Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

116
FXUS61 KLWX 190128
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
928 PM EDT Sat Apr 18 2026

.WHAT HAS CHANGED...
No changes to the forecast. A broad band of showers well ahead
of the surface cold front will continue to move east over the
next several hours. There could be some embedded lightning and
thunder, but probabilities are lower with each passing hour.

&&

.KEY MESSAGES...
- (1) A cold front crosses overnight into Sunday morning.

- (2) High pressure moves in early next week, with persistent
  cool temperatures and fire weather risk.

- (3) Warming temperatures late next week.

&&

.DISCUSSION...
KEY MESSAGE 1...A cold front crosses overnight into Sunday
morning.

A strong surface cold front, across western PA and southeast OH,
will move east overnight into Sunday morning. Well ahead of this
front is a broad band of showers and a few embedded rumbles of
thunder over southern PA and northeast WV. Much of this
activity is anticipated to weaken and break apart as it moves
near the Shenandoah Valley in a couple of hours. SPC currently
has the western half of our region in a General Thunderstorm
Risk. Therefore, there is a low chance of a thunderstorm or two.
Computer models are hinting of some of this shower activity
holding together then being accompanied by additional showers or
a thunderstorm later overnight and the first few hours of Sunday
morning. Rainfall activity should move over and east of the
Chesapeake Bay by Sunday afternoon. As the surface front moves
east, southeast to south winds will quickly shift to west and
northwest later overnight and during the day Sunday. Winds could
gust 40-45 mph immediately behind the front. High temperatures
Sunday will be reached early in the day, and are expected to be
15 to 25 degrees cooler.

Depending on how much rain falls and how quickly humidity
drops, a fire weather threat could develop mainly west of I-95
Sunday afternoon. See the Fire Weather section below for
details.


KEY MESSAGE 2...High pressure moves in early next week, with
persistent cool temperatures and fire weather risk.

Following a secondary cold front Monday, a strong upper-level
trough and shortwave will pivot overhead. Very cold air at
850-500 hPa will result in very steep lapse rates, with deep
inverted-V profiles noted in forecast soundings up to 8-12 kft.
This will result in wind gusts of 20 to 30 mph as dry low-level
air moves in. Given mid-level moisture and the shortwave, some
cloud cover and a few sprinkles or even a light/brief graupel
shower can`t be ruled out.

High pressure builds overhead Monday night into Tuesday leading
to lighter winds. The cold, dry airmass, clear skies and light
to calm winds Monday night into Tuesday morning are likely to
result in widespread frost/freezing temperatures.

As the high moves offshore Tuesday, winds turn out of the south
beginning the end of the early-week cool spell. Another cold
front will begin approaching from the north late Tuesday night
into Wednesday, but with little moisture to work with.


KEY MESSAGE 3...Warming temperatures late next week.

Temperatures begin to warm to the 70s and 80s in the later half of
next week, with a warm front on Friday pushing highs back into
the mid-80s range for much of the area. Some residual showers
may be possible on Wednesday stemming from low surface pressure
to the north. Thursday and Friday will see significant upper-
level ridging over the region, allowing for relatively light
winds and low rain chances.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Winds will remain S/SE into this evening with 15-20 kt gusts at
times. LLWS is possible as a LLJ pivots overhead. An abrupt
wind shift to the northwest is expected 06Z-12Z Sun with FROPA.
Some MVFR is possible Sun AM. Gusty winds of 30 to perhaps 40
kts are possible for a brief time right after FROPA. Gusts of 20
to 30 kts then linger through Sun eve before lighter winds
overnight. A secondary cold front likely results in 20 to 30 kt
gusts again heading into Mon with a spotty shower possible.
Otherwise, VFR Sun night through Tue. Winds shift to S by Tue.

Southerly winds shift northeast by Wednesday night as low
pressure passes to the north and a cold front drops in. Gusts
up to 15 knots are possible across terminals on Wednesday before
gradually decreasing overnight. Northerly winds are expected on
Thursday with VFR conditions across the area.

&&

.MARINE...
Southeast flow will remain gusty until a lull occurs overnight
for most waters. Winds will likely remain elevated over the
wider waters off southern MD, though. An abrupt shift to the
northwest is expected between 4 AM and 8 AM Sunday from
northwest to southeast, with gusts of 30-40 kts for a brief time
likely necessitating Special Marine Warnings even if there is
little to no precipitation as a strong cold front crosses the
waters.

Showers and gusty winds (SCAs) linger behind the front, with
drying expected by Sunday afternoon. Winds become lighter Sunday
night then increase again Monday with a secondary front. Light
winds Monday night turn southerly Tuesday with additional SCAs
possible by Tuesday night.

Small Craft Advisories may be needed Wednesday morning as winds flow
southerly with gusts up to 20-25 knots before gradually decreasing
later in the day. Winds shift to northerly overnight with winds
on Thursday likely falling below SCA criteria.

&&

.FIRE WEATHER...
Rain amounts may average a tenth to two tenths of an inch and
may not be sufficient to wet fuels significantly. It should be
noted some hi- res guidance does have localized amounts near a
half an inch, but pinpointing the exact locations of these
spotty amounts is very difficult. Strong gusty winds of 35 mph
with potential for gusts as high as 45 mph will create renewed
fire weather concerns despite marginal humidities and the
overall light rainfall Sunday into Monday. Given the short
duration of precipitation (6 hours or less for most), the
100-hour fuel moisture values aren`t likely to rise much at all.
The 10-hour fuel moisture likely rises considerably, but drops
quickly through the day Sunday due to the drying effects of
strong winds and rapidly lowering humidity especially west of
the Blue Ridge and Catoctin Mountains.

Much cooler temperatures are expected Monday and Tuesday with a
moderating trend in temperatures expected during the middle and
second half of the week. Strongest winds look to be on Monday out
of the northwest with gusts to 25 mph (30 mph over ridges). For
the rest of the week, winds will be on light side thanks to high
pressure overhead, but humidities will be marginally low to near
critical levels. A dry pattern seems likely to continue with
little to no rainfall.

&&

.TIDES/COASTAL FLOODING...
SE flow will cause tides to rise to around or a little over one
foot above normal through early Sunday morning ahead of a strong
cold front. Minor tidal flooding is possible at several sites
especially for the waters around central to southern MD, with
near moderate flooding possible in a high-end scenario at
Annapolis (though a wind shift to the northwest right around
high tide should prevent that).

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 6 AM to 6 PM EDT Sunday for MDZ008.
     Coastal Flood Advisory from 3 AM to 10 AM EDT Sunday for
     MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Sunday for
     ANZ530>533-535-536-538>542.
     Small Craft Advisory until 6 PM EDT Sunday for ANZ534-537-543.

&&

$$

DISCUSSION...KLW/DHOF/CPB/SRT
AVIATION...KLW/DHOF/CPB/SRT
MARINE...KLW/DHOF/CPB/SRT