753
FXUS61 KLWX 201350
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
950 AM EDT Sat Jul 20 2024

.SYNOPSIS...
Shower and thunderstorm chances return today as a weak piece of
energy traverses a stalled front draped along the Virginia and
North Carolina border. High pressure briefly returns Sunday
before a warm front lifts into the region Monday and Tuesday.
This will result in daily shower and thunderstorm chances along
with increased humidity throughout much of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Although the boundary remains stalled to the south, a steady
low-level southerly wind has kept humidity levels up across the
local area. Current dew point temperatures are mainly in the
upper 60s to low 70s, accompanied by mostly cloudy skies. Local
WSR-88 radar imagery shows some light shower activity gradually
nosing northward toward the I-64 corridor. However, based on
personal weather stations in the area, any activity has
struggled to reach the ground. Some low-level dry air noted in
the 12Z IAD sounding is the likely culprit.

Overall, this stalled boundary to the south is expected to
meander northward as a shortwave passes overhead. Precip chances
will increase from southwest to northeast through the day,
bringing some much needed rainfall to the area. Unfortunately,
guidance maintains meager QPF, with a half inch or less
rainfall, most of which is expected to fall west of I-81 and
along our southern periphery.

Cloud cover will keep high temperatures below normal, topping
out in the low to mid 80s for most of the area. Low clouds
remain near KCHO, but this is not expected to advance much
further northward through the day. Rain chances drop off
overnight as the shortwave exits and forcing is lost. Low
temperatures will be a few degrees cooler than Friday, in the
low to mid 60s for most.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The front likely remains stalled to our south into Sunday,
limiting PoPs to our southern zones. Expect coverage to be
reduced compared to Saturday with subsidence on the back end of
the exiting shortwave. Reduced cloud cover and southerly flow
brings highs back to the upper 80s to low 90s. Clouds build in
overnight resulting in milder lows, hovering in the 70s along
and east of the I-95 corridor, with mid-upper 60s expected
elsewhere.

On Monday, the boundary is expected to stall across the area.
A blocking synoptic pattern with the strong Bermuda ridge will
keep the area east of an upper trough, in ascent and SW flow
aloft. The result will be increasing moisture and chances for
showers and thunderstorms, especially in the afternoon. The
focus of rainfall will depend on where the front sets up, but
current WPC QPF projects 0.50-1 inch of rain for the area, which
again, we desperately need. Ample cloud cover will tamper temps
into the upper 80s, and keep lows mild overnight.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A strong Bermuda Ridge builds across the far southwest Atlantic and
Southeast states through the end of next week. This puts our area in
steady south to southwesterly flow that advects in deep moisture
from the Gulf of Mexico. Aloft, a series of mid-level shortwaves are
forecast to quickly traverse the region, then a stronger upper
trough and associated cold front cross the area late next week.
Abundant moisture and instability fuel scattered to widespread
showers and thunderstorms each afternoon to early evening. Most
rainfall should be beneficial given the ongoing extreme drought west
of US-15. Some minor flooding concerns could arise if any heavy rain
sets up over a metro area, though there should be enough mean wind
to keep storms moving. Afternoon highs each day range from the mid
80s to near 90F, and overnight lows in the upper 60s to mid 70s.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Mostly VFR conditions are expected through the weekend, with the
exception of CHO, where low clouds have neared the terminal from
the south. MVFR conditions are likely for CHO through this
morning, with some improvement to low-end VFR during the
afternoon. Shower and thunderstorm activity is expected today,
especially during the afternoon hours, which could bring brief
restrictions to the terminals. CHO could see another round of
low cigs/vsby late tonight. The boundary lingering to the south
could continue to bring MVFR conditions to CHO on Sunday as
well, where the greatest chance for afternoon showers and
thunderstorms will set up again.

The boundary stalls over the region on Monday, likely bringing
more widespread shower activity and associated brief
restrictions to terminals.

VFR conditions are likely to prevail through mid week. The main
aviation impact will come from scattered to widespread showers and
thunderstorms that develop each afternoon to early evening. Any
heavy shower or storm that moves over a terminal could produce a
brief period of sub-VFR conditions (mostly from reduced visibility).
Shower/storm activity wanes in the evening, though a few showers
could linger into the overnight each day.

&&

.MARINE...
S to SE winds are expected through the weekend and into Monday.
Winds are expected to be the most southerly on Sunday, but high
pressure briefly building in from the north should keep winds
light enough that channeling isn`t a concern. Showers and
thunderstorms could bring stronger gusts to the waters today and
Monday, but otherwise no hazardous boating conditions are
expected through Monday.

Increasing south to southwest winds by the middle of next week could
result in SCA conditions across the open waters of the Chesapeake
Bay. A Small Craft Advisory may eventually be needed Tuesday night
into Wednesday. Otherwise, the main impact to mariners will be the
afternoon showers and thunderstorms that develop each day. The
strongest storms could produce wind gusts near 35 knots.

&&

.TIDES/COASTAL FLOODING...
Light southeast to south winds today continue to result in a small
increase in water levels. Although minor flooding is unlikely,
vulnerable shoreline (such as Annapolis) could reach Action
Stage on Sunday and Monday mornings.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...EST
NEAR TERM...BRO/CAS
SHORT TERM...CAS
LONG TERM...KRR
AVIATION...BRO/CAS/KRR
MARINE...CAS/KRR
TIDES/COASTAL FLOODING...BRO/KRR