027
FXUS61 KLWX 041834
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
234 PM EDT Wed Jun 4 2025

.SYNOPSIS...
Warm and dry conditions continue this evening with increasing
humidity as high pressure pushes offshore. An area of low
pressure will move across the Carolinas Thursday and quickly off
the Delmarva coast Friday. Shower and thunderstorm chances will
increase during this time with more widespread coverage
expected Saturday as a cold front drops into the region. This
front may stall near the area into the early and middle part of
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Mostly sunny skies continue for the remainder of the afternoon
with temperatures ranging from the mid to upper 80s over central
MD and central VA with mid to upper 70s along the western shore
of the bay. The southerly winds off the cooler waters have put
the brakes on temperatures at DCA from making a run at 90
degrees. BWI and DMH on the otherhand have quickly surged into
the upper 80s and may pop the 90 degree mark before the
afternoon is out. (See previous discussion).

Warm and dry weather conditions are expected to continue today with
upper level ridging/high pressure remaining nearby. Some haze may be
noted from time to time as Canadian wildfire smoke continues to
funnel in aloft. The smoke/haze will be more diffuse overall given
increasing moisture from south to southwesterly flow. Outside
of the smoke expect mostly sunny to partly cloudy skies with
highs in the mid 80s to around 90 degrees. Today, looks to be
our warmest day of the next 5 days given the uptick in cloud
cover and moisture (shower/thunderstorm chances) heading into
the latter half of the workweek and weekend ahead. If we don`t
reach 90 in Washington DC and Baltimore today, it may be at
least another week or two for the next opportunity. This will
start to challenge the latest first 90 degree reading since 2003
(June 24) in both Washington and Baltimore (i.e climo sites
IAD, BWI, and DCA).

Outside of the increased heat will be the humidity. Dewpoints will
begin to climb back into the low to mid 60s leading to a slightly
muggier feel. Low temperatures tonight will fall back into the low
to mid 60s with a few upper 50s in the deeper river valleys.
Skies will trend partly to mostly cloudy with mid and high level
cloud cover increasing from the south/west as low pressure
lifts north and east across the coastal Carolinas.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Shower and thunderstorm chances will return to portions of the area
Thursday as the upper level ridge buckles and front/trough approach
from the Ohio River Valley. The incumbent front will allow an area
of low pressure over the coastal Carolinas to lift northward into
southeast Virginia and off the Delmarva coast late Thursday
night into Friday. This would sandwich our area between the two
storm systems with shower and thunderstorm activity focused
mainly off to the south and west Thursday before becoming more
widespread Friday as the front/trough inch closer to the region.
Outside of the shower and thunderstorm chances (mainly west of
the Blue Ridge and south of I-66/US-50) Thursday will be an
uptick in cloud cover. This will limit temperatures with highs
Thursday ranging from the upper 70s and low 80s along and south
of I-64 to mid 80s further north toward the Baltimore/Washington
DC metro areas. A few lingering showers and thunderstorms may
stick around Thursday night with muggy conditions otherwise and
lows in the low to mid 60s.

By Friday, we`ll continue to monitor the progression of a slow
moving cold front from the Ohio River Valley and broad extratropical
low pressure system working up along the Delmarva coast. With that
said, our area will remain caught between the two storm systems with
shower and thunderstorm activity once again tied to areas mainly
west of the Blue Ridge where a pre-frontal trough will reside. Some
uncertainty arises for storm development further east of the
mountains and toward the metros given subsidence along the outer
periphery of the departing low pressure just offshore. The track of
the low (whether it`s closer to the coast/or farther offshore) will
dictate how much subsidence will be at play and ultimately the
shower/storm coverage east of the Blue Ridge. For now, continuing to
maintain likely PoPs west of the Blue Ridge given the pre-
frontal trough and chance Pops further east given the added
subsidence from the departing coastal low. Outside of the shower
and thunderstorm chances expected a continuation of increased
humidity and added cloud cover. Highs will push into the upper
70s and low to mid 80s with dewpoints in the mid to upper 60s.
Lows Friday night will fall back into the low to mid 60s with
upper 60s expected in the metro areas.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A slow moving frontal boundary sags south into our area to start the
weekend as a decaying surface low off the VA coastline moves further
offshore. Deep westerly flow aloft is not overly impressive, with
nearly zonal flow in the mid-levels. As a result, the widespread
showers and thunderstorms that develop Saturday afternoon to evening
are forecast to be sub-severe for the most part, with some gusty
winds and locally heavy downpours possible. Widespread cloud cover
keeps highs in the upper 70s to low 80s. This could be the first
humid summer day as dew points reach around 70F for most of the
area.

The front clears the area Saturday night, with weak surface high
pressure building in briefly on Sunday. While there is a slight
chance of showers on Sunday (20pct), the thinking is conditions
remain mostly dry across the area with ample sunshine. Plenty of
warmth as highs reach the lower 80s areawide, though dew points are
noticeably lower in the upper 50s to low 60s.

Active weather returns for the start of next week as a weak wave of
low pressure crosses the area on Monday, then another cold front
moves through on Tuesday. The current guidance indicates better
forcing, instability, and moisture transport for Tuesday that could
result in locally heavy rainfall. Still, that is at the very end of
the forecast with high uncertainty at that time range.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected through the remainder of the afternoon
and evening as high pressure slowly pushes offshore. Light south to
southwesterly winds are expected through the afternoon with a
occasional gusts up to 20 knots. Some haze may be noted, but should
be a bit more mute across the terminals this afternoon given
the south to southwesterly return flow around the departing
surface high. No significant issues are expected from haze today
with vsbys remaining greater than 6SM.

Shower and thunderstorm chances return to some of the terminals
Thursday afternoon/evening as the area sits sandwiched between an
incoming front from the Ohio River Valley and area of low pressure
moving up from the coastal Carolinas. Any shower and thunderstorm
activity will be relegated to terminals west of KCHO and KMRB with
chances at or less than 30 percent at this time. Conditions should
remain VFR most of the day with sub-VFR conditions expected Thursday
night into Friday morning as low pressure passes to the southeast.

Additional shower and thunderstorm chances are expected Friday
leading to periods of sub-VFR especially west of the Blue Ridge. The
shower and thunderstorm chances are in association with a slow
moving cold front approaching from the west along with
departing low pressure offshore and a prefrontal trough draped
over the mountains. The highest confidence for showers and
thunderstorms looks to be west of the corridor terminals
although some activity could push east from the mountains late
Friday afternoon and evening. Low pressure off the coast may
provide the corridor terminals with enough subsidence to limit
thunderstorms over the corridor pending it`s placement and
track. VFR conditions are expected otherwise with light south to
southeast winds occasionally gusting up to 15 knots.

Sub-VFR conditions are possible at times Saturday as widespread
showers and thunderstorms develop along a slow moving cold front.
VFR conditions are likely behind the front Saturday night through
the rest of the weekend.


&&

.MARINE...
High pressure will slowly drift off the coast through this evening
leading to a period of southerly channeling from south to
southeasterly flow. The combination of warm air temperatures and
relatively cool water temperatures will yield SCA conditions
later this afternoon and into the overnight period for most of
the Chesapeake Bay and lower tidal Potomac. Southerly channeling
will become a bit more prevalent during the evening and
overnight hours as temperatures cool closer to the water
temperatures.

South to southeasterly winds will continue to prevail across
the waters Thursday as low pressure works north and east from
the coastal Carolinas. Some brief southerly channeling is
possible especially over the open waters although confidence
appears low for any advisories at this time. Most of the day
should be dry although and isolated shower/thunderstorm cannot
be ruled out over the southern bay Thursday night into Friday
morning.

An additional period of marginal southerly channeling is possible
along the bay late Friday afternoon and evening. This is in
association with a tightening gradient between an incoming front
from the west and area of low pressure sliding along the
Delmarva coast. A few thunderstorms may be possible Friday
afternoon and evening yielding the potential need for SMWs
given the warm/humid airmass. Storms may have trouble
maintaining themselves toward the waters given the fact that the
bay and tidal Potomac will sit on the periphery of the passing
coastal low pressure system yielding subsidence over the region.
Once again this will depend on the track and placement of the
low late Thursday night into the day Friday.

A slow moving cold front is forecast to drop south across the local
waters on Saturday. While winds are forecast to remain below SCA
conditions, there is likely to be widespread showers and
thunderstorms. These could pose a threat to mariners due to gusty
winds and lightning strikes. Winds briefly turn northwest to north
Sunday morning behind the front, then south by Sunday evening, all
while remaining below SCA levels at around 10 knots.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 1 AM EDT Thursday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 1 AM EDT Thursday for ANZ530>534-
     537>543.

&&

$$

SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...EST
LONG TERM...KRR
AVIATION...KRR/EST
MARINE...KRR/EST