Oldtown, Maryland Weather Forecast Discussion

001
FXUS61 KLWX 240702
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
302 AM EDT Wed Sep 24 2025
.SYNOPSIS...
Daily shower and thunderstorm chances look to continue through
Friday as a series of fronts cross the region. Low pressure over the
Ohio and Tennessee River Valleys will lift a warm front across
the region later today with a cold front set to follow late
Thursday into early Friday. The front will stall south and east
of the area this weekend leading to lingering shower chances
across southern portions of the forecast area. High pressure
returns from the north and west early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Longwave upper level troughing will gradually shift eastward from
the Great Lakes and mid-Mississppi River Valley today through
Thursday. At the surface, a cold front will remain stalled from the
eastern Great Lakes down into the Ohio and Tennessee River
Valleys. Multiple waves of low pressure will traverse this
boundary as it inches closer to the region.
As for today, expect a slight uptick in shower and thunderstorm
chances compared to what we saw on Tuesday afternoon (9/23). This is
largely due part to the convective initiation along the lee side
trough between the Alleghenies/Blue Ridge and a resultant piece of
shortwave energy/weak warm front that will lift across the area
later today into the overnight hours. The added lift combined
with subtle instability and a moist atmospheric profile should
lead to more thunderstorm development, especially in areas west
of the Blue Ridge. The Storm Prediction Center continues a
Marginal Risk for severe weather (Level 1 out of 5) for areas
west of I-81 this afternoon. Despite the outlook, 00z CAMS
suggest a pseudo wedge setup today across the region. This may
lend a hand in squashing convective chances and yielding more in
the way of showers/warm stratiform rain processes across the
region (later this afternoon and into tonight). The primary
concern with storms today will be beneficial heavy rainfall with
a secondary concern of gusty winds. PWATS continue to remain at
or above 1.5 inches with skinny CAPE and marginal shear
profiles per 00z hi-res model soundings. Recent drought will
help avoid any flooding concerns across the area given the
progressive nature of today`s activity.
High temperatures today will push into the upper 70s and low 80s
with mountain locations in the upper 60s. Shower chances will
likely linger through the first half of the night with areas of
fog late as the warm front lifts north of the region. Overnight
lows will remain on the mild side with most falling back into
the mid to upper 60s. Dewpoint values will remain near 70
degrees east of the mountains lending to a muggy late Summer
feel.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Shower and thunderstorm chances look to continue Thursday as the
front pushes into the region. Once again scattered to numerous
showers and thunderstorms are likely with a low end risk for
severe weather east of the Allegheny Mountains. The Storm
Prediction Center has a Marginal Risk (Level 1 out of 5) for
areas east of the mountains Thursday afternoon. Convection of
course will be dependent upon cloud cover with 00z CAMS
suggesting another day of marginal skinny CAPE and subtle shear
profiles given the increased moisture throughout the column.
Storms will be capable of gusty winds and heavy rainfall with
PWATS pushing up around 2 inches.
The front will slowly work across the area Thursday night into
Friday morning. The thunderstorm threat will diminish with showers
leftover through Friday afternoon and perhaps the evening hours.
This is largely due in part to a lag in the upper level trough and
evolving closed low over the southeast U.S. With that said, the
highest confidence for rain through Friday evening looks to be
across southeast portions of the forecast area. There is still some
uncertainty on where the cutoff point will be on the northern edge
given the placement of the departing front/trough and
timing/placement of the upper level low feature working north and
toward/along the southeast U.S coast.
High temperatures Thursday and Friday will push into the upper 70s
and low 80s east of the mountains with overnight lows in the mid to
upper 60s east of US-15 (upper 50s and low 60s west). Temperatures
may have to be tapered a bit Friday given the added cloud cover with
the lagging trough and shower chances that will linger through most
of the day east of the Blue Ridge. Confidence in this remains
low at this time.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Through the weekend and into early next week, a forming rex block is
the key highlight in the synoptic pattern ahead. Of interest, there
are random solutions that show some sort of tropical moisture
lifting from the tropical Caribbean along the western Atlantic.
Whether this actually materializes into an area of low pressure or
areas of low pressure is uncertain, but enhanced moisture looks to
lift toward the mid-latitudes by the Sunday-Tuesday timeframe.
Depending on the evolution of these systems, some ensembles do have
East Coast impacts, but low confidence at this juncture. For the
latest on the tropics, please visit hurricanes.gov. Among the
ensemble systems, the European (EPS) solution is the boldest in
maintaining a closed low and ushering precipitation back into the
area. Google Deep Mind model suite is less ambitious and keeps the
threat further east. Other ensembles are more washed out owing to
shearing out the closed low more readily. Thus, it remains to be
seen if shower threats emerge in this regime.
Fairly seasonable temperatures are expected through the period. On
Saturday through Tuesday, expect highs in the upper 70s to low 80s,
with the mountains in the 60s to low 70s. A secondary cold front
tracking through on Sunday should yield a gradual cool down into the
next work week. This also lowers dew points as winds turn more
northerly. As expected, ensemble spread increases next week as noted
by the increasing size of the box-and-whisker plots. This is likely
due to the unknowns around the meandering upper low over the
Tennessee Valley.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Continuing to monitor areas of fog this morning, especially in
locations that did see rain and back across the valleys west of
the Blue Ridge. Pockets of clear skies and thin clouds have
resulted in pockets of IFR to LIFR vsbys below 2 miles this
morning. Fog has been observed at KFDK, KMRB, and KCHO this
morning. Fog has also been noted between KDCA and KBWI/KMTN with
further development to the north across PA. Any fog will
quickly burn off after daybreak 13- 14Z/9-10am with partly to
mostly cloudy skies expected. Prevailing VFR conditions are
expected amongst most of the terminals for the front half of the
day with sub-VFR reductions at times this afternoon and
evening. This is due largely in part to another round of
scattered to numerous showers and thunderstorms as a warm front
lifts in from the south. Timing remains a bit uncertain in
regards to the storms with an emphasis on the late afternoon and
evening hours. For that reason, used PROB30s to encompass the
threat compared to TEMPOS given the lack of confidence. Cloud
cover could squash convection today leading to showers and
stratiform rain compared to thunderstorms. Similar sub-VFR
reductions are likely Thursday and Friday as the front stalls
overhead and several waves of low pressure pass along it. This
will lead to a continuation of scattered to numerous showers and
thunderstorms across the region. In addition to the storm
chances expect an uptick in low and mid level clouds with the
front stalled overhead.
Winds today will remain out of the south/southwest at 5 to 10 kts
with gusts up to 20 kts at times during the afternoon and evening
hours. More chaotic winds will be noted in and around thunderstorms.
South to southwesterly winds are expected Thursday before shifting
to the northwest Friday. Speeds will sit between 5 to 15 kts during
the afternoon and evening hours.
Winds turn southerly for the second half of Saturday. Expect VFR
conditions for the weekend while a secondary cold front tracks
through on Sunday.
&&
.MARINE...
A brief period of southerly channeling early this morning will give
way to sub-SCA southerly winds throughout much of the day. A nearby
warm front could result in scattered showers and thunderstorms
across the waters later this afternoon and into the evening hours.
No advisories or SMWS are expected at this time. Convection may be
more muted today with added cloud cover resulting in either showers
or pockets of stratiform rain that could create temporary vsby
reductions.
Shower and thunderstorm chances look to continue Thursday as a cold
front finally works across the waters. Scattered to numerous showers
and thunderstorms are likely resulting in SMWs Thursday afternoon.
The front does not look to cross until late Thursday evening into
early Friday morning. Southerly channeling will lead to brief SCA
conditions late Thursday morning into Thursday afternoon ahead of
the frontal passage. Winds switch to the northwest in the wake of
the front, but will likely stay below SCA levels Friday.
Overall wind fields should stay below advisory thresholds Saturday
given a relaxed gradient. A secondary cold front will cross the
waters Sunday, but winds remain below 10 kts.
&&
.TIDES/COASTAL FLOODING...
Anomalies are forecast to remain slightly elevated through Thursday,
so additional near minor flooding is possible at sensitive
locations such as Annapolis. This is most likely with the
higher daily tide cycle in the afternoon and evening, with the
strongest onshore flow and highest anomalies possible on
Thursday into Friday.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.
&&
$$
SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...EST
LONG TERM...CPB
AVIATION...CPB/EST
MARINE...CPB/EST
TIDES/COASTAL FLOODING...LWX

NWS LWX Office Area Forecast Discussion