721
FXUS61 KLWX 081341
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
941 AM EDT Sat Aug 8 2026

.WHAT HAS CHANGED...
The Storm Prediction Center has upgraded to a Slight Risk for
severe weather today along/eat of I-95.

&&

.KEY MESSAGES...
- 1) Typical Summertime pattern continues with building heat next
week. Storm chances today decreasing Sunday and Monday.

- 2) A cold front could arrive late next week bringing relief
  from the heat and humidity into the upcoming weekend.

&&

.DISCUSSION...
KEY MESSAGE 1... Typical Summertime pattern continues with building
heat next week. Storm chances today decreasing Sunday and Monday.

It`s a typical Summertime pattern as we enter the second weekend and
week of August. The forecast is on repeat with patchy morning dense
fog giving way to hot and humid conditions with late day afternoon
and evening thunderstorms.

This morning is already a bit active, with some decaying
thunderstorms moving into western portions of the forecast area.
These held together quite nicely into the Allegheny Front, but
seems to be decaying quickly as they cross it. Would expect
outflow from this decaying system, along with the approaching
upper-level energy to act as forcing mechanisms later this
afternoon.

Today, we`ll bring another passing shortwave disturbance which will
trigger an additional round of afternoon and evening strong
thunderstorms. Thunderstorm coverage will be a bit less due to mid
level west to west/west-southwest flow yielding some downsloping
flow east of the mountains. This is a stark contrast to the
southerly flow over the past few days yielding locally higher storm
coverage. Much like previous days, convection likely triggers
around Noon-2 PM along the I-81 corridor before moving into the
I-95 corridor by 4-6 PM. Most storms should be out of the area
by 8 PM, but could see some secondary convection along existing
outflows even up to a couple hours after sunset. Severe threat
with these would be less, but could provide some late evening
lightning.

Storms today will be isolated to scattered with a focus again along
and north of I-66/US-50 and east of the Allegheny Mountains.
Instability will remain high as a result of the high heat and
humidity. Shear values will sit around 30 to 35 kts as the
subtropical jet stream begins to strengthen. Thermodynamic
profiles also depict this sentiment with skinnier CAPE profiles
and inverted-V signatures towards the surface yielding a higher
ceiling for damaging wind potential. As such, with
higher shear today, decent mid-level lapse rates, and continued
high CAPE values, the ceiling for stronger storms is higher
today. This means that while we are less confident in coverage
of storms today, the ones that do get going should pose a higher
risk of becoming more organized. Damaging winds will be the
primary threat today, especially if we get any bowing segments
to develops. The Storm Prediction Center maintained a Marginal
Risk (level 1 out of 5) for severe weather for most spots, but
actually upgraded areas along/east of I-95 to a Slight Risk
(level 2 out of 5). This is due to pooling of higher dew points
near the waters, leading to higher levels of instability and
potential for the mos intense storms. Isolated instances of
flooding also cannot be ruled out, especially over the urban
areas around Baltimore/DC given the repetitive heavy rains the
last few days. Would expect to see some storms reach
instantaneous rainfall rates in excess of 3"/hr yet again. The
focus for the flooding threat is hard to pinpoint, but will be
wherever you get colliding boundaries to stall. Storms today
should have a bit more movement with stronger downbursts, so
thinking the threat is a bit less than yesterday. Lastly,
lightning will be a big concern again, with potential for
lightning well outside the core of any storm. It is important to
move indoors any time you hear thunder in the distance, as
lightning can strike several miles ahead of and behind storms.

Convection wanes a bit Sunday into Monday given quasi-zonal flow
aloft and the strengthening upper-level ridge axis nearby. A
few storms may develop over the higher elevations, but coverage
will be much less than in recent days. This will be short-lived
however, with storm chances increasing once again Tuesday
through the end of the week as a series of shortwave
disturbances pass through.

Outside of he storm chances expect highs in the upper 80s and low
90s with heat indices east of the Blue Ridge up around 100 degrees.
The hottest days look to be Monday and Tuesday given the
strengthened subtropical ridge over the region. Highs will push into
the mid 90s with heat indices closer to 105 degrees east of the Blue
Ridge/along the urban corridor.


KEY MESSAGE 2...A cold front could arrive late next week bringing
relief from the heat and humidity into the upcoming weekend.

Daily storm chances look to continue through at least Friday as a
more potent frontal system tracks toward the region. Ahead of that
front will be several fast moving shortwave disturbances which will
help aid in shower and thunderstorm development during the diurnal
period. Storm coverage is a bit uncertain with activity remaining
isolated to scattered Tuesday becoming a scattered to numerous
Wednesday into late week as the front tries to push through.
Speaking of the front, details remain a bit murky on it`s passage.
Most 00z ensemble/deterministic guidance suggests a frontal passage
Thursday afternoon into Saturday. Guidance also depicts an MCS type
setup during the Tuesday and Wednesday timeframe. Machine learning
guidance is grabbing onto this as well with probabilities running
between 15 to 30 percent for severe weather during the midweek
timeframe. SPC mentions areas back toward our west on the Day 4 and
5 outlook, so something we`ll continue to monitor, especially as the
subtropical ridge flattens.

There is a bit more uncertainty in regards to severe weather
Thursday through Saturday. Of course with any decent frontal passage
will have to be monitor given machine probabilities remaining
between 5-30 percent for severe weather. This will ultimately be
determined by the timing of the front in regards to the peak heating
period. Temperatures will cool from the 90s into the 80s late week.
Weather does look to improve for the upcoming weekend as Canadian
high pressure works into the region.

&&

.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
Prevailing VFR conditions are expected across the terminals through
the middle of next week given subtropical high pressure offshore and
the lack of any real front passing through. Brief periods of sub-VFR
are likely during the afternoon and evening hours due to
thunderstorms.

For today, expect storms to fire west of MRB between 15-18z/11am-2
pm before advancing eastward into the corridor (IAD-BWI-DCA) between
20-01z/4-9pm. PROB30s will be used to encompass this threat
given the coverage being isolated to scattered across the
region. Best chance for more organized storms is going to be in
the earlier portions of those timeframes for the metro
terminals, so may consider adding TEMPOs in with the next
update. However, PROB30s may be needed into the evening as well,
with potential for secondary convection to develop along any
existing outflow boundary collisions even into the late evening
hours.

Storm coverage drops off even more Sunday and Monday with
chances primarily west of MRB and south of CHO/SHD. Outside of
the thunderstorms expect patchy fog between the terminals each
morning through early next week. Winds will remain light out of
the west and southwest at less than 15 kts.

Temporary restrictions will continue at times through at least
Friday as we await a cold front to sweep through.

&&

.MARINE...
Small Craft Advisories are in effect for portions of the open
water due to southerly channeling mainly later this afternoon
and evening. Most days will see marginal conditions just below
the SCA threshold. Daily shower and thunderstorm chances are
expected each afternoon and evening through early next week. The
greatest coverage will be this afternoon/evening with a brief
reprieve Sunday and Monday. Special Marine Warnings may be
needed to encompass any any stronger thunderstorms that may
form. Damaging wind gusts and frequent cloud-to-ground lightning
will be the main threats between 19z-01z/ 3-9pm.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies remain elevated through early next week in response
to return southerly flow. Periods of coastal flooding are possible
at times of high tide at sensitive locations.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 3 PM this afternoon to midnight EDT
     tonight for ANZ534-537-543.

&&

$$

DISCUSSION...CJL/EST
AVIATION...CJL/EST
MARINE...CJL/EST

NWS LWX Office Area Forecast Discussion