Hagerstown, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

816
FXUS61 KLWX 220844
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
344 AM EST Mon Dec 22 2025

.SYNOPSIS...
High pressure will quickly pass through the area today. A weak area
of low pressure will track across Ontario/Quebec tonight into
Tuesday. High pressure will build back in for Wednesday. A warm
front may lift northward through the area on Thursday, with a
cold front potentially approaching by late Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
It`s a clear and cold start to the morning with surface high
pressure almost directly overhead. This high will progress offshore
by this evening. Warm advection doesn`t really kick in until the
afternoon, so high temperatures will be seasonable in the 40s. As
heights begin rising to the west, advection of mid level moisture
will result in increasing clouds this afternoon.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
A flat shortwave trough and relatively weak surface low will move
toward the Great Lakes tonight. Between this feature and the
departing high, warm and moisture advection will increase aloft,
resulting in thickening clouds. Initially the low levels will be
dry, with the main source of lift the mid level upglide. Thus it
remains uncertain if much measurable precipitation falls east of the
Allegheny Mountains. There may be some snow and sleet on the leading
edge before rain takes over as temperatures warm aloft. Surface
temperatures will likely be near or slightly above freezing. The
wintry component may largely depend on wetbulb processes, and
precipitation may not be heavy enough to be efficient at cooling the
low levels. In terms of snow probabilities, the greatest chance of a
dusting continues to be across northeast Maryland. Should wetbulbing
(or nocturnal cooling earlier in the night that doesn`t recover)
result in subfreezing temperatures, there may be some patchy
freezing rain as warming continues aloft. This appears most
plausible in the typical cold pockets along the Allegheny Front:
around Frostburg-Keyser and western Highland County. However,
precipitation will be fairly transient and may not last long east of
the Allegheny Front. Combined with the spotty/lighter amounts,
confidence is not yet high enough for an advisory in these areas.
Given the previous afternoon highs in the 40s and marginal overnight
temperatures, any impacts from wintry precipitation would likely be
limited.

Any lingering rain along the I-95 corridor should end by late
Tuesday morning. Some light rain or drizzle could continue along the
Alleghenies into Tuesday night. Temperatures will likely climb
quickly Tuesday, but the upper limit will depend on lingering cloud
cover. Some guidance hints at an in-situ type wedge that remains in
place behind the spotty light precip with low clouds and light
winds. Where these features remain entrenched, highs likely remain
in the mid 40s. Farther south, breaks of sun will result in
temperatures in the mid 50s to near 60. Have a feeling the NBM
may be too far north with the 50s. The associated cold front
will push through by Tuesday night. Higher elevations along the
Allegheny Front may approach wind advisory criteria, but lower
elevation winds are not expected to be very strong. Dry
advection will follow the front, but not much cold advection as
ridging and a warm airmass remain over much of the nation`s mid
section. Temperatures Tuesday night will only drop to the 30s to
lower 40s.

Surface high pressure will build in from the west on Wednesday. Dry
weather is expected, but there may be some residual low level
moisture in northwest flow aloft that results in stratocumulus
across northern/western areas. Then mid and high level clouds
will start to increase in the afternoon. Combined with a thermal
gradient will also be across the area, another wide range of
highs from the mid 40s to near 60 will be possible.

The next shortwave trough and area of isentropic lift will approach
the area Wednesday night. There`s still a lot of uncertainty with
how much and how quickly any precipitation will spread eastward,
with chances increasing the second half of the night. There`s a low
end potential that if the precip catches up to residual cold air in
northeastern Maryland that it could be wintry, but this seems like
an unlikely scenario at this time. Most of the area will have
temperatures safely above freezing, even in the mountains.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
It will feel more like Fall compared to Winter for the upcoming
Christmas holiday. We`ll trade the thick Christmas sweaters and
puffy winter jackets in for lighter layers as temperatures warm 10-
15 degrees above average for this time of year.

A broad 500 mb ridge axis will anchor itself over the southeastern
CONUS to finish out the holiday workweek. Meanwhile, several pieces
of shortwave energy will ride the periphery of the ridge from the
northern Plains/upper Midwest into the Great Lakes region through
the end of the holiday weekend. Each of these pieces of energy have
the chance to bring some rain to region (especially areas west of
the Blue Ridge and toward the Allegheny Mountains). Overall forcing
will remain to the north and west as each system looks to track
across the Great Lakes. As a result, we get the associated warm and
cold frontal boundaries passing through during the Christmas
Day/Friday timeframe as well as the weekend ahead.

The greatest rain chances appear to be for the first half of
Christmas Day and again Friday morning/afternoon. This is associated
with a warm frontal boundary that will gradually lift through the
region. It won`t be a total washout with the GFS/GEFS remaining the
wettest when it comes to the coverage of rain compared to the ECMWF,
GDPS, and ECS counterparts. With that said, looking at 25-35 percent
PoPS for most of the region with 60-80 percent PoPs over the
mountains for the Christmas holiday. This aligns with current NBM
probabilities of 60-90 percent for a quarter of an inch of rain over
the Alleghenies with 30-40 percent probs of a tenth of an inch or
less east of the Alleghenies and into the I-95 metros over a 72 hour
period.

For Christmas Day, expect cloudy to mostly cloudy skies with a few
passing showers during the front half of the day as the warm front
slowly pushes through. Temperatures will range from the upper 40s
and low 50s over the Alleghenies/north-central MD to low 60s over
the central VA Piedmont. Some sun may be noted later in the day,
especially south of I-66/US-50 pending the placement of the warm
frontal boundary lifting north of the region.

Warming is expected to continue Friday as southerly flow increases.
Cloud cover will remain with a few passing showers as another ripple
of shortwave energy and cold front pass through. Once again not
looking at a washout here with the highest rain chances confined to
areas west of the Blue Ridge. Highs Friday will range from the mid
50s over the Alleghenies/northeast MD to low/mid 60s over
northern/central VA. Locations closer to the VA Tidewater could push
toward 70 degrees.

The northern jetstream will remain fairly amplified heading into the
weekend and early next week as another low pressure system works
across the Great Lakes. The associated cold front with this low
pressure system will cross the area Sunday into Monday bringing
widespread rain chances to the region. Both deterministic and
ensemble solutions remain in good agreement on timing of this storm
system although the strength of the front has yet to be resolved.
Colder air will return in the wake of the boundary just in time to
finish out the month of December and the end of 2025.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
High pressure will quickly cross the area today with VFR conditions
expected. Mid level clouds increase during the afternoon and
evening. Light winds will become southerly by mid morning.

A warm front may bring some light precipitation late tonight into
Tuesday morning. It`s possible it could begin as some snow and
sleet before changing to rain, should precipitation fall at all.
Included PROB30 groups for a mix to highlight this possibility.
However, the light nature of the precip and temperatures a few
degrees above freezing should preclude much of an impact with no
accumulation expected. Ceilings may not drop to MVFR until
precipitation ends on Tuesday, and even that is a bit uncertain.
Overall, CHO has the lowest chance to see both precip and low
clouds.

The associated cold front will push through Tuesday evening,
shifting winds to the west and clearing out most lower clouds.
However, MRB could hang onto some MVFR ceilings at times through
early Wednesday.

VFR conditions are expected with high pressure on Wednesday. Clouds
may begin lowering with chances of rain increasing the second half
of Wednesday night as a warm front approaches.

Some light rain chances could lead to temporary sub-VFR reductions
during the front half of Thursday (Christmas Day) as a warm front
pushes through. Winds will turn to the south and southwest Thursday
as the front lifts through. South to southwesterly winds continue
Friday with VFR conditions returning as the warm front lifts north
of the region. Gusts of 15 to 20 kts are expected both Thursday and
Friday afternoon. Locally higher gusts can be expected along the
ridges and near the waters. VFR conditions continue Saturday with a
cold front set to cross Sunday. The front will bring another round
of rain to the region.

&&

.MARINE...
High pressure is building in this morning with the lingering
marginal Small Craft Advisory due to northerly channeling in the
middle Chesapeake/lower Potomac slated to end soon. Winds become
southerly today as the high passes east. Flow starts increasing
tonight, and will be issuing a Small Craft Advisory for most of the
Chesapeake and lower Potomac zones for the second half of the night.
These winds will linger into Tuesday morning before subsiding
Tuesday afternoon.

The associated cold front will cross the waters Tuesday night. A
period of SCA conditions is possible the second half of Tuesday
night through midday Wednesday in the northwesterly flow behind the
front. Another transient area of high pressure will pass overhead
Wednesday afternoon and evening, with winds turning back to the
south by late Wednesday night.

Sub-SCA level winds continue Thursday and Friday although brief
periods of SCA conditions are possible for portions of the waters
due to southerly channeling.  Similar conditions are expected
Saturday with SCA conditions potentially returning Sunday into
Monday as a cold front crosses the waters.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 1 AM to noon EST Tuesday for ANZ531-
     532-539-540.
     Small Craft Advisory until 6 AM EST early this morning for
     ANZ533-534-537-543.
     Small Craft Advisory from 1 AM to 3 PM EST Tuesday for ANZ533-
     534-537-541-543.

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...ADS
LONG TERM...EST
AVIATION...ADS/EST
MARINE...ADS/EST