Area Forecast Discussion Issued by NWS Sterling, VA
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000
FXUS61 KLWX 270744
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
344 AM EDT Wed Mar 27 2024
.SYNOPSIS...
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A slow-moving cold front will cross the Mid-Atlantic from west to
east through tonight. Low pressure developing near the Carolinas
will move northeastward along the front as it moves offshore
Thursday. High pressure will build in from the Ohio and Tennessee
River Valleys Friday, then a cold front will drop southward into the
Mid-Atlantic over the weekend into early next week.-- End Changed Discussion --
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.NEAR TERM /THROUGH TONIGHT/...
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A slow-moving cold front is approaching the Appalachians as of
early this morning. Warm/moist advection ahead of it via a
modest LLJ was causing some showers to begin breaking out on
either side of the Blue Ridge Mountains.
Shower activity is expected to become more widespread east of
the Blue Ridge Mountains, with waves of showers persisting
through much of the day as the front slowly moves in. The
onshore flow, clouds, and showers should keep temperatures in
the 50s for many areas east of I-81.
Rain showers will pivot east of I-95 and gradually diminish for
a time this evening as the front pushes east, but a wave of low
pressure developing offshore will likely bring another wave of
showers along and east of I-95 late overnight/early Thursday AM.-- End Changed Discussion --
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.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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Low pressure is expected to pass offshore Thursday into Thursday
night along the cold front that will have crossed the area
today. The heaviest rainfall amounts are expected south and east
of the local area, though around an inch of rain is possible
over southern MD.
As the low pulls away Thursday night into Friday, high pressure
will build in its wake from the OH/TN Valleys. This will lead to
fair and seasonable weather with blustery NW winds. Depending on
just how strong the gradient is between the departing low and
incoming high, gusts could approach or exceed Wind Advisory
criteria (40 kts/46 MPH) mainly over the higher elevations
Friday. Winds diminish Friday night with the loss of daytime
heating/mixing and as the gradient weakens.-- End Changed Discussion --
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.LONG TERM /SATURDAY THROUGH TUESDAY/...
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As high pressure moves out Friday into Saturday, we set up for a
generally unsettled weekend as a warm front moves into the Ohio
Valley and Mid-Atlantic and stalls in the area into early next week.
With a few minor disturbances passing overhead, some clouds and
shower activity are possible on Saturday and Sunday. Currently the
best chance for precipitation seems to be along the Alleghenies both
days with a slight chance north of I-66 Saturday and west of I-81
Sunday. Monday into Tuesday low pressure moves into the Ohio Valley
bringing greater rain chances to the region.
Temperatures will be well above normal over the weekend with highs
in the 60s to 70s outside of the mountains, and closer to normal for
the beginning of the week (50s to 60s) as the next low pressure
system approaches.-- End Changed Discussion --
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.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
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CIGs are FL006-FL012 are expected to persist through much of the
day, with the lowest CIGs pegged by guidance through about 15Z.
Brief LIFR CIGs are possible. Some guidance hints at patchy
dense fog/IFR VSBY in drizzle this morning before steadier
showers develop, as well. Shower activity is expected in waves
and could briefly reduce VSBY to MVFR through the day. A lull in
showers is expected this evening, but showers likely reappear to
the metro terminals early Thu AM as low pressure tracks up the
coast. Otherwise, IFR/LIFR CIGs look likely from mid to late
evening into the overnight. Light SE flow is expected.
Conditions improve to VFR Thu AM and persist through Fri with
gusty N/NW winds to 30+ kts at times. The strongest winds are
most likely Fri midday/afternoon.
Restrictions are possible Saturday and Sunday with shower activity
from a weak front lingering in the region. Winds could be gusty both
days up to around 20-25 kt, starting out of the southwest on
Saturday and becoming northwest on Sunday.-- End Changed Discussion --
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.MARINE...
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Light SE winds are expected today, becoming N late tonight.
Winds increase out of the N/NW Thursday-Friday, with solid SCA
conditions at times, and gale conditions possible mainly Friday.
Warmer air over cooler water could prevent mixing over the wider
cooler waterways during the day Friday, perhaps limiting the
strongest gusts to near the shore. Otherwise, periods of reduced
visibility in rain and patchy fog are expected through tonight.
Winds over the waters may approach SCA criteria during the day
Saturday and Sunday as a weak front lingers in the area.-- End Changed Discussion --
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.TIDES/COASTAL FLOODING...
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Tide anomalies have continued to increase on SE flow early this
morning. Widespread minor to localized moderate flooding is
expected through this morning before tide levels gradually
begin to come down a bit. Minor flooding is still likely at
many sites into tonight, possibly into Thursday depending on how
quickly tide levels respond/decrease due to increasing N/NW
flow Thursday into Friday. Given the persistent offshore flow,
low water level issues may arise by Friday before rebounding.-- End Changed Discussion --
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.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...Coastal Flood Advisory until 7 AM EDT this morning for DCZ001.
Coastal Flood Warning from 7 AM this morning to 2 PM EDT this
afternoon for DCZ001.
MD...Coastal Flood Advisory until 3 PM EDT this afternoon for
MDZ011-016-508.
Coastal Flood Warning until noon EDT today for MDZ014.
Coastal Flood Advisory from noon today to midnight EDT tonight
for MDZ014.
Coastal Flood Warning until 6 AM EDT early this morning for
MDZ017.
Coastal Flood Advisory until 8 PM EDT this evening for MDZ017.
Coastal Flood Advisory until 7 PM EDT this evening for MDZ018.
VA...Coastal Flood Advisory until 7 AM EDT this morning for VAZ054.
Coastal Flood Warning from 7 AM this morning to 2 PM EDT this
afternoon for VAZ054.
Coastal Flood Advisory until 3 PM EDT this afternoon for
VAZ053-055-057-527.
WV...None.
MARINE...Small Craft Advisory from 11 AM Thursday to 11 AM EDT Friday
for ANZ530>533-535-536-538>542.
Gale Watch from Friday morning through Friday afternoon for
ANZ530>533-535-536-538>542.
Small Craft Advisory from 11 AM Thursday to 4 AM EDT Friday
for ANZ534-537-543.
Gale Watch from late Thursday night through Friday afternoon
for ANZ534-537-543.-- End Changed Discussion --
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$$
SYNOPSIS...DHOF
NEAR TERM...DHOF
SHORT TERM...DHOF
LONG TERM...CAS
AVIATION...DHOF/CAS
MARINE...DHOF/CAS
TIDES/COASTAL FLOODING...DHOF