083
FXUS61 KLWX 191904
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
304 PM EDT Sat Oct 19 2024

.SYNOPSIS...
A large area of high pressure will remain over the East Coast
through Monday before beginning to shift east on Tuesday. A cold
front with limited moisture will cross the area late Wednesday
or early Thursday, followed by another expansive area of high
pressure.

&&

.NEAR TERM /THROUGH TONIGHT/...
Ridging at the surface and aloft continues to encompass much of
the eastern US. While the weak pressure gradient and seasonally
lowering sun angle are promoting somewhat modest mixing
heights, a dry airmass (precipitable water 0.3-0.4 inches) is
easily warming into the upper 60s to lower 70s this afternoon.
With clear skies continuing tonight, temperatures will fall
quickly to those low dew points, with outlying/low-lying areas
dropping into the 30s again. The ridges, cities, and bayshore
will remain in the mid 40s to near 50. While patchy frost is
possible in some locations where the growing season is active
(i.e. piedmont valleys), slight warming and moistening to the
airmass compared to previous nights may keep it isolated in
nature. The evening shift will monitor the need for any frost
advisories. Patchy fog could occur in a few valleys and low
spots as well.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Not much changes at the surface Sunday and Monday, although a
weak shortwave may cause the upper level pattern to become a bit
more baggy. At most, a few high clouds could occur at times. The
airmass will continue the slow warming and moistening trend
while maintaining the same diurnal character of warm days and
cool nights. Have likewise favored the forecast that way
compared to guidance, including lowering daytime dew points.
While likely not uniform everywhere, temperatures will average a
2-4 degree climb each day through Monday (when a few locations
could push 80F).

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
High pressure will remain in control Tuesday through Wednesday.
Dry conditions and light winds expected each day. Plenty of
sunshine will allow for temperatures to climb well into the 70s
to near 80 on Tuesday and reach the middle 70s on Wednesday. Low
temperatures will be a couple of degrees above average as well
reaching the upper 40s to lower 50s.

By Wednesday night as the high shifts to the east, a strong cold
front will plunge southeastward across the Lower Great Lakes into
the eastern Ohio Valley and mid-Atlantic. This front will only bring
minimal chances of any rain showers to the western and northwest
zones Wednesday night into early Thursday. There is more
likelihood of encountering daytime high temperatures about 15
degrees cooler on Thursday than ahead of the front on Tuesday
and Wednesday.

Cooler air will prevail on Friday behind the front with highs only
reaching the lower to middle 60s. Dry conditions will redevelop from
midday Thursday through Friday.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
VFR conditions with few to no clouds will continue through
Monday as a strong area of high pressure remains atop the
region. One exception could be some patchy early morning fog
near MRB. Wind direction will be difficult to pinpoint over the
next few days, with some guidance showing a complete 360 degree
progression to winds through Sunday morning. The good news is
that speeds should generally be 5 kt or less.

VFR conditions Tuesday through Wednesday night. Winds light and
variable Tuesday into Tuesday night, becoming southwest 5 to 10
knots on Wednesday ahead of a cold front.

&&

.MARINE...
A large area of high pressure will remain atop the region through
Monday, resulting in dry weather and light winds less than 10
kt. The general prevailing direction will be north to west, but
localized and diurnal variations will be possible with such a
weak pressure gradient.

No marine hazards Tuesday through Wednesday night. Winds light and
variable Tuesday and Tuesday night. Winds becoming southwest 5 to 10
knots Wednesday and Wednesday night.

&&

.TIDES/COASTAL FLOODING...
Increasing anomalies that have been suppressed to the south end
of the bay have worked northward, combining with high
astronomical tides. This may result in brief minor tidal
flooding at DC SW Waterfront and Annapolis during the next
couple high tide cycles. The highest confidence appears to be
this evening, where advisories have been issued. Action stages
are expected at several other locations. Overall water levels
are forecast to slowly decline heading into next week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory from 8 PM this evening to 1 AM EDT
     Sunday for DCZ001.
MD...Coastal Flood Advisory until 11 PM EDT this evening for MDZ014.
VA...None.
WV...None.
MARINE...None.

&&

$$

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