Alert archive / Pennsylvania / Areal Flood Advisories in 2021

Areal Flood Advisory 46, NWS Philadelphia/Mount Holly

July 3, 2021Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 3, 2021, 2:03 PM EDT for Delaware County, Pennsylvania. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 3, 2021, 2:03 PM EDT (18:03 UTC)
Expired
Jul 3, 2021, 4:13 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Delaware County, PA

The radar

The Philadelphia radar (KDIX), 88 km from the middle of the area, began a volume at 18:06 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 12:00Z, 6.1 hours before the alert went out and 197 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 2021-07-03Temperature 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 2021-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

977 
WGUS81 KPHI 031803
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
203 PM EDT Sat Jul 3 2021

PAC045-032115-
/O.NEW.KPHI.FA.Y.0046.210703T1803Z-210703T2115Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Delaware PA-
203 PM EDT Sat Jul 3 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Southwestern Delaware County in southeastern Pennsylvania...

* Until 515 PM EDT.

* At 203 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Minor flooding is ongoing or expected to begin 
  shortly in the advisory area.

* Some locations that will experience flooding include...
  Chester, Chelsea, Chester Township, Lima, Nether Providence 
  Township, Brookhaven, Upland, Chester Heights, Eddystone, Marcus 
  Hook, Parkside, and Trainer.

This includes the following highways...
	Interstate 95 in Pennsylvania between mile markers 1 and 6.
	Interstate 476 in Pennsylvania near mile marker 0.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3981 7540 3984 7550 3992 7552 3993 7547
      3993 7543 3987 7534 3981 7539

$$

MPS
1 follow-up statement
200 
WGUS81 KPHI 032013
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
413 PM EDT Sat Jul 3 2021

PAC045-032023-
/O.CAN.KPHI.FA.Y.0046.000000T0000Z-210703T2115Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Delaware PA-
413 PM EDT Sat Jul 3 2021

...FLOOD ADVISORY IS CANCELLED FOR SOUTHWESTERN DELAWARE COUNTY...

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

LAT...LON 3981 7540 3984 7550 3992 7552 3993 7547
      3993 7543 3987 7534 3981 7539

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 3, 1:38 PM EDTSpecial Weather StatementPHIDelaware52 min
Jul 3, 6:39 PM EDTAreal Flood AdvisoryPHIBucks, Lehigh, Northampton2 hr

Nearby

Areal Flood Advisories in Pennsylvania, 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.