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000 
FXUS61 KPHI 200715
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
315 AM EDT Fri Sep 20 2019

.SYNOPSIS...
High pressure across the Middle Atlantic region today will weaken 
and move offshore by the end of the weekend. Low pressure will move 
across Canada and cause a cold front to cross our region Monday 
night. More high pressure will build in next Tuesday and remain 
through the middle of next week. 

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The mid-level ridge over the eastern U.S. will sharpen today. As 
this occurs, surface high pressure across the northern Mid-Atlantic 
will settle across the Carolinas. 

Vertical profiles show little moisture today. The exception is right 
at the surface and between H5-H3. As a result, we could see a bit of 
fog right at sunrise and some high Cirrus as we move through the 
day. 

So, all-in-all, another quiet day.

Afternoon high temperatures should top out about 5 degrees warmer 
than yesterday. Most locations will make it into the mid to upper 
70s. There will be very little change in dewpoints compared to 
yesterday. Winds will be less than 10 mph from the west. 

A comfortable day ahead.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
Very little change expected in the overall pattern across the 
eastern U.S. tonight. The mid-level ridge axis shifts from the 
central Great Lakes to the eastern Great Lakes. Surface high 
pressure remains in place.

We will see some warm air advection. West winds will transport some 
warmer air from the Ohio Valley across the Mid-Atlantic. So even 
though skies will be mainly clear tonight and winds will go light 
once again, temperatures will be several degrees warmer compared to 
what's occurring right now at this hour.

Patchy shallow fog is possible toward daybreak.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Sat thru Sunday night...Fair weather with some increasing clouds 
Sunday night. High pressure to the south will weaken and move 
offshore. A return flow of mild and somewhat more humid air will be 
across the area. Highs both Sat and Sun will be above normal with 
readings Sunday in the mid/upper 80s. Sat night will be seasonably 
chilly, but Sunday night will be mild. Some patchy fog is possible 
Sun morning. 

Monday/Monday night...The high pressure will have moved away and a 
progressive H5 trough and sfc cold front will approach from the NW. 
Increasing clouds for Monday with chc pops overspreading the area 
from W to E. Monday will be another very warm day with highs like 
that on Sunday. 

Tue/Wed/Thu...More fair weather is expected during the mid-week 
period with another high pressure area building across the area. 
Temperatures Tue/Wed will be close to normal but then readings will 
jump back above normal for Thursday. 

&&


.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, 
KMIV, KACY and surrounding areas.

Today...VFR. Light W-SW winds in the morning, becoming W-SW 5 to 10 
kt in the afternoon. 

Tonight...Mainly VFR conditions expected. Patchy fog possible. Light 
W-SW winds.

Outlook...
Saturday thru Sunday night...VFR expected. Increasing clouds Monday. 
Patchy morning fog possible each day. 

Monday and Monday night...Mostly VFR. Scattered showers. 

Tue...VFR expected. 

&&

.MARINE...
Today...Southwest winds increasing to 10 to 15 knots. Seas at the 
buoys, very early this morning, are showing 5 to 8 feet. They are 
expected to diminish to 4 to 6 ft later today. But as a result of 
seas remaining 5 feet or higher, a SCA is in place. Dominant periods 
are long...about 9 to 12 seconds. But as the wind increases this 
afternoon, periods will effective shorten.

Tonight...SCA conditions should continue for much of the night. West 
winds should continue to gust in the 15 to maybe 20 kt range. Long 
period swells emanating from Humberto should begin to slowly drop 
off after midnight. 

Outlook... 
Sat/Sun...Sub-SCA conditions expected with fair weather. Winds and 
seas will slowly increase Sunday afternoon. 

Sun night/Monday...SCA conditions expected on the ocean and sub-SCA 
across Delaware Bay. Scattered showers Monday. 

Mon night thru Tue...Mostly sub-SCA expected. Few showers Mon 
night then fair. 

Rip Currents... A HIGH risk for the development of dangerous rip 
currents continues through today as the long period swells and high 
seas continue from Hurricane Humberto. A Rip Current Statement 
(under the Coastal Hazard Message) is carrying the related info.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Rip Current Risk through this evening for NJZ014-024>026.
DE...High Rip Current Risk through this evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ450>455.

&&

$$
Synopsis...O'Hara
Near Term...Kruzdlo

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