NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Oct 11, 11:11 AM EST, 49 minutes earlier.
Area forecast discussion, Oct 11, 11:11 AM EST, 49 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
1211 PM EDT Mon Oct 11 2021
.SYNOPSIS...
High pressure extended from Canada's Maritime Provinces
southwestward along the Appalachians early this morning. Low
pressure was located off the North Carolina coast with a weaker
secondary low well off southern New Jersey. The two lows are
forecast to drift farther out to sea. Meanwhile, the high is
expected to gain increasing influence over our weather for the
balance of the work week. A cold front approaching from the
northwest is expected to arrive during the afternoon or evening
on Saturday, followed by high pressure for Sunday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Not much needs to be changed with the update as clouds prevail
across mot areas and some clearing beginning to the north across
NJ and NE-most PA. This clearing will begin to work its way
southward into the afternoon.
Elongated low pressure continues to meander off the mid-Atlantic
coast. That means we are, yet again, in a northeast flow pattern
this afternoon with some lingering light rains and drizzle at
the shore. As we go through the rest of the day, the low offshore
will slowly shift further east, and the pressure gradient will
gradually relax. Winds will slowly decrease at the shore and srn
NJ areas by evening. Temperatures will depend on the amounts and
duration of any sunny breaks that develop, but most areas will
see highs in the lower 70s.
Tonight, the pressure gradient continues to slacken, and winds
will continue to trend down. As the offshore low slowly departs,
we may get some legitimate clearing over northwestern parts of
the areas. Eastern areas will remain mostly socked in the clouds
and continue to run the risk of some light showers or drizzle.
Lows from the mid 50s to the low 60s are expected. Lows to the
northwest are more uncertain, as the degree of clearing and
resultant radiational cooling for tonight remains to be seen.
More clearing would result in lows a little cooler than
forecast, and vice versa.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The complex surface low off the East Coast will continue to
drift farther out to sea on Tuesday and Wednesday, gradually
losing its influence over our region.
A mid level ridge is forecast to be located over the eastern
states on Tuesday morning. A short wave is expected to move from
the Great Lakes on Tuesday to the Saint Lawrence River Valley
on Wednesday, and it should flatten the ridge a bit. However, it
will have little impact on our weather other than to pull a
weak surface trough through our region on Wednesday night.
There is little chance of rain from Tuesday through Wednesday
night. Highs on Tuesday are forecast to range from the upper 60s
to the middle 70s, and they should be mostly in the 70s on
Wednesday. Overnight lows are expected to range mainly from the
middle 50s to the lower 60s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
The mid level ridge is expected to reassert itself over the
eastern states for Thursday before shifting off the coast on
Friday. The mild rain-free weather will likely continue. Highs
should approach 80 in much of our region on Thursday, with many
locations forecast to reach the lower 80s on Friday. Overnight
lows are anticipated to favor the upper 50s and lower 60s.
A cold front is forecast to approach from the northwest and it
should pass through our region on Saturday afternoon or Saturday
evening, bringing a chance of showers. High temperatures are
forecast to be in the 70s and lower 80s again on Saturday, with
cooler and less humid air arriving in the wake of the cold front
for Saturday night and Sunday.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
This afternoon... MVFR with gradual improvements in CIGs are
expected, and by late afternoon. A scattered shower or some
light drizzle is possible mainly near MIV and ACY until 18Z/19Z.
Northeast wind around 10 to 15 kt, with some lingering higher
gusts near the coast. Moderate confidence.
Tonight... Initially, mainly VFR with some lingering MVFR
possible near the coast. As the night progresses, it looks
probable we will see another round of MVFR CIGs develop,
especially near and southeast of PHL. Areas near RDG and ABE
will have a better chance of remaining VFR. Northeast winds
decreasing to 5 to 10 kt, and may even turn light and variable
in northern and western parts of the area. Moderate confidence.
Outlook...
Tuesday...Some morning low clouds and visibility restrictions
are possible, otherwise VFR. Northeast to east wind 5 to 10
knots. High confidence.
Wednesday...Some morning low clouds and visibility restrictions
are possible, otherwise VFR. West wind 5 to 10 knots. High
confidence.
Thursday...Some morning low clouds and visibility restrictions
are possible, otherwise VFR. Northwest wind 5 to 10 knots. High
confidence.
Friday...Some morning low clouds and visibility restrictions
are possible, otherwise VFR. Southwest wind 5 to 10 knots. High
confidence.
&&
.MARINE...
This afternoon...The Gale warning was converted to a SCA flag
since it is expected that the Gusts around 35 kts which have
been occurring at the shore will diminish. The SCA will
continue, as with the surrounding areas, until 6 PM Tue. Seas on
the ocean 6 to 10 ft this afternoon, so rough surf expected.
Tonight... Winds on the Atlantic coastal waters will gradually
decrease, with gusts falling below 25 kt after midnight.
However, seas will remain 6 to 8 ft, so the SCA will remain in
effect. For Delaware Bay, the northern part of the Bay will
remain sub-SCA with gusts around 20 knots. The southern Bay will
still have SCA gusts around 25 knots until around Midnight, so
the flag will continue there. Choppy/rough seas, especially
near the mouth of the Bay.
Outlook...
Tuesday...Small Craft Advisory conditions. A northeast wind 15
to 20 knots. Waves on our ocean waters should remain around 5 to
6 feet.
Wednesday through Friday...No marine headlines are anticipated.
&&
.TIDES/COASTAL FLOODING...
Offshore low pressure continues to keep the wind direction onshore,
leading to elevated water levels at the coast. Another round of
coastal flooding is expected with the late morning to midday high
tide today.
Water levels during the high tide on Sunday morning were lower than
forecast, apparently due to an earlier than expected shift to more
northerly winds. However, tidal departures have increased overnight,
and it still appears another round of widespread minor to locally
moderate flooding is likely today. With this making three days of
noteworthy flooding along the Atlantic coast and on Delaware Bay,
feel a Coastal Flood Warning remains prudent, even if we do not
quite get to the technical warning levels. A Coastal Flood Advisory
remains in effect for minor flooding along the tidal portion of the
Delaware River.
Finally, tidal levels on the eastern shore of Chesapeake Bay
approached minor flood thresholds at Claiborne and Tolchester Beach
on Sunday evening and will probably do so again this evening. For
now, we are not anticipating advisory-level flooding, but we will be
monitoring observations closely today.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 9 PM EDT this evening for PAZ070-
071-106.
NJ...Coastal Flood Warning until 5 PM EDT this afternoon for
NJZ012>014-020>027.
Coastal Flood Advisory until 9 PM EDT this evening for
NJZ017>019.
Coastal Flood Advisory until 6 PM EDT this evening for NJZ016.
DE...Coastal Flood Warning until 5 PM EDT this afternoon for
DEZ002>004.
Coastal Flood Advisory until 6 PM EDT this evening for DEZ001.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ450>455.
Small Craft Advisory until 11 PM EDT this evening for ANZ431.
&&
Synopsis...Iovino
Near Term...O'Brien/O'Hara
Short Term...Iovino
Long Term...Iovino
Aviation...Iovino/O'Brien/O'Hara
Marine...Iovino/O'Brien/O'Hara
Tides/Coastal Flooding...WFO PHI