434
FXUS61 KLWX 271402
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1002 AM EDT Sat Apr 27 2024

.SYNOPSIS...
Surface high pressure moves south along the eastern Appalachians
today. A warm front lifts through the area by Sunday bringing a
significant warm up heading into early next week. The next
chance for widespread precipitation arrives with a series of
cold fronts Tuesday into Wednesday next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A surface high just south of the southern coast of New England
slides south parallel to the Mid-Atlantic coast through tonight.
A weak mid-level disturbance rides atop the crest of a deep
ridge aloft that is building into our area from the south. This
is resulting in a period of scattered to widespread showers
this morning which will continue into the early portion of the
afternoon. Coverage is a bit higher than originally anticipated,
and also making it a bit farther south and east. Cloudy skies
keep highs in the upper 50s to lower 60s. Conditions dry out
from this initial round of precipitation this afternoon, with
precip exiting the area by early evening. However, another round
of light showers may occur more during the late evening/overnight
hours, per some of the latest hi-res guidance. Milder lows are
expected tonight in the upper 40s to 50s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Well above normal temperatures Sunday into Monday as a deep ridge
moves across the Southeast and Mid-Atlantic states. Highs are
forecast to reach the low to mid 80s Sunday, then mid to upper 80s
Monday with a few spots hitting 90F. Even in the mountains, highs
are forecast to reach the 70s both days. A couple of climate sites
could tie or be near their daily record highs for April 30 / Monday.
Very mild overnight lows mostly in the 60s, with 50s in the
mountains. A few showers and thunderstorms are possible each
afternoon.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
High pressure moves offshore Tuesday and a weak cold front
approaches from the west with increased cloud cover, resulting in
temperatures a few degrees cooler than Monday, but not much relief
in the scheme of things. Highs well into the 80s are currently
forecast for the duration of the extended with lows in the 50s and
60s.

Showers and thunderstorms could accompany the front in the afternoon
and evening and some could be strong to severe. Decent instability
will be available by the afternoon, but guidance has been weaker on
the shear. Recent runs have been consistent with the better bulk
shear (even then, only ~30 kt) in the morning/early afternoon and
generally along the Alleghenies (morning) and west of the Blue Ridge
(afternoon). As it stands, with decent CAPE not present until the
afternoon, early afternoon around the I-81 corridor seems the most
favorable for strong/severe storms, if any. Threat is marginal for
now but will continue to monitor. A weaker shortwave moves through
on Wednesday, and guidance has backed off further on the shear/CAPE
environment Wednesday, so some showers seem more likely than
thunderstorms.

The remainder of the week continues to look hot and unsettled with a
series of weak disturbances passing through, and severe environment
is similarly modest.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
A weak disturbance moves across the area today, bringing periods of
showers. Sub-VFR conditions are expected at CHO, MRB, and IAD, with
the worst restrictions at MRB. Any CIG restrictions at DCA, BWI, and
MTN would be just into MVFR and be short in duration. SE winds could
occasionally gust to around 20 knots this afternoon and evening.
Shower activity ends by early evening, with conditions improving
from west to east.

VFR conditions return this evening and remain in place through
Monday as high pressure builds across the region. Winds vary between
southwest to west at around 5-10 knots Sunday through Monday.

Sub-VFR conditions are possible with any showers and thunderstorms
as a weak cold front moves through on Tuesday. More showers are
possible on Wednesday but thunder seems less likely.

&&

.MARINE...
Southeast to south winds around 10-15 knots continue most of
the day today with a few light showers possible.

Southerly channeling is expected to produce SCA conditions once
again late this afternoon into tonight, mainly in the main channel
of the Chesapeake Bay. Some surrounding tidal rivers and bays on the
Eastern Shore could see SCA winds this evening, though confidence is
too low to issue a SCA at this time.

High pressure builds over the region Sunday into Monday, keeping
winds below SCA levels. Winds vary from southwest to west at or
around 10 knots.

Southerly flow on Tuesday pick up and turn westerly behind a cold
front on Tuesday and may approach SCA criteria by the afternoon.
Additionally, stronger gusts will be possible with any showers and
thunderstorms passing over the waters. Winds diminish and become
northwesterly on Wednesday, but some showers could bring higher
gusts to the waters.

&&

.TIDES/COASTAL FLOODING...
A Coastal Flood Advisories remains in effect for DC/SW Waterfront
this morning, but the other advisories that were out earlier
for Annapolis and Straits point have been expired/cancelled, and
fell a bit below what was anticipated.

Beyond this morning, additional tidal flooding is questionable
in the coming high tide cycles. While flow remains south/southwest,
high pressure and light winds may allow for gradual draining of
water from the estuary.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until 2 PM EDT this afternoon for
     DCZ001.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 5 PM this afternoon to 4 AM EDT
     Sunday for ANZ531>534-537-543.

&&

$$

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