Alert archive / New Jersey / Flash Flood Warnings in 2021
Flash Flood Warning 73, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 1, 2021, 6:08 PM EDT for Monroe County, Northampton County, Pennsylvania; 5 counties in New Jersey. It was in force for 6 hr. 13 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
- Sep 1, 2021, 6:08 PM EDT (22:08 UTC)
- Expired
- Sep 2, 2021, 12:15 AM EDT
- In force
- 6 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Monroe County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 119 km from the middle of the area, began a volume at 22:06 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 |
|---|---|---|---|
| Sep 1, 7:50 PM EDT | FLASH FLOOD | Great Meadows, NJ | FLOODING ON U.S. HIGHWAY 46 NEAR HOPE ROAD. ALL LANES CLOSED. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:05 PM EDT | FLASH FLOOD | 1 Ne Morristown, NJ | THE GAUGE ON THE WHIPPANY RIVER AT MORRISTOWN (WHIN4) REACHED FLOOD STAGE AT 805 PM 9/1, CRESTING AT 7.3 FEET (MODERATE FLOODING) AT 1240 AM 9/2. |
| Sep 1, 8:17 PM EDT | FLASH FLOOD | Washington Twp, PA | FLASH FLOODING OF WALTZ CREEK FORCED THE CLOSURE OF STATE HIGHWAY 191. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:28 PM EDT | FLASH FLOOD | 1 Sse Whippany, NJ | FLOODING ON STATE ROUTE 10 NEAR COUNTY ROAD 637 FORCED ITS CLOSURE. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 8:58 PM EDT | FLASH FLOOD | 1 Nne Morris Plains, NJ | FLOODING ON STATE HIGHWAY 10 NEAR U.S. HIGHWAY 202 INTERSECTION. ROAD CLOSED. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 9:00 PM EDT | FLASH FLOOD | 1 Ssw Chatham, NJ | THE GAUGE ON THE PASSAIC RIVER AT CHATHAM (CAMN4) REACHED FLOOD STAGE AT 900 PM 9/1, CRESTING AT 8.1 FEET (MODERATE FLOODING) AT 1230 AM 9/2. |
| Sep 1, 9:26 PM EDT | FLASH FLOOD | Chatham, NJ | FLOODING ON STATE HIGHWAY 124 NEAR WASHINGTON AVENUE FORCED ITS CLOSURE. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 9:32 PM EDT | FLASH FLOOD | 1 S Denville Twp, NJ | FLOODING ON STATE HIGHWAY 53 NEAR LUGER ROAD WITH ROAD CLOSURES. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 10:09 PM EDT | FLASH FLOOD | 1 Ssw Newton, NJ | FLOODING ON U.S. HIGHWAY 206 NEAR WOODSIDE AVENUE. ALL LANES CLOSED. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 10:14 PM EDT | FLASH FLOOD | Delaware Water Gap, PA | FLOODING FORCED CLOSURES ON I-80 NEAR THE DELAWARE RIVER. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 10:25 PM EDT | FLOOD | 3 W Echo Lake, PA | STATE ROUTE 402 FLOODED IN MIDDLE SMITHFIELD TOWNSHIP. TIME BASED ON DISPATCH REPORT. |
| Sep 1, 10:30 PM EDT | FLOOD | 2 Nne Echo Lake, PA | THE GAUGE ON BUSH KILL AT SHOEMAKERS (SHOP1) REACHED FLOOD STAGE AT 1030 PM 9/1, CRESTING AT 6.6 FEET (MINOR FLOODING) AT 630 AM 9/2. |
| Sep 1, 11:15 PM EDT | FLOOD | 1 N Delaware Water Gap, PA | THE GAUGE ON BRODHEAD CREEK AT MINISINK HILLS (MNSP1) REACHED FLOOD STAGE AT 1115 PM 9/1, CRESTING AT 11.15 FEET (MINOR FLOODING) AT 130 AM 9/2. |
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, 10.1 hours before the alert went out and 152 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
- 51 J/kg
- Mixed-layer CIN
- -80 J/kg
- Mixed-layer LCL
- 1274 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 31 m²/s²
- 0-3 km storm-relative helicity
- 201 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
755
WGUS51 KPHI 012208
FFWPHI
NJC019-027-035-037-041-PAC089-095-020415-
/O.NEW.KPHI.FF.W.0073.210901T2208Z-210902T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
608 PM EDT Wed Sep 1 2021
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Morris County in northern New Jersey...
North Central Somerset County in northern New Jersey...
Northeastern Hunterdon County in northwestern New Jersey...
Sussex County in northwestern New Jersey...
Warren County in northwestern New Jersey...
Northeastern Northampton County in eastern Pennsylvania...
Southeastern Monroe County in northeastern Pennsylvania...
* Until 1215 AM EDT Thursday.
* At 608 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 3 inches of rain
have fallen. Additional rainfall amounts of 1 to 3 inches 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, Newton, Montague, Dover, Madison, Hopatcong, Florham
Park, East Hanover, Lincoln Park, Kinnelon, East Stroudsburg, and
Hackettstown.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 0 and 48.
Interstate 80 in Pennsylvania between mile markers 309 and 314.
Interstate 287 in New Jersey between mile markers 30 and 53.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4083 7542 4112 7506 4108 7503 4114 7492
4129 7483 4135 7475 4136 7469 4120 7437
4109 7450 4104 7450 4105 7445 4102 7443
4100 7430 4091 7427 4091 7433 4083 7433
4076 7438 4075 7436 4072 7440 4076 7510
FLASH FLOOD...RADAR INDICATED
$$
CMS2 follow-up statements
723
WGUS71 KPHI 020009
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
809 PM EDT Wed Sep 1 2021
NJC019-027-035-037-041-PAC089-095-020415-
/O.CON.KPHI.FF.W.0073.000000T0000Z-210902T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Morris NJ-Somerset NJ-Sussex NJ-Warren NJ-Monroe PA-
Northampton PA-
809 PM EDT Wed Sep 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM EDT THURSDAY
FOR MORRIS, NORTH CENTRAL SOMERSET, NORTHEASTERN HUNTERDON, SUSSEX,
WARREN, NORTHEASTERN NORTHAMPTON, AND SOUTHEASTERN MONROE COUNTIES...
At 809 PM EDT, local law enforcement reported flash flooding across
the warned area. Several roads are closed in Warren County. Between
1.5 and 4 inches of rain have fallen. Additional rainfall amounts of
0.5 to 2 inches are possible in the warned area. Flash flooding is
already occurring.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Law enforcement reported.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Morristown, Newton, Montague, Dover, Madison, Hopatcong, Florham
Park, East Hanover, Lincoln Park, Kinnelon, East Stroudsburg, and
Hackettstown.
This includes the following highways...
Interstate 80 in New Jersey between mile markers 0 and 48.
Interstate 80 in Pennsylvania between mile markers 309 and 314.
Interstate 287 in New Jersey between mile markers 30 and 53.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4083 7542 4112 7506 4108 7503 4114 7492
4129 7483 4135 7475 4136 7469 4120 7437
4109 7450 4104 7450 4105 7445 4102 7443
4100 7430 4091 7427 4091 7433 4083 7433
4076 7438 4075 7436 4072 7440 4076 7510
FLASH FLOOD...OBSERVED
$$
CMS366
WGUS71 KPHI 020407
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1207 AM EDT Thu Sep 2 2021
NJC019-027-035-037-041-PAC089-095-020417-
/O.EXP.KPHI.FF.W.0073.000000T0000Z-210902T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Morris NJ-Somerset NJ-Sussex NJ-Warren NJ-Monroe PA-
Northampton PA-
1207 AM EDT Thu Sep 2 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 1215 AM EDT EARLY THIS MORNING
FOR MORRIS, NORTH CENTRAL SOMERSET, NORTHEASTERN HUNTERDON, SUSSEX,
WARREN, NORTHEASTERN NORTHAMPTON, AND SOUTHEASTERN MONROE COUNTIES...
A separate flash flood warning continues for much of Morris County.
The rest of this warning has been replaced by a flood warning.
Flooding is expected to continue through the night. Please continue
to heed road closures.
LAT...LON 4083 7542 4112 7506 4108 7503 4114 7492
4129 7483 4135 7475 4136 7469 4120 7437
4109 7450 4104 7450 4105 7445 4102 7443
4100 7430 4091 7427 4091 7433 4083 7433
4076 7438 4075 7436 4072 7440 4076 7510
$$
CMSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 6:19 AM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 116 min |
| Sep 1, 6:49 AM EDT | Flash Flood Warning | PHI | Chester, Delaware, Philadelphia | 86 min |
| Sep 1, 11:24 AM EDT | Areal Flood Advisory | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Sep 1, 12:07 PM EDT | Flash Flood Warning | PHI | Carbon, Monroe | 4 hr |
| Sep 1, 1:29 PM EDT | Flash Flood Warning | PHI | Berks, Lehigh | 6 hr |
| Sep 1, 2:53 PM EDT | Flash Flood Warning | PHI | Berks, Chester, Delaware, Montgomery | 9 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Montgomery | 36 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Chester, Montgomery, Philadelphia | 43 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Montgomery, Philadelphia | 41 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Philadelphia | 39 hr |
| Sep 1, 3:55 PM EDT | River Flood Warning | PHI | Berks | 24 hr |
| Sep 1, 4:02 PM EDT | River Flood Warning | PHI | Monroe | 24 hr |
| Sep 1, 4:04 PM EDT | Areal Flood Warning | PHI | Carbon, Monroe, Northampton | 24 hr |
| Sep 1, 4:10 PM EDT | River Flood Warning | PHI | Monroe | 19 hr |
| Sep 1, 4:12 PM EDT | Flash Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery, Northampton | 7 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Lehigh, Northampton | 25 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Lehigh, Northampton | 24 hr |
| Sep 1, 4:12 PM EDT | River Flood Warning | PHI | Carbon | 15 hr |
| Sep 1, 4:13 PM EDT | Tornado Warning | PHI | Chester | 32 min |
| Sep 1, 4:20 PM EDT | River Flood Warning | PHI | Montgomery | 22 hr |
| Sep 1, 4:21 PM EDT | River Flood Warning | PHI | Bucks | 29 hr |
| Sep 1, 4:42 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery | 6 hr |
| Sep 1, 5:07 PM EDT | River Flood Warning | PHI | Chester | 17 hr |
| Sep 1, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 47 min |
| Sep 1, 5:15 PM EDT | Tornado Warning | PHI | Delaware, Montgomery, Philadelphia | 30 min |
| Sep 1, 5:26 PM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 9 hr |
| Sep 1, 5:34 PM EDT | Tornado Warning | PHI | Bucks, Montgomery, Philadelphia | 26 min |
| Sep 1, 5:42 PM EDT | Flash Flood Warning | PHI | Bucks | 10 hr |
| Sep 1, 5:57 PM EDT | Tornado Warning | PHI | Bucks | 33 min |
| Sep 1, 6:20 PM EDT | Tornado Warning | PHI | Bucks | 40 min |
| Sep 1, 6:22 PM EDT | Tornado Warning | PHI | Philadelphia | 23 min |
| Sep 1, 6:38 PM EDT | River Flood Warning | PHI | Chester, Delaware | 26 hr |
| Sep 1, 6:42 PM EDT | Tornado Warning | PHI | Bucks, Philadelphia | 33 min |
| Sep 1, 6:59 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 61 min |
| Sep 1, 7:04 PM EDT | Tornado Warning | PHI | Bucks | 26 min |
| Sep 1, 7:05 PM EDT | Flash Flood Warning | PHI | Bucks | 8 hr |
| Sep 1, 7:22 PM EDT | Tornado Warning | PHI | Bucks | 11 min |
| Sep 1, 7:23 PM EDT | Areal Flood Warning | PHI | Berks, Lehigh | 14 hr |
| Sep 1, 7:31 PM EDT | Flash Flood Warning | PHI | Bucks | 4 hr |
| Sep 1, 7:53 PM EDT | River Flood Warning | PHI | Delaware | 13 hr |
| Sep 1, 3:23 AM EDT | Gale Warning | PHI | 32 hr | |
| Sep 1, 3:23 AM EDT | Small Craft Advisory | PHI | 41 hr | |
| Sep 1, 4:34 AM EDT | Rip Current Statement | PHI | Atlantic, Cape May, Monmouth, Ocean | 39 hr |
| Sep 1, 7:58 AM EDT | Severe Thunderstorm Warning | PHI | Burlington, Ocean | 47 min |
| Sep 1, 8:39 AM EDT | Severe Thunderstorm Warning | PHI | Monmouth, Ocean | 39 min |
| Sep 1, 9:11 AM EDT | Special Marine Warning | PHI | 64 min | |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Morris, Somerset | 6 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Morris, Passaic | 8 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Morris, Passaic | 6 days |
| Sep 1, 4:27 PM EDT | River Flood Warning | PHI | Essex, Passaic | 21 days |
| Sep 1, 4:33 PM EDT | River Flood Warning | PHI | Morris, Passaic | 46 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Hunterdon, Somerset | 36 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Somerset | 22 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Middlesex, Somerset | 42 hr |
| Sep 1, 4:40 PM EDT | River Flood Warning | PHI | Middlesex, Somerset | 48 hr |
| Sep 1, 4:41 PM EDT | River Flood Warning | PHI | Somerset | 61 hr |
| Sep 1, 5:33 PM EDT | Special Marine Warning | PHI | 27 min | |
| Sep 1, 5:35 PM EDT | Tornado Warning | PHI | Cumberland, Salem | 25 min |
| Sep 1, 5:57 PM EDT | Tornado Warning | PHI | Gloucester, Salem | 33 min |
| Sep 1, 6:05 PM EDT | Flash Flood Warning | PHI | Hunterdon, Mercer, Middlesex, Morris, Somerset | 10 hr |
| Sep 1, 6:14 PM EDT | Special Marine Warning | PHI | 61 min | |
| Sep 1, 7:28 PM EDT | Tornado Warning | PHI | Mercer, Middlesex, Morris, Somerset | 47 min |
| Sep 1, 7:44 PM EDT | Special Marine Warning | PHI | 61 min |
Nearby
Flash Flood Warnings in New Jersey, 2021Flash Flood Warnings in Pennsylvania, 2021Every flash flood warning in 2021
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.