Alert archive / Pennsylvania / Areal Flood Advisories in 2021

Areal Flood Advisory 66, NWS Philadelphia/Mount Holly

July 12, 2021Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, Camden County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 12, 2021, 1:59 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, Camden County, New Jersey. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 12, 2021, 1:59 PM EDT (17:59 UTC)
Expired
Jul 12, 2021, 5:00 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 39 km from the middle of the area, began a volume at 17:59 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

Brookhaven, NY (KOKX), launched 12:00Z, 6.0 hours before the alert went out and 180 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 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 857 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, Brookhaven, NY at 12:00Z on 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 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
857 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
697 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

294 
WGUS81 KPHI 121759
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
159 PM EDT Mon Jul 12 2021

NJC005-007-PAC017-091-101-122100-
/O.NEW.KPHI.FA.Y.0066.210712T1759Z-210712T2100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Camden NJ-Bucks PA-Montgomery PA-Philadelphia PA-
159 PM EDT Mon Jul 12 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Northwestern Burlington County in southern New Jersey...
  Northwestern Camden County in southern New Jersey...
  Southeastern Bucks County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Northern Philadelphia County in southeastern Pennsylvania...

* Until 500 PM EDT.

* At 159 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 another 1 to 2 inches possible.

* Some locations that may experience flooding include...
  Philadelphia, Camden, Bensalem, Willingboro, Florence, Burlington, 
  Bristol, Riverside, Palmyra, and Jenkintown.

This includes the following highways...
	New Jersey Turnpike between exits 6 and 7A.
	Pennsylvania Turnpike between mile markers 348 and 359.
	Interstate 95 in Pennsylvania between mile markers 23 and 40.
	Interstate 76 in Pennsylvania between mile markers 338 and 340.
	Interstate 295 in New Jersey between mile markers 48 and 57.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4018 7502 4025 7484 4022 7477 4019 7475
      4018 7474 4016 7472 4015 7472 4016 7471
      4017 7470 4017 7471 4018 7471 4018 7470
      4017 7468 4017 7466 4015 7463 4015 7462
      4014 7462 3993 7508 4002 7523

$$

Iovino

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 10:21 PM EDTSevere Thunderstorm WarningPHIBerks24 min
Jul 11, 10:22 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton38 min
Jul 12, 2:12 PM EDTFlash Flood Warning EmergencyPHIBucks, Philadelphia7 hr
Jul 12, 2:28 PM EDTAreal Flood AdvisoryPHIChester3 hr
Jul 12, 3:08 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia67 min
Jul 12, 4:16 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia114 min
Jul 12, 5:08 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia67 min
Jul 12, 5:26 PM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia2 hr
Jul 12, 5:41 PM EDTSevere Thunderstorm WarningPHIChester34 min
Jul 12, 6:01 PM EDTFlash Flood WarningPHIPhiladelphia102 min
Jul 12, 6:18 PM EDTFlash Flood WarningPHIDelaware84 min
Jul 12, 7:06 PM EDTSevere Thunderstorm WarningPHIChester, Delaware69 min
Jul 12, 2:20 PM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Monmouth3 hr
Jul 12, 2:37 PM EDTFlash Flood WarningPHIMercer, Middlesex, Monmouth93 min
Jul 12, 3:31 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth41 min
Jul 12, 4:26 PM EDTSpecial Marine WarningPHI2 hr
Jul 12, 4:33 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean42 min
Jul 12, 4:52 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean98 min
Jul 12, 5:08 PM EDTAreal Flood AdvisoryPHISussex5 hr
Jul 12, 5:36 PM EDTSpecial Weather StatementPHISussex24 min
Jul 12, 5:41 PM EDTAreal Flood AdvisoryPHIBurlington83 min
Jul 12, 5:57 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex63 min
Jul 12, 6:08 PM EDTAreal Flood AdvisoryPHIMorris98 min
Jul 12, 6:43 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester93 min
Jul 12, 6:52 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex34 min
Jul 12, 7:00 PM EDTAreal Flood AdvisoryPHIGloucester, Salem112 min
Jul 12, 7:11 PM EDTFlash Flood WarningPHIMorris, Sussex35 min
Jul 12, 7:33 PM EDTSpecial Marine WarningPHI58 min

Nearby

Areal Flood Advisories in Pennsylvania, 2021Areal Flood Advisories in New Jersey, 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.