Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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

000
FXUS61 KLWX 201417
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1017 AM EDT Fri Apr 20 2018

.SYNOPSIS...
Strong high pressure over the Upper Midwest will
migrate eastward into the Northeast by Sunday before moving
offshore Monday. Low pressure will approach the area from the
southeast U.S. during the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Temperatures are rising steadily through the 40s and 50s as of
late this morning. As strong high pressure builds over the
Great Lakes region today, we will see winds pick back up as
mixing increases. Winds won`t be nearly as gusty as yesterday,
but expect gusty northwest breezes of 20 to 30 mph through this
evening, before winds subside. Temperatures through tonight will
continue the below normal trend, topping out today generally in
the middle 50s to near 60 degrees, while the warmest locations
across the Central Foothills and the Northern Piedmont of
Virginia will extend in to the 60s. Lows tonight will fall back
in to the 30s. Temperatures aloft will be warming but clear
skies and light winds will be more favorable for radiational
cooling. A Freeze Watch is in effect tonight for counties
surrounding the I-81 corridor, including portions of north
central Maryland and the Shenandoah Valley. Freezing
temperatures may also be observed across the central Virginia
piedmont where winds go light. They may need to end up being
added to any Freeze Warning that would be issued later today.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The weather pattern this weekend will be dominated by the
aforementioned area of high pressure to our north, delivering dry
conditions, light winds, and slowly moderating, yet still below
normal temperatures for the middle of April. Expect some high to mid
level clouds to move overhead for the latter half of Saturday and
persisting into Sunday as a jet max and some mid level energy
crosses the northern portion of our CWA. Highs will range in the
lower to middle 60s, with lows bottoming out in the upper 30s to
lower 40s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Strong sfc high pressure over the Northeast Mon will move
offshore in the afternoon with an easterly flow developing late
Mon night resulting in low clouds with light rain or drizzle
along and west of the Blue Ridge. Stratiform rain will
overspread the area later Tue into Wed as easterly flow
strengthens between departing high and sfc low lifting from the
Southeast into the Mid-Atlantic. The low will begin to move
away from the area during the second half of the week with a
gradual drying trend expected, but it won`t be completely dry.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR conditions prevailing through the weekend as high pressure
builds to our north. Gusty northwest winds expected to return this
morning as mixing commences, gusting to around 25 knots during the
day before abating late this afternoon and evening. Winds will
remain light through the weekend, mainly northerly on Saturday, then
veering to the northeast Sunday, then east southeast through Sunday
night.

MVFR conditions will begin to develop Mon night as easterly flow
develops. Widespread clouds with stratiform rain is expected Tue
into Wed with flight restrictions likely.

&&

.MARINE...
Small Craft conditions will continue today with gusty northwest
winds expected over the waters. Winds are forecast to subside this
evening as the pressure gradient relaxes and high pressure over the
Great Lakes wedges overhead. One exception to this will be the lower
Chesapeake, where winds will likely reach marginal SCA conditions
after midnight, continuing towards daybreak. With high pressure
dominating the weather pattern through the weekend, light northerly
winds are expected with no advisories or headlines anticipated.

&&

.TIDES/COASTAL FLOODING...
Early to middle of next week a decent east to southeast flow
will develop which will result in water levels rising. Would
expect minor coastal flooding in the Tue-Wed time frame.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Freeze Watch from late tonight through Saturday morning for
     MDZ003>006-507.
VA...Freeze Watch from late tonight through Saturday morning for
     VAZ025>031-507-508.
WV...Freeze Watch from late tonight through Saturday morning for
     WVZ051>053.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ530>543.
     Small Craft Advisory from 2 AM to 8 AM EDT Saturday for ANZ534-
     543.

&&

$$
SYNOPSIS...LFR
NEAR TERM...BKF/DHOF
SHORT TERM...BKF
LONG TERM...LFR
AVIATION...BKF/LFR
MARINE...BKF/LFR
TIDES/COASTAL FLOODING...LFR



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