662
FXUS61 KLWX 180130
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
930 PM EDT Fri May 17 2024

.SYNOPSIS...
Low pressure will track to our south tonight, before progressing
offshore this weekend. High pressure will build into the area
early next week. A cold front will approach from the west during
the middle of the week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 9 PM, showers and a few thunderstorms are ongoing from
central Virginia into the Potomac Highlands. Coverage of showers
and storms will increase through the remainder of the evening
and into the first half of the overnight as a shortwave
disturbance and attendant jet streak at upper levels approaches
from the south and west. Multiple rounds of rain and
thunderstorms will be possible across the Potomac Highlands,
Shenandoah Valley, and central Virginia, where a Flood Watch
remains in effect through 4 AM.

Further north and east, showers will gradually move in during
the first half of the overnight. Instability will be lacking,
so a steady soaking rain is expected, as opposed to the embedded
thunderstorms further southwest. The second half of the night
will feature rainy conditions, but no issues with flooding are
anticipated. Low temperatures overnight are expected to be in
the upper 50s to near 60.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
Weak upper troughing will progress overhead tomorrow, causing
cloudy and showery conditions to linger through the day. With
the thick cloud cover in place and easterly winds off the ocean,
conditions will remain cool, with temperatures only reaching
into the low 60s.

Upper troughing will start to progress off to our south and east
on Sunday. This should lead to a reduction in shower activity,
with some breaks of sun developing by afternoon, especially to
the west of the Blue Ridge. Low cloud cover and periods of
drizzle may try to linger through the morning to the east of
the Blue Ridge within easterly low-level flow, but some breaks
in the clouds cover still appear likely there during the
afternoon. Highs on Sunday are expected to reach into the 70s
(warmer further west, cooler further east).

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
High pressure and dry conditions prevail for the start of the
extended. Winds will be generally light, starting off out of the
east early Monday, then becoming southerly return flow behind the
center of high pressure as it moves east. This, combined with ample
sunshine, will allow temperatures to rise into the upper 70s on
Monday, and possibly into the 80s by Tuesday.

A potent low pressure system moves from the Northern Plains into the
Great Lakes on Wednesday, swinging a strong cold front through our
area Wednesday into Thursday. The area will be well primed with
temperatures in the 80s and ensembles indicating upwards of 1500
J/kg of CAPE. Shear is less certain, the more favorable shear
arriving Wednesday night into Thursday. Much could stand to change
this far out, but we will continue to monitor the severe threat for
this system.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Ceilings are currently high end MVFR to low end VFR this
evening, and should eventually drop back down to MVFR and then
IFR later tonight. Coverage of showers and thunderstorms will
increase through the evening into the first half of the
overnight as a disturbance approaches from the southwest. CHO
stands the greatest chance of having a thunderstorm overnight.
The steadiest rainfall is expected during the second half of the
night.

Showers and IFR ceilings will linger across much of the area
tomorrow into tomorrow night. Chances for showers will decrease
on Sunday, but IFR to MVFR ceilings will continue. Winds will
be out of the southeast tonight, and then east this weekend.

VFR conditions are expected Monday and Tuesday with high pressure
and dry conditions.

&&

.MARINE...
Sub-SCA southeasterly winds are expected tonight. Winds turn
easterly this weekend. Winds may reach SCA levels in easterly
flow tomorrow.

Sub-SCA criteria winds are expected Monday and Tuesday with light
easterly winds to start on Monday turning out of the south. Winds
increasing out of the south on Tuesday could result in some
southerly channeling, but not currently expected.

&&

.TIDES/COASTAL FLOODING...
Persistent onshore flow will continue through early next week.
This will result in elevated tide levels. Minor flooding is
expected in more sensitive locations over the next several
tidal cycles.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until 8 AM EDT Saturday for DCZ001.
MD...Coastal Flood Advisory until 7 AM EDT Saturday for MDZ014.
     Coastal Flood Advisory until 3 AM EDT Saturday for MDZ016.
     Coastal Flood Advisory until 2 AM EDT Saturday for MDZ017-018.
VA...Coastal Flood Advisory until 3 AM EDT Saturday for VAZ057.
     Flood Watch until 5 AM EDT Saturday for VAZ025>027-029-030-
     036>040-050-051-503-504-507-508.
WV...Flood Watch until 5 AM EDT Saturday for WVZ055-501-502-505-506.
MARINE...None.

&&

$$

SYNOPSIS...KJP
NEAR TERM...KJP
SHORT TERM...KJP
LONG TERM...CAS
AVIATION...KJP/CAS
MARINE...KJP/CAS
TIDES/COASTAL FLOODING...