Lothian, Maryland Weather Forecast Discussion

641
FXUS61 KLWX 010127
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
927 PM EDT Tue Sep 30 2025
.SYNOPSIS...
Canadian high pressure builds south from Ontario and Quebec
through the week. A strong cold front will track across the
area tonight bringing cooler and drier weather for the middle
and latter part of this week. Moderating trend in temps this
weekend.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Sprinkles have finally pushed south of the area and cloud cover
is eroding from the northwest. The front pushing through tonight
represents advection of cooler and drier air from strong high
pressure to the north though absent any sort of wind shift. Dew
points in the lower 50s and 40s are beginning to enter the area
from the north, continuing to spread into the area overnight.
High level clouds may take into Wednesday morning to completely
clear, and there also may be a patch of lower clouds that fills
in behind the front. Models indicated reduced ceilings and
visibility over the mountains late tonight, though it is
uncertain how the low cloud deck balances with river valley fog
formation. Northerly winds may kick up a bit as the front passes
(especially near the waters and along the ridges), but overall
inland areas should remain a bit decoupled. Lows should drop
into the 50s to lower 60s, though some high elevation valleys
may drop into the 40s.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Given the quiescent pattern, no major changes to the short
term. Building 1090+ mb high pressure from Quebec will be the
main story for the middle and second half of the week supporting
clear skies Wed and Wed night. NNE to NE winds will start
shifting more to the E Thu as high pressure over the Northeast
slides offshore. Models show more cloud cover Thu with a
stratocu deck developing as onshore winds develop. Temps will
cool down Wed and Thu with highs around 70 and falling into the
40s west of I-95. Some patchy frost can`t be ruled out in the
most sheltered valleys west of the Blue Ridge with the favored
areas making a run at 32F. Will look to nail down temperature
forecast for Wed and Thu night in future shifts, but given the
low Tds in the 30s, think some areas could truly bottom out.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Continued influence of strong surface high pressure will remain
along the eastern seaboard through the weekend, perhaps
drifting slowly eastward early next week. Initially rather flat
ridging aloft will expand eastward and amplify by early next
week as a series of troughs move through the western part of the
continent. Dry conditions should prevail, although there are
some hints some moisture could start wrapping around the ridge
from the south by Monday. Below normal temperatures on Friday
will moderate back above normal over the course of the weekend.
Given moderating trend in temps, no frost/freeze concerns
overnight.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
Mid and high level clouds gradually erode tonight into Wednesday
morning. There may be some scattered low clouds behind a front
tonight into Wednesday morning, but it appears any sub-VFR
conditions will be relegated to the mountains. Onshore winds
Thu may result in a continued stratocumulus deck, though no
restrictions expected at this time. NNE winds will strengthen
late tonight into Wed with gusts up to 20 kt possible. Winds
begin to diminish later Wed.
No significant weather is expected Fri and Sat as strong high
pressure remains overhead.
&&
.MARINE...
N to NNE winds will strengthen tonight into Wed with SCA
conditions expected as the pressure gradient tightens with the
high to the north and tropical system offshore. Winds will
begin to gradually diminish later Wed, but SCA conditions may
persist into Thu evening for portions of the waters.
Winds will become southerly Fri, but should remain below
advisory criteria into Sat as high pressure remains centered
nearby.
&&
.TIDES/COASTAL FLOODING...
North to northeast winds are forecast to strengthen tonight
into Wednesday as strong high pressure builds in from the north.
This is going to keep tidal anomalies in check.
The threat for widespread minor coastal flooding, and possible
moderate coastal flooding at Annapolis could occur during the late
part of the week. Have issued a Coastal Flood Watch to account
for this during the Wednesday night high tide. This will be due
to a snapback tide when the strong northeast winds start to
diminish Wednesday night, then turn east to southeast Thursday
afternoon into Friday.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 6 PM EDT Wednesday for MDZ008.
     Coastal Flood Watch from Wednesday evening through Thursday
     morning for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT Wednesday for ANZ530>533-
     538>542.
     Small Craft Advisory until midnight EDT Wednesday night for
     ANZ534-537-543.
     Small Craft Advisory from 4 AM to 6 PM EDT Wednesday for
     ANZ535-536.
&&
$$
SYNOPSIS...CPB
NEAR TERM...ADS/CPB
SHORT TERM...CPB
LONG TERM...CPB
AVIATION...ADS/CPB
MARINE...ADS/CPB
TIDES/COASTAL FLOODING...CPB

NWS LWX Office Area Forecast Discussion