457
FXUS61 KLWX 211423 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
1023 AM EDT Thu May 21 2026

.WHAT HAS CHANGED...
Small Craft Advisory added for the middle and upper tidal
Potomac River for today.

&&

.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.

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. 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 /14Z THURSDAY THROUGH MONDAY/...
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 all the waters 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 until 6 PM EDT this evening for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ530>533-535-536-538>542.
     Small Craft Advisory until 6 AM EDT Friday for ANZ534-537-543.

&&

$$

DISCUSSION...LFR/DHOF/EST
AVIATION...LFR/DHOF/EST
MARINE...LFR/DHOF/EST

NWS LWX Office Area Forecast Discussion