Area Forecast Discussion
Issued by NWS Sterling, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
000
FXUS61 KLWX 200224
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
924 PM EST Fri Jan 19 2018

.SYNOPSIS...
High pressure to the south will dominate the weather through
the weekend. A cold front will approach the region Monday before
passing through Monday night into Tuesday. High pressure will return
for Wednesday through Thursday of next week before moving offshore
Friday.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
High pressure is centered over the southeastern U.S. this
evening with its ridge extending across our region. After
temperatures reached the 50s at most locations this afternoon,
they have backed off in to the 30s since sunset, with upper 20s
being observed at our favored radiational cooling spots. By
morning, overnight lows will range in the middle 20s to lower
30s across the region. Light winds and mostly clear skies will
prevail. Forecast remains on track with no major changes
needed.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
While the high pressure ridge remains in place through the
weekend, there will be a couple of transitory features in the
mean westerly flow: southern stream 500 mb shortwave/cyclone
along the Gulf coast, and northern stream low pressure across
southern Canada with weak attendant boundary emanating
west/southwest from it.

While neither will have a direct impact locally, warm advection
in the wake of the former disturbance will spread moisture
north Saturday-Saturday night. Saturday will still be sunny. At
this time, it appears as though any precip will be confined to
mountains Saturday night. Further, it is looking more likely
that temperatures will remain above freezing through this time,
so have removed mention of freezing rain.

Sunday will be cloudier, in part due to the pressure weakness.
But forcing will be too meager for anything but clouds.
Thermally, the cloud cover likely will lead to slightly cooler
temperatures, but highs will still be at-or-above 50 degrees.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
A cold front will approach from the west Monday before passing
through Monday night into Tuesday. Showers are expected ahead of the
boundary...especially Monday night into Tuesday. A southerly flow
ahead of the boundary will allow for mild conditions Monday...but
low clouds and fog are possible and if this develops it would cause
temps to be a bit cooler than currently forecasted.

The cold front will move off to the east later Tuesday and high
pressure will return for Wednesday and Thursday. Dry and seasonably
chilly conditions are expected during this time.

The high will move offshore late in the week and milder conditions
will return due to a southerly flow.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will prevail through the weekend with high
pressure positioned just southwest of the terminals. Winds will
be light and favor a west to southwest direction.

A cold front will approach from the west Monday. Low clouds and fog
are possible ahead of the cold front due to warm and moist air
overrunning cooler air near the surface...but confidence is low at
this time.

The cold front will pass through Monday night into Tuesday...
bringing showers and subVFR conditions. High pressure will return
for later Tuesday and Wednesday with VFR conditions likely.

&&

.MARINE...
With high pressure centered southwest of the region, winds will
remain light at 10 knots or less through the weekend. Flow will
have a primary southwest component, but will veer west/northwest
by Sunday as a front approaches.

A cold front will approach the waters Monday before passing through
Monday night or Tuesday. High pressure will return for the middle
portion of next week. A Small Craft Advisory may be needed for
portions of the waters Monday night through Wednesday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BKF
SHORT TERM...HTS
LONG TERM...BJL
AVIATION...BJL/BKF/HTS
MARINE...BJL/BKF/HTS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.