Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 151419 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
1019 AM EDT Fri Mar 15 2024

.SYNOPSIS...
A cold front will cross the area this afternoon and evening bringing
showers and thunderstorms to the area. Cool high pressure
briefly returns to the area Saturday before a secondary cold
front crosses Sunday into early next week. This brings a return
to below normal temperatures next week.

&&

.NEAR TERM /THROUGH TONIGHT/...

High dense overcast is expected to persist all day until cdfnt
pushes south of the area. This will inhibit air mass
destabilization and thus convective potential. Have cut back in
PoPs significantly from earlier forecasts for areas north of
I-66 and US-50. Expect most of the activity to concentrate south
of the Capital Beltway across southern MD and the VA Piedmont.
Temps are still running higher than at this yesterday due to the
very warm start and should still get into the mid to upper 70s,
no 80s like yesterdat, except near Charlottesville.


Previous afd...

An upstream cold front currently extending from northeastern
Ohio back toward southern Illinois will play a key role in
today`s weather. This boundary is forecast to cross through the
local area during the afternoon to early evening before sagging
south into the night. Expect scattered to numerous showers to
cross through as this system approaches. The air mass is fairly
dry so it may take some saturation of the lower atmosphere to
see appreciable rainfall. Although convective chances are not
terribly high, isolated thunderstorms are in the forecast mainly
from I-66/U.S. 50 southward. This spans the afternoon into early
evening hours before any remaining instability wanes. MUCAPE
values largely top out in the 200-400 J/kg range. Rain chances
diminish into the night with low temperatures in the mid 30s
over the mountains to the 40s elsewhere.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Behind the exiting frontal system, high pressure briefly returns
for the first half of the weekend. This will promote a dry
forecast over the region with cooler temperatures owing to a
period of northwesterly winds. While still above average for
this time of year, it will feel cooler as highs are expected to
be in the 60s with 50s across mountain locales. As the
anticylone exits the Atlantic coast, winds shift back to
southerly for the second half of the day. Skies should be filled
with plenty of sunshine despite some passing clouds. Nighttime
temperatures remain mild given the return flow.

The next frontal system of interest currently resides over
northern Alberta. Over the next couple of days, this feature
will race southeastward, bringing it to the Appalachian chain by
early Sunday. This system will bring another round of
northwesterly winds, albeit more gusty than the previous day.
Afternoon gusts could reach 20 to 25 mph, while being closer to
35 to 45 mph over the Allegheny Front. This could bring a few of
the higher peaks to near Wind Advisory criteria. While this
cold front may bring a few showers to western Maryland early
Sunday, the day will largely be dry. Forecast highs are mild
which generally sit in the upper 50s to 60s, with 40s to low 50s
in the mountains. Winds may stay up a bit into the night with
low temperatures in the 30s to low 40s, with 20s along the
Alleghenies.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The first half of next week looks colder than normal as large scale
troughing pivots across the eastern CONUS. Embedded shortwaves may
bring periods of mountain snow showers Monday and Tuesday, and a
flurry, sprinkle, or shower or two are possible east of the
mountains depending on the strength of each of the waves (though
most if not all of the time/area east of the Alleghenies should stay
dry). This period early in the week will also feature blustery
conditions in a tight gradient between low pressure to the northeast
and high pressure building in from the west.

Moderating temperatures are likely heading into the second half of
next week. As the pattern shifts a bit, another storm system may
develop which would bring more widespread (likely liquid)
precipitation chances to the region later next week, but uncertainty
surrounds the specifics given the extended time range and shifting
pattern locally.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...

Will likely be dropping VCTS for all the airports except KCHO.
High dense overcast present is likely to inhibit sufficient
destabilization. Still a stray shower is possible and will just
keep VCSH, except VCTS at KCHO.

For the remainder of the weekend, expect VFR conditions at the
area terminals. With high pressure shifting offshore, winds
turn over to southerly on Saturday afternoon while continuing
into the night. The next cold front takes aim at the area early
Sunday leading to gustier northwesterly flow. Gusts up to 20 to
25 knots are possible behind this front.

Mainly VFR Mon-Tue with blustery NW winds; gusts to 30 kts
possible.

&&

.MARINE...

For the remainder of the day, some convection may impact the
waters this afternoon and evening which would bring some gale-
force winds to the waters. As the cold front pushes through
early this evening, northerlies ensue in the wake. This may
bring Small Craft Advisory criteria to the southern waters late
this evening into early Saturday. With a shift back to
southerlies, some channeling effects may yield additional
advisories along the Chesapeake Bay for Saturday evening into
portions of the night. A quick moving cold front leads to a
return to northwesterlies on Sunday. Winds near advisory levels
at times.

Blustery northwest winds and mainly dry conditions are expected
Monday into Tuesday. Gusts of 20 to 30 knots are most likely.

&&

.TIDES/COASTAL FLOODING...
Elevated tide levels in southerly flow are forecast through tonight.
The higher of the two tides astronomically is the morning, and this
is the most likely tide to experience minor flooding, especially for
the typically more vulnerable shoreline locales.

Depending on the timing of a wind shift to offshore heading into
Saturday, flooding chances may linger into the morning. Overall,
though, tide levels will decrease through the weekend. Persistent
offshore flow could lead to some lower then normal levels early next
week, as well.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until 4 PM EDT this afternoon for
     DCZ001.
MD...Coastal Flood Advisory until 2 PM EDT this afternoon for
     MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for ANZ533-
     534-537-543.
     Small Craft Advisory from 11 PM this evening to 8 AM EDT
     Saturday for ANZ533-534-537-543.

&&

$$

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


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