Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 86, NWS Philadelphia/Mount Holly

September 23, 20214 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 23, 2021, 1:42 PM EDT for 4 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey. It was in force for 4 hr. 21 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 23, 2021, 1:42 PM EDT (17:42 UTC)
Expired
Sep 23, 2021, 6:00 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

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

The radar

The Philadelphia radar (KDIX), 76 km from the middle of the area, began a volume at 17:46 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 23, 1:51 PM EDTFLOOD1 Nw Philadelphia, PAFLOODING ON INTERSTATE 676 NEAR BROAD STREET WITH LANE RESTRICTIONS. TIME BASED ON DISPATCH REPORT.
Sep 23, 2:00 PM EDTFLOODHaddon Heights, NJHEAVY RAIN, STREET FLOODING; WATER OVER CURBS IN LOW LYING STREETS.
Sep 23, 2:00 PM EDTFLASH FLOOD1 Ssw Summerdale, PATHE GAUGE ON FRANKFORD CREEK AT FRANKFORD (FRCP1) REACHED FLOOD STAGE AND CRESTED AT 9.21 FEET (MODERATE FLOODING) AT 215 PM.
Sep 23, 2:00 PM EDTFLASH FLOODChester, PASEVERAL ROADS FLOODED AND CLOSED IN CHESTER. TIME BASED ON SURROUNDING DISPATCH REPORTS. REPORT VIA SOCIAL MEDIA.
Sep 23, 2:05 PM EDTFLOODDoylestown, PASTREET FLOODING; ESTIMATED RAIN RATE OF 2-3 INCHES PER HOUR.
Sep 23, 2:19 PM EDTFLOODSellersville, PASTREET FLOODING.
Sep 23, 2:20 PM EDTFLASH FLOOD2 Ese South Philadelphi, PABROAD STREET EXIT OFF INTERSTATE 95 IS FLOODED AND IMPASSABLE. TIME BASED ON SOCIAL MEDIA REPORT.
Sep 23, 2:30 PM EDTFLASH FLOODEastwick, PASEVERAL REPORTS OF FLOODING ON INTERSTATE 95 NEAR PHILADELPHIA INTERNATIONAL AIRPORT. RAMP CLOSURES AND LANE RESTRICTIONS REQUIRED. TIME BASED ON DISPATCH REPORTS.
Sep 23, 2:36 PM EDTFLOOD1 Wsw Mt. Ephraim, NJFLOODING ON INTERSTATE 76 NEAR EXIT 1A. TIME BASED ON DISPATCH REPORT.
Sep 23, 2:38 PM EDTFLASH FLOOD1 Ene Whitman Park, NJCOMBINATION OF FLASH FLOODING AND COASTAL FLOODING FORCED ROAD CLOSURES AND LANE RESTRICTIONS NEAR U.S. HIGHWAY 30 AND BAIRD AVENUE. TIME BASED ON DISPATCH REPORTS.
Sep 23, 2:45 PM EDTFLASH FLOODBrooklawn, NJCOMBINATION OF FLASH FLOODING AND COASTAL FLOODING HAS CLOSED U.S. HIGHWAY 130 IN PORTIONS OF BROOKLAWN. TIME BASED ON DISPATCH REPORT.
Sep 23, 2:47 PM EDTFLASH FLOODWestville, NJCOMBINATION OF FLASH FLOODING AND COASTAL FLOODING HAS CLOSED STATE HIGHWAY 47 IN PORTIONS OF BROOKLAWN. TIME BASED ON DISPATCH REPORT.
Sep 23, 2:50 PM EDTFLASH FLOOD3 Se Point Breeze, PAFLOODING ON INTERSTATE 76 NEAR THE PENNSYLVANIA AND NEW JERSEY BORDER. SEVERAL REPORTS OF LANE RESTRICTIONS AND RAMP CLOSURES. TIME BASED ON DISPATCH REPORTS.
Sep 23, 3:00 PM EDTFLASH FLOODCamden, NJSEVERAL ROADS FLOODED IN DOWNTOWN CAMDEN WITH ROAD CLOSURES REQUIRED. TIME BASED ON SOCIAL MEDIA POSTS AND DISPATCH REPORTS.
Sep 23, 3:00 PM EDTFLASH FLOODGloucester City, NJVEHICLES STUCK IN FLOOD WATERS ON BROADWAY. TIME BASED ON RADAR AND SURROUNDING REPORTS. REPORT AND VIDEO FROM SOCIAL MEDIA.
Sep 23, 3:44 PM EDTHEAVY RAIN 1.7East Rockhill Twp, PA1.70 INCHES OF RAINFALL SINCE NOON.
Sep 23, 3:58 PM EDTFLOODLogan Twp., NJCOMBINATION OF FRESHWATER AND TIDAL FLOODING FORCED LANE RESTRICTIONS ON U.S. HIGHWAY 130 NEAR ISLAND ROAD. TIME BASED ON DISPATCH REPORT.
Sep 23, 4:40 PM EDTFLOODBensalem, PAPOQUESSING CREEK OVERFLOWING ITS BANKS.
Sep 23, 4:40 PM EDTFLASH FLOODBensalem, PACORRECTS PREVIOUS FLOOD REPORT FROM BENSALEM. POQUESSING CREEK OVERFLOWING ITS BANKS.
Sep 23, 5:00 PM EDTHEAVY RAIN 1.67Warwick Twp, PAROAD FLOODING REPORTED ON SOCIAL MEDIA. TIME ESTIMATED.
Sep 23, 5:33 PM EDTHEAVY RAIN 2.112 Nw New Britain, PAROAD FLOODING REPORTED.

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 12:00Z, 5.7 hours before the alert went out and 212 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 12:00Z on 2021-09-23Temperature 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, Washington/Dulle, VA at 12:00Z on 2021-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -71 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
517 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
-71 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

122 
WGUS51 KPHI 231742
FFWPHI
NJC005-007-015-PAC017-045-091-101-232200-
/O.NEW.KPHI.FF.W.0086.210923T1742Z-210923T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
142 PM EDT Thu Sep 23 2021

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...
  Northwestern Gloucester County in southern New Jersey...
  Western Bucks County in southeastern Pennsylvania...
  Southeastern Delaware County in southeastern Pennsylvania...
  Central Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until 600 PM EDT.

* At 142 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving into the warned area. Between 0.5 and 1 inch of 
  rain has fallen. The expected rainfall rate is 1 to 2.5 inches in 
  1 hour. 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, Gloucester City, Cherry Hill, Bensalem, 
  Mount Laurel, Chester, Willingboro, Deptford, West Deptford, 
  Lansdale, and Lumberton.

This includes the following highways...
	New Jersey Turnpike between exits 2 and 5.
	Pennsylvania Turnpike between mile markers 336 and 354.
	Interstate 95 in Pennsylvania between mile markers 11 and 39.
	Interstate 76 in Pennsylvania between mile markers 349 and 351.
	Interstate 76 in New Jersey between mile markers 0 and 3.
	Interstate 295 in New Jersey between mile markers 9 and 48.
	Interstate 676 in Pennsylvania near mile marker 1.
	Interstate 676 in New Jersey between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4052 7535 3998 7475 3969 7530 3969 7531
      3969 7532 3970 7534 3971 7536 3973 7538
      3975 7538 3984 7536 3986 7532 3993 7517
      4014 7525 4023 7533 4030 7557

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2.5 INCHES IN 1 HOUR

$$

CMS
1 follow-up statement
578 
WGUS71 KPHI 232151
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
551 PM EDT Thu Sep 23 2021

NJC005-007-015-PAC017-045-091-101-232201-
/O.EXP.KPHI.FF.W.0086.000000T0000Z-210923T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Camden NJ-Gloucester NJ-Bucks PA-Delaware PA-
Montgomery PA-Philadelphia PA-
551 PM EDT Thu Sep 23 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM EDT THIS EVENING FOR 
NORTHWESTERN BURLINGTON, NORTHWESTERN CAMDEN, NORTHWESTERN 
GLOUCESTER, WESTERN BUCKS, SOUTHEASTERN DELAWARE, CENTRAL 
MONTGOMERY, AND PHILADELPHIA COUNTIES...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

A Flash Flood Watch remains in effect until 200 AM EDT Friday for 
portions of northern Delaware...and southeast Pennsylvania.

A Flash Flood Watch remains in effect until 200 AM EDT Friday for 
portions of east central Pennsylvania...northeast Pennsylvania...and 
southeast Pennsylvania.

LAT...LON 4052 7535 3998 7475 3969 7530 3969 7531
      3969 7532 3970 7534 3971 7536 3973 7538
      3975 7538 3984 7536 3986 7532 3993 7517
      4014 7525 4023 7533 4030 7557

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 23, 9:12 AM EDTCoastal Flood AdvisoryPHIBucks, Delaware, Philadelphia10 hr
Sep 23, 10:52 AM EDTAreal Flood AdvisoryPHIChester3 hr
Sep 23, 11:33 AM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery, Philadelphia3 hr
Sep 23, 11:40 AM EDTAreal Flood AdvisoryPHIBerks, Bucks, Carbon, Lehigh, Montgomery, Northampton3 hr
Sep 23, 11:57 AM EDTFlash Flood WarningPHIChester, Delaware3 hr
Sep 23, 12:12 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia48 min
Sep 23, 12:28 PM EDTFlash Flood WarningPHIChester, Delaware, Montgomery, Philadelphia4 hr
Sep 23, 12:54 PM EDTSpecial Weather StatementPHIPhiladelphia51 min
Sep 23, 12:56 PM EDTAreal Flood AdvisoryPHIBucks, Carbon, Lehigh, Monroe, Montgomery, Northampton and 1 more3 hr
Sep 23, 12:57 PM EDTSpecial Weather StatementPHIBucks33 min
Sep 23, 1:13 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia47 min
Sep 23, 1:48 PM EDTRiver Flood WarningPHIChester5 hr
Sep 23, 1:58 PM EDTSpecial Weather StatementPHIBucks32 min
Sep 23, 2:37 PM EDTAreal Flood AdvisoryPHIBucks, Northampton3 hr
Sep 23, 3:26 PM EDTFlash Flood WarningPHIBucks2 hr
Sep 23, 4:26 PM EDTAreal Flood WarningPHIChester, Delaware, Montgomery, Philadelphia80 min
Sep 23, 7:18 PM EDTAreal Flood WarningPHIBerks, Montgomery36 min
Sep 22, 8:43 PM EDTGale WarningPHI18 hr
Sep 23, 2:47 PM EDTSpecial Weather StatementPHIHunterdon, Mercer28 min
Sep 23, 2:52 PM EDTSpecial Weather StatementPHICamden23 min
Sep 23, 3:13 PM EDTSpecial Weather StatementPHIMercer, Somerset32 min
Sep 23, 3:16 PM EDTSpecial Weather StatementPHIBurlington29 min
Sep 23, 3:23 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset52 min
Sep 23, 3:50 PM EDTSpecial Weather StatementPHIBurlington25 min
Sep 23, 4:21 PM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth, Morris, Ocean, Somerset, Sussex15 min
Sep 23, 4:36 PM EDTFlash Flood WarningPHIMiddlesex, Monmouth, Morris, Somerset, Sussex3 hr
Sep 23, 5:00 PM EDTSpecial Weather StatementPHIMonmouth30 min

Nearby

Flash Flood Warnings in Pennsylvania, 2021Flash Flood Warnings in New Jersey, 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.