Alert archive / New Jersey / Flood Watches in 2026

Flood Watch 4, NWS Philadelphia/Mount Holly

July 17, 202610 counties in Pennsylvania; 13 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this flood watch at Jul 17, 2026, 1:40 PM EDT for 10 counties in Pennsylvania; 13 counties in New Jersey; New Castle County, Delaware. It took effect at Jul 18, 2026, 10:00 AM EDT. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
Jul 17, 2026, 1:40 PM EDT (17:40 UTC)
In effect from
Jul 18, 2026, 10:00 AM EDT
Expired
Jul 18, 2026, 10:53 PM EDT
In force
13 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None
All 24 counties

New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 70 km from the middle of the area, began a volume at 17:41 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 5.7 hours before the alert went out and 196 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.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2026-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2026-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1592 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

987 
WGUS61 KPHI 171740
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
140 PM EDT Fri Jul 17 2026

DEZ001-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-070-071-
101>106-180800-
/O.NEW.KPHI.FA.A.0004.260718T1400Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-Northwestern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Morristown, Honey Brook, Mount Holly,
Media, Moorestown, Morrisville, Somerville, Chalfont, Bethlehem,
Pottstown, Flemington, Glassboro, New Brunswick, Cherry Hill,
Washington, Jim Thorpe, Newton, Reading, Lansdale, Trenton,
Perkasie, Wilmington, West Chester, Philadelphia, Norristown,
Pennsville, Kennett Square, Easton, Freehold, Doylestown, Oxford,
Allentown, Collegeville, Stroudsburg, and Camden
140 PM EDT Fri Jul 17 2026

...FLOOD WATCH IN EFFECT FROM SATURDAY MORNING THROUGH LATE SATURDAY 
NIGHT...

* WHAT...Flash flooding caused by excessive rainfall is possible.

* WHERE...Portions of northern Delaware, including the following 
  area, New Castle, New Jersey, including the following areas, 
  Camden, Gloucester, Hunterdon, Mercer, Middlesex, Morris, 
  Northwestern Burlington, Salem, Somerset, Sussex, Warren and 
  Western Monmouth, and Pennsylvania, including the following areas, 
  Berks, Carbon, Delaware, Eastern Chester, Eastern Montgomery, 
  Lehigh, Lower Bucks, Monroe, Northampton, Philadelphia, Upper 
  Bucks, Western Chester and Western Montgomery.

* WHEN...From Saturday morning through late Saturday night.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Creeks and streams may rise out of their banks. Flooding may occur 
  in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Multiple rounds of heavy showers and thunderstorms are
    expected for Saturday into Saturday night. Storms will be
    capable of producing rainfall amounts of 2 to 3 inches within
    a period of just one to two hours leading to flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Fitzsimmons
4 follow-up statements
977 
WGUS61 KPHI 180125
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Mount Holly NJ
925 PM EDT Fri Jul 17 2026

NJZ014-020-026-027-181330-
/O.EXA.KPHI.FA.A.0004.260718T1400Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Eastern Monmouth-Ocean-Coastal Ocean-Southeastern Burlington-
Including the cities of Wharton State Forest, Long Beach Island,
Jackson, and Sandy Hook
925 PM EDT Fri Jul 17 2026

...FLOOD WATCH IN EFFECT FROM SATURDAY MORNING THROUGH LATE SATURDAY 
NIGHT...

* WHAT...Flash flooding caused by excessive rainfall continues to be 
  possible.

* WHERE...Portions of central and southern New Jersey, including the 
  following areas, in central New Jersey, Eastern Monmouth. In 
  southern New Jersey, Coastal Ocean, Ocean and Southeastern 
  Burlington.

* WHEN...From Saturday morning through late Saturday night.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Creeks and streams may rise out of their banks. Flooding may occur 
  in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Multiple rounds of heavy showers and thunderstorms are
    expected for Saturday into Saturday night. Storms will be
    capable of producing rainfall amounts of 2 to 3 inches within
    a period of just one to two hours leading to flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

DEZ001-NJZ001-007>010-012-013-015>019-PAZ054-055-060>062-070-071-
101>106-181330-
/O.CON.KPHI.FA.A.0004.260718T1400Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-Northwestern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Bethlehem, Lansdale, Perkasie, Honey
Brook, Philadelphia, Kennett Square, Media, Doylestown, Camden,
Newton, Wilmington, Moorestown, Morristown, Reading, Allentown,
Flemington, Somerville, Stroudsburg, Morrisville, Pennsville,
Oxford, Mount Holly, Norristown, Pottstown, New Brunswick,
Freehold, Cherry Hill, Collegeville, West Chester, Chalfont,
Glassboro, Jim Thorpe, Easton, Trenton, and Washington
925 PM EDT Fri Jul 17 2026

...FLOOD WATCH REMAINS IN EFFECT FROM SATURDAY MORNING THROUGH LATE 
SATURDAY NIGHT...

* WHAT...Flash flooding caused by excessive rainfall continues to be 
  possible.

* WHERE...Portions of northern Delaware, including the following 
  area, New Castle, New Jersey, including the following areas, 
  Camden, Gloucester, Hunterdon, Mercer, Middlesex, Morris, 
  Northwestern Burlington, Salem, Somerset, Sussex, Warren and 
  Western Monmouth, and Pennsylvania, including the following areas, 
  Berks, Carbon, Delaware, Eastern Chester, Eastern Montgomery, 
  Lehigh, Lower Bucks, Monroe, Northampton, Philadelphia, Upper 
  Bucks, Western Chester and Western Montgomery.

* WHEN...From Saturday morning through late Saturday night.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Creeks and streams may rise out of their banks. Flooding may occur 
  in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Multiple rounds of heavy showers and thunderstorms are
    expected for Saturday into Saturday night. Storms will be
    capable of producing rainfall amounts of 2 to 3 inches within
    a period of just one to two hours leading to flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Hoeflich
153 
WGUS61 KPHI 180135
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
935 PM EDT Fri Jul 17 2026

DEZ001-NJZ001-007>010-012>020-026-027-PAZ054-055-060>062-070-071-
101>106-181345-
/O.CON.KPHI.FA.A.0004.260718T1400Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Coastal Ocean-Southeastern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Bethlehem, Lansdale, Perkasie, Honey
Brook, Philadelphia, Kennett Square, Media, Jackson, Doylestown,
Camden, Newton, Wilmington, Moorestown, Morristown, Reading,
Allentown, Flemington, Somerville, Stroudsburg, Wharton State
Forest, Morrisville, Pennsville, Oxford, Mount Holly, Norristown,
Pottstown, New Brunswick, Freehold, Sandy Hook, Cherry Hill,
Collegeville, West Chester, Chalfont, Glassboro, Jim Thorpe,
Easton, Trenton, Washington, and Long Beach Island
935 PM EDT Fri Jul 17 2026

...FLOOD WATCH REMAINS IN EFFECT FROM SATURDAY MORNING THROUGH LATE 
SATURDAY NIGHT...

* WHAT...Flash flooding caused by excessive rainfall continues to be 
  possible.

* WHERE...Portions of northern Delaware, including the following 
  area, New Castle, New Jersey, including the following areas, 
  Camden, Coastal Ocean, Eastern Monmouth, Gloucester, Hunterdon, 
  Mercer, Middlesex, Morris, Northwestern Burlington, Ocean, Salem, 
  Somerset, Southeastern Burlington, Sussex, Warren and Western 
  Monmouth, and Pennsylvania, including the following areas, Berks, 
  Carbon, Delaware, Eastern Chester, Eastern Montgomery, Lehigh, 
  Lower Bucks, Monroe, Northampton, Philadelphia, Upper Bucks, 
  Western Chester and Western Montgomery.

* WHEN...From Saturday morning through late Saturday night.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Creeks and streams may rise out of their banks. Flooding may occur 
  in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Multiple rounds of heavy showers and thunderstorms are
    expected for Saturday into Saturday night. Storms will be
    capable of producing rainfall amounts of 2 to 3 inches within
    a period of just one to two hours leading to flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Hoeflich
662 
WGUS61 KPHI 180613
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
213 AM EDT Sat Jul 18 2026

DEZ001-NJZ001-007>010-012>020-026-027-PAZ054-055-060>062-070-071-
101>106-190600-
/O.CON.KPHI.FA.A.0004.260718T1400Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Coastal Ocean-Southeastern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Lansdale, Honey Brook, Long Beach Island,
Morristown, Cherry Hill, Morrisville, Pennsville, Newton, Oxford,
Norristown, Perkasie, Trenton, Pottstown, Glassboro, Somerville,
Mount Holly, Sandy Hook, West Chester, New Brunswick, Kennett
Square, Moorestown, Wharton State Forest, Collegeville,
Doylestown, Camden, Washington, Flemington, Jim Thorpe, Easton,
Jackson, Stroudsburg, Media, Philadelphia, Wilmington, Reading,
Allentown, Chalfont, Freehold, and Bethlehem
213 AM EDT Sat Jul 18 2026

...FLOOD WATCH REMAINS IN EFFECT FROM 10 AM EDT THIS MORNING THROUGH 
LATE TONIGHT...

* WHAT...Flash flooding caused by excessive rainfall continues to be 
  possible.

* WHERE...Portions of northern Delaware, including the following 
  area, New Castle, New Jersey, including the following areas, 
  Camden, Coastal Ocean, Eastern Monmouth, Gloucester, Hunterdon, 
  Mercer, Middlesex, Morris, Northwestern Burlington, Ocean, Salem, 
  Somerset, Southeastern Burlington, Sussex, Warren and Western 
  Monmouth, and Pennsylvania, including the following areas, Berks, 
  Carbon, Delaware, Eastern Chester, Eastern Montgomery, Lehigh, 
  Lower Bucks, Monroe, Northampton, Philadelphia, Upper Bucks, 
  Western Chester and Western Montgomery.

* WHEN...From 10 AM EDT this morning through late tonight.

* IMPACTS...Excessive runoff may result in flooding of rivers, 
  creeks, streams, and other low-lying and flood-prone locations. 
  Creeks and streams may rise out of their banks. Flooding may occur 
  in poor drainage and urban areas.

* ADDITIONAL DETAILS...
  - Multiple rounds of heavy showers and thunderstorms are
    expected for Saturday into Saturday night. Storms will be
    capable of producing rainfall amounts of 2 to 3 inches within
    a period of just one to two hours leading to flash flooding.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

RCM
391 
WGUS61 KPHI 190253
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
1053 PM EDT Sat Jul 18 2026

DEZ001-NJZ001-007>010-012>020-026-027-PAZ054-055-060>062-070-071-
101>106-190400-
/O.CAN.KPHI.FA.A.0004.000000T0000Z-260719T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Coastal Ocean-Southeastern
Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-Delaware-
Philadelphia-Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
Including the cities of Honey Brook, Camden, Philadelphia,
Somerville, Newton, Easton, Moorestown, Jackson, Wilmington,
Trenton, Jim Thorpe, Kennett Square, Long Beach Island,
Stroudsburg, Mount Holly, Flemington, Pottstown, Chalfont,
Norristown, Morrisville, Perkasie, Glassboro, Cherry Hill,
Wharton State Forest, Reading, West Chester, Oxford, Freehold,
New Brunswick, Pennsville, Media, Bethlehem, Allentown, Sandy
Hook, Doylestown, Lansdale, Morristown, Washington, and
Collegeville
1053 PM EDT Sat Jul 18 2026

...FLOOD WATCH IS CANCELLED...

The Flash Flood Watch is cancelled for portions of northern 
Delaware, including the following area, New Castle, New Jersey, 
including the following areas, Camden, Coastal Ocean, Eastern 
Monmouth, Gloucester, Hunterdon, Mercer, Middlesex, Morris, 
Northwestern Burlington, Ocean, Salem, Somerset, Southeastern 
Burlington, Sussex, Warren and Western Monmouth, and Pennsylvania, 
including the following areas, Berks, Carbon, Delaware, Eastern 
Chester, Eastern Montgomery, Lehigh, Lower Bucks, Monroe, 
Northampton, Philadelphia, Upper Bucks, Western Chester and Western 
Montgomery.

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

$$

Hoeflich

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 8:02 PM EDTTornado WarningPHIBurlington, Ocean28 min
Jul 16, 8:25 PM EDTSevere Thunderstorm WarningPHIOcean48 min
Jul 16, 8:37 PM EDTSpecial Marine WarningPHI72 min
Jul 16, 9:08 PM EDTSpecial Marine WarningPHI97 min
Jul 16, 9:24 PM EDTSpecial Marine WarningPHI25 min
Jul 16, 9:51 PM EDTSpecial Marine WarningPHI84 min
Jul 17, 1:49 PM EDTSmall Craft AdvisoryPHI40 hr

Nearby

Flood Watches in New Jersey, 2026Flood Watches in Pennsylvania, 2026Flood Watches in Delaware, 2026Every flood watch in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.