327
FXUS61 KLWX 131544
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1044 AM EST Sat Dec 13 2025
.SYNOPSIS...
A blast of wintry precipitation and bitter cold temperatures is
expected to impact the area late tonight into Sunday. Accumulating
snow will push into the mountains this afternoon before spreading
east later this evening and into the overnight hours. Gusty winds
behind the front will lead to plunging temperatures with wind chills
values expected in the teens and single digits by late Sunday
afternoon. Arctic high pressure settles over the region Monday
before shifting offshore Tuesday. This will yield a pattern change
with warming temperatures heading into the middle and end of next
week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Went ahead and updated some onset times for wintry precipitation
later this evening into the overnight hours. These times can be
found at weather.gov/lwx/winter as well as in the latest Winter
Weather Advisory/Warning bulletins.
Overall not too much of change in the current forecast package
outside of some subtle tweaking of temperatures, winds, and cloud
cover in the near term period. Should remain quiet through later
this afternoon and evening as high pressure continues offshore. All
eyes shift toward the Arctic cold front back to the west later this
evening and a ripple of low pressure that will like develop to the
south/west along the boundary. The front per latest satellite
imagery( is now working toward Detroit, Michigan and south toward
Indianapolis, Indiana. In addition to the front you can see some
subtle enhancement on water Vapor over Illinois which may in fact be
a piece of the resultant energy that will traverse the front
combined with the 100+kt jet streak aloft to produce the lift needed
for snow tonight (especially along the Baltimore/Washington DC I-95
corridor.
In the meantime, expect dry and cloudy conditions east of the
mountains through 5-7pm given weak upper level ridging departing and
west to southwest low level downsloping flow. Further west into the
Alleghenies light flurries and and freezing fog are expected
through midday with snow showers/squalls picking up later this
afternoon and evening. Winter Storm Warnings remain in effect
for western Garrett and western Grant counties, where 4-8 inches
of snow is expected. Winter Weather Advisories remain in effect
for eastern Garrett, western Allegany, and western Pendleton
Counties, where 2-4 inches of snow is expected.
Snow will gradually spread east during the late evening and
overnight period as the open wave of energy ejects eastward into the
region Most models continue to show jet steak developing
downstream, with forcing for ascent increasing within the
equatorward entrance of the jet streak. Most solutions show the jet
entrance region lining up right along I-95. Ascent within the jet
entrance region may cause precipitation to jump eastward and develop
in-situ along the I-95 corridor, largely skipping locations between
the Allegheny Front and Blue Ridge.
The precipitation may begin as a brief period of rain or mixed rain
and snow, especially along and southeast of the I-95 corridor. This
mix should be short-lived however, as much colder air rushes in
behind an Arctic front that will move through over the course of the
night. In terms of timing, some light precipitation could begin as
early as the mid-late evening hours (7-10pm), but the bulk of
the precipitation along the I-95 corridor is expected to occur
between roughly 11 PM and 6 AM.
The band that will develop will be a relatively narrow with
moderate to heavy snow at times. Snowfall rates within the band
could near or potentially briefly exceed one inch per hour at
times late Saturday night. With a narrow feature producing heavy
precipitation, snow totals will be heavily dependent on the
ultimate placement of this band. This, combined with the
potential for a bit of mixing with rain at onset makes for a
challenging snowfall forecast. Latest guidance shows a
northward progression of the band with the highest confidence
for 3"+ totals generally from Baltimore points north and east
into NJ.
Expecting 1-3 inches for most with some higher totals closer to
4-5 inches in far northeast MD (Harford and Cecil counties).
There is still that potential for a boom scenario, particularly
northeast of the DC metro into northeast MD, where in a worst
case scenario up to 6 inches could be possible. Winter Weather
Advisories will continue for these areas from later this
evening through early Sunday morning.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Fast moving low pressure and it`s associated Arctic cold frontal
boundary will exit the area Sunday with a strong dome of Canadian
high pressure building in. This will allow for bitterly cold
conditions Sunday afternoon through Monday night. Temperatures look
to rebound as the Arctic high shifts offshore Tuesday into Wednesday
next week.
Snow will end from northwest to southeast a few hours either
side of daybreak, with the back edge of the snow clearing
southern Maryland by around mid- morning. Residual upslope
snow showers will likely linger over the mountains through
Sunday night given predominant west to northwest flow.
Meanwhile, 1044-1050 mb Arctic/Canadian high pressure over the
upper Midwest will build eastward. The tightened gradient
between the departing Arctic cold front and building Arctic
surface high will lead to brisk and blustery conditions Sunday
afternoon/evening. Wind gusts of 30-40 mph are possible with
locally higher gusts over the ridges/waters. This will yield to
a combination of plummeting temperatures and wind chills
throughout Sunday into Monday as winds remain elevated. Overall
looking at a non-diurnal temperatures spread Sunday with high
temperatures likely occurring close to midnight and falling
into the mid to upper 20s (single digits and teens mountains)
throughout the day. Lows Sunday night will range from near 0
over the mountains to the mid and upper teens east of the Blue
Ridge/I-95 metros. These values are 5 to 15 degrees above record
territory for this time of year. Wind chill values will drop
into the single digits and low teens east of the mountains
Sunday afternoon with near 0 to subzero values over the
mountains. Wind chills could drop as low as -20 to -30 degrees
for a period of time over the highest elevations above 3000 feet
late Sunday night into Monday morning. Cold weather hazards may
need to be evaluated to encompass this threat pending on how
the forecast evolves in the coming model cycles.
Cold high pressure settles overhead Monday into Monday night
allowing the winds to gradually settle down. Gusts of 15 to 25 mph
can be expected through the afternoon with highs for most struggling
to make freezing. Mountain locations will remain in the mid to upper
teens throughout the day. The added wind will keep wind chills in
the single digits over the mountains with low to mid 20s elsewhere
across the region. Lows Monday night will fall into the mid to upper
teens and low 20s under clear skies.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
The cold weather pattern will be replaced with a warmer one Tuesday
into Wednesday. The deep upper level trough that dominated the
weather pattern over the last several days shifts offshore with
ridging building aloft. This will allow for more of a zonal flow
pattern into the region. WAA will ensue at the surface late Tuesday
into Wednesday as a warm front lifts toward the region. This will
bring rain showers Wednesday that linger into Thursday. Highs
Wednesday look to push back into the mid 40s and low 50s with mid to
upper 50s Thursday. Mountain locations will remain a touch cooler in
the low to mid 40s. High pressure builds again over the area to end
the week.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions and light southwesterly winds are expected at
all terminals during the day today.
Lower ceilings and snow are expected to develop across much of
the forecast area, starting as early as this evening. BWI, MTN,
DCA, and IAD are most likely to experience the greatest impacts
from snow, with a couple inches of accumulation possible during
the second half of the night. The precipitation could also
briefly mix with rain at onset. Chances for snowfall are a bit
lesser at MRB, but would be on the earlier side of things,
starting as early as 01z tonight. But accumulations look to be
very minimal if they occur at all at MRB. Snow appears as
though it will likely avoid CHO altogether, though can`t rule
out a few flurries overnight into early Sunday.
Conditions are expected to improve back to VFR by mid-morning
Sunday at all terminals as the band of snow quickly retreats
towards the east. Northwesterly gusts of up to 35 knots are
possible throughout the afternoon in the wake of this strong
front.
While VFR conditions are forecast for Monday, winds remain gusty
in the wake of the aforementioned arctic front. Expect gusts up
to 25 knots during the first half of the day. These taper off
during the afternoon, going nearly calm Monday night.
VFR conditions Tuesday and Wednesday as high pressure moves
overhead and eventually offshore. Winds light and variable
Tuesday as the high is overhead, but will turn out of the
southwest Tuesday night into Wednesday, albeit remaining light.
&&
.MARINE...
Due to some southerly channeling up the Chesapeake Bay early
this morning, a brief period of near-SCA winds is possible
around daybreak. Confidence was too low for an SCA though, but
should this occur, an MWS may suffice to cover this threat. Will
continue to monitor over the next couple of hours.
Sub-SCA level southwesterly winds are expected during the day
today. Winds will then turn out of the northwest and pick up
fairly rapidly in magnitude during the second half of the night
as an Arctic front moves over the waters. Gale Warnings have
been hoisted with the overnight forecast package to cover this
threat. However, the peak winds may not occur until mid-late
morning. Still, conditions will deteriorate quickly around
daybreak. Freezing spray may also be possible at times during
the day Sunday and into Sunday night, especially over the wider
waters of the Chesapeake Bay, where waves may be up to 5 feet
at times and winds remain Gale-force.
Gale conditions gradually taper off overnight from northwest to
southeast, but will linger over the lower Tidal Potomac and
middle Bay until early Monday morning.
SCA conditions expected to continue Monday with gusts up to 25
kt, diminishing gradually through the day and night, and
dropping below SCA threshold by daybreak Tuesday.
Lighter winds expected on Tuesday and Wednesday, with no marine
hazards expected.
&&
.TIDES/COASTAL FLOODING...
Following the passage of a strong arctic cold front Sunday,
gusty northwest winds will push water south and towards the
southern portions of the Chesapeake Bay fairly rapidly. Blowout
tides seem likely for many areas along the western shoreline of
the Chesapeake Bay by the Sunday evening low tide cycle and
continuing into Monday as well.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Winter Weather Advisory from midnight tonight to 10 AM EST
Sunday for DCZ001.
MD...Winter Weather Advisory from midnight tonight to 10 AM EST
Sunday for MDZ008-011-013-014-016-018-503>506-508.
Gale Warning from 6 AM to 6 PM EST Sunday for MDZ008.
Small Craft Advisory from 6 PM Sunday to 6 AM EST Monday for
MDZ008.
Winter Weather Advisory from 8 PM this evening to 7 AM EST
Sunday for MDZ005-006-507.
Winter Weather Advisory from 4 PM this afternoon to 1 PM EST
Sunday for MDZ501-510.
Winter Storm Warning until 4 PM EST Sunday for MDZ509.
VA...Winter Weather Advisory from midnight tonight to 10 AM EST
Sunday for VAZ053-054.
Cold Weather Advisory from 7 AM Sunday to 10 AM EST Monday for
VAZ503.
Cold Weather Advisory from 1 PM Sunday to 1 AM EST Monday for
VAZ504-507-508.
WV...Winter Weather Advisory from 4 PM this afternoon to 1 PM EST
Sunday for WVZ503-505.
Winter Storm Warning until 4 PM EST Sunday for WVZ501.
Cold Weather Advisory from 7 AM Sunday to 10 AM EST Monday for
WVZ501-505.
Cold Weather Advisory from 1 PM Sunday to 1 AM EST Monday for
WVZ506.
MARINE...Winter Weather Advisory from midnight tonight to 10 AM EST
Sunday for ANZ530.
Gale Warning from 6 AM to 6 PM EST Sunday for ANZ530-531-535-
536-538-539.
Small Craft Advisory from 6 PM Sunday to 6 AM EST Monday for
ANZ530-531-535-536-538-539.
Gale Warning from 6 AM Sunday to 6 AM EST Monday for
ANZ532>534-537-540>543.
&&
$$
SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...CJL/KJP/EST
LONG TERM...CPB
AVIATION...ADS/CJL/CPB
MARINE...CJL/CPB
TIDES/COASTAL FLOODING...
NWS LWX Office Area Forecast Discussion