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000
FXUS61 KLWX 201908
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
308 PM EDT Sat Apr 20 2024

.SYNOPSIS...
High pressure will build into the area tonight through early
next week. An area of low pressure will track to our north on
Wednesday, causing a cold front to move through Wednesday night.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 230 PM, visible satellite imagery shows high clouds
clearing off to our east, with a few fair weather cumulus
developing from the Northern Virginia Piedmont to southern
Maryland. Elsewhere, skies are sunny. The clearing trend is
expected to continue through the remainder of the afternoon.
Temperatures have climbed up into the upper 60s to lower 70s and
are nearing their highs for the day. Winds are starting to pick
up out of the west to northwest, with gusts of 20-30 mph
common.

Skies will start out clear tonight, which when coupled with
decreasing winds could yield some pretty quick radiational
cooling in sheltered valleys this evening. High clouds will be
on the increase later tonight as low pressure passes to our
south. Low temperatures will be in the mid 30s to lower 40s for
most. The current thinking is the presence of high clouds and
very low dewpoints (in the low-mid 20s) should preclude the
formation of frost in locations that do drop into the mid 30s,
but it`s possible that there could be some patchy frost in the
most sheltered valleys to the west of the Blue Ridge.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Low pressure will continue to track off to our south tomorrow.
This area of low pressure is expected to stay far enough south
to keep precipitation south of the forecast area, although a
sprinkle or light shower can`t be ruled out from central
Virginia to southern Maryland. It will stay cooler tomorrow,
with highs in the mid-upper 50s (40s mountains).

Skies will clear out tomorrow night as the area of low pressure
progresses out to sea. The combination of light winds and clear
skies will lead to ideal conditions for radiational cooling.
Frost and/or freezing temperatures appears possible to the west
of I-95 tomorrow night, where low temperatures are currently
forecast to be in the low-mid 30s. High pressure will continue
to build in from the west on Monday. Sunny skies, light winds,
and high temperatures in the low-mid 60s (50s mountains) are
expected.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Tuesday will also be dry to start before high pressure moves
offshore and low pressure with an associated cold front approaches
from the west. Rain chances expand NW to SE across the area late
Tuesday night into Wednesday and exiting by Wednesday night.
Guidance has trended a little later and a little drier, with only
the Allegheny Front seeing likely PoPs before sunrise Wednesday
morning, and the greater chance of precip during the day mostly
restricted to northern MD and portions of the eastern WV panhandle.

As another area of high pressure moves in behind the system, a tight
pressure gradient between the low pressure and the high pressure on
the front and back ends of the system likely results in gusty winds
during the day Tuesday and continuing through Wednesday night, and
possibly lingering into Thursday. Southerly winds on Tuesday could
gust up to 20-25 kt (a bit higher along the ridges). Stronger NW
gusts are likely behind the cold front on Wednesday during the day,
up to around 25-30 kt.

Dry conditions continue Thursday into Friday. The next chance for
precipitation approaches Friday night into Saturday as a warm front
associated with a surface low over the Midwest moves in from the
southwest.

Temperatures will be above normal Tuesday into Wednesday with the
southerly flow. Highs on Wednesday will depend on the timing of the
cold frontal passage as temps drop behind it. As such, expect it to
be cooler on Thursday before moderating on Friday.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
VFR conditions are expected at the terminals through Monday.
Winds will be out of the west to northwest through Monday, with
gusts of 20-25 kt possible this afternoon. Thereafter, somewhat
lighter winds are forecast.

VFR conditions are expected Tuesday. Dry conditions prevail with
southerly and gusty winds, up to around 20-25 kt. As a cold front
approaches Tuesday night, showers and possible sub-VFR conditions
move into the forecast area but likely don`t reach the terminals
until Wednesday morning. Guidance has trended drier, but any precip
should exit by Wednesday night. MRB, BWI and MTN seem the most
likely to receive rain of the terminals. Winds turn out of the NW on
Wednesday with gusts 20-25 kt.

&&

.MARINE...
Flow is just starting to turn offshore this afternoon, with
southerly flow still maintained over much of the waters. Wind
will continue to turn out of the northwest through the
afternoon, with gusts to around 20-25 knots possible during that
time. Gusts of 20-25 knots will also be possible in northerly
flow overnight. SCAs are in effect for both the Bay and Tidal
Potomac through tonight. Sub-SCA level west to northwesterly
winds are forecast for both Sunday and Monday.

As low pressure approaches the area, gusty southerly winds on
Tuesday will likely exceed SCA criteria by the afternoon, and
continue through Wednesday, becoming northwesterly behind the cold
front.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies continue to decrease with northwesterly flow
this afternoon. No further flooding is expected over the next
couple days, although a few locations may enter Action Stage at
times.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 AM EDT Sunday for ANZ530-535-536-
     538.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ531-532-539-
     540.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ533-541-542.
     Small Craft Advisory from 8 PM this evening to 6 AM EDT Sunday
     for ANZ534-537-543.

&&

$$

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