164
FXUS61 KLWX 061827
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
227 PM EDT Mon Oct 6 2025

.SYNOPSIS...
Warm temperatures and increasing humidity are expected today through
Tuesday as high pressure pushes offshore. A strong cold front will
cross the area late Tuesday into the early Wednesday bringing
beneficial rainfall to the region. Cooler and drier conditions
return behind the front as high pressure builds from the north
Thursday and Friday. Additional rain chances are possible this
weekend as coastal low pressure works north from the southeast
U.S coast.

&&

.NEAR TERM /THROUGH TONIGHT/...
Broad 1024 mb surface high pressure continues to maintain it`s grip
across the region as it pushes offshore later this afternoon. After
starting in the 40s and 50s this morning, expect above average
temperatures this afternoon in the low to mid 80s (70s in the
mountains). Highs in the upper 80s cannot be ruled out in the
downslope areas of the Alleghenies (Cumberland, MD to Petersburg,
WV) and Blue Ridge (Front Royal/Warrenton, VA down to Luray, VA). A
few passing fair weather cumulus clouds are possible this afternoon
given the increased moisture on light southerly flow. Overall skies
will trend sunny/mostly sunny with passing clouds likely at times
into Tuesday as the cold front approaches from the Ohio River
Valley. With the front approaching from the west and an uptick in
moisture with southerly flow at the surface/aloft expect dewpoints
to climb back into the upper 50s and low 60s this afternoon.

Mostly clear to partly cloudy skies are expected tonight. Winds will
remain light out of the south at 5 to 10 mph reducing fog formation
across a large chunk of the region. Some patchy fog may be possible
in the sheltered valley areas as well as along the western shore of
the bay (northeast-central MD) where the winds look to be the
weakest. Hi-res CAMS illustrate this concern, but even here fog
looks to remain patchy and even less in coverage compared to earlier
today. Lows tonight will fall back into the mid 50s and low 60s.


&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
High pressure will continue to push further offshore Tuesday while
an upper level trough/surface cold front approach from the Ohio
River Valley and Great Lakes region. Expect increasing clouds
throughout the day with perhaps a few showers working into areas
west of the I-81 corridor as early as Tuesday afternoon. Most of the
precipitation looks to hold off until late Tuesday evening/night as
the front works from northwest to southeast across the area. No
severe weather is expected given the timing of the front and forcing
shunted north of the region. A stray thunderstorm or two cannot be
ruled out Tuesday night into Wednesday morning given the large scale
ascent ahead of the upper level trough working through. As for
rainfall, it looks to be beneficial and widespread across the
region. Most of the modeling continues to show a solid quarter to
three quarters of an inch of rain across the region. A few hi-res
CAMS even have an inch of rain in a few locations east of the Blue
Ridge including the southern Shenandaoh Valley and southern MD. Any
rain that does fall will help limit any further degradation when it
comes to the recent moderate to severe drought as well as limit fire
weather concerns heading into the back half of the workweek.

Overall looking at a 6 to 8 hour window of rainfall starting late
Tuesday evening and carrying through Wednesday mid-morning.
Rain will quickly come to an end in most locations Wednesday
midday as the front sags south and east of the region. Hi-res
CAMS, deterministic, and ensemble guidance show a sharp decrease
in dewpoints post-front Wednesday under northwest flow.
Dewpoints will fall into the mid to upper 40s and low 50s
Wednesday afternoon compared to values in the 60s Tuesday as low
level moisture is quickly scoured out.

Highs Tuesday will climb back into the upper 70s and low 80s outside
the mountains. South to southwesterly winds will increase to 5 to 15
mph with occasional gusts up to 25 mph at times, especially near the
waters and along the ridges. Temperatures fall back into the upper
50s and low 60s Tuesday night with upper 40s over the mountains. By
Wednesday, high temperatures struggle to get out of the mid to upper
60s and low 70s with upper 50s over the mountains. Cold/dry air
advection will continue to funnel into the region Wednesday night as
cool Canadian high pressure builds to our north. This will lead to
relaxing winds and clear skies across the region which means a prime
radiational cooling setup, especially for those west of the
I-95 corridor. Frost and freeze headlines may be needed for a
good chunk of the area with widespread lows falling into the mid
30s and low 40s. Highest confidence for frost/freeze headlines
would be west of the I-81 corridor.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Strong high pressure over southern Ontario,CA will settle over
southern New England by Fri morning and support a cool and dry
air mass. Frost and freeze conditions are likely west of the
Blue Ridge Mountains early Fri morning.

There is strong ensemble support for a non-tropical low pressure
system to develop across the FL Straits on the east side of a cutoff
low over the southeastern U.S. over the weekend with the system
tracking northward along the East Coast per many ensemble solutions
or offshore as suggested by the 12Z CMC. Depending on eventual track
and strength of this system, potential impacts from this system
include storm force winds along the western shore of the Chesapeake
Bay, moderate coastal flooding, heavy rainfall, and possible
flooding. Difficult to pinpoint any specific hazards at this time
given wide array of solutions.


&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
VFR conditions are expected for all terminals through Tuesday
morning. Winds will remain light out of the south at less than
10 kts. Some patchy fog and low clouds, remain possible over the
western shore of the bay from KBWI to KMTN. Additional patchy
fog is possible over areas west of KFDK and KMRB in particularly
across sheltered river valleys. Fog should not be as pronounced
tonight given increased southerly winds and incoming high level
cloud cover from the cold front approaching from the Great
Lakes/Ohio River Valley.

High clouds will gradually increase Tuesday as the cold front
advances closer to the region. VFR conditions will prevail through
most of the day with sub-VFR conditions likely at times late Tuesday
night into early Wednesday. Showers and perhaps a few thunderstorms
are likely during this time leading to temporary sub-VFR reductions.
VFR conditions will quickly return Wednesday afternoon and night as
high pressure builds north of the region. Southerly winds Tuesday
will gusts up to 20 kts at times with winds switching to the
northwest behind the front Wednesday. Gusts up to 20 kts will remain
possible in post-frontal northwest flow. It`s not until Wednesday
night when the winds look to fall back below 10 kts.

VFR conditions are expected Thursday and Friday as strong Canadian
high pressure builds over the northeastern U.S. Winds will continue
to gusts 15 to 20 kts out of the north and northeast as the
high wedges into the region. Winds will switch to the east while
decreasing Friday into the start of the weekend.

Next chance of sub-VFR conditions arrive this weekend as an area of
low pressure works up along the VA/NC coast.

&&

.MARINE...
Southerly winds will gradually increase through this evening as the
gradient tightens between the departing high pressure system and
incoming cold front from the Ohio River Valley. Small Craft
Advisories have been issued for the main channel of the bay this
evening through tonight for gusts up to 20 kts in southerly
channeling. These advisories may need to be expanded to the open
waters tonight and all waters Tuesday and Wednesday. Southerly winds
will continue over the waters Tuesday before turning to the north
and northwest behind the cold front Wednesday. Gusts up to 20 kts
are possible during this time.

SCA conditions will likely continue into Thursday with wedging high
pressure north of the region. Winds will turn to the north and
northeast with gusts up to 20 kts. Winds will decrease as high
pressure slides toward coastal New England Friday with gusts
hovering between 10 to 15 kts.  Winds may start increasing late
Friday night assuming coastal low tracks up along the southeast and
mid-Atlantic coasts.

&&

.TIDES/COASTAL FLOODING...
Anomalies are expected to hold relatively steady over the next few
days within southerly flow, before decreasing behind a cold front in
northwesterly flow on Wednesday. Several sites may potentially reach
into Action stage around the time of high tide today and Tuesday,
but no flooding is expected. Anomalies look to climb later this week
and into the upcoming weekend as onshore flow increase with low
pressure moving north along the coast from the southeast U.S.
Additional coastal flooding threats are possible during this time
although yet to be determined due to the track and placement of the
approaching low from the south.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 6 PM this evening to 6 AM EDT
     Tuesday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 AM EDT
     Tuesday for ANZ530>534-539>541.

&&

$$

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