Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 211620
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1220 PM EDT Sun Apr 21 2019

.SYNOPSIS...
An upper level low pressure system will affect our weather
into Monday before weakening. Another disturbance will cross
north of the area Tuesday and cause a cold front to cross the
area Tuesday night. High pressure will move in for Wednesday and
Thursday. Another low and front will affect the weather for
next Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
For the 12 PM update...cloud cover is slowly increasing due to
instability caused by the upper level low. Spotty showers can be
expected this afternoon, although not every location will see
one, and any shower activity that does occur isn`t expected to
produce much rain. Prev discussion below...


The mid and upper level closed low remains over our
region for another day. Though there remains little reflection
of the low at the surface or in the boundary layer, the mid and
upper level low will likely be enough to keep considerable cloud
cover over the region, and limited coverage of showers through
the day. Many models show dry conditions through the day.
However, I changed the PoPs little from the previous forecast as
it looks like many models are bringing drier air into the low
levels too quickly. Given the weak southerly/southwesterly flow
through the day, this seems suspicious.

For temperatures, cloud cover will likely play a critical role for
today. If we see few breaks in the clouds, then highs are likely to
be in the 60s. If we see some breaks in the clouds, even for just a
few hours, then some areas could get well into the 70s. I suspect
the cloud cover will be persistent, so have stayed close to the
previous forecast, with highs mostly in the 60s to near 70 across
the region.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
The mid and upper level low will finally start to dig south and
east, away from our region. However, it will still be close enough
to the region to affect our weather for another night. Similar to
today, we could see persistent cloud cover and limited coverage of
rain showers. At the surface however, flow should switch to northerly,
which should help promote dry air advection. Therefore, any rain
will likely be very light.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Monday...The upper low and weakening sfc low move away, but still
close enough to produce chc for showers Monday. Mild, with highs in
the low 70s and lows mostly in the 50s.

Monday night/Tue...Mostly fair with above normal temperatures. High
pressure from the SE states extends across the Middle Atlantic
region.

Tue night thru Thu...Unsettled with a trough and sfc low/front
affecting the area Tue night/Wed. Several weak vort maxs cross the
area Wed/Thu. Chcs for showers thru the period. Temperatures mostly
normal or above.

Thu night/Friday...Another upper trough and sfc low affect the area.
Chances of showers thru the period. Higher chc with a cold front
scheduled to cross Friday.

Saturday...While it`s difficult to get too specific at this
period now, the GFS and EC both show high pressure building in
for Sat/Sun, so we`ll have a dry fcst for now. Temperatures will
be seasonable for late April with upper 60s/low 70s for highs
and lows in the 40s N/W and low 50s S/E.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Mostly VFR conditions are expected with a persistent mid
level deck of clouds between 6000 and 10000 ft AGL. Scattered rain
showers are expected, but coverage is still expected to be too
limited to include in the TAFs. Even if a shower directly
affects a terminal, conditions will likely remain VFR. Winds may
start light and variable, but should eventually settle out of
the SW less than 10 kt by 15Z.

Tonight...Mostly VFR conditions continue. Isolated to scattered rain
showers may continue overnight, but coverage will be limited, so
have not included it in the TAFs at this time. Winds are expected to
go light and variable near or shortly after 00Z.

OUTLOOK...

VFR for much of the outlook period. There will be chances of showers
each day, which will cause short period of lower CIGS or VSBYS.

&&

.MARINE...
On the Delaware Bay, winds and seas should remain below Small Craft
Advisory criteria today and tonight.

On the NJ and DE Atlantic coastal waters, elevated seas above 5 feet
are likely to continue today and tonight. Therefore, the SCA
continues. However, wind gusts should remain below 25 kt.

Outlook...
Monday...SCA extended into Monday for the ocean as the enhanced
seas this weekend continue to diminish. Chc showers.

Monday night thru Thu...Mostly sub-SCA with chcs for showers
much of the time, except TUe.

&&

.TIDES/COASTAL FLOODING...
Minor flooding continues on Barnegat Bay as southerly winds
continue to prevent water evacuation, mainly north of Barnegat
Inlet. A coastal flood statement remain in effect thru 7 AM.

Took down the CF Advisory for the tidal Delaware River. The high
tide is occurring now and will be back below FS in an hour or
so. The worst of any flooding has already occurred.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ450>455.

&&

$$
Synopsis...O`Hara
Near Term...Johnson/Miketta
Short Term...Johnson
Long Term...O`Hara
Aviation...Johnson/Miketta/O`Hara
Marine...Johnson/Miketta/O`Hara
Tides/Coastal Flooding...


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