675
FXUS61 KLWX 032359
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
759 PM EDT Wed Sep 3 2025

.SYNOPSIS...
A cold front will approach from the west Thursday bringing renewed
chances for showers and thunderstorms. A much stronger and more
potent cold front will cross the area Saturday with another round of
showers and thunderstorms. Canadian high pressure will build in from
the Ohio River Valley for the early and middle part of next week.


&&

.NEAR TERM /THROUGH THURSDAY/...
Current forecast package remains on track with some slight
alterations to overnight lows tonight and shower chances this
evening mainly west of the Blue Ridge. Broad upper level troughing
will continue over eastern CONUS heading into the weekend ahead. A
weak shortwave trough will approach from southwest Virginia and
central West Virginia this evening promoting a few showers and
perhaps a spotty thunderstorm mainly west of the Blue Ridge. Any
activity will likely die out before midnight with mid and high level
clouds leftover for the front half of the night mainly west of us-
15. Dry conditions are expected to continue otherwise with mostly
clear skies expected. Southerly flow will increase in the wake of
the departing shortwave early Thursday morning and ahead of the
incoming cold frontal boundary. This will prevent most locations
from decoupling overnight leading to milder conditions compared to
the last few nights across the area. Expect lows in the upper 50s
and low to mid 60s. Cooler high mountain valleys will likely drop
into the upper 40s and low 50s.

Scattered shower and thunderstorm chances return Thursday afternoon
and evening mainly between 1-9pm as a cold front washes out over the
region. A deep upper level low will push northward from the upper
Great Lakes toward Hudson Bay while a trailing shortwave trough
drops southward from Lake Michigan Thursday morning. This
trough will eventually lift northward toward the St. Lawrence
Valley Thursday afternoon pushing a cold frontal boundary
southeastward into the region. The front will cross the area
Thursday night before dissipating to the east Friday.

Thunderstorms are expected to develop Thursday afternoon as large
scale ascent associated with that system overspreads a destabilizing
airmass.Temperatures should reach well into the 80s for most, with
dewpoints potentially climbing into the low-mid 60s. Isolated
showers may reach the Allegheny Front as early as late morning, but
more scattered to widespread shower/thunderstorm activity is
expected to develop tomorrow afternoon. These storms will likely
impact locations to the west of the Blue Ridge between roughly 1-5
PM, and locations to the east of the Blue Ridge from 2-8 PM. Model
soundings show around 500-1000 J/kg of MLCAPE, with around 35-40
knots of effective bulk shear. Hodographs are relatively straight,
with near unidirectional southwesterly flow. Much of the shear is
present in the lowest 3 km. DCAPE appears to be on the lower side,
with relatively moist mid-levels. However, most models show well
mixed sub-cloud layers with relatively steep low- level lapse rates.
CAMs show a mixed multicell/marginal supercell mode. Small bowing
segments may be capable of producing damaging winds, and any
supercells could produce either damaging winds or hail. Supercell
splits may be possible given the straight hodograph shape. HREF UH
tracks hint at this potential, showing both positive and negative UH
swaths, albeit relatively weak in magnitude. SPC continues to
outlook much of the area in a Marginal Risk for severe
thunderstorms.
&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
Any thunderstorm activity should weaken and/or progress off to our
southeast by late evening, resulting in dry conditions overnight.
Lows tomorrow night should be in the upper 50s to the west of the
Blue Ridge, with low to mid 60s further east.

Height rises will ensue aloft between disturbances on Friday.
The vast majority of guidance keeps conditions dry, although the 3km
NAM does have a few thunderstorms forming during the afternoon along
a surface trough. Warmer temperatures are forecast for Friday, with
highs reaching into the mid 80s to near 90. Lows Friday night will
remain mild in the  60s and low 70s. Mountain locations will cool
into the upper 50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A cold front is set to move across the area to start the weekend,
bringing at least scattered showers and thunderstorms. There should
be sufficient instability for convection during the afternoon to
early evening as temps climb to the mid to upper 80s, especially
east of the Blue Ridge. Dew points are also going to be in the mid
to upper 60s, and close to 70F in Central VA to along I-95. Looking
at model soundings it is definitely possible that we see severe
thunderstorms in the area. Deep-layer shear around 40-50 knots
and steep low-level lapse rates could result in organized
convection capable of damaging wind gusts.

High pressure quickly builds into the region Saturday night and
persists into the start of next week. Dry, much cooler, fall-like
weather returns Sunday as highs only reach the low to mid 70s. Highs
in the mid 70s for Monday and Tuesday. Overnight lows drop to the
upper 40s to 50s.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR conditions are expected to continue through Thursday midday.
Winds will remain out of the south tonight at less than 10kts. Winds
will increase out of the south late Thursday morning before turning
to the southwest Thursday afternoon with gusts between 20 to 25 kts.
Thunderstorm chances will also return to the terminals Thursday
afternoon and evening as a cold front crosses the area. Not everyone
will see the thunderstorms with scattered coverage expected hence
the usage of PROB30s compared to TEMPOs. Storms should push into
areas west of KMRB and KSHD between noon-3pm/16-19z before working
east into the I-95 corridor terminals between 3-8pm/19z-00z. Main
threat with storms looks to be damaging winds along with isolated
large hail. Any residual thunderstorm activity will quickly die out
after sunset Thursday (00-02z/8-10pm) as the front slowly pushes
east and dissipates across the region. Areas of fog will remain
possible especially west of the Blue Ridge where clearing will
likeLy take place sooner heading into early Friday morning. VFR
conditions are expected Friday afternoon and evening with light west
to southwest winds across the region.

Additional sub-VFR conditions are possible Saturday afternoon as a
cold front brings scattered showers and thunderstorms to the area.
High pressure builds in behind the front Saturday night into Sunday,
bringing VFR conditions and breezy north winds.

&&

.MARINE...
Southerly channeling is expected overnight across the middle part of
the bay. SCAS remain in effect to encompass this threat, but may
need to be expanded to the open waters of the bay/tidal Potomac
heading into the pre-dawn hours of Thursday morning. SCA conditions
are expected for all waters within south to southwesterly flow
during the day Thursday. SMWs may also be needed late Thursday
afternoon and evening (between 3-9pm) as thunderstorms move over the
waters. SCA conditions will likely linger through much of Thursday
night within southerly flow. Borderline SCA level winds appear
possible within southerly flow Friday into Friday night.

A cold front will move across the area sometime Saturday, bringing
scattered showers and thunderstorms to the waters. Behind the front
period of northerly channeling could produce SCA conditions Saturday
evening into Saturday night. High pressure builds in from the north
on Sunday, though northerly winds could remain elevated through
Sunday evening.

&&

.TIDES/COASTAL FLOODING...
Water levels are starting to increase within southerly flow.
Confidence in Annapolis reaching minor flood increases tonight with
a Coastal Flood Advisory in place for the upcoming high tide cycle
at 329am Thursday. Peak water anomalies appear to occur Thursday
night ahead of a front in strong southerly flow. More locations may
reach minor flood, and some guidance has Annapolis approaching
moderate flood. A Coastal Flood Watch is in effect for Annapolis for
the tide cycle Thursday night. Water levels may decrease a bit
Friday as the first front fizzles out, but minor flooding may still
occur at Annapolis Friday night as southerly flow strengthens again
ahead of the next front. This front will bring a wind shift Saturday
which will decrease water levels.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 11 AM Thursday to 2 AM EDT Friday
     for MDZ008.
     Coastal Flood Advisory from midnight tonight to 7 AM EDT
     Thursday for MDZ014.
     Coastal Flood Watch from late Thursday night through Friday
     morning for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 11 AM Thursday to 2 AM EDT Friday
     for ANZ530-535-536-538>540.
     Small Craft Advisory from midnight tonight to 2 AM EDT Friday
     for ANZ531-532.
     Small Craft Advisory from midnight tonight to 6 AM EDT Friday
     for ANZ533.
     Small Craft Advisory from 11 AM Thursday to 6 AM EDT Friday
     for ANZ534-537-541>543.

&&

$$

SYNOPSIS...EST
NEAR TERM...KJP/EST
SHORT TERM...KJP/EST
LONG TERM...KRR
AVIATION...KJP/KRR/EST
MARINE...KJP/KRR/EST
TIDES/COASTAL FLOODING...LWX