Alert archive / Pennsylvania / Areal Flood Warnings in 2021

Areal Flood Warning 40, NWS Philadelphia/Mount Holly

September 2, 20214 counties in Pennsylvania; 4 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood warning at Sep 2, 2021, 2:23 AM EDT for 4 counties in Pennsylvania; 4 counties in New Jersey; New Castle County, Delaware. It was in force for 9 hr. 7 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 2, 2021, 2:23 AM EDT (06:23 UTC)
Expired
Sep 2, 2021, 11:00 AM EDT
In force
9 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 84 km from the middle of the area, began a volume at 06:24 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

TimeReportWhereRemark
Sep 2, 3:00 AM EDTFLOODHenry Clay, DETHE GAUGE ON BRANDYWINE CREEK AT WILMINGTON (WMND1) REACHED FLOOD STAGE AT 300 AM 9/2, CRESTING AT 23.14 FEET (MAJOR FLOODING) AT 915 AM 9/2.
Sep 2, 3:30 AM EDTFLOODHenry Clay, DERISING SUN LANE CLOSED OVER BRANDYWINE CREEK FROM FLOODING. TIME BASED ON DISPATCH REPORT.
Sep 2, 3:30 AM EDTFLOODWestfield, DECORRECTS PREVIOUS FLOOD REPORT FROM WESTFIELD. THE GAUGE ON RED CLAY CREEK AT STANTON (STND1) REACHED FLOOD STAGE AT 330 AM 9/2, CRESTING AT 17.66 FEET (MINOR FLOODING) AT 515 AM 9/2.
Sep 2, 5:00 AM EDTFLOOD1 Nne Mantua, PALIVE TV STREAM SHOWS BOATHOUSE ROW HOMES SUBMERGED IN SEVERAL FEET OF WATER. SCHUYLKILL RIVER IS OUT OF ITS BANKS.
Sep 2, 5:00 AM EDTFLOODManayunk, PALIVE TV BROADCAST SHOWS SEVERE FLOODING IN MANAYUNK WITH SEVERAL FEET OF FLOWING WATER THROUGH THE DOWNTOWN STREETS.
Sep 2, 5:09 AM EDTFLOOD1 W Rittenhouse Square, PAPICTURE OF THE SCHUYLKILL RIVER TRAIL UNDERWATER.
Sep 2, 5:39 AM EDTFLOOD1 Nw Rittenhouse Square, PALIVE TV BROADCAST SHOWS THE SCHUYLKILL RIVER OVERFLOWING ITS BANKS ONTO THE SCHUYLKILL EXPRESSWAY (I-76) AT THE MARKET STREET BRIDGE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.4 hours before the alert went out and 199 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, Washington/Dulle, VA at 00:00Z on 2021-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2021-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.193958Sfc1 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
569 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

137 
WGUS41 KPHI 020623
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
223 AM EDT Thu Sep 2 2021

DEC003-NJC005-007-015-033-PAC017-045-091-101-021500-
/O.NEW.KPHI.FA.W.0040.210902T0623Z-210902T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Burlington NJ-Camden NJ-Gloucester NJ-Salem NJ-Bucks
PA-Delaware PA-Montgomery PA-Philadelphia PA-
223 AM EDT Thu Sep 2 2021

The National Weather Service in Mount Holly has issued a

* Flood Warning for...
  Northern New Castle County in northern Delaware...
  Northwestern Burlington County in southern New Jersey...
  Northwestern Camden County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Northwestern Salem County in southern New Jersey...
  South Central Bucks County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until 1100 AM EDT Thursday.

* At 223 AM EDT, emergency management reported widespread flooding 
  in the warning area. Several rivers and streams remain in flood, 
  and numerous roads remain closed. Do not cross flooded roadways!

* Some locations that may experience flooding include...
  Philadelphia, Camden, Wilmington, Gloucester City, Bensalem, 
  Chester, Pennsville, Yeadon, Burlington, Riverside, Carneys Point, 
  and Conshohocken.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 333 and 352.
	Interstate 95 in Pennsylvania between mile markers 0 and 38.
	Interstate 95 in Delaware between mile markers 5 and 23.
	Interstate 76 in Pennsylvania between mile markers 331 and 351.
	Interstate 76 in New Jersey near mile marker 3.
	Interstate 295 in New Jersey between mile markers 0 and 17.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.
	Interstate 676 in New Jersey between mile markers 1 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 3963 7561 3961 7574 3997 7543 4025 7518
      4008 7486 3990 7513 3974 7538 3964 7553

$$

CMS
1 follow-up statement
930 
WGUS81 KPHI 021452
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
1052 AM EDT Thu Sep 2 2021

DEC003-NJC005-007-015-033-PAC017-045-091-101-021502-
/O.EXP.KPHI.FA.W.0040.000000T0000Z-210902T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Burlington NJ-Camden NJ-Gloucester NJ-Salem NJ-Bucks
PA-Delaware PA-Montgomery PA-Philadelphia PA-
1052 AM EDT Thu Sep 2 2021

...FLOOD WARNING WILL EXPIRE AT 11 AM EDT THIS MORNING FOR NORTHERN 
NEW CASTLE, NORTHWESTERN BURLINGTON, NORTHWESTERN CAMDEN, 
NORTHWESTERN GLOUCESTER, NORTHWESTERN SALEM, SOUTH CENTRAL BUCKS, 
DELAWARE, SOUTHEASTERN MONTGOMERY, AND PHILADELPHIA COUNTIES...

This flood warning will be allowed to expire. There are additional 
flood warnings in effect across the area.

LAT...LON 3963 7561 3961 7574 3997 7543 4025 7518
      4008 7486 3990 7513 3974 7538 3964 7553

$$

Kruzdlo

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 8:29 PM EDTRiver Flood WarningPHILehigh10 hr
Sep 1, 9:47 PM EDTRiver Flood WarningPHIBerks18 hr
Sep 1, 10:24 PM EDTFlash Flood WarningPHIBucks, Philadelphia4 hr
Sep 1, 10:29 PM EDTRiver Flood WarningPHIBucks49 hr
Sep 1, 10:32 PM EDTRiver Flood WarningPHIBucks31 hr
Sep 1, 10:42 PM EDTAreal Flood WarningPHIBerks, Bucks, Montgomery12 hr
Sep 1, 10:47 PM EDTAreal Flood WarningPHIBucks, Carbon, Lehigh, Northampton23 hr
Sep 1, 10:52 PM EDTAreal Flood WarningPHIBucks12 hr
Sep 1, 11:38 PM EDTAreal Flood WarningPHIBerks, Chester, Delaware, Montgomery10 hr
Sep 2, 12:01 AM EDTAreal Flood WarningPHIMonroe, Northampton40 hr
Sep 2, 2:29 AM EDTAreal Flood WarningPHIBucks, Philadelphia5 hr
Sep 2, 2:41 AM EDTAreal Flood WarningPHIBucks14 hr
Sep 2, 3:52 AM EDTAreal Flood WarningPHIBucks8 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHINorthampton37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks37 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks33 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIBucks34 hr
Sep 2, 4:45 AM EDTRiver Flood WarningPHIMonroe, Northampton5 hr
Sep 2, 5:02 AM EDTRiver Flood WarningPHILehigh11 hr
Sep 2, 6:05 AM EDTCoastal Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia6 hr
Sep 2, 6:44 PM EDTCoastal Flood AdvisoryPHIBucks, Delaware, Philadelphia7 hr
Sep 1, 8:02 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIMiddlesex, Morris, Somerset5 hr
Sep 1, 9:01 PM EDTFlash Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean5 hr
Sep 1, 9:43 PM EDTRiver Flood WarningPHIMercer33 hr
Sep 1, 10:05 PM EDTFlash Flood Warning Considerable damage threatPHIMorris, Somerset4 hr
Sep 1, 10:23 PM EDTCoastal Flood StatementPHIOcean13 hr
Sep 1, 10:35 PM EDTRiver Flood WarningPHIBergen, Morris, Passaic30 hr
Sep 1, 10:37 PM EDTRiver Flood WarningPHIMorris, Passaic41 hr
Sep 1, 10:38 PM EDTRiver Flood WarningPHIMorris, Somerset21 days
Sep 2, 12:28 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Gloucester3 hr
Sep 2, 12:31 AM EDTAreal Flood AdvisoryPHIMonmouth, Ocean2 hr
Sep 2, 1:38 AM EDTAreal Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean4 hr
Sep 2, 1:52 AM EDTAreal Flood WarningPHIMorris, Somerset13 hr
Sep 2, 3:53 AM EDTAreal Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset8 hr
Sep 2, 4:00 AM EDTRiver Flood WarningPHIMorris48 hr
Sep 2, 1:20 PM EDTAreal Flood WarningPHIMiddlesex21 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2021Areal Flood Warnings in New Jersey, 2021Areal Flood Warnings in Delaware, 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.