Alert archive / New Jersey / Areal Flood Advisories in 2021

Areal Flood Advisory 166, NWS Philadelphia/Mount Holly

August 29, 2021Atlantic County, Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 29, 2021, 11:20 AM EDT for Atlantic County, Cape May County, New Jersey. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Aug 29, 2021, 11:20 AM EDT (15:20 UTC)
Expired
Aug 29, 2021, 2:17 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Atlantic County, NJ, Cape May County, NJ

The radar

The Dover AFB radar (KDOX), 82 km from the middle of the area, began a volume at 15:24 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 3.3 hours before the alert went out and 158 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, Wallops Is Stn, VA at 12:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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, Wallops Is Stn, VA at 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -36 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
87 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
568 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-36 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

460 
WGUS81 KPHI 291520
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
1120 AM EDT Sun Aug 29 2021

NJC001-009-291830-
/O.NEW.KPHI.FA.Y.0166.210829T1520Z-210829T1830Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-
1120 AM EDT Sun Aug 29 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Southeastern Atlantic County in southern New Jersey...
  Northeastern Cape May County in southern New Jersey...

* Until 230 PM EDT.

* At 1120 AM EDT, Doppler radar indicated heavy rain. Minor flooding 
  is ongoing or expected to begin shortly in the advisory area. 
  Between 0.5 and 1 inch of rain has fallen.

* Some locations that may experience flooding include...
  Atlantic City, Ocean City, Pleasantville, Somers Point, Ventnor 
  City, Northfield, Margate City, Sea Isle City, Avalon, Longport, 
  Corbin City, and Marmora.

This includes the following highways...
	Garden State Parkway between mile markers 12 and 27...and
	between mile markers 29 and 30...and
	between mile markers 32 and 36.
	Atlantic City Expressway between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3911 7481 3930 7465 3941 7457 3938 7447
      3935 7439 3905 7469 3908 7475

$$

SFJ
1 follow-up statement
949 
WGUS81 KPHI 291817
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
217 PM EDT Sun Aug 29 2021

NJC001-009-291827-
/O.CAN.KPHI.FA.Y.0166.000000T0000Z-210829T1830Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-
217 PM EDT Sun Aug 29 2021

...FLOOD ADVISORY IS CANCELLED FOR SOUTHEASTERN ATLANTIC AND 
NORTHEASTERN CAPE MAY COUNTIES...

The threat for widespread flooding has increased over the area. 
Therefore the Flood Advisory has been replaced by a Flash flood 
Warning. Please refer to that bulletin for more information.

LAT...LON 3911 7481 3930 7465 3941 7457 3938 7447
      3935 7439 3905 7469 3908 7475

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 12:37 PM EDTFlash Flood WarningPHIAtlantic, Cape May4 hr

Nearby

Areal 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.