920
FXUS61 KLWX 200057
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
857 PM EDT Wed Aug 19 2026
.WHAT HAS CHANGED...
No significant changes were made to the latest forecast package.
The 18Z high-resolution models still show a decent signal for
active convection on Thursday afternoon/early evening. However,
there are a few solutions that remain more tame in nature.
&&
.KEY MESSAGES...
- 1) Shower and thunderstorm chances return on Thursday, with
precipitation chances lingering Friday and Saturday.
- 2) Numerous showers and thunderstorms Saturday with lingering
showers Sunday. Turning cooler and dry next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Shower and thunderstorm chances return on
Thursday, with precipitation chances lingering Friday and
Saturday.
While the afternoon stratocumulus deck has largely eroded with
the loss of daytime heating, additional clouds have begun to
move in from the Ohio Valley. This is all occurring ahead of a
cold front currently arcing along/north of I-70 in northern
Ohio/Indiana. Off to the south, a stalled boundary draped over
the Carolinas drifts north as waves of low pressure traverse
along it. Precipitation chances increase overnight with showers
possible Thursday morning, particularly over western Maryland.
Tonight`s low temperatures will be in the 60s to low 70s.
Convective chances increase throughout the day on Thursday as
shortwave energy tracks towards the mid-atlantic from the Ohio
river valley. There is uncertainty regarding the strength of
storms due to morning precipitation and location of the fronts
coinciding with peak daytime heating. Best chances for strong
to severe thunderstorms is along and east of the I-95 corridor
where the best conditions overlap. Here, SPC has a slight risk
for severe weather with damaging wind gusts, large hail, and a
brief tornado possible. Effective shear nearing 40 knots
combined with CAPE 2000 J/kg allows discrete cells to become
more organized into a line as storms track eastward. Confidence
is highest along and east of the I-95 corridor tomorrow
afternoon and into early the evening.
In addition to the severe threat, PWATS nearing and exceeding 2"
lead to an isolated flooding threat. Storms will be capable of
producing heavy rainfall but progressive storm motions should
limit flooding threat to sensitive areas.
KEY MESSAGE 2...Numerous showers and thunderstorms Saturday
with lingering showers Sunday. Turning cooler and dry for next
week.
The longwave pattern is forecast to amplify significantly this
weekend into next week as trough digs across the Great Lks and OH
Valley. This will drive a pair of cold fronts across the area Sat
and Sun providing focus for showers and thunderstorms. Saturday
looks like the more unstable day as we remain in WSW flow aloft and
with better forcing ahead of the trough axis. By Sunday, the first
cold front should have pushed the deep moisture and instability to
the south limiting the coverage and intensity of showers while the
trough axis moves overhead limiting the upper level forcing.
As trough axis shifts east of the area Sunday night, expect a cooler
and drying trend to start the new work week.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Cloud cover and precipitation chances increase across the
terminals overnight, although primarily VFR conditions are
expected through early Thursday morning. Morning convection may
impact MRB as showers and thunderstorms track across western
MD/eastern panhandle of WV. Showers and thunderstorms impact the
terminals Thursday afternoon with restrictions likely during
heavy precipitation. Highest chances for strong to severe
thunderstorms remains along and east of I-95 terminals. After
precipitation moves out of the area, low ceilings are possible
Thursday night into Friday.
Sct convection Sat through Sun.
&&
.MARINE...
Winds remain below Small Craft Advisory criteria through
Thursday morning. A Small Craft Advisory is in effect for the
southern Chesapeake Bay Thursday afternoon. SMWs are possible
Thursday afternoon as strong to severe thunderstorms track
across the waters. Otherwise, non hazardous marine weather is
expected through the end of the week.
&&
.TIDES/COASTAL FLOODING...
Current tidal anomalies largely range from 0.25 to 0.50 feet
this evening. These may rise slightly in time, but only locations
like Annapolis and perhaps Alexandria could hit Action stage during
the next couple of days. This will particularly be the case during
the higher of the two astronomical high tides.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 PM to 6 PM EDT Thursday for ANZ533-
534-543.
&&
$$
DISCUSSION...AVS/LFR/BRO
AVIATION...AVS/LFR
MARINE...AVS/LFR
TIDES/COASTAL FLOODING...BRO
NWS LWX Office Area Forecast Discussion