NWS Winter Weather Discussion
County Warning Area [CWA]: LWX
Regional NWS Weather Office: Baltimore/Washington DC, Virginia

Likely Snow or Ice Ranges and Start Times Snow or Ice Storm Fall Probabilities

Likely Snow or Ice Ranges and Start Most Likely Snow or Ice Storm Total Expect at Least this much Snow or Ice
Potential for this much Snow or Ice Likely Start Time of Winter Precipitation
Most Likely Ice Glaze
Most Likely Snow Fall Totals 1300Z Outlook
  
Images courtesy of the NWS Baltimore,MD-Washington,DC Office
 Forecast Disussion
Forecast Discussion

000
FXUS61 KLWX 171435
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
935 AM EST Wed Jan 17 2018

.SYNOPSIS...
A cold front will cross the area early today. High pressure
will build into the area later today, then shift south and east
of the region later this week into the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
855 AM UPDATE: Extended the Winter Weather Advisory for Stafford
and King George Counties until noon as steady light snow
continues in these areas. Elsewhere, have dropped the headlines
as accumulating snow is ending. A few flurries will remain
possible as a left exit region of the upper jet crosses through
about noon, but little or no additional impactful accumulation
is expected. Gusty northwest winds will bring in colder
temperatures but also drier air, which should allow many surface
to dry out during the day.

Previous discussion...
Surface cold front is pushing across the Mid-Atlantic this
morning while an upper level trough is located west of the
Appalachians. The best moisture within the frontal zone is just
arriving, but with that said, forcing is weak in our CWA. Expect
intermittent light snow to continue to progress south and
eastward through the early morning hours. It`s still looking
like most areas will receive less than an inch, although locally
slippery roads will be possible. Will make adjustments to the
advisory based on observational trends. We`ll have to watch
what, if any, banding develops across central Virginia to
perhaps southern Maryland in the left exit region of an
approaching jet max. It`s possible snow could linger well into
the afternoon in these locations. Basically, our CWA will be
right near the gradient of what will be a decent snow event
south/west of Richmond.

To the northwest, skies will gradually clear, and it will
become a bit blustery with wind gusts up to 25 mph or so.
Calendar day high temperatures may have already occurred in some
locations. Daytime temperatures will hold fairly steady in the
mid 20s to lower 30s, with teens in the higher elevations.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
As the upper level trough pushes east tonight, low pressure
will develop off the Carolina coast. So the pressure gradient
will remain fairly tight with cold air advection continuing. Low
temperatures will be in the teens for most, with around 20 in
the cities and single digits in the higher elevations. While it
seems the highest winds will remain above an inversion, limiting
wind advisory potential on the ridges, there will still be
enough wind to cause wind chills to potentially drop below -10
at the highest elevations. A wind chill advisory has been issued
for Highland, Pendleton, and western Grant Counties. Expect
single digit wind chills across the rest of the CWA.

Heights will begin rising Thursday with the airmass moderating
due to warm advection aloft and downsloping westerly flow. There
will still be a bit of a breeze, but highs will range from the
mid 30s to mid 40s. High pressure will remain to the southwest
on Thursday night, so decoupling will likely be localized. Teens
will be possible in these areas with 20s elsewhere.

A weak upper level trough will be passing early Friday but
should have minimal impacts other than a few extra clouds.
Otherwise high pressure will be building south of the area and
winds will be turning south of west. Further warming will occur,
with high temperatures in the 40s to around 50, and Friday
night lows in the mid 20s to lower 30s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
High pressure will settle to the south of the region over the
weekend, allowing a milder flow of air from the southwest to
dominate. A warm front lifting to the north to the west of the
region may bring clouds to the area, and some showers are
possible in the westernmost portion of the region along the
ridges, but further east it looks fairly dry. Highs will reach
the 50s, with lows in the 30s and 40s.

High pressure will slide east off the coast on Monday as a cold
front approaches from the west. Showers look likely to stay
west early on Monday, but should move east across the region
later in the day and at night as the cold front crosses the
area. Highs will reach the 50s again.

Cooler air will move into the region behind the system on
Tuesday, with a decreasing chance of rain as high pressure
builds back into the region. Highs will be in the 30s and 40s.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
VFR returning to all terminals at present (as of 930 AM), except
still MVFR vsby at CHO (probably for another 1-2 hours). Expect
clearing skies through the afternoon. Northwest winds will
continue to increase as well, with some gusts up to 25 kt
possible this afternoon.

No further cig/vsby issues are expected through Friday as high
pressure builds south of the area. West winds could gust to
around 20 kt on Thursday, with lighter southwest winds by
Friday.

Generally VFR over the weekend as high pressure to the south
dominates.

&&

.MARINE...
Northwest winds have been established behind a cold front this
morning. SCA conditions will commence shortly, with gusts of 25
kt possible through the day and perhaps through the evening.
Have still allowed the SCA to drop at midnight on the narrower
waterways where there will be some decoupling, but it`s quite
possible sporadic 20 kt gusts continue through the night. It may
be a little more marginal on Thursday, but there does seem to
be enough potential for 20 kt gusts to include all waters in a
SCA until 4 PM. High pressure will build south of the area on
Friday, with winds becoming southwesterly around 10 kt.

Winds will mostly stay below SCA over the weekend with a
southwest flow on the north side of high pressure.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...Winter Weather Advisory until noon EST today for VAZ036-037-
     050-055>057-508.
     Wind Chill Advisory from 7 PM this evening to 9 AM EST
     Thursday for VAZ503-504.
WV...Wind Chill Advisory from 7 PM this evening to 9 AM EST
     Thursday for WVZ501-505-506.
MARINE...Small Craft Advisory until midnight EST tonight for ANZ530-531-
     535-536-538>540-542.
     Small Craft Advisory from 8 AM to 4 PM EST Thursday for ANZ530-
     531-535-536-538>540-542.
     Small Craft Advisory until 4 PM EST Thursday for ANZ532>534-
     537-541-543.

&&

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

Record Report from: NOAA-NWS
Script developed by: El Dorado Weather & modified by: SE Lincoln Weather