358
FXUS61 KLWX 130114 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
914 PM EDT Mon Aug 12 2024

.SYNOPSIS...
Tranquil weather conditions are expected through Wednesday as
surface high pressure resides over the Northeast and Mid-Atlantic
states. Precipitation chances return later this week and into the
weekend as a slow moving area of low pressure and series of fronts
cross the region.

&&

.NEAR TERM /THROUGH TUESDAY/...

Scattered mid-high level clouds are expected overnight as
shortwave energy moves across the area. Low temperatures will be
similar to this morning, if not a touch warmer.


&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As the upper level trough lifts off to the northeast early on
Tuesday, high pressure is expected to build over our region and
remain in place through the majority of this week. North to
northwesterly flow will remain in place leading to continued dry
conditions and near normal temperatures through Wednesday for most
of the region. Some model guidance has a chance for a few
thunderstorms over central Virginia on Wednesday due to a
combination of an upper level jet and an upper trough nearby, but a
lack of low level moisture will limit threat for storms and showers.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Messages:

1) Increasing chances for showers and thunderstorms Friday into the
upcoming weekend.

2) Near normal temperatures expected through the period.

Not too much of a change in the extended period although both
deterministic and ensemble models continue to slow the progression
of an approaching low pressure system over the Great Lakes and it`s
associated fronts for the latter half of the workweek. Thursday
continues to trend dry with an outside chance of an isolated shower
or thunderstorm over ridges west of the Blue Ridge. This is largely
due in part to brief upper level ridging building back overhead with
the trough exiting east and the incoming trough back across the
Midwest/Ohio River Valley. One thing to note will be the low level
flow out of the south ushering in more humidity and high
temperatures around 90 degrees Thursday afternoon.

By Friday, eyes turn toward the amplifying shortwave trough digging
south from the Ohio River Valley. With the trough will come an area
of low pressure ejecting north and east from the Upper Midwest into
the northern Ohio River Valley and Great Lakes region. As the low
pressure system, lifts north and east it`s associated warm front
will cross the area Friday into Saturday followed by a cold front
Sunday into early next week. Until the cold front passes low level
flow will remain out of the south and southwest advecting more
moisture into the region. This will lead to increased shower and
thunderstorm chances Friday and into the weekend especially for
areas along and west of the Blue Ridge. As of now, severe weather
and flooding do not appear to be a concern given the several dry
days of weather leading up to the weekend. Current 12z precipitable
waters from both the ensembles and deterministic runs average around
1.25-1.75 inches. Any rain that we do see will be beneficial as we
continue to chip away at the drought across the region.

Temperatures will remain near normal throughout the period. 850 mb
temperatures will sit right around +15 to +17 degrees C Friday
through SUnday. This will yield highs in the mid to upper 80s east
of the Alleghenies with lows in the 60s and 70s. One caveat would be
that temperatures could be slightly cooler than normal this weekend
given abundant cloud cover and increased precipitation chances with
multiple fronts nearby.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
Winds will remain out of the north to northwest through Wednesday
with afternoon gusts of 16 to 20 knots possible. Scattered high
clouds are expected overnight. Cloud cover will thin out on
Tuesday with VFR conditions expected through Wednesday and winds
generally out of northwest.

Prevailing VFR conditions expected Thursday and Friday at all
terminals with high pressure nearby. Light north to northwest flow
Thursday will switch to the south Friday as high pressure slides
offshore. Periods of sub-VFR are expected this weekend as shower and
thunderstorm chances increase with an area of low pressure and it`s
associated fronts set to cross the region.

&&

.MARINE...
Light north to northwesterly winds are expected through
Wednesday with subSCA conditions.


No marine hazards are expected through Friday morning as surface
high pressure slowly slides east of the area. Light north to
northwest winds are expected Thursday switching to the south Friday.
SCA level winds may return as early as Friday afternoon and night
due to southerly channeling. Additional concerns for southerly
channeling can be expected Saturday and Sunday as the gradient
tightens with the next front set to cross the region. Shower and
thunderstorm chances will also pose a threat to mariners during the
afternoon and evening hours this weekend.

&&

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

&&

$$

SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...JMG
LONG TERM...EST
AVIATION...LFR/EST
MARINE...LFR/EST