Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Philadelphia/Mount Holly

June 9, 2021Bucks County, Philadelphia County, Pennsylvania; Burlington County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 9, 2021, 3:49 PM EDT for Bucks County, Philadelphia County, Pennsylvania; Burlington County, New Jersey. It was in force for 3 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
Jun 9, 2021, 3:49 PM EDT (19:49 UTC)
Expired
Jun 9, 2021, 6:45 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

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

The radar

The Philadelphia radar (KDIX), 43 km from the middle of the area, began a volume at 19:51 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
Jun 9, 4:15 PM EDTFLOOD1 N Cooperstown, NJSTREET FLOODING NEAR EDGEWATER PARK.

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, 7.8 hours before the alert went out and 193 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 2021-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 556 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 2021-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.1939Sfc1 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
556 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
927 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

506 
WGUS51 KPHI 091949
FFWPHI
NJC005-PAC017-101-092245-
/O.NEW.KPHI.FF.W.0008.210609T1949Z-210609T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
349 PM EDT Wed Jun 9 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Burlington County in southern New Jersey...
  Southeastern Bucks County in southeastern Pennsylvania...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until 645 PM EDT.

* At 349 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 0.5 to 1 inch 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 will experience flash flooding include...
  Philadelphia, Bensalem, Mount Laurel, Willingboro, Medford, 
  Lumberton, Florence, Burlington, Bristol, Mount Holly, Riverside, 
  and Palmyra.

This includes the following highways...
	New Jersey Turnpike between exits 5 and 7A.
	Pennsylvania Turnpike between mile markers 349 and 359.
	Interstate 95 in Pennsylvania between mile markers 29 and 40.
	Interstate 295 in New Jersey between mile markers 38 and 57.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4002 7505 4014 7502 4015 7501 4016 7487
      4014 7469 4005 7456 3986 7486

FLASH FLOOD...RADAR INDICATED

$$

NC
2 follow-up statements
370 
WGUS71 KPHI 092116
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
516 PM EDT Wed Jun 9 2021

PAC017-101-092126-
/O.CAN.KPHI.FF.W.0008.000000T0000Z-210609T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Philadelphia PA-
516 PM EDT Wed Jun 9 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN BUCKS AND 
NORTHEASTERN PHILADELPHIA COUNTIES...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 4014 7473 4014 7469 4005 7456 3986 7486
      4001 7504 4002 7501 4007 7494 4008 7486
      4010 7484 4013 7482 4012 7478

$$

NJC005-092245-
/O.CON.KPHI.FF.W.0008.000000T0000Z-210609T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-
516 PM EDT Wed Jun 9 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT THIS 
EVENING FOR NORTHWESTERN BURLINGTON COUNTY...

At 516 PM EDT, Doppler radar indicated thunderstorms have produced 
heavy rain across the warned area. Between 1 and 2.5 inches of rain 
have fallen. 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 will experience flash flooding include...
  Mount Laurel, Willingboro, Medford, Lumberton, Florence, 
  Burlington, Bristol, Mount Holly, Riverside, Palmyra, Bordentown, 
  and Beverly.

This includes the following highways...
	New Jersey Turnpike between exits 5 and 7A.
	Interstate 295 in New Jersey between mile markers 38 and 57.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4014 7473 4014 7469 4005 7456 3986 7486
      4001 7504 4002 7501 4007 7494 4008 7486
      4010 7484 4013 7482 4012 7478

FLASH FLOOD...RADAR INDICATED

$$

NC
903 
WGUS71 KPHI 092235
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
635 PM EDT Wed Jun 9 2021

NJC005-092245-
/O.EXP.KPHI.FF.W.0008.000000T0000Z-210609T2245Z/
/00000.U.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-
635 PM EDT Wed Jun 9 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM EDT THIS EVENING FOR 
NORTHWESTERN BURLINGTON COUNTY...

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

LAT...LON 4014 7473 4014 7469 4005 7456 3986 7486
      4001 7504 4002 7501 4007 7494 4008 7486
      4010 7484 4013 7482 4012 7478

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 4:54 PM EDTFlash Flood WarningPHIBerks, Montgomery112 min
Jun 9, 5:27 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Northampton23 min
Jun 9, 5:32 PM EDTSevere Thunderstorm WarningPHIBucks28 min
Jun 8, 8:40 PM EDTSpecial Marine WarningPHI65 min
Jun 9, 1:46 PM EDTSpecial Marine WarningPHI59 min
Jun 9, 1:48 PM EDTSpecial Weather StatementPHISalem27 min
Jun 9, 1:52 PM EDTSpecial Weather StatementPHIAtlantic23 min
Jun 9, 2:07 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem23 min
Jun 9, 2:14 PM EDTSpecial Weather StatementPHISalem31 min
Jun 9, 2:21 PM EDTFlash Flood WarningPHICumberland, Gloucester, Salem73 min
Jun 9, 2:47 PM EDTSpecial Marine WarningPHI58 min
Jun 9, 3:32 PM EDTSpecial Weather StatementPHIBurlington28 min
Jun 9, 3:48 PM EDTSpecial Marine WarningPHI57 min
Jun 9, 3:51 PM EDTSpecial Weather StatementPHIHunterdon24 min
Jun 9, 6:46 PM EDTSpecial Marine WarningPHI59 min
Jun 9, 6:50 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean87 min
Jun 9, 7:42 PM EDTSpecial Marine WarningPHI63 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.