Forecast Discussion for Willowsford Farm and vicinity from the NWS in Sterling, Virginia

000
FXUS61 KLWX 261412
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
912 AM EST Tue Jan 26 2021

.SYNOPSIS...
Low pressure will pass through the area today. High pressure
will briefly return Wednesday. An upper-level disturbance is
expected to pass through the area Thursday morning while low
pressure develops well southeast of the area. High pressure will
return briefly Friday and Saturday before another storm system
approaches for late in the weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Temperatures are rising slowly but surely this morning. Have
extended the Winter Storm Warning for Mineral, Allegany and
Garrett Counties (as well as the Winter Weather Advisory for the
eastern WV Panhandle and north-central MD) until 1 PM given
continued drizzle and temperatures only slowly rising toward
freezing. Also extended the Winter Weather Advisory until 11 AM
for portions of northern Virginia where temperatures are
hovering right around freezing.

By this afternoon, temperatures should rise above freezing and
any lingering precipitation should transition fully over to
plain rain.

The surface low pressure will pull off the eastern seaboard
this evening. Dry conditions expected for most of our region
this evening into early Wednesday with some upslope snow
showers possible along and west of the Allegheny Front.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
High pressure will build to the northwest over the Great Lakes
region and eastern Canada on Wednesday. A weak easterly flow
will become light out of the northwest which will allow for a
broken cloud deck to linger into Wednesday. Dry conditions are
expected with afternoon temperatures warming into the 40s to
lower 50s. An upper-level trough over the Plains will drive a
surface low pressure system eastward into the southeastern U.S.
on Wednesday. Models have trended southward with this system
which has decreased the threat for snow over our region late
Wednesday into early Thursday. We have kept the highest PoPs
down in central Virginia and have at least slight chance PoPs
everywhere by 12Z Thursday. If precipitation does move northward
into our region, the precipitation will likely fall as a
rain/snow mix to start and then quickly transition over to all
snow Thursday morning. The Euro does try to bring in some snow
showers Thursday morning to all of our region as the low
pressure pulls northeastward off the eastern seaboard, but the
NAM and GFS are drier.

The high pressure off to the northeast will build into our
region behind the exiting low pressure on Thursday. Dry and
clear conditions are expected with the wind becoming northwesterly.
Depending on the track of the low pressure, strong gusts of 30
to 40 mph will be possible near and east of the Blue Ridge and
Catoctin Mountains, with the strongest wind focused over southern
Maryland. Daytime temperatures will be much cooler in the mid
to upper 30s due to strong cold air advection. Thursday overnight
low temperatures will be chilly in the teens to lower 20s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A reinforcing shot of cold air will cross the region Friday as
a trough passes to the north. We wouldn`t rule out a few
flurries or a snow shower with it, but mostly dry and brisk
conditions are expected overall. High temperatures in the 30s
will help Friday rank as one of the coldest so far in this
otherwise mild winter.

High pressure will nose southward over the region for Friday
night through Saturday night with a cold but dry air mass and
lessening winds. Radiational cooling should allow at least
Friday night to drop near, or colder than, the coldest night so
far this winter, but that`s not saying much given how little
true cold we have seen. Low temperatures may be in the teens
across much of the area, with high temperatures Saturday in the
30s once again. Depending on cloud cover, Saturday night could
be similarly cold to Friday night, though increasing clouds
ahead of an approaching storm system could keep it a bit
milder.

Models continue to indicate a storm system approaching from the
south-central U.S. will move across the region in pieces Sunday
into Monday. With cold air looking more plentiful at the start
than it did last night, we may have a better chance at a
widespread snowfall. Ensemble probabilities have definitely
become snowier for Sunday, but it`s still 5 days out. That
said, given our very limited winter weather last winter and so
far this winter, anything more than an inch or two could become
the snowiest storm since 2019 for much of our area.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
Drizzle and light rain, some freezing, continue across most
terminals this morning, but should taper off by midday as
temperatures rise and the causative low pressure moves away.
IFR/MVFR will likely persist much of the day and possibly into
tonight as there will not be much wind to mix things out.

VFR conditions should return during the day on Wednesday but a
surface low pressure system moving to the south of our region
will bring another chance for wintry precipitation to the CHO
terminal late Wednesday into Thursday. Clouds associated with
this system will overspread all terminals and subVFR conditions
will be possible into early Thursday morning. The main effect
from this low pressure will be a strong gusty wind out of
northwest on Thursday with the strongest winds affecting the
I-95 corridor terminals.

VFR conditions are expected Friday and Saturday, aside from the
very low risk of a stray flurry or snow shower Friday. A
blustery northwesterly wind Friday should be lighter than that
on Thursday, and should lighten further on Saturday.

&&

.MARINE...
No Small Craft Advisories are expected through Wednesday at
this time. A strong low pressure moving to our south will bring
strong wind gusts of 25 to 35 knots Thursday into Friday. Small
Craft Advisories are expected Wednesday evening through Thursday
night with Gale Warnings possible.

SCA conditions still likely Friday, but the wind should be
notably lighter than Thursday. High pressure building just to
the north should help the wind relax further on Saturday,
decreasing the risk of SCA conditions.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Winter Weather Advisory until 1 PM EST this afternoon for
     MDZ003>006-008-011-503>508.
     Winter Storm Warning until 1 PM EST this afternoon for MDZ001-
     501-502.
VA...Winter Weather Advisory until 11 AM EST this morning for
     VAZ027-028-030-031-040-501-505.
WV...Winter Weather Advisory until 1 PM EST this afternoon for
     WVZ051>053.
     Winter Storm Warning until 1 PM EST this afternoon for WVZ503-
     504.
MARINE...None.

&&

$$
SYNOPSIS...JMG
NEAR TERM...DHOF/JMG
SHORT TERM...JMG
LONG TERM...RCM
AVIATION...RCM/DHOF/JMG
MARINE...RCM/JMG

NWS LWX Office Area Forecast Discussion