A predecessor rainfall event set up ahead of the remnants of Tropical Storm Debby. A hot and humid airmass was in place, resulting in a very moist and unstable airmass.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PHI wrote it up.
A predecessor rainfall event set up ahead of the remnants of Tropical Storm Debby. A hot and humid airmass was in place, resulting in a very moist and unstable airmass. A few showers and thunderstorms developed, producing very heavy rain in southeastern PA.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Aug 6, 6:31 PM EST, 29 minutes earlier.
Area Forecast Discussion
National Weather Service Mount Holly NJ
731 PM EDT Tue Aug 6 2024
.SYNOPSIS...
A cold front will continue to sag south across the area through
tonight and stall to our south Wednesday and Wednesday night.
This front will likely lift back north into the area as Tropical
Storm Debby or its remnants move into the area later Friday
into Saturday. Another cold front will move across the area
Saturday into Saturday night, helping to kick what is left of
Debby out. High pressure tries to move toward the area Sunday
into early next week.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
Severe Thunderstorm Watch #606 continues across eastern
Pennsylvania and much of New Jersey.
The Heat Advisory was cancelled at 6 PM.
Severe weather possibilities continue across SE PA and southern
NJ with perhaps a few outside the box into northern DE for the
next several hours. Flooding concerns for many areas too with
very intense rain rates being observed. Numerous Flood/Flash
flood warnings and a few severe warnings too. Updated POPs/Wx as
best as possible with winds adjusted in places too. Pay
attention to the latest warnings from our office tonight as
several threats/impacts are expected to continue.
The Flood Watch will remain across the area as heavy rain will
occur with any showers or storms. With the high PW values,
widespread 2-3 inches of rain, with locally higher amounts of 5
inches or more remain possible, especially within the watch
area. These areas remain under a Moderate Risk (3 of 4) for
Excessive Rain according to the Weather Prediction Center (WPC).
We have received numerous reports of flooding and excessive
rains so far this evening.
The cold front will continue to sag south overnight into Wednesday,
and eventually push to our south. However, there will remain a
chance of showers and thunderstorms through the day Wednesday.
Wednesday will be markedly cooler than Tuesday, with temperatures
in the 70s to low 80s.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
High pressure offshore to the east/northeast and the remnants of
Debby across the Southeast states will keep a deep onshore flow
across the Middle Atlantic through the period. Frequent showers and
a few tstms will be around much of the period. Heavy rains and
flooding will be concerns with the isolated/scattered convection Wed
night/Thu and then again with the more concentrated activity Thu
night Friday. While excessive rain totals are expected, the exact
areas are not certain yet. Cool temperatures will replace the
hot temperatures of late as there will be an abundance of
clouds. The humidity levels will remain high and uncomfortable
however.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A rather dry forecast after a wet period late this week. The start
of the long term will have the last of the rains associated with the
remnants of Debby. The system, which will be exiting the area
Saturday afternoon will be quickly followed by high pressure which
ridges in from the Ohio Valley and remains into next week. Pops
which will still be likely/categorical Fri night will taper to
chance for Sat and further decrease Sat night. Flooding will still
be possible Fri night/early Sat since tropical moisture and decent
lift will be across the area.
Temperatures will be closer to normal, if not a few degrees below
normal, for the weekend and into next week. Mostly low/mid 80s for
highs with some 70s for the far N/W areas. Humidity levels will not
be oppressive either, so a welcome break from the very steamy
summer.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Tonight...Limited confidence. Showers and tstms across most
areas the first half of tonight. IFR/low-end MVFR during their
occurrence. After that, lower CIGS continue with areas of fog
and scattered showers late. Variable winds becoming mostly N or
NE.
Wednesday...Off and on showers and thunderstorms will continue
through Wednesday with MVFR and IFR conditions expected. Winds
remain northeast to east 5 to 10 kt. Moderate confidence.
Outlook...
Wednesday night thru Saturday... Periods of IFR/MVFR conditions
during occasional/frequent showers and tstms. Late afternoon
and evening periods are favored. Fog possible during the
overnights.
Sat night thru Monday... VFR expected. Fog at times overnight.
&&
.MARINE...
A Small Craft Advisory remains in effect for portions of the
Atlantic Ocean coastal waters offshore of the central and
southern New Jersey coast for this afternoon and into this
evening as winds are expected to increase to 25 knots. For the
northern New Jersey waters, and Delaware waters, wind are
expected to remain below 25 knots.
Conditions are then expected to remain below advisory levels for
the rest of tonight through Wednesday.
VSBY restrictions in showers and thunderstorms starting this
afternoon and into tonight. The strongest thunderstorms will be
capable of wind gusts in excess of 40 kt and hail. The severe
thunderstorm threat diminishes tonight, but VSBY restrictions in
showers and scattered thunderstorms, with heavy rain being the
main culprit, are expected tonight through Wednesday.
Outlook...
Wed night... sub-SCA mostly with scattered showers and tstms.
Thu thru Sat... SCA conditions much of the time. Occasional showers
and tstms expected.
Sat night/Sunday... sub-SCA. Fair weather
Rip Currents...
Wednesday...Breaking waves 2-3 feet for Ocean County NJ and
northwards, 1-2 feet southwards. Though winds will not be as
strong as Tuesday, they will be directly onshore through much of
the period. There is a MODERATE risk for the development of
dangerous rip currents for both the New Jersey Shore and the
Delaware beaches.
Thursday...Breaking waves 2-3 feet for the NJ shore communities
with 1-2 feet across the Delaware Beaches. Direct onshore flow
and medium period building swells will most likely lead to a
HIGH risk of dangerous rip currents for Ocean and Monmouth
counties and MODERATE risk for the development of dangerous rip
currents for Atlantic/Cape May counties in New Jersey and the
Delaware beaches.
For specific beach forecasts, visit weather.gov/beach/phi
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Wednesday morning for PAZ054-055-060>062-
070-071-101>106.
NJ...Flood Watch through Wednesday morning for NJZ001-007>010-
012>020-026-027.
DE...Flood Watch through Wednesday morning for DEZ001.
MD...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for
ANZ451>453.
&&
SYNOPSIS...Robertson
NEAR TERM...MPS/Robertson/OHara
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...OHara/Robertson
MARINE...Deal/OHara/RobertsonPreliminary Local Storm Report
National Weather Service Mount Holly NJ
714 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0432 PM Tstm Wnd Dmg 1 E Ocean Twp. 40.25N 74.04W
08/06/2024 Monmouth NJ Public
Multiple trees down throughout Deal. Time
estimated.
&&
DeSilvaPreliminary Local Storm Report
National Weather Service Mount Holly NJ
716 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0647 PM Flash Flood Monmouth Beach 40.33N 73.98W
08/06/2024 Monmouth NJ 911 Call Center
Relayed report of a disabled vehicle
submerged in water along River Ave. Time
estimated.
&&
DeSilvaPreliminary Local Storm Report
National Weather Service Mount Holly NJ
721 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0525 PM Tstm Wnd Dmg Far Hills 40.68N 74.64W
08/06/2024 Somerset NJ 911 Call Center
Multiple reports of trees and wires down
throughout Far Hills. Time estimated from
radar.
&&
DeSilvaPreliminary Local Storm Report
National Weather Service Mount Holly NJ
722 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0524 PM Tstm Wnd Dmg Bedminster Twp 40.68N 74.65W
08/06/2024 Somerset NJ 911 Call Center
Multiple reports of trees and wires down
throughout Bedminster. Time estimated from
radar.
&&
DeSilvaPreliminary Local Storm Report
National Weather Service Mount Holly NJ
749 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0502 PM Tstm Wnd Dmg 3 ENE Pennington 40.35N 74.75W
08/06/2024 Mercer NJ Public
Multiple large trees down lying across W
Shore Dr and Arvida Dr near Pennington. Time
estimated.
&&
DeSilvaPreliminary Local Storm Report
National Weather Service Mount Holly NJ
800 PM EDT Tue Aug 6 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0757 PM Flash Flood 1 E Merchantville 39.95N 75.03W
08/06/2024 Camden NJ Trained Spotter
Trained spotter relays video of flash
flooding at intersection of Haddonfield Rd
and Maple Ave in Cherry Hill.
&&
DeSilvaThe Philadelphia radar (KDIX), 109 km away, was scanning. The volume nearest the first event began at 00:04 UTC.
3 flash flood. Local standard time, as filed.
Multiple water rescues were reported in Forks Township during the heaviest rain. Time estimated based on radar.
A picture was shared on social media of a street flooded to the point of being impassable in Bensalem.
There were several reports of roads being impassable due to flooding in Bristol Additionally, there was a roof collapse of a commercial building due to the water load on the roof.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2024Every state in 2024This day in weather historyWarnings in Pennsylvania, August 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1214324, 1214333, 1214337.