781
FXUS61 KLWX 131837
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
237 PM EDT Tue Aug 13 2024

.SYNOPSIS...

Broad high pressure will continue to maintain mainly dry weather
conditions and low humidity through Thursday. Precipitation chances
return by Friday and into the weekend as a slow moving area of low
pressure and series of fronts cross the region. This system exits
off the coast Monday into Tuesday with high pressure set to return
to the region by the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...

The cold front that impacted our region over the weekend has
continued to drift southward into parts of Georgia and Southeast
South Carolina this afternoon. Behind this boundary, high pressure
has slowly built into our region from the midwest and Great Lakes
regions. Below normal temperatures are being observed for the second
day in row this afternoon with dewpoints in the 50s making it feel
like mid to late September.

The morning showers that were observed in parts of central Virginia
have dissipated and clouds are slowly starting to break up.
Scattered to broken cloud decks continue to be observed in areas
along and south of I-66 with light winds generally out of the north
to northwest. Dry and below normal temperatures are expected to
continue through this evening.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...

Upper level ridging will slowly build over the region from the west
on Wednesday with high pressure in control at the surface. Winds
will continue out of the north and lead to another day of near
normal temperatures with dewpoints in the 50s once again. Skies will
be much clearer than today with mostly sunny conditions expected.

The pattern starts to break down on Thursday as the upper level
ridge shifts off to the east, but high pressure will remain in
control. Winds will begin shifting out of the south leading to
increasing temperatures and dewpoints. High temperatures should
return near normal with highs in the upper 80s to lower 90s.

Upper level troughing starts to build into the region late Thursday
evening. Shortwave energy dropping into our region from the west
will bring increasing chances for showers during the overnight
periods into early Friday morning.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...

1) Not a washout this weekend, although scattered to numerous
showers and thunderstorms are expected.

2) Near normal temperatures expected through the period.

3) Drying back out early next week.

12z deterministic and ensemble guidance continues to show an
amplifying shortwave trough digging south from the Ohio River Valley
for the end of the workweek. 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 Saturday especially for areas along
and west of the Blue Ridge. More widespread shower and thunderstorm
activity is likely Sunday as the cold front and upper level trough
swing through the region. Once again no washouts are expected on any
given day between Friday through Sunday with the bulk of any
thunderstorm coverage contained to the afternoon and evening hours.

After several dry days of weather flooding does not appear to be an
issue. Any rain that we do see will be beneficial as we continue to
chip away at the drought across the region. Precipitable water
values through the weekend will run between 1.25-1.75 inches due in
part to increased southerly low level flow. As for the severe
weather threat, it remains very low. Will continue to monitor this
threat for Friday as the warm front lifts into the region and the
weekend as we sit in the warm sector ahead of the approaching upper
level trough. Trailing shortwave energy will follow the front Monday
leading to additional shower chances east of the Blue Ridge. It`s
not until the middle of next week when surface high pressure builds
back into 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 /19Z TUESDAY THROUGH SUNDAY/...


VFR conditions are expected through Wednesday with winds generally
out of the north. A period of 15 to 18 knots gusts will be possible
in the afternoon during peak mixing.

Prevailing VFR conditions expected Thursday through Sunday 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 (mainly
during the afternoon & evening hours) as shower and thunderstorm
chances increase with an area of low pressure and it`s associated
fronts set to cross the region. Winds Saturday and Sunday increase
out of the south with gusts around 15-20 kts both afternoons.



&&

.MARINE...

SubSCA conditions are expected through Wednesday with winds
generally out of the north.

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. The open
waters in the central and southern Bay are the areas most likely to
reach SCA criteria.

Shower and thunderstorm chances will also pose a threat to mariners
during the afternoon and evening hours this weekend.


&&

.TIDES/COASTAL FLOODING...

Tidal Anomalies remain relatively low, but a few tide cycles
may reach action stage at a couple of sensitive sites.

&&

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

&&

$$

SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...EST
AVIATION...JMG/EST
MARINE...JMG/EST
TIDES/COASTAL FLOODING...