204
FXUS61 KLWX 271406
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1006 AM EDT Wed May 27 2026

.WHAT HAS CHANGED...
Moderate to heavy rain continues across the northern half of the
forecast area. Sensitive areas or areas that received notable
rain over the past few days are most prone to hydro issues.

&&

.KEY MESSAGES...
- 1) Severe thunderstorms and a few instances of flooding are
  possible this afternoon and evening.

&&

.DISCUSSION...
KEY MESSAGE 1...Severe thunderstorms and a few instances of flooding
are possible this afternoon and evening.

No major changes to the forecast today. Ongoing rain this
morning resulting in some ponding of water in construction zones
or poor drainage areas. Will continue to evaluate SVR wx threat
this afternoon, may be a tier of counties south than previously
thought. Previous modified discussion follows..

The Bermuda High remains in place today across the southwest
Atlantic, with a stream of tropical moisture advecting northward to
the Mid-Atlantic on the ridge`s western periphery. The 12Z IAD
sounding had upwards of 1.82" PWAT, and that moisture is
expected to remain in place today. Aloft, a strong upper trough
digs south over the eastern Great Lakes, dragging with it an
associated surface cold front. A stalled frontal boundary
remains in place across southern VA this morning, and is
expected to lift slightly north this afternoon. Several waves of
energy aloft traverse across the stalled boundary through this
evening.

This is going to produce at least a couple rounds of showers and
thunderstorms across the area. The first will be from early morning
convection over OH/WV that reaches the Allegheny Front around
sunrise this morning. These showers/storms are going to be slow
moving and could produce a quick 1-3" across parts of western MD and
the upper Potomac Highlands. Given the saturated ground conditions
from days of rain, this produce instances of flooding. As such, a
Flood Watch remains in effect for these areas through this afternoon.

The timing for the next round of thunderstorms remains a bit
uncertain. 00Z CAM guidance indicate storms developing earlier, from
late morning to mid afternoon, though the RRFS still has the main
thunderstorm window from mid afternoon to early evening.

SPC has maintained the Slight Risk (level 2 out of 5) for south of
the Potomac River, including DC and southern MD, with a Marginal
Risk (level 1 of 5) to the  north. Storm motion is going to be
faster as deep-layer winds increase, but locally heavy rainfall
could produce some flood threat, especially in urban areas.

Damaging wind gusts are going to be the primary threat from any
severe thunderstorms that develop today. While not expecting
widespread severe storms, a few could produce wet microbursts in
a nearly saturated environment. Low-level lapse rates are
forecast around 7-7.5 C/km, and effective deep shear around 40
knots. This favors some organized multi-cell clusters or line
segments that cross the area from northwest to southeast.

By late evening the majority of these thunderstorms will push
south of the area, with residual some showers/storms lingering
into the early part of the night. Not expecting severe weather
with any late convection in the area.

The front moves south of the area by early Thursday morning, with
clearing skies and mostly dry conditions behind it. A reinforcing
front moves through Thursday afternoon, which could kick off a few
showers and storms in Central VA where some moisture lingers. Rain
chances are low at around 20-30pct. After that, dry and seasonal
conditions expected Friday.

A few extra clouds may be noted Saturday, especially north of
I-66/US-50 and south of I-64 as a series of upper level low
pressure systems pass nearby. The bigger story for the extended
period will be the return of sunshine and seasonable/slightly
below normal temperatures. Expect highs in the 70s (60s
mountains) through Tuesday with overnight lows in the 40s and
50s. Upper level ridging will persists through the middle of
next week with a gradual warming trend expected.

&&

.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
Low clouds and fog develop this morning, producing IFR to LIFR
conditions at area terminals. These restrictions will persist for
much of the day as multiple rounds of showers and thunderstorms move
across the area. The most likely time for stronger thunderstorms
will be during the afternoon to evening, though timing remains
uncertain. A cold front sweeps through tonight, bringing dry and VFR
conditions Thursday and Friday.

VFR conditions are expected Friday through early next week.
Light northwest winds less than 10-15 kts.

&&

.MARINE...
Showers and thunderstorms are forecast to move across the waters
this afternoon to evening. Some of these storms will be capable of
producing strong wind gusts, in addition to lightning strikes.
Special Marine Warnings will likely be needed for parts of the
waters. A cold front sweeps through on Thursday, and northerly
channeling behind the front could produce SCA conditions through
Thursday evening. Sub-SCA conditions likely Friday.

Additional SCAs will be needed Saturday afternoon and evening
due to northerly channeling. Sunday and Monday bring no marine
hazards at this time.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Flood Watch until 4 PM EDT this afternoon for MDZ501-509-510.
VA...None.
WV...Flood Watch until 4 PM EDT this afternoon for WVZ501-503-505.
MARINE...None.

&&

$$

DISCUSSION...CPB/KRR/EST
AVIATION...CPB/KRR/EST
MARINE...CPB/KRR/EST

NWS LWX Office Area Forecast Discussion