Area Forecast Discussion
Issued by NWS Sterling, VA

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176
FXUS61 KLWX 110757
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
357 AM EDT Sat May 11 2024

.SYNOPSIS...
Low pressure sliding by to our north today will drag a cold
front through the region later this afternoon into this evening.
Drier conditions return with brief high pressure Sunday into
early next week. High pressure pushes offshore by the middle of
next week leading to a return of warmer temperatures and
unsettled conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
Starting to see a decrease in drizzle activity across the region
and even some gradually clearing of low-level clouds in spots
this morning. Drier conditions will continue to take hold into
the early afternoon.

An upper trough and associated surface cold front look to
approach the area later today into this evening, bringing
widespread showers and perhaps a few thunderstorms. Given the
timing being later in the afternoon/evening, best chance for
thunderstorms seems to be areas west of the I-95 corridor,
especially west of the Blue Ridge mid-afternoon. Temperatures
will reach the middle 60s this afternoon.

Showers will slowly depart to the east overnight, with most of
the region returning to dry conditions by Sunday morning. Low
temperatures generally reach the upper 40s to low 50s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The aforementioned cold front will move east of the area Sunday
morning, though some residual moisture on the backside of the
broad low could bring some on-and-off showers to the eastern
half of the area through Sunday afternoon.

Conditions dry out Sunday evening as high pressure builds in
from the west. Highs will generally be in the 60s, with some
low 70s possible in Central VA Sunday afternoon. Overnight lows
mostly in the 40s to low 50s.

For Monday, expect dry conditions with high temperatures well
into the 70s. A slight chance of showers will return that
evening ahead of the next approaching trough, but timing is
still a bit uncertain with that. If anything, model guidance
seems to be a touch slower, so rain may not even arrive until
Tuesday. Overall, would plan for a very average day for mid-May
with pretty low humidity as well.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Unsettled weather returns Tuesday and Wednesday as a trough moves
eastward from the mid Mississippi Valley. Some thunderstorms are
possible during this time, but overall instability appears to be
limited. The most widespread rain chances will occur Tuesday
afternoon and evening as lift and moisture flux maximize ahead of
the low`s approach. A period of moderate to locally heavy rain is
possible, but richer moisture will likely remain south of the area.
Ultimately the low is forecast to move to the east Wednesday, but
there appears to be plenty of wrap around moisture that will keep
shower chances high through the day. Despite the clouds and precip,
high temperatures will be near or slightly below normal.

Thursday still appears to be a relative break with seasonable
temperatures as ridging briefly builds overhead. However, this could
change as model spread increases in the upper level pattern. Despite
this divergence, there is enough agreement on a trough emerging
toward the eastern US on Friday that rain chances will increase
again.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
CIGs are beginning to improve this morning, which should
continue today. Light north winds this morning quickly shift to
south by late morning.Shower and thunderstorms are possible
again this afternoon/evening as a cold front approaches the
region. Best chance for thunder will be at MRB, IAD, CHO, and
DCA. BWI and MTN may be impacted later into the evening, when
instability will have decreased.

Light north winds this morning quickly shift to south by late
morning.

A cold front sweeps through early Sunday, with winds shifting
to northwest behind the front. Behind this, high pressure
returns with VFR conditions expected through Monday.

Sub-VFR ceilings along with showers and a few thunderstorms are
possible Tuesday and Wednesday as a low pressure system moves slowly
across the area.

&&

.MARINE...
Winds will gradually taper off this morning across the
Chesapeake Bay. After that, winds will generally be AOB 10 kts
today, at least until showers and thunderstorms potentially
impact the waters again this evening into tonight. Not looking
at any strong storms at this point, but can`t rule out some
brief sub-SMW level wind gusts if a storm does manage to get
somewhat organized.

Winds will increase for a brief period tonight just ahead of
the approaching cold front. Have issued an SCA between 00z and
08z for this brief uptick in winds, which should mainly be over
the Chesapeake Bay.

Winds may increase yet again on Sunday afternoon as northwest
winds increase behind a cold front that crosses the local waters
Sunday morning. This could necessitate an SCA, but not
confident enough this far out at this point.

Winds will then taper off Sunday night through Monday as high
pressure returns to the region.

Advisories may be needed Tuesday and Tuesday night in southerly flow
as a low pressure system approaches. The low will pass to the east
Wednesday, and additional advisories may be needed in northwest flow
Wednesday and Wednesday night. A few thunderstorms are possible both
Tuesday and Wednesday as well.

&&

.TIDES/COASTAL FLOODING...
While flow is generally out of the N to NNE, tidal anomalies
have remained elevated overnight. In fact, many spots continue
to increase. This has lead to several Coastal Flood Advisories
being issued up the Chesapeake Bay and Potomac. Straits Point
even looks to hit moderate with this high tide cycle. Expect
elevated tidal anomalies to continue into the next high tide
cycle or two as winds shift quickly out of the S/SE this
afternoon ahead of a cold front.

Tidal anomalies should begin to drop off by Sunday when
offshore northwest flow kicks in across the area.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory from 8 AM this morning to 2 PM EDT this
     afternoon for DCZ001.
MD...Coastal Flood Advisory from 7 AM this morning to noon EDT
     today for MDZ011.
     Coastal Flood Advisory until 1 PM EDT this afternoon for
     MDZ014.
     Coastal Flood Advisory until 8 AM EDT this morning for MDZ016-
     018.
     Coastal Flood Warning until 9 AM EDT this morning for MDZ017.
VA...Coastal Flood Advisory until 8 AM EDT this morning for VAZ057.
WV...None.
MARINE...Small Craft Advisory until 4 AM EDT early this morning for
     ANZ530>533-538>541.
     Small Craft Advisory from 8 PM this evening to 4 AM EDT Sunday
     for ANZ530>534-538-543.
     Small Craft Advisory until 8 AM EDT this morning for ANZ534-
     537-542-543.

&&

$$

SYNOPSIS...CJL
NEAR TERM...CJL
SHORT TERM...CJL/KRR
LONG TERM...ADS
AVIATION...ADS/CJL
MARINE...ADS/CJL
TIDES/COASTAL FLOODING...CJL