546
FXUS61 KLWX 200020
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
820 PM EDT Sat Sep 19 2026

.WHAT HAS CHANGED...
Added some light sprinkles in across western and central MD this
evening. Additional scattered showers early Sunday morning and again
Sunday afternoon as a front slides through. Small Craft
Advisories expanded.

&&

.KEY MESSAGES...
- 1) Scattered showers and perhaps a few thunderstorms look to
finish out the weekend as a front passes through.

- 2) Daily shower chances and cooler temperatures persists through
midweek with drier conditions for the upcoming weekend.

&&

.DISCUSSION...
KEY MESSAGE 1...Scattered showers and perhaps a few thunderstorms look to
finish out the weekend as a front passes through.

Added some light showers and sprinkles in across central and western
MD this evening as spotty activity drops south from central and
western PA. Outside of these showers and sprinkles, is increased low
and mid level cloudiness. This is in association with a squeeze play
between fronts with moisture advection increasing from the south and
east and a cold front slowly dropping down from the Great Lakes
region. Low and mid level clouds will remain abundant overnight with
some filtered breaks the further south you get toward the I-64
corridor. Most will remain dry overnight, but with moisture
advection increasing over a shallow cool layer aloft expect humidity
values to gradually climb and spotty showers likely developing over
the mountains heading into Sunday morning. This shower activity will
be scattered in nature and in association with the warm front and
lead piece of shortwave energy ahead of the front that is currently
located back across the eastern Great Lakes and Ohio River Valley.
The first round of showers should exit the area around midday with a
secondary area of showers and perhaps a few thunderstorms working
through the region Sunday afternoon and evening as the cold front
drops through. Current hi-res guidance has slowed the front up a bit
while dissipating/washing it out over the region Sunday evening into
Sunday night. Deterministic synoptic guidance has a similar
solution while keeping a ripple of low pressure riding along the
boundary Sunday evening into Sunday night forcing it south.
With that said, severe weather does not appear to be a concern
although a few thunderstorm cannot be ruled out over central VA,
southern MD, and the northern neck of VA where some breaks of
sun may filter through. Any of these storms will be capable of
locally gusty winds, heavy rainfall, and lightning.

The front will eventually shunt southward heading into Monday
morning although on and off shower activity will persists into
the new workweek given increased onshore flow. Expect a
noticeable cooling trend beginning Monday in the wake of the
cold front late Sunday night. Highs Sunday will push into the
upper 70s and low 80s (low 70s mountains) with overnight lows in
the upper 50s and mid 60s. Highs Monday will struggle to get
out of the upper 60s and low 70s as more of a wedging pattern
sets up with increasing onshore flow.

KEY MESSAGE 2...Daily shower chances and cooler temperatures persists through
midweek with drier conditions for the upcoming weekend.

Mid-level moisture overhead will coincide with an area of low
pressure just off the East Coast tracking north on Wednesday. Weak
instability at the surface will suppress thunderstorm activity for
the most part, but expect rain showers to continue through Wednesday
and Thursday as shortwave disturbances track across the Mid-
Atlantic. High temperatures continue to range in the 60s as
these disturbances move through.

As the coastal low skirts the Mid-Atlantic coastline, winds will
be elevated Wednesday and Thursday with wind gusts between 20-30 MPH
possible, especially along the Chesapeake Bay. Winds could
potentially be higher over the waters, and this onshore flow
combined with stronger tidal influence could increase coastal flood
risk during this period. Refer to the coastal flooding section below
for more details.

As this system tracks north towards the end of the week, winds along
the coastline should gradually decrease. Mid-level dry air moves in
overhead from the Midwest, which should lead to diminishing rainfall
potential heading into the weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR conditions look to continue through at least 02z/10pm with
MVFR cigs settling in overnight as low and mid level clouds
thicken. Low and mid level clouds will persists through Sunday
afternoon as a result of increased moisture advection ahead of a
series of fronts pushing through. Most locations will remain
dry tonight outside of a passing shower or sprinkle for
terminals west of MRB. Shower coverage will increase early to
mid Sunday morning between 10- 16z/6am-12pm as a result of a
warm front lifting into the region. Moisture advection with this
front combined with a leading piece of shortwave energy will
yield scattered light to moderate showers mainly at terminals
north of KCHO. Expect a lull in the showers midday with an
additional round of scattered showers and perhaps a few
thunderstorms Sunday afternoon beyond 19z-23z/3-7pm. Greatest
opportunity for a thunderstorm would be south of the corridor
from DCA down to CHO/RIC where breaks of sun will be more
prevalent. Severe weather is not expected although locally gusty
winds and brief heavy rain cannot be ruled out with any
thunderstorms that form. CIGS become more scattered to broken
Sunday evening into Sunday night before restrictions return
Monday as onshore east to northeast flow increases.

Expect a mashup of MVFR to perhaps periods of IFR cigs on both
Monday and Tuesday as a result of increased onshore flow. Low and
mid level cloudiness will be persistent through midweek along with
daily chances for showers. Sub-VFR conditions could persist through
Thursday as scattered showers continue throughout the region. Gusty
winds between 20-25 knots are possible on Thursday. Winds flow from
northeasterly to northerly by Friday.

&&

.MARINE...
Small Craft Advisories have been expanded to encompass not only the
open waters of the bay and tidal Potomac, but the middle waters of
bay north toward the Baltimore Inner Harbor. SCA level winds will
continue on and off through Sunday midday as onshore flow increases
and the gradient tightens ahead of the incumbent frontal boundaries.
Additional SCA level conditions may be needed for the waters late
Sunday afternoon and evening and again early next week.

North to northeasterly wind gusts remain elevated through Wednesday
and Thursday as an area of low pressure remains off the East Coast.
Showers & a couple of thunderstorms are possible over the waters
during this period. As this system begins to track north late in the
week, winds should begin to decrease heading into the weekend.

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisory has been issued for Anne Arundel County.
CBOFS guidance seems like the only guidance performing well with
the elevated water levels and showing the rapid response due to
the onshore flow.

Onshore flow will persist through at least the middle of next
week with water levels remaining elevated with minor coastal
flooding expected at times of high tide. At this time, the risk
of moderate coastal flooding seems low.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 5 AM EDT Sunday for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for ANZ531>534-
     537>543.

&&

$$

DISCUSSION...EST/SRT
AVIATION...EST/SRT
MARINE...EST/SRT

NWS LWX Office Area Forecast Discussion