Alert archive / New Jersey / Areal Flood Warnings in 2021
Areal Flood Warning 12, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Jul 18, 2021, 2:41 AM EDT for Mercer County, New Jersey. It was in force for 4 hr. 1 report 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 18, 2021, 2:41 AM EDT (06:41 UTC)
- Expired
- Jul 18, 2021, 6:47 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Mercer County, NJ
The radar
The Philadelphia radar (KDIX), 43 km from the middle of the area, began a volume at 06:41 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 18, 3:00 AM EDT | FLOOD | 1 Nnw Hamilton Twp, NJ | THE MERCERVILLE USGS GAUGE ROSE ABOVE FLOOD STAGE ON THE ASSUNPINK CREEK AT 3:00 AM. |
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 00:00Z, 6.7 hours before the alert went out and 172 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
- 1431 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 988 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 54 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted.
615 WGUS41 KPHI 180641 FLWPHI BULLETIN - IMMEDIATE BROADCAST REQUESTED Flood Warning National Weather Service Mount Holly NJ 241 AM EDT Sun Jul 18 2021 NJC021-181245- /O.NEW.KPHI.FA.W.0012.210718T0641Z-210718T1245Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mercer NJ- 241 AM EDT Sun Jul 18 2021 The National Weather Service in Mount Holly has issued a * Flood Warning for... Southwestern Mercer County in central New Jersey... * Until 845 AM EDT Sunday. * At 241 AM EDT, Doppler radar and automated rain gauges indicated heavy rain due to thunderstorms. Flooding is ongoing or expected to begin shortly in the warned area. Between 2 and 3 inches of rain have fallen. Flooding is expected along the Assunpink Creek at Mercerville. * For Assunpink Creek at Mercerville: At 2:30am the stage was 9.37 feet. Flood Stage is 9.5 feet. PRECAUTIONARY/PREPAREDNESS ACTIONS... Motorists should not attempt to drive around barricades or drive cars through flooded areas. && LAT...LON 4023 7474 4025 7475 4027 7472 4024 7470 $$ JEO
1 follow-up statement
933 WGUS81 KPHI 181047 FLSPHI Flood Statement National Weather Service Mount Holly NJ 647 AM EDT Sun Jul 18 2021 NJC021-181057- /O.CAN.KPHI.FA.W.0012.000000T0000Z-210718T1245Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Mercer NJ- 647 AM EDT Sun Jul 18 2021 ...FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN MERCER COUNTY... Flood waters have receded. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures. LAT...LON 4023 7474 4025 7475 4027 7472 4024 7470 $$ Staarmann
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 8:00 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Mercer, Monmouth | 45 min |
| Jul 17, 8:09 PM EDT | Flash Flood Warning | PHI | Mercer, Somerset | 4 hr |
| Jul 17, 8:35 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Gloucester | 40 min |
| Jul 17, 8:36 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset | 54 min |
| Jul 17, 8:46 PM EDT | Special Marine Warning | PHI | 59 min | |
| Jul 17, 8:53 PM EDT | Areal Flood Advisory | PHI | Mercer, Middlesex, Monmouth | 3 hr |
| Jul 17, 9:25 PM EDT | Areal Flood Advisory | PHI | Burlington, Camden, Gloucester, Salem | 2 hr |
| Jul 17, 9:27 PM EDT | Severe Thunderstorm Warning | PHI | Gloucester, Salem | 48 min |
| Jul 17, 9:30 PM EDT | Severe Thunderstorm Warning | PHI | Cape May | 29 min |
| Jul 17, 9:36 PM EDT | Flash Flood Warning | PHI | Camden, Gloucester, Salem | 2 hr |
| Jul 17, 9:44 PM EDT | Special Marine Warning | PHI | 61 min | |
| Jul 17, 9:48 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Gloucester, Mercer, Salem | 42 min |
| Jul 17, 10:21 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean | 54 min |
| Jul 17, 10:22 PM EDT | Tornado Warning | PHI | Burlington, Monmouth, Ocean | 23 min |
| Jul 17, 10:27 PM EDT | Special Weather Statement | PHI | Burlington, Camden | 33 min |
| Jul 17, 10:38 PM EDT | Tornado Warning | PHI | Burlington, Monmouth, Ocean | 16 min |
| Jul 17, 10:43 PM EDT | Flash Flood Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean | 79 min |
| Jul 17, 10:47 PM EDT | Special Marine Warning | PHI | 118 min | |
| Jul 17, 10:51 PM EDT | Special Marine Warning | PHI | 114 min | |
| Jul 17, 11:07 PM EDT | Special Weather Statement | PHI | Middlesex | 38 min |
| Jul 17, 11:08 PM EDT | Areal Flood Warning | PHI | Hunterdon | 12 hr |
| Jul 17, 11:11 PM EDT | Special Weather Statement | PHI | Monmouth, Ocean | 34 min |
| Jul 17, 11:20 PM EDT | Special Marine Warning | PHI | 115 min | |
| Jul 17, 11:26 PM EDT | Areal Flood Warning | PHI | Somerset | 10 hr |
| Jul 18, 3:48 AM EDT | River Flood Warning | PHI | Mercer | 3 hr |
| Jul 18, 9:08 AM EDT | Areal Flood Warning | PHI | Somerset | 2 hr |
| Jul 18, 11:03 AM EDT | River Flood Warning | PHI | Middlesex, Somerset | 88 min |
Nearby
Areal Flood Warnings in New Jersey, 2021Every areal 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.