531
FXUS61 KLWX 011847
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
247 PM EDT Wed May 1 2024

.SYNOPSIS...
Brief high pressure settles over the region today through Thursday
leading to a warm and dry conditions. A weak cold front will cross
the area late Thursday into Friday before sinking south this
weekend. An additional cold front and area of low pressure will pass
through the area Sunday into early next week. This will result in
increased chances for showers and thunderstorms along with cooler
conditions.


&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The cold front from yesterday continues to push south and east of
the region this afternoon while brief shortwave ridging/surface high
pressure takes over the lower Ohio River Valley. Outside of a few
mid and high level clouds mainly along and east of the Blue Ridge
mostly sunny skies prevail. High temperatures today will push into
the low to mid 80s with mountain locations remaining in the 60s and
70s. Humidity values will come down as well with dewpoints hovering
in the upper 40s and lower 50s this afternoon. Winds will remain
light out of the northwest at 5-10 mph with a few sporadic gusts up
to 15 mph (given terrain and bay breeze circulations).

High pressure slides over the southern Appalachians and southern
Blue Ridge this evening into Thursday leading to a continuation of
quiet weather conditions. Lows tonight will fall into the mid to
upper 50s with low 60s over the Baltimore/Washington DC metro areas.
Some patchy river and bay fog are possible although confidence is
lower for fog development given dry air advection moving in.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Upper level ridging firmly builds over the area Thursday leading
to a continuation of warm and dry conditions. 850 mb
temperatures will be back up around +14 to +18 degrees C with
PWAT values around 1". Meanwhile, a moisture starved cold front
will sit across far western portions of the forecast area acting
as a catalyst for perhaps an isolated mountain shower or
thunderstorm (chances less than 15 percent). Elsewhere across
the region expect dry conditions with passing fair weather
strato-cumulus during the peak heating of the day. High
temperatures will remain above average in the upper 80s and low
90s with upper 70s and low 80s over the mountains. Lows Thursday
night will fall back into the upper 50s and low to mid 60s.

By Friday, the weak cold front looks to cross the region. Once again
most areas will remain dry with high pressure slowly pushing
offshore and increased heights across the region. Some showers and
thunderstorms are likely over the mountains given added orographic
lift and increasing moisture from southeasterly flow. Temperatures
will remain above average with highs in the upper 70s and low to mid
80s despite increasing clouds.

The front will continue south of the region late Friday into
Saturday as strong high pressure over eastern Canada wedges south.
This will allow for onshore east to southeast flow to increase
across the area especially east of the Blue Ridge. As a result,
expect increased cloud cover, cooler temperatures, and rain at times
for the start of the weekend. Shower activity will be fairly
scattered throughout the day with even a few rumbles of thunder west
of the Blue Ridge and Allegheny Front where better heating can take
place. Overall we should remain stable limiting any severe weather
concerns. Locally heavy rainfall will remain possible especially
late Saturday into Sunday as an area of low pressure and cold front
move into the region. With that said, no washouts are expected, but
the increasing need for wet weather gear will come in handy this
weekend. PWATS will run 1.25 to 1.75 inches Saturday which is within
the 90 to 97.5 percentile of 30 year climatology for this time of
year. Rainfall amounts of a quarter to three quarters of an inch are
expected Saturday with an additional quarter to a half an inch
Sunday as the front passes through. High temperatures Saturday will
push into the upper 50s and low to mid 60s. Overnight lows Saturday
night will into the low to mid 50s. East to southeast winds will
remain sustained at 5 to 15 mph with gusts up to 25 mph at times
especially along the ridges/waters.


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Unsettled weather returns for the weekend along and and ahead of a
surface low pressure and associated cold fronts that will impact the
region. Rain chances increase by late Friday night from west to
east. Saturday does not look like a total washout, with the better
forcing remaining off to the west. Nonetheless, off and on showers
will continue through the day on Saturday. Thunderstorm chances will
likely remain fairly low with the limited instability across the Mid-
Atlantic during that time. Highs will mostly be in the 60s for most
of the area Saturday afternoon.

By late Saturday night into Sunday, precipitation rates and
thunderstorm chances will likely increase. The front will slowly
cross the area and bring rainfall totals potentially beyond one inch
in localized areas. Given the drier antecedent conditions, isolated
instances of flooding will be possible on Sunday.

Afternoon showers and isolated thunderstorms will be possible Monday
and Tuesday as a result of a warm front lifting north of the area
and lingering moisture sticking around Tuesday with highs continuing
to climb across the area from 70s on Monday to low 80s by
Tuesday.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions are expected through Friday. Outside of mid and high
level clouds at terminals east of KMRB and KSHD clear skies prevail.
Winds remain light out of the northwest at 5-10 kts with a few
sporadic gusts up to 15 kts at times. SKC conditions are expected
tonight into Thursday as strong high pressure builds in from the
lower Ohio River Valley. Winds will turn to the west and southwest
Thursday at 5-10 kts. River valley fog may develop late tonight.
Confidence on this happening is low.

Mid and high level clouds will move back into the area Friday as a
weak cold front drops in the region. Sub-VFR conditions are possible
at terminals west of the Blue Ridge where a few showers and
thunderstorms are possible Friday afternoon. Areas further east will
likely stay dry with increasing cloud cover. Winds will switch to
the east and northeast late Friday into Saturday.

Multiple cold fronts will bring showers and perhaps an isolated
thunderstorm to the terminals both Saturday and Sunday. Sub-VFR
conditions are expected at times on both days. In addition to
reduced CIGs and VSBYs, southeasterly winds will gusts up to 20
knots on Saturday and 10-15 knots on Sunday. Additional chances for
sub-VFR conditions are possible early next week as the chances for
showers and thunderstorms remain with multiple fronts passing
through.

&&

.MARINE...
No marine hazards are expected through Friday morning. SCA level
winds return Friday afternoon and into the weekend as a series of
fronts drop into the region. Winds will remain light out the
northwest today before switching to the west and southwest Thursday.
Onshore SCA level winds develop Friday into Saturday.

Gusty southeasterly winds will gust between 15-25 knots on Saturday
as multiple cold fronts bring showers and isolated thunderstorms to
the waters. Small Craft Advisories are likely both Saturday and
Sunday. While winds diminish slightly on Sunday, gusts 15-20 knots
are possible in the afternoon.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...EST
LONG TERM...ADM/EST
AVIATION...ADM/EST
MARINE...ADM/EST