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000
FXUS61 KLWX 230042
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
842 PM EDT Mon Apr 22 2024

.SYNOPSIS...
High pressure will build overhead tonight, before departing off
to the east tomorrow. A cold front will move through Wednesday,
before high pressure builds back in for the end of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
EVENING UPDATE: No changes in the near term forecast, but have
added a fire weather section below for Tuesday and perhaps
Wednesday as well.

High pressure will build overhead tonight. Wind will go calm
beneath the high, and clear skies are expected. This will create
ideal conditions for radiational cooling. As a result, another
chilly night is expected, with temperatures dropping back into
the 30s for most. The exceptions will be the ridgetops, as well
as downtown DC and Baltimore, which will stay in the 40s. Freeze
Warnings are in effect tonight for the Central Shenandoah
Valley, as well as portions of the Potomac Highlands. Frost
Advisories are in effect for much of the rest of the forecast
area. The exceptions are the Alleghenies (where the growing
season hasn`t started yet), as well as St. Mary`s and Calvert
Counties, where temperatures are expected to stay in the upper
30s to around 40.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
High pressure will progress offshore tomorrow, which will cause
winds to turn out of the south. This will result in a warming
trend, with temperatures climbing into the upper 60s to low 70s
beneath mostly sunny skies.

A shortwave will track southeastward from the Great Lakes toward
the Northeast/Mid-Atlantic Tuesday night. It will be a rather
moisture starved system, so precipitation totals are expected to
be light. A few showers will be possible across the area,
especially late Tuesday night into early Wednesday morning. The
system`s cold front will move through Wednesday morning, causing
winds to turn northwesterly in its wake. Gusts out of the
northwest to around 20-30 mph will be possible during the
afternoon hours Wednesday. A stray shower or thunderstorm can`t
be ruled out behind the cold front/beneath the upper trough axis
Wednesday afternoon, but most locations should remain dry. High
temperatures on Wednesday are expected to be in the upper 60s to
near 70.

Strong cold advection will ensue in north to northwesterly flow
Wednesday night. As a result, temperatures are forecast to drop
into the upper 30s and lower 40s by daybreak. If some locations
were to decouple, temperatures could drop even further,
potentially leading to additional frost/freeze concerns.
However, the expectation at this time is for winds to remain up,
thereby minimizing the threat for frost/freeze.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Dry conditions return Thursday into Friday with high pressure
building into the region. 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. As
it stands, along and west of the I-81 corridor has the best chance
at seeing precipitation Saturday, but primarily upslope showers are
expected with some spilling over the mountains. A lull in shower
activity occurs Saturday night, followed by a similar upslope setup
on Sunday, but with higher PoPs making it a bit further east.
Thunderstorms are possible both afternoons, with the greater
potential for thunder on Sunday.

Thursday and Friday will be cooler, but gradually warming to near
normal by Saturday. Sunday looks significantly warmer behind the
warm front with forecast highs currently in the 70s to low 80s.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR conditions are expected through Tuesday. Winds will go calm
tonight with high pressure overhead. Southerly winds are
expected tomorrow, with gusts to around 15-20 knots during the
afternoon. A few showers may be possible Tuesday night into
Wednesday as a cold front crosses the area. Winds will turn
northwesterly behind the front on Wednesday, with gusts to
around 20-25 knots possible Wednesday afternoon.

VFR conditions are expected Thursday and Friday with high pressure
in place yielding dry conditions. Could still see some clouds on
Thursday with onshore flow and gusty winds 15-20 kt early Thursday
morning diminish by the afternoon. Winds become gusty and more S/SE
by Friday afternoon and clouds increase through the day with an
approaching warm front.

&&

.MARINE...
Winds really taper off tonight, going nearly calm, as high
pressure moves overhead.

Winds will turn southerly tomorrow and gradually pick up through
the day. Small Craft Advisories have been introduced to the
forecast as a result.

A cold front will move over the waters on Wednesday, causing
winds to turn northwesterly. SCAs will likely be needed Wednesday
into Wednesday night.

SCAs may be needed early Thursday morning with departing low
pressure and again Friday afternoon and evening with an approaching
warm front.

&&

.FIRE WEATHER...
Planning to introduce an increased fire danger threat for
Tuesday given the combination of increasing southerly winds,
warm temperatures, and RH values below 30 percent. This could
even continue into Wednesday, depending on how much rain
actually falls with the frontal passage on Tuesday night.

&&

.TIDES/COASTAL FLOODING...
Anomalies are just above one foot currently and will hover
there through Tuesday. While flooding appears unlikely during
this time, sensitive locations could be close. Southerly winds
will drive an increase in anomalies Tuesday night, and this
appears the most likely time for some locations to experience
minor flooding. NW winds Wednesday will push water levels back
down.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Frost Advisory from 2 AM to 8 AM EDT Tuesday for DCZ001.
MD...Frost Advisory from 2 AM to 8 AM EDT Tuesday for MDZ003>006-
     008-011-013-014-016-503>508.
VA...Frost Advisory from 2 AM to 8 AM EDT Tuesday for VAZ028-030-
     031-036>040-050-051-053>057-501-502-505>508-526-527.
     Freeze Warning from 2 AM to 8 AM EDT Tuesday for VAZ025>027-
     029.
WV...Frost Advisory from 2 AM to 8 AM EDT Tuesday for WVZ051>053.
     Freeze Warning from 2 AM to 8 AM EDT Tuesday for WVZ050-055.
MARINE...Small Craft Advisory from 3 PM Tuesday to 6 AM EDT Wednesday
     for ANZ530>534-537>543.
     Small Craft Advisory from noon to 10 PM EDT Tuesday for ANZ535-
     536.

&&

$$

SYNOPSIS...KJP
NEAR TERM...CJL/KJP
SHORT TERM...KJP
LONG TERM...CAS
AVIATION...CJL/KJP/CAS
MARINE...CJL/KJP/CAS
FIRE WEATHER...CJL
TIDES/COASTAL FLOODING...ADS