Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 040928
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
528 AM EDT Tue Oct 4 2022

.SYNOPSIS...
Lingering coastal low pressure will continue to influence our
weather until it pushes off to the east Wednesday. High pressure
builds for Thursday before a cold front crosses the area Friday.
More high pressure with cool temperatures arrive for the
weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
The main change with the early morning forecast update was to
further slow the departure of the ongoing system and also
increase QPF amounts. The NBM has been a bit slow to catch on to
this trend so QPF forecast was blended heavily with 0z
deterministic models. While I still don`t think there will be
significant freshwater hydro issues given this event`s long
duration and mostly stratiform nature, do have increasing
concerns we could see some urban and poor drainage type flooding
issues cropping up into today around the urban corridor.

As of 5 AM, the low continues to sit and spin over the ocean
ESE of Delmarva with the associated upper level low/trough
centered near Virginia. This is resulting in bands of light to
moderate rain continuing to rotate back in from the east.

As we go into the day today, we will continue to see more of the
same. In fact as an additional piece of vorticity gets wrapped
into the stalled upper low this should actually help to
strengthen the low a bit and pull it back to the west. In
addition, progged soundings show there being some elevated
instability working in from the E/SE as well. The upshot of all
this is that it will be a rainy day region wide...even today in
places like the southern Poconos which did not see much rain
Monday. There will be continue to be some periodic breaks in the
precip but also periods where the rain may fall heavier within
any embedded thunderstorms that may occur. This is what could
result in some localized urban flooding issues. It will also
remain cool and raw with N/NE winds gusting 20 to 30 mph inland
and 30 to 40 mph near the coast. And the temperatures won`t rise
too much as they hold mostly in the 50s resulting the potential
for record low maxes (see climate section below) so not a very
pleasant day.

For tonight, conditions won`t change too much as the low remains
stalled offshore resulting in periods of rain continuing. It does
look though like rain rates should be lighter.

Even Wednesday now is looking to remain on the wet side, especially
near and S/E of the urban corridor. The good news is that the low
pressure system will be finally be starting to weaken and pull away
bringing a gradual end to precip from NW to SE...ending first in
places like the Leigh Valley into the southern Poconos but
potentially not until late day near and S/E of the urban corridor.
Our forecast high temps for Wednesday are a few degrees warmer than
Tuesday but still quite cool with highs mostly in the 50s.

In terms of total additional rain amounts from this point forward, a
widespread 1-2 inches is likely with locally higher amounts
possible. The heaviest of this additional rain should be through the
day today.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
The end of the wet weather commences later Wed as the upper low
finally pushes east and out to sea. Showers will end across the
coastal areas of NJ/DE during the evening and clouds will decrease
overnight. The rest of Thu and Thu night will be fair with mostly
clear skies. Fog will likely develop Wed night and Thu night with
the moist ground and mostly clear skies. We have included the fog in
the grids for the fcst with confid in it occuring good. Highs Thu will
be seasonable with upper 60s (N/W) and low to mid 70s elsewhere.
Overnight lows will mostly be in the 40s Wed night and low/mid 50s
for Thu night.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The dry pattern that begins during the short term continues into the
weekend. An upper trough across the Northeast states and Middle
Atlantic flattens and is replaced with more zonal from by late
weekend. A short wave will move through early next week. The only
surface feature of significance will be a cold front which will move
across the area Fri night.

The forecast is dry through the period. High pressure will prevail
with only a cold front moving though late Friday. I have kept the
slight chance of showers (from the earlier forecast) in for the
southern Poconos and northern NJ for Fri night. Temperatures will be
a little above normal Friday but after that, a turn towards chilly
autumn temperatures is expected. Highs over the weekend will be
largely be in the upper 50s/low 60s for our region. Overnight lows
will be mostly in the 40s but 30s for the southern Poconos and
northern NJ. A bout of early season front possible for the southern
Poconos if the present lows remain.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Today... The offshore storm will rotate back towards the area and
bring another round of low clouds and rain with MVFR/IFR ceilings
and visibility. Lehigh Valley sites should stay VFR through early-
mid morning before ceilings drop to MVFR/IFR conditions. Confidence
in MVFR is high for all terminals. Both ceilings and visibility
may reach IFR at all terminals at times through the day today,
but confidence was too low for prevailing IFR at this time. The
most likely timeframe for possible degradation to IFR would be
this afternoon. NE winds around 10-15 knots with gusts to 25
knots. Gusts up to 35 knots are possible at KACY/KMIV.

Tonight...MVFR/IFR ceilings and visibilities expected to continue
with periods of light to moderate rain. Confidence again is low on
timing and development of IFR conditions. NE winds around 10-20
knots with gusts to 25 knots. Gusts up to 30 kts are possible at
KACY/KMIV.

Wednesday... MVFR/IFR ceilings and visibilities expected to continue
in the morning with periods of rain and low clouds. Conditions may
improve to MVFR/VFR in the afternoon as rain departs. N winds 10-15
knots with gusts to 20 knots. Moderate confidence.

Outlook...
Wed night thru Saturday... VFR. Patchy (mostly) rural fog around
the pre-dawn hours Thu/Fri.

&&

.MARINE...
Gale conditions look to persist at least through the day today over
our ocean zones and at least through this morning over the DE Bay.
This will be accompanied by 10-15 foot seas over the ocean 3-6 foot
seas over the lower Bay. The winds should come down somewhat into
tonight but may still hover near Gale conditions especially over our
northern ocean zones off the NJ coast. Over the Delaware Bay for
tonight, winds should be solid SCA.

Further improvement gradually occurs into Wednesday but it looks to
still remain at SCA levels through the day for our ocean zones with
seas 6 to 9 feet.

Outlook...

Wed night... Winds and seas continue to subside behind the departing
storm. SCA waves on the ocean will decrease overnight.  Fair weather.

Thu thru Sat... sub-SCA conditions with fair weather.

Rip Currents...
A HIGH risk of rip currents is expected today.

The SRF forecast for the 2022 season will continue through Wednesday,
October 5.

&&

.TIDES/COASTAL FLOODING...
The latest TWL number have been issued with a strong preference
to the ETSS guidance. The improving onshore flow today leads me
to not make many drastic changes to the Coastal flooding flags,
but the Advisory previously in effect for Monmouth and
Middlesex counties will be upgraded to a Warning. Much of the
guidance indicating Moderate category flooding there with the
late afternoon high tide. Elsewhere, guidance is mostly the same
or slightly lower. At some sites, the category will be the same
while the magnitude of the expected flooding is lower. Parts of
southern Monmouth county may have issues with elevated fresh
water levels (Manasquan River) arriving at the shore during the
high tide today.

Tide levels for the tidal Delaware River will mostly be in the
low end of the minor range. Here, the numbers are a bit lower
than earlier fcsts, but we will choose to keep the advisory for
now.

Tide levels are expected to remain below minor flooding thresholds
for the upper eastern shore of Chesapeake Bay.

&&

.CLIMATE...
Record cool maximum temperatures are possible today .

Site Today
PHL  55/2010
ILG  53/2010
ABE  52/2010
ACY  55/1987
TTN  52/1998
RDG  51/1974
GED  50/1974
MPO  45/2003
55N  45/1912

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 9 PM EDT this evening for PAZ070-
     071-106.
NJ...Coastal Flood Advisory until 9 PM EDT this evening for
     NJZ016>019-021.
     Coastal Flood Warning until 9 PM EDT this evening for
     NJZ012>014-020-022>027.
     High Rip Current Risk through Wednesday evening for NJZ014-
     024>026.
     High Surf Advisory until midnight EDT tonight for NJZ014-
     024>026.
DE...Coastal Flood Advisory until 9 PM EDT this evening for DEZ001.
     Coastal Flood Warning until 9 PM EDT this evening for
     DEZ002>004.
     High Rip Current Risk through Wednesday evening for DEZ004.
     High Surf Advisory until midnight EDT tonight for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ430.
     Gale Warning until 10 AM EDT this morning for ANZ431.
     Gale Warning until 6 PM EDT this evening for ANZ450>455.

&&

$$
SYNOPSIS...OHara
NEAR TERM...Fitzsimmons
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...Brudy/OHara
MARINE...Fitzsimmons/OHara
TIDES/COASTAL FLOODING...
CLIMATE...


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