Alert archive / New Jersey / Flash Flood Warnings in 2025
Flash Flood Warning 78, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 31, 2025, 1:48 PM EDT for Morris County, Somerset County, New Jersey. It was in force for 4 hr. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 31, 2025, 1:48 PM EDT (17:48 UTC)
- Expired
- Jul 31, 2025, 6:00 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Morris County, NJ, Somerset County, NJ
The radar
The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 17:50 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 31, 2:01 PM EDT | FLASH FLOOD | 3 Sse Far Hills, NJ | Flooding on I-78 Eastbound At East of Exit 29 - I-287/US 202/US 206 (Bridgewater Twp), 1 right lane of 3 lanes closed. |
| Jul 31, 2:30 PM EDT | FLASH FLOOD | 1 Nnw North Plainfield, NJ | Flooding on US 22 Both Directions At East of CR 531/Somerset Av/Watchung Av (North Plainfield), 2 right lanes of 3 lanes closed eastbound; 2 right lanes of 3 lanes closed westbound. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 12:00Z, 5.8 hours before the alert went out and 140 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1000 J/kg
- Mixed-layer CIN
- -70 J/kg
- Mixed-layer LCL
- 970 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -13 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.4
The text
As transmitted.
644
WGUS51 KPHI 311748
FFWPHI
NJC027-035-312200-
/O.NEW.KPHI.FF.W.0078.250731T1748Z-250731T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
148 PM EDT Thu Jul 31 2025
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Southeastern Morris County in northern New Jersey...
Northern Somerset County in northern New Jersey...
* Until 600 PM EDT.
* At 148 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 2 inches of rain
have fallen. Additional rainfall amounts up to 1 inch are possible
in the warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
* Some locations that may experience flash flooding include...
Morristown, Somerville, Bridgewater, Madison, Middlesex, Florham
Park, Bound Brook, Manville, Chatham, Mendham, Peapack And
Gladstone and Far Hills.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4076 7475 4080 7436 4076 7438 4076 7436
4072 7439 4072 7440 4067 7446 4066 7445
4066 7443 4066 7442 4067 7440 4063 7442
4061 7444 4058 7451 4056 7452 4054 7467
4069 7472 4070 7472 4072 7473
FLASH FLOOD...RADAR INDICATED
$$
MPS2 follow-up statements
724
WGUS71 KPHI 312106
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
506 PM EDT Thu Jul 31 2025
NJC027-035-312200-
/O.CON.KPHI.FF.W.0078.000000T0000Z-250731T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morris NJ-Somerset NJ-
506 PM EDT Thu Jul 31 2025
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM EDT THIS EVENING
FOR SOUTHEASTERN MORRIS AND NORTHERN SOMERSET COUNTIES...
At 506 PM EDT, Doppler radar indicated thunderstorms produced heavy
rain across the warned area and resulted in 2 and 4 inches of rain.
Up to 0.50 inches of additional rain is possible. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Morristown, Somerville, Bridgewater, Madison, Middlesex, Florham
Park, Bound Brook, Manville, Chatham, Mendham, Peapack And
Gladstone and Far Hills.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4076 7475 4080 7436 4076 7438 4076 7436
4072 7439 4072 7440 4067 7446 4066 7445
4066 7443 4066 7442 4067 7440 4063 7442
4061 7444 4058 7451 4056 7452 4054 7467
4069 7472 4070 7472 4072 7473
FLASH FLOOD...RADAR INDICATED
$$
MPS886
WGUS71 KPHI 312150
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
550 PM EDT Thu Jul 31 2025
NJC027-035-312200-
/O.EXP.KPHI.FF.W.0078.000000T0000Z-250731T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morris NJ-Somerset NJ-
550 PM EDT Thu Jul 31 2025
...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM EDT THIS EVENING FOR
SOUTHEASTERN MORRIS AND NORTHERN SOMERSET COUNTIES...
Although the heavy rain has ended, continue to heed any road
closures that may be in effect due to earlier flooding.
A Flood Watch remains in effect until 600 AM EDT Friday for portions
of northern Delaware, New Jersey, and southeast Pennsylvania.
&&
LAT...LON 4076 7475 4080 7436 4076 7438 4076 7436
4072 7439 4072 7440 4067 7446 4066 7445
4066 7443 4066 7442 4067 7440 4063 7442
4061 7444 4058 7451 4056 7452 4054 7467
4069 7472 4070 7472 4072 7473
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 2:24 AM EDT | Small Craft Advisory | PHI | 70 hr | |
| Jul 31, 3:56 AM EDT | Rip Current Statement | PHI | Atlantic, Cape May, Monmouth, Ocean | 4 days |
| Jul 31, 1:27 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Middlesex, Morris, Somerset | 48 min |
| Jul 31, 1:49 PM EDT | Tornado Warning | PHI | Middlesex, Somerset | 26 min |
| Jul 31, 1:55 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer | 18 min |
| Jul 31, 2:05 PM EDT | Severe Thunderstorm Warning | PHI | Gloucester, Salem | 40 min |
| Jul 31, 2:27 PM EDT | Flash Flood Warning | PHI | Camden, Gloucester | 4 hr |
| Jul 31, 2:30 PM EDT | Flash Flood Warning | PHI | Morris | 4 hr |
| Jul 31, 2:38 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex | 52 min |
| Jul 31, 2:46 PM EDT | Flash Flood Warning | PHI | Gloucester, Salem | 4 hr |
| Jul 31, 2:52 PM EDT | Flash Flood Warning | PHI | Middlesex | 4 hr |
| Jul 31, 2:55 PM EDT | Severe Thunderstorm Warning | PHI | Camden, Gloucester, Salem | 50 min |
| Jul 31, 2:57 PM EDT | Special Marine Warning | PHI | 63 min | |
| Jul 31, 3:03 PM EDT | Severe Thunderstorm Warning | PHI | Middlesex, Monmouth | 42 min |
| Jul 31, 3:10 PM EDT | Flash Flood Warning | PHI | Burlington, Camden, Gloucester, Mercer, Monmouth, Ocean | 4 hr |
| Jul 31, 3:10 PM EDT | Tornado Warning | PHI | Camden, Gloucester, Salem | 35 min |
| Jul 31, 3:12 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Ocean | 48 min |
| Jul 31, 3:49 PM EDT | Flash Flood Warning | PHI | Camden, Gloucester, Salem | 4 hr |
| Jul 31, 4:31 PM EDT | Flash Flood Warning | PHI | Middlesex, Monmouth | 3 hr |
| Jul 31, 4:36 PM EDT | Special Marine Warning | PHI | 54 min | |
| Jul 31, 4:39 PM EDT | Special Marine Warning | PHI | 36 min | |
| Jul 31, 4:43 PM EDT | Flash Flood Warning | PHI | Monmouth, Ocean | 4 hr |
| Jul 31, 5:21 PM EDT | Flash Flood Warning | PHI | Cumberland | 3 hr |
| Jul 31, 5:53 PM EDT | Flash Flood Warning | PHI | Atlantic, Burlington, Cape May, Ocean | 4 hr |
| Jul 31, 6:17 PM EDT | Special Marine Warning | PHI | 58 min | |
| Jul 31, 6:42 PM EDT | Special Marine Warning | PHI | 63 min | |
| Jul 31, 7:29 PM EDT | Special Marine Warning | PHI | 91 min |
Nearby
Flash Flood Warnings in New Jersey, 2025Every flash flood warning in 2025
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.