Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 150130 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
930 PM EDT Mon Aug 14 2017

.SYNOPSIS...
A frontal boundary will remain offshore through Tuesday. Weak
high pressure will build over the area mid week. A frontal
boundary will approach the area at the end of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
Model guidance and Blended TPW product show moisture increasing
tonight especially over eastern areas on deep layered SSW flow.
Forcing, however, appears to weaken overnight with more showers
moving into southwest areas toward daybreak. Expect current showers
over northeast MD to lift to the northeast in the next couple
of hrs with not much happening overnight other than developing
stratus/lowering ceilings ovr southern MD into DC metro.
Otherwise, plenty of mid-high level clouds over the area
overnight. Lowered POPs to chance this evening, but increased
them overnight for southwest areas as activity over ern KY moves
northeast.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Showers will end from northwest to southeast Tue evening with a
dry period Tue night into Wed night as high pressure builds to
the north.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
A weak upper level ridge will be moving over the region
Thursday, while at the surface, a warm front will be advancing
back north across the region. The end result will be a
significant warm up, with temperatures possibly reaching 90 for
the first time in quite a while (since August 4th at DCA, August
2nd at BWI, and July 24th at IAD). With the frontal passage,
however, we will have a returning risk of showers and t-storms.
We will be solidly in the warm sector on Friday as well, so if
we don`t make it Thursday, we could definitely still get there
Friday. By then however, a shortwave and cold front will be
approaching, which will result in an increased risk of showers
and t-storms, perhaps with a severe threat. The timing of the
next cold front crossing the region is still a bit uncertain,
with various models depicting a range from Friday night to
Saturday. However, by Sunday, we should be solidly behind the
front with cooler and drier weather taking hold, and likely
remaining through Monday.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
Developing stratus overnight with cigs dropping to IFR even
possibly LIFR. Chance of very light rain overnight, but rain
will probably hold off until tomorrow for most places.

Main concern Thursday and Friday will be possible intervals of sub-
VFR cigs and vis due to thunderstorms. Risk is mainly
afternoon/evening hours both days, as is typical with
convection.

&&

.MARINE...
Light winds through Thu night.

Winds mainly sub SCA Thursday and Friday, but will need to watch for
potential southerly channeling as a warm front moves through
and the next cold front approaches. Other concern will be
potential gusty winds with thunderstorms, which will be possible
both Thursday and Friday.

&&

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

&&

$$
SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...LFR
LONG TERM...RCM
AVIATION...RCM/LFR
MARINE...RCM/LFR



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