507
FXUS61 KLWX 251300
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
900 AM EDT Sat Apr 25 2026

.WHAT HAS CHANGED...
Have issued a Coastal Flood Advisory for Anne Arundel County
(Annapolis) for this afternoon`s high tide as water levels are
rising in onshore flow.

&&

.KEY MESSAGES...
1) A frontal boundary will linger nearby through Sunday morning,
leading to chances for showers and thunderstorms.

2) Another low pressure system and its associated cold front
will bring widespread showers mid-week.

&&

.DISCUSSION...
KEY MESSAGE 1...A frontal boundary will linger nearby through
Sunday morning, leading to chances for showers and
thunderstorms at times.

The current frontal analysis places a boundary across the
Virginia Tidewater region back along the I-64 corridor into
western Maryland. Moisture overrunning this stalled front
continues to spread isolated showers across southeastern
Pennsylvania into the Delaware Bay. Further, this area of
enhanced lift also consists of extensive low/mid-level clouds
which have begun to blanket northeastern Maryland. Off to the
south, scattered high clouds are observed on GOES-19 nighttime
satellite imagery. Temperatures are fairly seasonable with early
morning readings primarily in the 50s.

The larger scale pattern remains amplified with an expansive
deep upper trough centered over southern Saskatchewan and
additional troughing well off the New England coast. Sandwiched
in between these negative height anomalies is a collapsing
mid/upper ridge. Subtle height falls push across the region
today which will help spread additional shower activity.

The 00Z HREF solution favors such precipitation arriving during
the afternoon hours, while continuing into much of the night.
As the frontal zone sits near I-64, the thermodynamic
environment to the north will be more stable owing to the low-
level easterly onshore flow. As such, have lowered thunder
chances for those along/north of I-66/U.S. 50. Otherwise, a
warmer/moister air mass will reside closer to I-64 which is
where the best chance for any afternoon thunderstorms will be.

Periods of rain continue through the evening and into the night.
Given the continued drought conditions, this is likely to be a
beneficial rain with total rainfall amounts around 0.50 to 1.00
inches. This is accompanied by much cooler conditions owing to
the easterly onshore flow. Today`s highs are likely to top out
in the upper 50s to 60s. Further removed from these marine
influences, 70s should be more commonplace south of I-66 in
Virginia, as well as the Shenandoah Valley and Allegheny
mountain valleys. Heading into tonight, thickening low clouds
are expected with some residual showers. Lows fall into the 40s
which sets the stages for a chilly Sunday.

Some morning showers could linger into Sunday morning which
comes with increasing northeasterly breezes through the day.
Widespread highs will only make it into the 50s which is well
below average for late April. Temperatures do rebound some to
start off the new work week.


KEY MESSAGE 2...Another low pressure system and its associated
cold front will bring widespread showers mid-week.

Ridging will build over the region Tuesday with a dying front
remaining north of the area. Low pressure organizing south of Lake
Erie Wednesday will track northeast into eastern Canada bringing a
sharp cold front through the area Wed night. Widespread showers are
expected, particularly Wed night with beneficial rainfall of a
quarter to half inch of rain expected. Severe weather is not
anticipated due to weak instability, but general thunderstorms seem
possible.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
CIGs of FL012-FL023 were steadily spreading across the region
east of the Blue Ridge as of 12Z. Expect MVFR ceilings through
much of the day which comes with widespread showers beginning
this afternoon (generally after 20Z or so for the metros, an
hour or two earlier for KCHO/KMRB). Rain continues into the
evening and at least the first half of the overnight hours. Any
thunderstorm chances should be confined to KCHO which is near
the stalled frontal zone. Have maintained a PROB30 group
between 19-23Z to cover this threat.

As rain slowly winds down overnight, ceilings likely further
lower to IFR and stay that way through Sunday morning. Aviation
guidance shows some improvements possible later in the day, but
this should be gradual in nature. Drier conditions are expected
for Sunday afternoon into early next week as high pressure
builds to the north. Conditions will be breezy at times as
initial easterlies give way to northeasterlies on Sunday. Gusts
up to 20 to 25 knots are possible at times. With high pressure
to the north and a frontal zone stalled to the south, winds
remain out of the east to northeast into Monday as well.

Restrictions will again be possible by Tuesday and Wednesday as
another frontal system is set to impact the region. This is
expected to bring another round of widespread rain showers,
along with a few thunderstorms. Winds during this period
gradually shift over to southeasterly.

&&

.MARINE...
As a frontal zone has begun to sag south of the waterways, a
rather prolonged period of onshore flow is expected.
Consequently, Small Craft Advisories will be in effect across
all waters through at least Sunday evening. The strongest gusts
are likely to be across the Chesapeake Bay where wind gusts up
to 25 knots are possible. Easterly winds eventually give way to
northeasterlies on Sunday. Given the upward trend in guidance,
some 25 to 30 knot gusts are possible at times, especially over
the Chesapeake Bay waters. Winds turn more north to northeasterly
by Monday as high pressure remains centered across New England
into Quebec and New Brunswick. Small Craft Advisories will
likely need to be extended into Sunday night and much of Monday.
Winds eventually decrease to below advisory thresholds by
Monday night.

Winds remain below Small Craft Advisory levels into Tuesday and
Wednesday as well.

&&

.TIDES/COASTAL FLOODING...
Onshore flow due to a developing area of low pressure off the
Delmarva will cause increased tide levels along the Chesapeake
Bay and Potomac River. Many locations will reach Action Stage
during high tide over the weekend, with minor tidal flooding
possible.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 6 PM EDT this evening for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT Sunday for ANZ530>543.

&&

$$

DISCUSSION...LFR/BRO/DHOF
AVIATION...BRO/DHOF
MARINE...LFR/BRO/DHOF

NWS LWX Office Area Forecast Discussion