Alert archive / New Jersey / Areal Flood Advisories in 2021

Areal Flood Advisory 94, NWS Philadelphia/Mount Holly

July 17, 2021New Castle County, Delaware; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 17, 2021, 9:25 PM EDT for New Castle County, Delaware; 4 counties in New Jersey. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 17, 2021, 9:25 PM EDT (01:25 UTC)
Expired
Jul 17, 2021, 11:40 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 01:26 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.4 hours before the alert went out and 216 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 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 933 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
933 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
1286 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

131 
WGUS81 KPHI 180125
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
925 PM EDT Sat Jul 17 2021

DEC003-NJC005-007-015-033-180400-
/O.NEW.KPHI.FA.Y.0094.210718T0125Z-210718T0400Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Burlington NJ-Camden NJ-Gloucester NJ-Salem NJ-
925 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory 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...

* Until midnight EDT.

* At 925 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Minor flooding is ongoing or expected to begin 
  shortly in the advisory area. Between 0.5 and 1 inch of rain has 
  already fallen in spots with an additional 1.0 to 1.5 inches 
  possible.

* Some locations that may experience flooding include...
  Camden, Wilmington, Newark, Gloucester City, Cherry Hill, Evesham, 
  Mount Laurel, Chester, Willingboro, Deptford, and Voorhees.

This includes the following highways...
	New Jersey Turnpike between exits 1 and 7A.
	Interstate 95 in Delaware between mile markers 0 and 23.
	Interstate 76 in New Jersey between mile markers 0 and 3.
	Interstate 295 in New Jersey between mile markers 0 and 57.
	Interstate 676 in New Jersey between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3952 7578 3972 7579 3981 7568 3984 7555
      3980 7542 3985 7534 3988 7515 3996 7513
      4006 7494 4008 7486 4013 7482 4013 7474
      4018 7470 4014 7459 4007 7455 3953 7554

$$

Iovino
1 follow-up statement
597 
WGUS81 KPHI 180340
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
1140 PM EDT Sat Jul 17 2021

DEC003-NJC005-007-015-033-180350-
/O.CAN.KPHI.FA.Y.0094.000000T0000Z-210718T0400Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Burlington NJ-Camden NJ-Gloucester NJ-Salem NJ-
1140 PM EDT Sat Jul 17 2021

...FLOOD ADVISORY IS CANCELLED FOR NORTHERN NEW CASTLE, NORTHWESTERN 
BURLINGTON, NORTHWESTERN CAMDEN, NORTHWESTERN GLOUCESTER, AND 
NORTHWESTERN SALEM COUNTIES...

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

LAT...LON 3952 7578 3972 7579 3981 7568 3984 7555
      3980 7542 3985 7534 3988 7515 3996 7513
      4006 7494 4008 7486 4013 7482 4013 7474
      4018 7470 4014 7459 4007 7455 3953 7554

$$

Iovino

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 8:40 PM EDTSpecial Weather StatementPHIKent35 min
Jul 17, 9:27 PM EDTSevere Thunderstorm WarningPHINew Castle48 min
Jul 17, 9:36 PM EDTFlash Flood WarningPHINew Castle2 hr
Jul 17, 10:36 PM EDTSpecial Weather StatementPHIKent24 min
Jul 17, 10:54 PM EDTAreal Flood AdvisoryPHIKent48 min
Jul 17, 10:55 PM EDTSevere Thunderstorm WarningPHIKent50 min
Jul 17, 8:00 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Mercer, Monmouth45 min
Jul 17, 8:09 PM EDTFlash Flood WarningPHIMercer, Somerset4 hr
Jul 17, 8:35 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester40 min
Jul 17, 8:36 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean, Somerset54 min
Jul 17, 8:46 PM EDTSpecial Marine WarningPHI59 min
Jul 17, 8:53 PM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Monmouth3 hr
Jul 17, 9:30 PM EDTSevere Thunderstorm WarningPHICape May29 min
Jul 17, 9:44 PM EDTSpecial Marine WarningPHI61 min
Jul 17, 9:48 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer, Salem42 min
Jul 17, 10:21 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean54 min
Jul 17, 10:22 PM EDTTornado WarningPHIBurlington, Monmouth, Ocean23 min
Jul 17, 10:27 PM EDTSpecial Weather StatementPHIBurlington, Camden33 min
Jul 17, 10:38 PM EDTTornado WarningPHIBurlington, Monmouth, Ocean16 min
Jul 17, 10:43 PM EDTFlash Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean79 min
Jul 17, 10:47 PM EDTSpecial Marine WarningPHI118 min
Jul 17, 10:51 PM EDTSpecial Marine WarningPHI114 min
Jul 17, 11:07 PM EDTSpecial Weather StatementPHIMiddlesex38 min
Jul 17, 11:08 PM EDTAreal Flood WarningPHIHunterdon12 hr
Jul 17, 11:11 PM EDTSpecial Weather StatementPHIMonmouth, Ocean34 min
Jul 17, 11:20 PM EDTSpecial Marine WarningPHI115 min
Jul 17, 11:26 PM EDTAreal Flood WarningPHISomerset10 hr
Jul 18, 2:41 AM EDTAreal Flood WarningPHIMercer4 hr
Jul 18, 3:48 AM EDTRiver Flood WarningPHIMercer3 hr
Jul 18, 9:08 AM EDTAreal Flood WarningPHISomerset2 hr
Jul 18, 11:03 AM EDTRiver Flood WarningPHIMiddlesex, Somerset88 min

Nearby

Areal Flood Advisories in New Jersey, 2021Areal Flood Advisories in Delaware, 2021Every areal flood advisory 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.