Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 260759
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
359 AM EDT Tue Mar 26 2024

.SYNOPSIS...
Surface ridging will keep fair and seasonable weather conditions
today. Showers return to the area tonight as a weak cold front
approaches and eventually crosses the area Thursday morning. A
backdoor front will cross the area Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
High level cirrus has been streaming into the area from the west
early this morning. Meanwhile, marine layer stratocu is moving in
from the east with onshore flow. This trend continues through the
day with increasing cloud cover and high pressure exiting.

As a slow-moving cold front approaches from the west, rain
chances increase generally west to east through the day, but
most of the area east of the mountains is expected to remain dry
through the afternoon. High temperatures cap out in the 50s for
much of the area. Rain moves in tonight and low temperatures
fall into the low to mid 40s.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A slow-moving cold front will make its way through the area
Wednesday into Thursday, bringing widespread showers. Shower
activity may be more scattered to start early Wednesday with less
favorable forcing as an upper trough moves off to the northeast
before a secondary shortwave digs to our south. Rain chances
gradually decrease west to east Thursday.

Rainfall totals will be dependent on the track of the coastal low
associated with the secondary shortwave, but for now anticipate
0.50" to 0.75". Locally higher amounts are possible over portions of
central VA and southern MD based on the current forecast track of
the low.

Highs will be in the 50s both Wednesday and Thursday for most of the
area, though a bit cooler in the 40s along the Alleghenies on
Thursday behind the cold front. Lows on Wednesday night will also
drop behind the cold front in the mountains by Thursday night (30s)
but the rest of the area should remain in the 40s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Low pressure will be moving toward coastal New England Friday while
high pressure builds across the southeastern states. A tight
pressure gradient will result in gusty northwest winds. Gusts could
come close to Wind Advisory criteria, especially in the higher
elevations. Otherwise clearing skies are expected with seasonable
temperatures.

High pressure slides to the south Friday night as a warm front
approaches from the west. The front will likely stall near the area
over the weekend as the flow becomes more zonal. Shortwave troughs
interacting with this boundary may bring some chances for showers,
although timing is uncertain and rainfall amounts would likely be
light. PoP/Sky forecasts are currently modest due to the timing
differences, but there is some consensus of at least some scattered
showers at some point over the weekend. Temperatures will likely
trend above normal over the weekend.

If the front remains close enough by on Monday, shower chances will
remain. It may be a little cooler though since there is some
agreement on the front slipping south of the area. More appreciable
rain chances will eventually arrive as a stronger trough approaches
from the Midwest, but this may not be until Monday night or
Tuesday.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
VFR conditions early this morning are expected to deteriorate to
MVFR for the metro terminals as the marine stratocu moves in from
the east. Some improvement is possible this afternoon before rain
moves in tonight. IFR to LIFR cigs start late tonight and likely
continue through Wednesday and into Thursday.

VFR conditions are expected Friday but with northwesterly wind gusts
of 25-35 kt. A weak front may approach Saturday and provide a chance
of showers and perhaps some wind gusts to around 20 kt, but
confidence in both is low as computer model spread increases.

&&

.MARINE...
SCAs remain in effect early this morning before diminishing after
sunrise. Winds over the waters will be east to southeast through
Wednesday before increasing out of the northwest Thursday behind the
cold front. SCAs will likely be needed Thursday afternoon into
Friday.

Strong northwest flow is expected Friday behind the departing low.
SCAs are likely and marginal gales are possible. Winds diminish some
Friday night, but SCAs may continue. Current NBM forecast indicates
advisories are possible on Saturday as well as a weak front
approaches, but model spread increases during this time.

&&

.TIDES/COASTAL FLOODING...
Water level anomalies are around 1.5-2 feet above normal this
morning. While they have recently leveled off, models indicate
another half to three quarters foot rise is possible through early
Wednesday as onshore flow continues. Previous forecasts were running
a bit high, so have made a few headline adjustments through today.
However, the primary message remains the same that fairly widespread
minor to locally moderate flooding is expected through the middle of
the week. Water levels will begin falling Thursday after a front
pushes through.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until 5 PM EDT this afternoon for
     DCZ001.
     Coastal Flood Watch from this afternoon through Wednesday
     afternoon for DCZ001.
MD...Coastal Flood Advisory until 3 PM EDT Wednesday for MDZ011-016.
     Coastal Flood Advisory until 1 PM EDT this afternoon for
     MDZ014.
     Coastal Flood Warning from 1 PM this afternoon to noon EDT
     Wednesday for MDZ014.
     Coastal Flood Advisory until 11 AM EDT this morning for MDZ017.
     Coastal Flood Warning from 11 AM this morning to 6 AM EDT
     Wednesday for MDZ017.
     Coastal Flood Advisory until 7 PM EDT Wednesday for MDZ018.
     Coastal Flood Advisory from 9 AM this morning to 3 PM EDT
     Wednesday for MDZ508.
VA...Coastal Flood Advisory until 3 PM EDT Wednesday for VAZ054-057.
     Coastal Flood Advisory from 7 PM this evening to 3 PM EDT
     Wednesday for VAZ053-055-527.
WV...None.
MARINE...Small Craft Advisory until 5 AM EDT early this morning for
     ANZ534-537-543.

&&

$$

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


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