Alert archive / Pennsylvania / Flash Flood Warnings in 2023

Flash Flood Warning 83, NWS Philadelphia/Mount Holly

September 10, 2023Burlington County, Camden County, New Jersey; Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 10, 2023, 6:03 PM EDT for Burlington County, Camden County, New Jersey; Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 3 hr. 4 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 10, 2023, 6:03 PM EDT (22:03 UTC)
Expired
Sep 10, 2023, 9:00 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Burlington County, NJ, Camden County, NJ, Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 60 km from the middle of the area, began a volume at 22:04 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 10, 6:19 PM EDTFLOOD1 Nw Eddington, PAReport from mPING: Street/road flooding; Street/road closed; Vehicles stranded.
Sep 10, 6:20 PM EDTFLOOD1 Nnw Holmesburg, PAPennypack Creek at Philadelphia gauge PLLP1 reached minor flood stage.
Sep 10, 7:51 PM EDTFLOOD1 E Lower Moreland Twp, PARoad closures due to flooding along Philmont Avenue near Tomlinson Road.
Sep 10, 8:00 PM EDTFLASH FLOOD1 N Richmond, PAVideo shared on social media of Kensington Avenue completely flooded. Video indicates sewer system could not handle amount of rainfall seen.

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 209 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 2023-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1034 joules per kilogram.LCLLFCEL10008507005003002001001 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 2023-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
1034 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
789 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

579 
WGUS51 KPHI 102203
FFWPHI
NJC005-007-PAC017-091-101-110100-
/O.NEW.KPHI.FF.W.0083.230910T2203Z-230911T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
603 PM EDT Sun Sep 10 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Burlington County in southern New Jersey...
  Northwestern Camden County in southern New Jersey...
  South Central Bucks County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until 900 PM EDT.

* At 603 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts up to 0.5 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...
  Philadelphia, Camden, Bensalem, Palmyra, Jenkintown, Rockledge, 
  Abington, Bryn Athyn, Wissinoming, Tacony, Holmesburg, and 
  Northeast Philadelphia.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 346 and 353.
	Interstate 95 in Pennsylvania between mile markers 20 and 38.
	Interstate 76 in Pennsylvania between mile markers 339 and 344.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.
	Interstate 676 in New Jersey near mile marker 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4005 7521 4012 7513 4017 7506 4019 7503
      4011 7490 4000 7499 3999 7503 3993 7514
      3998 7524

FLASH FLOOD...RADAR INDICATED

$$

MLB

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 9:37 AM EDTSpecial Weather StatementPHIAtlantic53 min
Sep 10, 10:14 AM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Somerset107 min
Sep 10, 11:37 AM EDTAreal Flood AdvisoryPHIMonmouth85 min
Sep 10, 5:48 PM EDTAreal Flood AdvisoryPHIBurlington, Camden3 hr
Sep 10, 6:07 PM EDTSpecial Marine WarningPHI23 min
Sep 10, 7:11 PM EDTAreal Flood AdvisoryPHIHunterdon, Warren3 hr
Sep 10, 7:37 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Mercer, Middlesex, Monmouth3 hr
Sep 10, 7:55 PM EDTFlash Flood WarningPHIBurlington, Mercer3 hr
Sep 9, 8:09 PM EDTAreal Flood AdvisoryPHIBerks20 min
Sep 9, 8:29 PM EDTFlash Flood WarningPHIBerks2 hr
Sep 9, 9:12 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe116 min

Nearby

Flash Flood Warnings in Pennsylvania, 2023Flash Flood Warnings in New Jersey, 2023Every flash flood warning in 2023

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.