663
FXUS61 KLWX 240131
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
931 PM EDT Mon Sep 23 2024

.SYNOPSIS...
A front will remain stalled off to the south and west through
tonight. Meanwhile, strong high pressure across eastern Canada
builds southward along the Appalachians. A strong front and area
of low pressure over the Great Lakes and Upper Midwest will
approach through the middle of the week. High pressure will
build to the north mid to late week while low pressure
approaches from the south.

&&

.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
With a stalled frontal boundary off to the southwest of the
region, a persistent onshore flow will maintain a thick band of
low clouds across the Mid-Atlantic. Regional radar imagery
continues to show a mixture of drizzle to light showers pushing
southeastward across the metros. Additionally, patchy fog may
develop, particularly for areas west of I-95. Overnight low
temperatures will only fall into the low to mid 60s.

&&

.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A warm front lifts further north on Tuesday, with increasing
shower chances into the afternoon. Cannot rule out a few
isolated thunderstorms, especially west of the Blue Ridge where
better forcing and instability will likely reside. Afternoon
highs will top out in the mid to upper 60s.

There may be enough forcing with the incoming shortwave Tuesday
and Wednesday afternoons combined with sufficient instability
and shear (mainly aloft) to result in a few stronger storms
capable of a little hail, or perhaps some gusty surface winds
near and west of the Allegheny Front. Additionally, there may be
enough heavy rain across our far southwestern counties in VA to
allow for isolated instances of flooding Tuesday afternoon and
evening. Tuesday`s temperatures look cool during the day with a
wedge firmly in place, but daytime temperatures may warm a bit
Wednesday as the wedge weakens.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Narrow ridge will build over the Mid Atlantic sandwiched between an
upper low over New England and a large upper low over the Mid-South.
At the sfc, a cold front will drop across the area Thursday with
only isolated showers and thunderstorms expected. Latest NHC
forecast has Potential Tropical Cyclone Nine becoming Hurricane
Helene by 12Z Wed making landfall over the Big Bend area of FL by
Fri morning. Helene then gets absorbed into a large upper level low
over the Mid-South. Remnant moisture from Helene makes into our area
Fri night into the weekend. Sfc ridging builds again over the area
Sat night into Sun suppressing moisture and bringing dry air for the
second half of the weekend.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
MVFR CIGs look to persist at most TAF sites through Tuesday,
with bouts of IFR possible especially at MRB/CHO and/or during
the overnight/early AM hours each day. Conditions may improve
slightly by Wednesday. This is all thanks to onshore flow around
a wedge of high pressure over the region. Meanwhile, a frontal
system slowly approaching from the west could result in a few
showers or even an elevated thunderstorm (especially west of
I-95) through mid week. Lastly, some patchy drizzle is possible
at times in onshore flow, most likely during the AM hours.

Low clouds Fri morning will likely cause flight restrictions.

&&

.MARINE...
Onshore flow will mainly remain sub-SCA the next few days,
though a couple pushes of easterly flow may result in 20 kt
gusts tonight, Tuesday evening/night, and Wednesday
afternoon/evening. A few showers are possible at times as a
frontal system approaches from the west, with most thunder
chances likely remaining west of the waters until at least late
Tuesday into Wednesday.

Winds strengthen again Fri night through Saturday with SCA
conditions likely.

&&

.TIDES/COASTAL FLOODING...
Minor to moderate coastal flooding will persist until further
notice. From an astronomical standpoint, tonight`s astronomical tide
will be the highest over the next several days as Moon Phase moves
from Last Quarter to Waning Crescent. So, we`ll likely be seeing the
last episode of moderate coastal flooding tonight with water levels
gradually coming down during the second half of the week, but with
minor coastal flooding persisting through the end of the week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Warning until 4 AM EDT Wednesday for DCZ001.
MD...Coastal Flood Warning until 4 AM EDT Wednesday for MDZ014.
     Coastal Flood Advisory until 4 AM EDT Wednesday for MDZ011-016-
     018-508.
     Coastal Flood Warning until 10 PM EDT Tuesday for MDZ017.
VA...Coastal Flood Warning until 4 AM EDT Wednesday for VAZ054.
     Coastal Flood Advisory until 4 AM EDT Wednesday for VAZ057.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...BRO/DHOF/ADM
NEAR TERM...BRO/DHOF/ADM
SHORT TERM...DHOF/ADM
LONG TERM...LFR
AVIATION...LFR/DHOF/ADM
MARINE...LFR/DHOF/ADM
TIDES/COASTAL FLOODING...LFR