Winter Storm in West Virginia, April 4 to 6, 2024

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
304 PM EDT Wed Apr 3 2024

.SYNOPSIS...
A frontal boundary lingers over the area through this evening.
Unsettled weather is expected to continue as multiple rounds of
showers and thunderstorms impact the region. A series of cold fronts
will sweep through the area tonight and Thursday, bringing windy
conditions that last through the weekend. High pressure builds
overhead Sunday into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A round of showers and thunderstorms are advancing northeast
along and east of the I-95 corridor this afternoon with a few
isolated showers off to the northwest of the line.

A very favorable kinematic environment continues to support the
chance for flash flooding and severe storms. A cold front is
moving across the area with a rapidly deepening wave of low
pressure. As it moves across, strong to severe storms are
possible, primarily in King George, Charles and St. Marys
counties where a Tornado Watch is in effect until 7PM this
evening. A few tornadoes cannot be ruled out.

Some clearing is expected behind the front, some already
evident on visible satellite over portions of the Shenandoah
Valley. Mostly dry conditions follow, though some residual
showers are possible along and east of the Blue Ridge through
this evening. Additionally, the Alleghenies can expect a mix of
rain/show showers begins by late evening. Little accumulation
is expected due to marginal temperatures right around freezing.
Elsewhere, lows tonight drop to the mid 30s to low 40s.

Flood Threat: Repeated rounds of rain and storms over the past two
days has saturated the ground, especially north of US-50. As
additional widespread heavy rains occur this afternoon, the
threat for flooding is expected to increase. The western segment
of the Flood Watch has been allowed to expire, but areas east of
the Alleghenies remain under the Watch into this evening.

As the cold front and surface low cross the area, a line of
heavy showers and storms is expected to develop along and east
of US-15 this afternoon. Rain rates of 1-2" per hour are
possible in the strongest storms. This could result in scattered
instance of flooding, especially in urban centers and areas
with very saturated grounds. Low water crossings are likely to
flood in some areas, along with poor-drainage and flood-prone
spots.

Severe Threat: As the aforementioned line of storms develops and
moves through the area, the environment will be supportive of
damaging wind gusts and QLCS tornadoes. The threat for severe storms
is greatest for portions of southern Maryland and the central
Virginia Piedmont. This is where SPC has a Slight Risk (level 2
of 5) of severe storms, where a Tornado Watch is currently in
effect. Remember, QLCS tornadoes form rapidly and with little
lead time. If a Tornado Warning is issued for your area, seek
shelter immediately in a sturdy structure.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The deep low moves right over the area Thursday, then pushes east as
a reinforcing cold front sweeps through. Scattered to widespread
showers, with embedded thunderstorms, are likely Thursday late
morning into the afternoon. The synoptic environment is extremely
favorable for many of these stronger showers/storms to produce
graupel. Model soundings indicate the cloud bearing layer being
mostly below freezing and steep mid-level lapse rates up to 8 C/km.
Combined with the forcing from the low overhead, and very cold temps
aloft (500mb temps from -27C to -32C) the strongest storms could
produce some large graupel. Lingering showers dissipate Thursday
evening, except for along the Alleghenies.

Lingering moisture, continued troughing aloft, and some instability
due to diurnal heating result in scattered showers Friday afternoon.
Another reinforcing cold front sweeps through Friday night, though
it does not completely scour out all moisture. High temperatures
Thursday and Friday in the upper 40s to mid 50s, and overnight lows
mainly in the 30s. Near to below freezing temperatures most of this
time for the Alleghenies.

West winds gusting 25-30mph, and up to 35-45mph in the mountains on
Thursday. Slightly less on Friday, with gusts of 20-30mph, and up to
40mph in the mountains.

Rain/snow showers continue in the Alleghenies Thursday, eventually
becoming all snow Thursday night. A prolonged period of accumulating
snow is possible into Saturday morning, but could be some return to
rain during the day given marginal temperatures and the April sun
angle. This makes for a challenging accumulation forecast, especially
considering the potential for brief periods of higher snow rates
during heavy snow showers and snow squalls. For now, the highest
snow totals are expected above 3000ft. Winter Weather Advisories
have been issued for the Allegheny Front counties, and more
headlines could be added.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The upper low will start to make eastward progress on Saturday, but
we'll still remain under the influence of its western flank. We'll
likely start off with mostly sunny skies, but clouds should increase
heading into the afternoon hours in response to daytime heating and
resultant mixing. Conditions should remain dry for most, but some
light upslope snow showers may linger along the Allegheny Front.
High temperatures will range from the mid-upper 30s in the mountains
to the low-mid 50s to the east of the Blue Ridge.

Ridging will build in both at the surface and aloft for Sunday,
leading to mostly sunny skies and light winds. High temperatures
will be in the 50s to lower 60s. Upper level ridging will remain in
place aloft through early next week as an upper low tracks into the
Northern Plains/Western Great Lakes. This will lead to a continued
warming trend in temperatures, along with an increase in cloud cover
and a slight chance for showers. High temperatures may reach into
the 70s by Tuesday.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A line of showers and thunderstorms has developed near CHO
earlier this afternoon, quickly progressing eastward to along
and east of the I-95 corridor. Some of these storms will be
strong to severe, and be capable of producing wind gusts in
excess of 40KT and hail. A brief tornado or two is possible.
After this line sweeps through, conditions begin to improve. CHO
has already seen rapid improvement in conditions. Some showers
may redevelop this evening around 23-1z and bring rain to the
terminals, but confidence is too low to explicitly mention
cig/vis restrictions in the TAF. VFR conditions return tonight
after showers depart.

Scattered showers and isolated thunderstorms are likely to develop
across the area Thursday afternoon. Some of these storms will be
strong enough to produce graupel, and it could be large graupel in
the strongest storms.

Another front moves through Thursday night, with northwest winds
gusting to 20-25kt Friday afternoon into Friday night.

VFR conditions and northwesterly winds are expected on Sunday.
Continued VFR conditions are expected on Monday, along with
southerly winds.

&&

.MARINE...
SCA conditions are expected to continue as a wave of low
pressure deepens over the area and a line of showers and
thunderstorms quickly moves across all the waters. Special
Marine Warnings are likely needed as the strongest storms will
be capable of producing wind gusts in excess of 35KT, hail, and
waterspouts.

Behind the line of storms winds diminish over the Tidal Potomac this
evening and tonight, though SCA conditions are likely to continue
over the open waters of the Chesapeake Bay.

West winds increase Thursday, then winds increase even more Thursday
night through Friday night. Additional SCAs are going to be needed
through the weekend.

Winds may reach low-end SCA levels in northwesterly flow on Sunday.
Sub-SCA level southerly winds are expected on Monday.

&&

.HYDROLOGY...
Repeated rounds of showers and thunderstorms are expected
through this afternoon. Given multiple opportunities for heavy
rain over increasingly saturated soils, the potential for
flooding (and perhaps isolated flash flooding) will increase
today.

Additional rainfall amounts of 1 to 1.5 inches is likely over
most of the area, with localized amounts up to 2 inches
possible. Rain rates of 1-2" per hour are possible in the
strongest storms. Rises, some rapid, on smaller streams and
creeks, as well as rises on larger stem rivers, are possible as
a result.

Flooding may persist on the main stem Potomac River may persist
through at least Thursday as excess water runs downstream.

&&

.TIDES/COASTAL FLOODING...
An onshore flow will cause minor tidal flooding for sensitive areas
with the high tide cycle late this afternoon into this evening.

The flow will turn offshore and this will allow for anomalies to
fall some tonight. However, the flow may turn south of west Thursday,
and this may allow for elevated water levels to persist. Minor tidal
flooding is possible in sensitive areas, but confidence is low since
the flow will still have a stronger westerly component to it (west
to southwest).

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flood Watch until 6 PM EDT this evening for DCZ001.
     Coastal Flood Advisory until 6 PM EDT this evening for DCZ001.
MD...Flood Watch until 6 PM EDT this evening for MDZ004>006-008-011-
     013-014-503>508.
     Winter Weather Advisory from 8 AM Thursday to midnight EDT
     Thursday night for MDZ001.
     Flood Watch until 4 PM EDT this afternoon for MDZ003.
     Coastal Flood Advisory until 4 PM EDT this afternoon for
     MDZ014.
     Coastal Flood Advisory until 7 PM EDT this evening for MDZ508.
VA...Flood Watch until 6 PM EDT this evening for VAZ038>040-051-053-
     054-501-502-505-506-526-527.
     Coastal Flood Advisory until 6 PM EDT this evening for VAZ054.
     Winter Weather Advisory from 8 AM Thursday to midnight EDT
     Thursday night for VAZ503.
     Flood Watch until 4 PM EDT this afternoon for VAZ027>031-507.
WV...Winter Weather Advisory from 8 AM Thursday to midnight EDT
     Thursday night for WVZ501-505.
     Flood Watch until 4 PM EDT this afternoon for WVZ050>053-055.
MARINE...Small Craft Advisory until 6 AM EDT Thursday for ANZ530>534-
     537>543.
     Small Craft Advisory until 8 PM EDT this evening for ANZ535-
     536.

&&

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

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>