
that will still be very favorable for producing heavy rainfall.
Forecast soundings still show 2000-3000 J/kg of MLCAPE, deep
saturated profiles, PWATs near or in excess of 2 inches, and
high freezing levels. A Flood Watch for flash flooding will
likely be needed for much of the area once again. Storms may
fire over the higher elevations of western MD and the WV
Panhandle, as well as along the Bay Breeze further east. Much
like today, outflows from these areas of storms may eventually
meet up.

The aforementioned cold front will stall out overhead on
Tuesday, with slightly drier air filtering in behind the front,
especially in the mid-upper levels. The drier air moving in
aloft and lack of large scale forcing may limit thunderstorm
development across northwestern portions of the forecast area on
Tuesday. Better chances for showers and thunderstorms will
reside further southeast, where they`ll hang on to deeper
moisture.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
On Wednesday, a southeastern U.S. upper ridge will continue to bulge
northward into the Mid-Atlantic region. Eventually the northern
extent of this ridge axis erodes in response to amplification in the
northern branch of the jet. As this occurs, shortwave intrusions
over subsequent days will augment convective chances, particularly
in light of the continued warm and humid conditions in place.
Although these impulses should only offer a grazing blow to the
region, even subtle height falls can still have notable effects on
the quality of the forcing. Given the unpredictability of such
shortwaves, plus any storm-scale features which are unknown at this
time, will contribute to a low confidence convective forecast. By
late next weekend into the following week, a few deterministic
solutions attempt to show a deeper trough on the horizon. However,
as expected, global ensembles favor a more conservative elongated
longwave trough over much of eastern North America. The
aforementioned cold front will stall out overhead on Tuesday

Looking at the surface pattern, the early week boundary which stalls
nearby is expected to return northward as a warm front on Wednesday.
This returns the area into the broadening warm/moist sector and more
90 degree temperatures. The next frontal system of interest enters
the picture by Friday into Saturday. While daily afternoon/evening
thunderstorm chances are possible through the period, they will
likely further increase with the approach of this cold front. At
this point, like typical summertime boundaries, this system may
stall nearby toward the end of next weekend.

Daily high temperatures through the period will mainly rise into the
upper 80s to low 90s (70s to mid 80s across the mountains). For low
temperatures, expect readings in the upper 60s to mid 70s (low/mid
60s for mountain locations). Global ensembles are fairly consistent
in this signal with some downtick next weekend as the trough/front
moves through.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Most of the convection from this afternoon has now dissipate,
with isolated showers/storms through the night. While VFR
conditions are likely to prevail, will have to monitor for the
possibility of low stratus developing late tonight into Monday
morning.

Additional thunderstorms are expected tomorrow afternoon as a
cold front approaches from the north and west. Coverage of the
storms should be higher tomorrow afternoon into tomorrow
evening. Storms may be possible again on Tuesday afternoon, but
the highest coverage will likely be further south (in the
vicinity of CHO).

With convection perpetually in the forecast, restrictions are
possible each afternoon/evening from Wednesday through Friday. Each
day carries a 50 to 70 percent chance of showers and thunderstorms.
Thus, it is difficult to say which day will be more active than the
other. However, outside of these thunderstorms, VFR conditions
should be anticipated. Given the warm/moist conditions in place,
patchy fog cannot be ruled out at night, particularly for areas
which see appreciable rainfall. Winds through the period meander
between south to southwesterly before turning more westerly in
nature by Friday. Afternoon gusts could push into the 10 to 15 knot
range.

&&

.MARINE...
Sub-SCA level winds are expected over the waters through
Tuesday. Winds shift to the south late tonight through Tuesday.
SMWs are likely to be needed at times Monday and Tuesday
afternoon to evening as thunderstorms move across the waters.

A stalled frontal zone is expected to lift north of the waters on
Wednesday. As this occurs, south to southwesterly winds pick up in
strength Wednesday evening into much of Thursday. Wind gusts across
the southernmost waters could near 20 knots at times which would
warrant Small Craft Advisories. Elsewhere, gusts of 10 to 15 knots
are expected. The threat for convection increases through the period
with a 40 to 60 percent chance of showers and thunderstorms on both
Wednesday and Thursday afternoon/evening. Special Marine Warnings
may be needed for some of the stronger storms.

&&

.TIDES/COASTAL FLOODING...
A prolonged period of southeasterly winds will lead to elevated
tidal anomalies today and into early next week. This carries
most of the tidal locations into Action stage, particularly
during the higher of the two astronomical high tide cycles.
Sensitive locations, such as Annapolis, are forecast to stay
just below Minor stage during the high tide cycles Sunday and
Monday morning.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch from 1 AM to 2 AM EDT Monday for DCZ001.
MD...Flood Watch from 1 AM to 2 AM EDT Monday for MDZ011-013-014-
     016-503>506.
     Flood Watch until 2 AM EDT Monday for MDZ003>006-501-502-
     507>510.
VA...Flood Watch from 1 AM to 2 AM EDT Monday for VAZ025>027-
     029>031-036>040-050-051-053>057-501>508-526-527.
     Flood Watch until 2 AM EDT Monday for VAZ028.
WV...Flood Watch until 2 AM EDT Monday for WVZ050>053-055-501>506.
MARINE...None.

&&

$$

SYNOPSIS...
NEAR TERM...KRR
SHORT TERM...KJP
LONG TERM...BRO
AVIATION...KRR/KJP/BRO
MARINE...KRR/KJP/BRO
TIDES/COASTAL FLOODING...LWX