NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Oct 2, 2:57 PM EST, 42 minutes earlier.
Area forecast discussion, Oct 2, 2:57 PM EST, 42 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
357 PM EDT Sun Oct 2 2022
.SYNOPSIS...
Coastal low pressure will continue to influence our weather through
Wednesday as it lingers off the coast. Surface high pressure
dominates Thursday. Weak cold front looks to pass through Friday
with high pressure following behind. High pressure looks to dominate
Saturday and Sunday.
&&
.NEAR TERM /THROUGH MONDAY/...
Low pressure was centered off the Delmarva coast early this
afternoon. Rain, some of it heavy, has filled in across
southeastern Pennsylvania and southern New Jersey. Additional
rainfall amounts through tonight should generally be on the
order of 1/2 to 1 inch along and south/east of the I-95
corridor, with up to 3 inches across southern Delaware and
extreme southeastern New Jersey. It shouldn't be enough to
cause any hydro issues outside of poor drainage type flooding
but it could exacerbate coastal flooding issues.
Wind gusts across the entire area will increase to at least
25-35 mph, however, wind gusts across the coastal areas are
likely to increase up to 60 mph especially along the Delaware
and southern New Jersey coasts.
By Monday, the center of the mid-level low will be stalled near the
mid-Atlantic region. This will cause the coastal low to meander
just offshore of the mid- Atlantic region. Several waves of
vorticity will be pushed around the mid-level low creating an
impulse for continuing rain across most of the area. Northerly
to northeasterly winds will gust up to 50 mph over the open
waters and in the vicinity of the Jersey and Delaware shores.
Additionally, wind-driven minor to moderate coastal flooding
remains an issue on Monday. This may be exacerbated by
the expected rainfall which could be upwards of another .50 to
.75 inches near the coast.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Unsettled weather will remain across the area for the Monday night
through Wednesday period with cool, windy, and rainy conditions
continuing. The coastal low pressure will continue to meander near
the Mid Atlantic states through the period, and in fact may actually
move back closer to land Tuesday into Tuesday night, before finally
pulling away from the area Wednesday into Wednesday night. At the
same time, a mid level low will pinwheel across the Mid Atlantic
states as well. Multiple short wave/vorticity impulses will round the
mid level low, and lead to enhanced lift across the area, which will
combine with enhanced moisture to create multiple round of showers.
There may even be just enough instability for a few isolated
lightning strikes or rumbles of thunder Tuesday into Tuesday night.
While there could be scattered periods of moderate to heavy
rainfall, the rainfall will occur over a pretty long period, so we
do not expect widespread flooding issues outside of any poor
drainage/low lying flooding concerns.
Winds will remain gusty across the area as the pressure gradient
will remain tight between the coastal low to our south and high
pressure building to our north. Winds through the period will gust
at least 20 to 30 mph, with even stronger winds of 30-40 mph
possible Tuesday into Tuesday night.
Finally by Wednesday night, the low will move farther away from our
area and have less of an effect on our weather. There may still be
some showers and gusty winds across the coastal areas during the
evening, but the winds and rain will dissipate overnight.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Surface high pressure centered to our southwest Thursday should hold
a strong influence on the region throughout the day with the coastal
low now well offshore. However, in the upper levels a positively
tilted trough to our northwest will be swinging southeastward with
time, likely have some frontogenesis associated with it. The
result of this is that a weak cold front will look to pass
through the region during the time frame of Friday. Latest
guidance indicates an even drier trend with this weak front than
yesterday. Hence, have not introduced any chance of PoPs with
this forecast. Surface high pressure follows behind this front
and looks to hold a dominate grip on the region Saturday and
Sunday while migrating generally eastward with time. There is
slight indication of a very weak cold front swinging down from
the north later on Sunday but it is too early to have any
confidence in this feature.
Highs look to reach the lower and mid 70s on Thursday and Friday.
Saturday and Sunday should see below average temperatures overall.
Highs in the upper 50s and lower 60s are possible Saturday and highs
in the lower 60s remain possible Sunday.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Rest of Today...IFR/LIFR conditions in periods of rain. NE
winds 10 to 20 kts with gusts up to 40 kts southern New Jersey
and southern Delaware.
Tonight...Low CIGS and some low VSBYS as showers end overnight.
NE winds 10 to 15 kts with gusts up to 40 knots southern New Jersey
and southern Delaware.
Monday...MVFR with some VFR at times NW. Scattered showers and
some drizzle/fog at times. NE winds 10 to 15 kts with gusts up to 40
knots southern New Jersey and southern Delaware. Medium
confidence.
Outlook...
Monday night-Wednesday...Poor conditions with low clouds, windy
conditions, and rain for much of the area during the period. Periods
of MVFR and IFR conditions will continue across much of the area.
ABE and RDG have a better chance for better conditions, and ACY and
MIV have a better chance for long lasting poor conditions. Winds
likely remain northeast 10-20 knots, with gusts 20-30 knots at times
through the period. Moderate confidence.
Wednesday night...Low conditions early, likely improving to VFR
overnight. Winds become north to northwest 5-10 knots overnight.
Thursday...VFR. Northwesterly winds backing to southwesterly with
time around 5 kts. High confidence.
Friday...Mainly VFR. Southwesterly winds veering to northwesterly
winds around 10 kts. Medium confidence.
&&
.MARINE...
NE Gales this afternoon all areas and Storm force winds
expected by tonight for our southern marine zones. The storm
Warning runs until 6 AM Monday.
The winds will decrease somewhat into Monday though will still
be fairly strong with Gale conditions continuing through the day
over our ocean zones.
Seas will average 9 to 13 feet through Monday.
Outlook...
Monday night-Tuesday night...At least Small Craft Advisory level
conditions through the periods, with gale force conditions possible
for some of the waters.
Wednesday...Small Craft Advisory level conditions likely to continue.
Wednesday night...Winds lower to below advisory levels, however,
seas may remain elevated through the night.
Thursday...Mainly northwesterly winds around 10 kts backing to
southwesterly with time. Seas 3 to 5 feet.
Friday...Southwesterly winds veering to northwesterly winds
throughout the day around 10 to 15 kts. Seas 3 to 4 feet.
Rip Currents...
Sunday into Monday...With continuing strong onshore flow, a
medium/long period (8-10 seconds) east/northeast swell, and
breaking waves around 5 to 8 feet, there will be a HIGH risk for
the development of dangerous rip currents along the Jersey
Shore and Delaware Beaches. A High Surf Advisory remains in
effect through Monday.
Given the current conditions and the forecast over the next few
days, we will extend the SRF forecast period through Wednesday.
&&
.TIDES/COASTAL FLOODING...
The biggest changes with this latest tide forecast is that minor
flooding is forecast on the NE Chesapeake Bay with this evening's
high tide. Also, there is an increasing risk for at least spotty
minor tidal flooding with Sunday and Monday high tide cycles for the
tidal Delaware River and northern shores of the Delaware Bay where
we previously were not expecting tidal flooding.
For the northeastern Chesapeake Bay: tidal departures since this
morning's high tide have been about 0.1 to 0.4 ft above guidance.
Despite the unfavorable wind direction, don't expect these
departures to decrease significantly before this evening's high
tide. Therefore, have issued a coastal flood advisory for Kent,
Caroline, Queen Anne's, and Talbot Counties with the next high tide
cycle. Guidance suggests that tidal departures will decrease after
that, and the northeasterly wind direction would suggest that will
occur. However, if water is slow to evacuate out of the southern
Chesapeake Bay, then there could be a cumulative effect leading to
additional cycles of minor or spotty minor tidal flooding. Given the
uncertainty though, will watch the trends with this evening's high
tide cycle before making any adjustments for subsequent high tide
cycles.
For the northern shores of the Delaware Bay and the tidal Delaware
River, current trends and guidance suggests spotty minor tidal
flooding will be possible starting with the Sunday afternoon high
tide as water is slow to evacuate out of the Delaware Bay. By Monday
afternoon, we may even see widespread minor flooding, primarily
along the northern shores of the Delaware Bay. As with the
Chesapeake Bay, however, the unfavorable wind direction means that
confidence is lower so will watch trends closely over the next few
high tide cycles.
As for the southern shores of the Delaware Bay and the Atlantic
coast, few changes in the current forecast. Tide levels today were
slightly lower than forecast, but given that we should see winds
increase again tomorrow, don't expect this trend to last. It still
appears as if we should see widespread minor flooding with the high
tide cycle Sunday afternoon, and then potential for some moderate
flooding, primarily from Ocean County southward, with the Monday
afternoon high tide. Due to the prolonged nature of the onshore
flow, expect conditions on bay bays to get progressively worse as
compared to the ocean side with each subsequent high tide.
Additional advisories or watches may be needed for the coming tide
cycles, so be sure to monitor the latest forecasts
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory from 1 PM Monday to 9 PM EDT Tuesday
for PAZ070-071-106.
NJ...Coastal Flood Advisory from 1 PM Monday to 9 PM EDT Tuesday
for NJZ016>019-021.
Coastal Flood Warning until 9 PM EDT Tuesday for NJZ020-
022>027.
Wind Advisory until 4 AM EDT Monday for NJZ021-022-027.
High Wind Warning until 4 AM EDT Monday for NJZ023>025.
High Rip Current Risk through Monday evening for NJZ014-
024>026.
High Surf Advisory until midnight EDT Monday night for NJZ014-
024>026.
Coastal Flood Advisory until 9 PM EDT Tuesday for NJZ012>014.
Wind Advisory until midnight EDT tonight for NJZ013-014-020.
High Wind Warning until midnight EDT tonight for NJZ026.
DE...Coastal Flood Advisory from 1 PM Monday to 9 PM EDT Tuesday
for DEZ001.
Coastal Flood Warning until 9 PM EDT Tuesday for DEZ002>004.
Wind Advisory until 4 AM EDT Monday for DEZ002.
High Wind Warning until 4 AM EDT Monday for DEZ003-004.
High Rip Current Risk through Monday evening for DEZ004.
High Surf Advisory until midnight EDT Monday night for DEZ004.
MD...None.
MARINE...Gale Warning until 6 AM EDT Monday for ANZ430.
Storm Warning until 6 AM EDT Monday for ANZ431-451>455.
Gale Warning until 6 PM EDT Monday for ANZ450.
&&
SYNOPSIS...Fitzsimmons/Wunderlin
NEAR TERM...Franklin/Robertson
SHORT TERM...Robertson
LONG TERM...Wunderlin
AVIATION...Franklin/Robertson/Wunderlin
MARINE...Franklin/Robertson/Wunderlin
TIDES/COASTAL FLOODING...