Area Forecast Discussion Issued by NWS Sterling, VA
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000
FXUS61 KLWX 290108
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
908 PM EDT Thu Mar 28 2024
.SYNOPSIS...
Low pressure will continue to slide by to our east today before
pushing off to the northeast and strengthening on Friday. High
pressure will build to our south on Friday, resulting in gusty
winds over the region. Multiple upper level disturbances will
pass overhead this weekend into early next week resulting in
generally unsettled weather.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Rain has ended across the area, with the cold front continuing
to track through the area. Some gusty northwest winds are
already filling in just behind the front. Clouds will continue
over the next several hours across the far eastern areas before
clearing out.
Previous Discussion Follows:
Another shortwave will dive through the larger trough late
tonight, bringing a return of some clouds and a brief period of
upslope snow showers. Snow amounts should generally be less than
one inch. Overnight lows will be in the 30s for most of the
area (upper 20s along the higher ridges of the Allegheny Front).
Winds will sharply increase with the arrival of this next
shortwave tonight. A Wind Advisory was issued for Grant,
Highland, and Pendleton counties for gusts up to 50 mph. This
should really pick up between 3-6 AM and likely continue through
Friday.-- End Changed Discussion --
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.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The aforementioned low pressure system will track toward the
Canadian Maritimes on Friday as high pressure simultaneously
builds to our south. A strong pressure gradient over the region
will be the result, with gusty northwesterly winds expected
across the area. Gusts will generally range from 30-45 mph, but
could be even up to 50 mph in the mountains. As mentioned in the
near term section above, Wind Advisories will continue through 8
PM Friday along the Allegheny Front. While there is some
potential for Wind Advisories further east, the best certainty
for now was out west. There is still a bit of uncertainty
regarding the height of the inversion and how aligned the winds
will be with height. Any slight deviations in either of those 2
variables could keep us just below advisory criteria. Will
leave the final decision to a later forecast cycle at this time.
Any lingering clouds will clear through the day, and high
temperatures will range from the upper 40s in the mountains to
the lower to middle 60s across Central Virginia.
Relative humidity values are expected to crash tomorrow in
strong northwest flow to around 20 to 25 percent. This paired
with the strong winds could lead to an elevated fire danger
Friday afternoon. More on that in the fire danger section below.
Friday night should remain dry although with some increase in
clouds. A thermal gradient will begin to develop across the area
as warm advection begins ahead of a low pressure system in the
Great Lakes. This will result in lows in the mid 30s across
northeast Maryland to the lower to mid 40s across the central
Shenandoah Valley and central Virginia.
This warm front will remain draped across the area through
Saturday as the low tracks toward the Mid Atlantic. The track of
this low and the warm frontal position will have influence on
high temperatures (50s north/60s to near 70 south) as well as
where the most rain falls. The highest rain chances currently
stretch across the eastern West Virginia panhandle and northern
Maryland. Clouds may linger Saturday night along with some rain
showers along the Alleghenies. Lows will be in the 40s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A warm front lingering around the Ohio Valley and Mid-Atlantic
through the weekend will bring clouds and some shower activity.
Currently the greatest chance for precipitation on Sunday is along
the Alleghenies, expanding eastward from there with 20-30 PoPs but
generally remaining west of I-95 during the day.
Low pressure approaches from the west Monday into Tuesday, bringing
greater chances of rain for the start of the week. Guidance has
trended colder after the system exits Wed/Thurs, bringing possible
upslope snow along the Alleghenies to finish off the extended.
Temperatures will be well above normal Sunday with highs in the 60s
to 70s outside of the mountains, and closer to normal for the start
of the week (50s to 60s) as the next low pressure system moves
through. Behind the system will be near to slightly below normal.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
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VFR conditions are expected for the remainder of the night as
the majority of the clouds and moisture have shifted to the
east. Gusty winds will pick up late tonight as a surge of
northwest flow builds in.
VFR conditions expected Friday, but northwest winds will gust
25-35 kt through the day. Sub-VFR conditions along with light
rain are possible Saturday north of a warm front which will
waver near MRB and the metro areas.
Restrictions are possible Sunday into early next week with shower
activity from a weak front lingering in the region followed by a low
pressure system. Winds could be gusty on Sunday, up to around 20-25
kt out of the northwest. Monday will be less gusty with winds out of
the east/northeast.-- End Changed Discussion --
&&
.MARINE...
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Small Craft Advisories are in effect for all waters through
tonight. Winds are expected to reach gale force late tonight
near southern Maryland as low pressure passes off the coast,
thus a Gale Warning has been issued starting at midnight and
going through 6 AM.
Winds will then increase across all waters Friday. A Gale
Warning has been issued for the entire day Friday for much of
the waters. Highest gusts are likely in the upper Potomac and
northern/central Bay zones.
At this time, sub-SCA conditions are most likely Friday night
into Saturday night.
Winds over portions of the waters may approach SCA criteria during
the day Sunday and Monday as a weak front and low pressure system
move through the area.-- End Changed Discussion --
&&
.FIRE WEATHER...
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For Friday, winds will increase (25 to 35 knots) with localized
higher gusts in the highest elevations. These winds will be
coupled with RHs in the low to mid 20s in the eastern WV
panhandle, north-central and western MD as well as portions of
northern and central VA. An SPS for elevated fire danger is in
effect Friday afternoon through early evening in the
aforementioned area. While 10-hr fuel moistures may not
necessarily be near threshold, local observations from fire
behavior analysts today indicated the 1-hr fuels were sufficient
enough to burn this afternoon. Lingering cloud cover may
inhibit the RHs a bit for a period in the morning but should
diminish late in the morning into the early afternoon. Further
extensions of the SPS may be needed overnight as new guidance
comes in.-- End Changed Discussion --
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...Wind Advisory from 4 AM to 8 PM EDT Friday for VAZ503-504.
WV...Wind Advisory from 4 AM to 8 PM EDT Friday for WVZ501-502-505-
506.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ530-531-535-
536-538>542.
Gale Warning from 6 AM to 6 PM EDT Friday for ANZ530-531-535-
536-538>542.
Small Craft Advisory until midnight EDT tonight for ANZ532>534-
537-543.
Gale Warning from midnight tonight to 6 PM EDT Friday for
ANZ532-533.
Small Craft Advisory from 6 AM to 6 PM EDT Friday for ANZ534-
537-543.
Gale Warning from midnight tonight to 6 AM EDT Friday for
ANZ534-537-543.
&&
$$
SYNOPSIS...CJL
NEAR TERM...CJL/ADM
SHORT TERM...CJL
LONG TERM...CJL
AVIATION...CJL/ADM
MARINE...CJL
FIRE WEATHER...CJL/ADM