-- Discussion containing changed information from previous version are highlighted. --
531
FXUS61 KLWX 121338
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
938 AM EDT Sun May 12 2024

.SYNOPSIS...
A potent upper low will pivot across the northeastern portion of
the forecast area today, bringing cool and unsettled conditions.
High pressure returns tonight into Monday. A slow moving low
pressure system will bring more unsettled weather Tuesday into
the middle of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A potent upper low spinning over the northeast CONUS will pivot
across northeast portions of the forecast area today. At the
surface, a cold front will finally push through the region,
which will turn winds out of the southwest. The combination of
these two features will keep it seasonably cool and unsettled
today with highs only reaching the 60s.

The early morning convection that moved across the DC Metro into
Southern MD is finally dissipating and moving east of the area
toward the Eastern Shore. Conditions mostly dry for the next
couple of hours before additional showers move into northern to
northeast MD from PA. Most of the precip today will focus in the
Baltimore metro to northeast MD, though at least a few showers
could develop as far west/south as US-50.

The upper low may linger across northeast MD, resulting in some
lingering cloud cover as well. Elsewhere, skies should clear
out pretty efficiently as high pressure builds in from the west.
Low temperatures will again reach the 40s for most (50s near
the water).
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
For Monday, high pressure will move overhead and eventually
offshore, so expect dry conditions and high temperatures in mid
to upper 70s.

For Monday night, sky cover will be on the increase ahead of an
approaching low pressure system. Low temperatures will only drop
into the mid 50s to low 60s.

Showers and thunderstorms are expected on Tuesday as an area of
low pressure approaches from our southwest. Given the warm and
moist air mass in place, could even see some locally heavy
rainfall during the afternoon. Severe threat at this time seems
rather low.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
On Wednesday, surface low pressure will likely be nearby or moving
off the coast. An upper trough will also be overhead. Enough
moisture will remain in place that showers will likely continue. A
few thunderstorms are also possible, but instability will be
limited. High temperatures will likely remain slightly below normal.
Since a closed low will potentially be involved, there is some
uncertainty with how quickly it will pull away. There does still
appear to be a brief period of ridging sometime in the Thursday to
Friday period. However, northeast flow between the low offshore and
high pressure well to the north could keep some extra low level
moisture and clouds around. If Thursday does end up mostly sunny,
there should be a corresponding slight boost to temperatures.

The next trough will quickly approach from the mid Mississippi
Valley Friday into Saturday. Shower chances increase as a result.
Instability appears to remain limited with this system as well, so
thunderstorm chances are more in question. Southerly flow could
result in another slight increase to temperatures, but this may be
offset by clouds/precip...so overall remaining seasonable.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
Winds have shifted to northwest behind a cold front that passed
through earlier this morning. Afternoon to evening showers and
possibly a thunderstorm or two are expected for BWI and MTN,
with possibly VCSH at MRB, IAD, and DCA. Winds gusts to around
20 knots from late morning through the afternoon. Winds turn
northeast tonight, which could bring in some lower CIGs to BWI
and MTN.

Otherwise, VFR conditions expected through Monday as high
pressure returns. Winds will also taper off a good bit on Monday
as well and gradually turn out of the south.

By Tuesday, winds remain southerly and begin to pick up ahead of
an approaching low pressure. Rain chances will be on the
increase as well with numerous showers and some thunderstorms
expected. This could lead to flight restrictions at all
terminals potentially.

Sub-VFR ceilings may attempt to lift Wednesday as low pressure pulls
offshore. However, showers will likely continue and a few
thunderstorms can`t be ruled out. High pressure may build in
Thursday, but some low level moisture could linger if the low
pressure system is slow to move offshore. Northerly winds may gust
up to 20 kt at times both Wednesday and Thursday.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
Winds have turned northwest late this morning behind a cold
front that pushed through the waters earlier. Winds could gust
to SCA levels for a few hours during the afternoon. Winds
diminish Sunday night into Monday as high pressure builds into
the region.

SCA conditions will likely return on Monday afternoon/evening,
continuing into Tuesday, due to southerly channeling of winds
up the Chesapeake Bay. Shower and thunderstorm chances also
return Tuesday as an area of low pressure approaches from the
southwest.

Low pressure will gradually move offshore Wednesday into Thursday.
Northerly winds may necessitate Small Craft Advisories for portions
of the waters during this time. Showers and a few thunderstorms will
continue Wednesday before drier conditions arrive Thursday.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Continued southerly flow, as well as coming off of a King Tide,
have continued to result in elevated tidal anomalies. A brief
directional change in the winds out of the NW could briefly drop
anomalies this afternoon, though some coastal flooding is still
possible during the evening high tide. Southerly flow will
return quickly late tonight and continue for the foreseeable
future. Additional period of coastal flooding seem likely in the
coming days.
-- End Changed Discussion --

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...Coastal Flood Advisory until 3 PM EDT this afternoon for
     DCZ001.
MD...Coastal Flood Advisory until 3 PM EDT this afternoon for
     MDZ011.
     Coastal Flood Warning until 3 PM EDT this afternoon for MDZ014.
     Coastal Flood Advisory until 11 AM EDT this morning for MDZ016-
     018.
     Coastal Flood Advisory until 5 PM EDT this afternoon for
     MDZ508.
VA...Coastal Flood Advisory until 3 PM EDT this afternoon for
     VAZ054.
     Coastal Flood Advisory until 11 AM EDT this morning for VAZ057.
WV...None.
MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ531-
     532-538>540.
     Small Craft Advisory until 7 PM EDT this evening for
     ANZ533>537-541>543.
-- End Changed Discussion --

&&

$$

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