906
FXUS61 KLWX 150754
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
354 AM EDT Sun Jun 15 2025

.SYNOPSIS...
Daily chances for showers and thunderstorms with the risk of
localized flash flooding look to continue through early next week as
a stalled frontal boundary remains nearby. The coverage of showers
and thunderstorms decreases today through Monday for most of the
area outside of central Virginia. A warm front lifts back through
the area Tuesday into Wednesday with a strong cold front to follow
late week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Daily shower and thunderstorm chances look to continue today
although coverage looks to be far less than recent days and mainly
confined to portions of the Allegheny Highlands as well as central
VA. The pesky stalled front continues to sit in the vicinity of
Potomac River. Several ripples of upper level energy continue to
traverse this boundary with one exiting early this morning and
another ejecting out of western WV and southeast Ohio. This is noted
per water vapor imagery this morning along with radar/satellite
which shows a subtle swirl down around the
Huntington/Parkersburg, WV area. Widespread shower and
thunderstorm activity continues in those aforementioned
locations early this morning with a decrease in activity across
our region as subsidence settles in behind the departing ripple
of shortwave energy/jet max. Meanwhile, weak high pressure off
the Canadian Maritimes will wedge southward today helping push
the front further south into central Virginia and westward into
the Allegheny Mountains. Areas south of the boundary will have
the greatest concern for widespread shower and thunderstorm
activity today along with instances of flash flooding. Locations
further north still have a risk at a few showers and
thunderstorms although coverage will be far less pronounced
especially along and north of I-66/US-50. Low and mid level
clouds will continue to prevail leading to mostly cloudy to
overcast skies as easterly onshore flow increases. Some wildfire
smoke may also be noted below the inversion this morning and as
things mix out this afternoon due in part to ongoing wildfires
in southern NJ. This may hamper air quality in both the
Baltimore/Washington DC metro areas throughout the day where
concentrations look to be the highest.

Highs today will be much cooler compared to recent days with many
locations struggling to get out of the upper 60s and low to mid 70s,
especially north of the boundary where a maritime airmass will take
shape. Locations south of the boundary (i.e the southern Shenandoah
Valley and VA Piedmont will see highs in the mid to upper 70s to
around 80s degrees. These locations have a better bet of seeing
filtered breaks of sunshine which will help the atmosphere
reload for convective development during the afternoon and
evening hours. Current 00z CAM guidance suggest storms along and
south of line from Grant Co. WV down toward Staunton/Richmond,
VA. Once again looking at multicellular clusters developing
between 2-8pm along the boundary before waning after midnight.
Storms will fuel off of MUCAPE values of 500-100 j/kg with 0-6
km shear values under 35 kts. Rain rates of 1-2"/hr remain
possible with PWATS still hovering between 1.5 to 2 inches.
Flood Watches may need to be considered for portions of central
VA and the Allegheny Highlands later this morning to encompass
this threat. Decided to forgo for now given some uncertainty in
the placement of the boundary and overall convective coverage.

Showers and thunderstorms will diminish tonight with areas of fog
and low clouds persisting. Lows tonight will fall back into the low
to mid 60s. A few upper 50s are possible in the river valleys and
areas along the PA/MD line as slightly drier air works in.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
High pressure over eastern Canada and northern New England will
shunt a stationary boundary south of the region. Onshore
maritime flow will continue as a result with multiple pieces of
shortwave energy traversing the boundary to the south. The
stalled front will remain close enough for increased chances of
shower activity especially south of the Baltimore/DC metro
areas. Highest shower chances will be during the early morning
and late afternoon/evening hours. Once again isolated instances
of flash flooding are possible given the antecedent conditions
over the last few days. Warm stratiform rain processes will be
more of the theme compared to convective due in part to a
slightly more stable airmass overhead. Highs Monday will remain
in the upper 60s and low to mid 70s with the influence of high
pressure along the New England coast still wedging south and the
front slowly push back north from central and southern VA.

The stalled surface boundary that will have lingered over the area
for several days will finally start to dissipate and lift north of
the area as a warm front Tuesday into Wednesday. Meanwhile, a weak
upper trough will approach from the Ohio Valley. Showers and
thunderstorms are expected to form during the afternoon hours within
a very humid airmass (surface dewpoints around 70). High
temperatures on Tuesday are expected to be reach into the upper 70s
and lower 80s for most.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
High pressure strengthens offshore moving into the middle of the
week, leading to south to southwesterly low-level flow and
increasing heat and humidity locally. Temperatures should reach into
the 90s on both Wednesday and Thursday. When combined with dewpoints
in the lower 70s, heat indices may approach 100 on Thursday.
Thunderstorms appear possible both days, but the greater coverage
should be on Thursday as an upper trough tracks off to our north
across the Great Lakes, with its associated cold front approaching
from the west. Current model guidance suggests that ample
instability and shear may be present on Thursday, so some storms may
be on the stronger side. Upper troughing is expected to dig in from
the Great Lakes on Friday. Cooler and drier conditions are expected
locally in the wake of the system`s cold front heading into next
weekend.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Low clouds, fog, and drizzle continue across the terminals this
morning as a stalled front sits nearby. The corridor terminals as of
08z continues to bounce between IFR to LIFR with MVFR TO IFR
conditions across the Shenandoah Valley and Alleghenies. IFR to
pockets of LIFR cigs and vsbys can be expected through at least 15z
amongst the terminals with subtle improvement into the mid-afternoon
hours. Onshore flow and a moist marine airmass look to linger
throughout the day and into the first part of next week. BKN-OVC
MVFR TO IFR cigs are expected this afternoon and evening with the
front wavering nearby. Another round of showers and
thunderstorms will also follow with the highest concentration of
activity south of a line form KEKN to KCHO/KSHD and KRIC.
Storms look to bubble in these aforementioned locations between
19-00z/3-8pm. Areas further north into the corridor terminals
will contend with a passing shower or thunderstorm after
20z/4pm. Locally heavy rainfall will be the biggest threat with
storms today which will reduce vsbys. Gusty winds also cannot be
ruled out along with frequent lightning. Any convection will
slowly wane after 00z-04/8pm-12am with passing showers and
drizzle/fog leftover during the overnight hours.

IFR/sub-IFR cigs/vsbys are expected across all terminals
tonight into Monday morning as onshore flow remains. Winds today
will remain light out of the north/east at 5-10kts with
occasional guts up to 15 kts along the stalled front to the
south and near the waters. Additional periods of sub-VFR
conditions are likely to continue for Monday and Tuesday.
Shower and thunderstorm chances will remain during the afternoon
and evening hours especially at terminals south and east of
KCHO Monday before becoming more scattered areas wide as the
front lifts northward Tuesday. Areas further north will remain
in a marine airmass with persistent low clouds and areas of
fog/low clouds during the overnight/early morning periods.

Sub-VFR conditions may be possible Tuesday morning, but improvement
back to prevailing VFR conditions is expected Tuesday afternoon
through Wednesday. Temporary drops to sub-VFR conditions may be
possible in thunderstorms both Tuesday and Wednesday afternoon.

&&

.MARINE...

A stalled front will sit south of the waters today through Monday.
Onshore easterly flow will persists with occasional gusts up close
to SCA levels this morning and into the afternoon/evening hours.
This is especially true over middle and lower portions of the
Chesapeake Bay compared to the sheltered harbors/inlets. Low
clouds and some marine fog is possible this morning and again
tonight given the moist airmass in place. Less shower and
thunderstorm activity is also expected today through Monday
given the proximity of the boundary south of the region. Even
with that said, an isolated shower or thunderstorm cannot be
ruled out during the afternoon and evening hours. Sub-SCA level
winds less than 15 kts are expected through Monday.

Sub-SCA level southerly winds are expected over the waters on both
Tuesday and Wednesday.SCA conditions look to return Thursday
into Friday as a strong cold front crosses the waters.

&&

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

&&

$$

SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...EST
LONG TERM...KJP/CPB
AVIATION...CPB/EST
MARINE...CPB/EST