207
FXUS61 KLWX 210648
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
248 AM EDT Thu May 21 2026

.WHAT HAS CHANGED...
Pockets of beneficial rainfall continue early this morning with more
widespread rain chances this afternoon and evening. Continuing to
monitor for hydro concerns in vulnerable urban and poor drainage
areas with a rainy pattern persisting through the weekend.

&&

.KEY MESSAGES...
1) Turning sharply cooler today through Saturday with multiple
opportunities for much needed rainfall.

2) Rain chances persist into early next week, but with gradually
warming temperatures.

&&

.DISCUSSION...
KEY MESSAGE 1... Turning sharply cooler today through Saturday with
multiple opportunities for much needed rainfall.

What a difference a day makes as we go from the sultry record
breaking heat of Tuesday and Wednesday back to the early Spring
chill today through the holiday weekend ahead. High temperatures
will take a 25 to 30 degree nose dive today with highs struggling to
get into the mid to upper 60s compared to the mid 90s of yesterday
afternoon. Light to moderate showers and isolated thunderstorms
early this morning will decrease in coverage prior to daybreak with
pockets of drizzle and low clouds leftover. More widespread light to
moderate shower activity will work back over the region later this
morning and into the afternoon as additional waves of low pressure
move along a transient cold front that will sink south of the
region. Overrunning along this boundary will keep on and off rain
chances in place through the weekend, especially during the
afternoon and evening periods.

This is largely due in part to the synoptic pattern with weak
troughing over the Ohio River Valley and wedging high pressure over
New England. Increased onshore/maritime flow will keep things gray
and gloomy with limited sunshine and high temps today through
Saturday in the upper 50s and mid 60s. The greatest rain chances
look to be during the afternoon and evening periods with a quarter
to half an inch (perhaps three quarters of an inch of rain) expected
each day. This will yield rainfall amounts of 1 to 3 inches through
Monday with localized amounts of 4"+ across the Alleghenies/eastern
WV Panhandle and up into central/northeast MD. With that said, this
should ease some of the severe and extreme drought across the
region. conditions across the region.

With persistent rain chances and cloud cover expect below normal
temperatures throughout the holiday weekend stretch. We`ll trade the
shorts and tees for rain jackets/long sleeves with highs in many
locations Friday struggling to push 60 degrees. Similar values are
expected Sunday although the outer fringes of the wedge (i.e
southern Shenandoah Valley and southern MD) could push into the
upper 60s and low 70s with slightly thinner cloud cover.

KEY MESSAGE 2...Rain chances persist into early next week, but with
gradually warming temperatures.

A transient/wedge will gradually relent early next week. A warm
front meandering south of the area will push to the north on Monday,
continuing rain and thunderstorm chances into the start of next
week. Temperatures still vary a bit in the ensemble outlooks, but
temperatures should start to gradually climb again, with early
outlooks showing highs in the low 80s again by Tuesday. High
pressure moves into the area by midweek, reducing rain chances by
Wednesday into Thursday (into the 20-30 pct range mainly to the
southwest of the Potomac River).

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Pockets of light to moderate rain showers over the corridor will
continue to decrease prior to 9z/5am this morning with stratiform
rain showers/drizzle lingering as cold front slowly sinks south of
the region. With the front nearby expect a patchwork of VFR, MVFR,
and IFR conditions amongst the terminals. Expect MVFR to IFR
conditions later this morning and into the evening hours as
widespread overrunning light to moderate showers overtake the
terminals. These conditions will continue on and off through the
upcoming holiday weekend as the front stalls nearby. Greatest
coverage of rain at all terminals looks to be during the afternoon
and evening hours, especially with a focus north of KCHO given the
placement of the front and waves of low pressure moving along it.
Wind gusts could reach 15 to 20 kts later this morning into the
afternoon under north/northeast flow. Winds will decrease tonight
with east to northeast flow Friday and Saturday at 5-15 kts.

As for thunderstorms, expect the probabilities to remain low through
Saturday given the lack of instability from added cloud cover and
stability north of the boundary. Thunderstorm chances do return
Sunday afternoon and evening as a warm front lifts back into the
region. Winds will shift from the east and northeast back to the
south and southeast at 5 to 15 kts. Periodic sub-VFR potential
persists into early next week (Monday-Tuesday) with daily chances of
showers. Winds generally remain between 5-10 knots during this time,
with northeast winds shifting southerly by Monday evening through
Tuesday.

&&

.MARINE...
Increasing onshore flow today as a slow moving cold front sags south
of the waters. SCAs are in effect for most of the bay and lower
tidal Potomac this morning through late afternoon for northerly
channeling. Expect gusts up to 20 kts before a gradual tapering of
the winds tonight.

East to northeast SCA level winds are expected over much of the bay
and surrounding inlets Friday and Saturday given increased onshore
flow. No marine hazards are expected Sunday with winds slowly
switching back to the south and southeast. Winds continue below SCA
levels through Monday, with northeast winds shifting southerly by
Monday evening. Winds may increase in southerly flow Tuesday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 7 AM this morning to 6 PM EDT this
     evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 7 AM this morning to 6 PM EDT this
     evening for ANZ530>533-538>542.
     Small Craft Advisory from 7 AM this morning to 6 AM EDT Friday
     for ANZ534-537-543.

&&

$$

DISCUSSION...AVS/DHOF/EST
AVIATION...AVS/DHOF/EST
MARINE...AVS/DHOF/EST

NWS LWX Office Area Forecast Discussion