166
FXUS61 KLWX 051952
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
352 PM EDT Tue May 5 2026

.WHAT HAS CHANGED...
Chances for thunderstorms to the east of the Blue Ridge tomorrow
afternoon are trending upward.

&&

.KEY MESSAGES...
- 1) Warm and dry conditions expected today, followed by
  beneficial rainfall tomorrow morning, and a chance for
  thunderstorms tomorrow afternoon..

- 2) High pressure moves in at the end of the week, followed by
 weekend showers and fluctuating temperatures.

&&

.DISCUSSION...
KEY MESSAGE 1...Warm and dry conditions expected today, followed by
beneficial rainfall tomorrow morning, and a chance for
thunderstorms tomorrow afternoon.

Broad upper troughing spans across most of North America this
afternoon, with flanking ridges over the eastern Pacific and
western Atlantic. At the surface, a deep and highly occluded
surface low resides beneath an embedded upper low in the
vicinity of James Bay, while high pressure resides offshore in
the western Atlantic. A cold front extends well south and west
of the surface low through the Great Lakes, Ohio Valley,
Mississippi Valley, and Southern Plains. Such a surface pattern
has led to southwesterly winds locally. This southwesterly flow
has advected warmer air into the region. Temperatures have
climbed into the low to mid 80s this afternoon beneath mostly
sunny skies. Winds are gusting around 25 to 35 mph out of the
south to southwest.

High clouds will be on the increase later this afternoon into
this evening in advance of the upper trough and associated
surface cold front. This system will make very slow
southeastward progress later tonight through the day tomorrow.
Clouds will continue to thicken overnight, with light stratiform
rain overspreading the area from northwest to southeast late
tonight through mid-morning tomorrow. Most locations should
experience a few-hour long window with light rain between late
tonight and the early afternoon hours tomorrow. This stratiform
rain will move out early tomorrow afternoon, potentially
allowing for some limited breaks of sun tomorrow afternoon in
advance of the system`s cold front. Exactly how much
destabilization we see in the wake of tomorrow morning`s light
rain remains a big forecast question.

Recent guidance has trended a bit slower with the front`s
progression through the area, which could potentially allow for
a bit more destabilization tomorrow afternoon. As a result, the
trend has also been slightly upward with CAPE values. Much of
the destabilization appears to occur as a result of low-level
moisture convergence in the vicinity of the surface front, which
causes dewpoints to rise into the low to mid 60s. That being
said, there is still a fair amount of uncertainty with respect
to how much destabilization occurs, and also the areal coverage
of storms that form.

Shear certainly won`t be lacking tomorrow, with most soundings
showing long, straight hodographs, with around 60 knots of
effective bulk shear and over 100 knots of shear in the cloud
bearing layer. So, if storms form, there is a conditional threat
for supercells. The 12z HRRR for example, hinted at this
possibility, with weak UH tracks.

The thermodynamic environment is a bit odd, and casts
uncertainty with respect to what hazards storms could
potentially produce, if they occur at all. Model soundings show
long, straight hodographs, which would normally be supportive of
hail production. However, profiles are nearly saturated and
moist-adiabatic at low-levels, with a considerable amount of the
CAPE below the freezing level, which is unfavorable for hail
production. Winds in the mid-upper levels are very strong, but
aren`t overly impressive just above the surface. And model
soundings show a good amount of dry air in the mid-levels (which
yields DCAPE values around 700 J/kg), but very moist air at
low-levels and poor low-level lapse rates, which would be
unfavorable for transporting higher momentum air down from
aloft. Machine learning guidance is downplaying the potential
for severe thunderstorms, and SPC currently has us outlooked in
general thunder. However, tomorrow is at least worth monitoring
from a severe thunderstorm perspective given the CAPE/shear
combination that could potentially be in place (high end
scenario of around 1000 J/kg of MLCAPE, and 60 knots of
effective bulk shear).

The best chance for thunderstorms tomorrow afternoon will be to
the east of the Blue Ridge. Any showers and storms will progress
eastward with the front tomorrow evening. Winds will turn
northwesterly behind the front. While chances for thunderstorms
will come to an end, showers may linger on and off behind the
front tomorrow night through much of the day Thursday.


KEY MESSAGE 2...High pressure moves in at the end of the week,
followed by weekend showers and fluctuating temperatures.

Surface high pressure moves into the region by Thursday night after
Wednesday`s frontal boundary transitions offshore, maintaining
temperatures in the 50s and 60s until the end of the week.
Temperatures start to increase again going into the weekend, with
highs in the 70s on Saturday and Sunday. A few rain showers
associated with a shortwave upper level trough are possible on
Saturday.

Looking ahead, another Great Lakes frontal boundary looks to be
making its way towards the East Coast by early next week, bringing
additional chances for rainfall.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected this afternoon, along with
southwesterly winds gusting to around 20-30 knots. Winds will
remain out of the south to southwest tonight. Current thinking
is that winds will remain gusty overnight, but if we were to
lose the gusts, there could be low-level wind shear overnight at
some sites. Light rain moves in from northwest to southeast late
tonight into early tomorrow morning. Ceilings will also drop
tomorrow morning, with most sites experiencing a few hours of
low-end MVFR to IFR conditions mid-morning through mid-
afternoon. A brief lull in the rainfall is expected during the
early afternoon hours, as ceilings slowly improve back to VFR by
mid-late afternoon. Winds tomorrow will again be out of the
south to southwest at around 20 to 25 knots. Showers and
thunderstorms appear possible late tomorrow afternoon into early
tomorrow evening as a cold front moves through. PROB30 groups
highlighting thunderstorm chances were introduced for late
tomorrow afternoon at DCA, BWI, and IAD. Chances for
thunderstorms should come to an end tomorrow evening.

Winds will shift to out of the north to northwest behind the
front tomorrow night. Sub-VFR ceilings may develop again
tomorrow night, especially at CHO.

Northerly winds on Thursday shift southwest by Friday evening, with
gusts up to 10-15 knots. Periodic sub-VFR conditions are still
possible on Thursday as a strong cold front transitions offshore.
VFR conditions on Friday. Showers and thunderstorms are possible
on Saturday with sub-VFR conditions expected during heaviest
rain showers in the afternoon.

&&

.MARINE...
SCA-level gusts are expected to continue within south to
southwesterly flow through tomorrow afternoon. A cold front will
move over the waters late tomorrow afternoon into tomorrow
evening. Some thunderstorms may accompany the frontal passage,
potentially leading to the issuance of SMWs late tomorrow
afternoon into tomorrow evening. Winds will shift to out of the
north behind the front, with sub-SCA level north to
northwesterly winds expected tomorrow night through the day
Thursday. Sub-SCA level westerly winds are forecast for Friday.

South winds Saturday morning gust near SCA criteria. Winds
diminish to below SCA criteria Saturday evening.

&&

.FIRE WEATHER...
Warm, dry, and windy conditions today lead to elevated to near
critical fire weather conditions this afternoon. Gusty winds 30
to 35 mph, low humidities in the mid 20s, and fuel moisture
between 8-10% are expected today, with the greatest risk for
dangerous fire wx behavior west of the Blue Ridge where recent
cool temperatures and freezes have slowed down green-up. Greener
vegetation east of the Blue Ridge Mountains should preclude any
fires from exhibiting extreme fire behavior, but gusty winds of
30-35 mph may still cause fire containment difficulty even
though fuels are not as dry as they were two weeks ago. Special
Weather Statements for Elevated Fire Danger have been issued
across Virginia, the Eastern Panhandle of West Virginia, and
Western Maryland through 7 PM this evening.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 6 PM EDT Wednesday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT Wednesday for ANZ530>543.

&&

$$

DISCUSSION...KJP/SRT/AVS
AVIATION...KJP/SRT
MARINE...KJP/SRT

NWS LWX Office Area Forecast Discussion