Alert archive / New Jersey / Areal Flood Advisories in 2018

Areal Flood Advisory 247, NWS Philadelphia/Mount Holly

August 19, 2018Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 19, 2018, 1:03 AM EDT for Cape May County, New Jersey. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Aug 19, 2018, 1:03 AM EDT (05:03 UTC)
Expired: Aug 19, 2018, 5:00 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Cape May County, NJ

The radar

The Dover AFB radar (KDOX), 59 km from the middle of the area, began a volume at 05:04 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 00:00Z, 5.1 hours before the alert went out and 137 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1988 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 748 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood advisory went out at Aug 18, 11:50 PM EDT, 1 hour 13 minutes earlier.

Area forecast discussion, Aug 18, 11:50 PM EDT, 1 hour 13 minutes before

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Hazardous weather outlook, Aug 18, 11:36 PM EDT, 1 hour 27 minutes before

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In the hours before

Local storm report, Aug 18, 7:46 PM EDT, 5 hours 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
746 PM EDT SAT AUG 18 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0707 PM     MARINE TSTM WIND 2 SSW SEASIDE HEIGHTS   39.91N  74.09W
08/18/2018  M40 MPH          ANZ451             NJ   MESONET

&&

EVENT NUMBER PHI1801407

JRK

Special weather statement, Aug 18, 8:52 PM EDT, 4 hours 11 minutes before

Special Weather Statement
National Weather Service Mount Holly NJ
852 PM EDT SAT AUG 18 2018

NJZ020-026-027-190115-
Coastal Ocean-Ocean-Southeastern Burlington-
852 PM EDT SAT AUG 18 2018

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL OCEAN AND EAST CENTRAL
BURLINGTON COUNTIES...

At 852 PM EDT, a strong thunderstorm was located over Old Halfway, or
14 miles southwest of Toms River, moving east at 15 mph.

Winds up to 40 mph are possible with this storm.

This storm will be near...
  Bamber Lake around 910 PM EDT.
  Barnegat and Brookville around 915 PM EDT.

Other locations impacted by this storm include Island Heights,
Gilford Park, South Toms River, Waretown and Holiday Heights.

Torrential rainfall is occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is also occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3980 7409 3987 7409 3986 7413 3981 7417
      3978 7411 3980 7417 3977 7419 3974 7449
      3991 7450 3996 7411 3994 7415 3993 7411
      3990 7414 3987 7413 3988 7409 3994 7409
      3995 7407
TIME...MOT...LOC 0052Z 269DEG 13KT 3983 7440

JRK

Special weather statement, Aug 18, 9:49 PM EDT, 3 hours 14 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 8:52 PM EDT	Special Weather Statement	PHI	Ocean	23 min
Aug 18, 9:07 PM EDT	Special Marine Warning	PHI		83 min
Aug 18, 9:23 PM EDT	Special Marine Warning	PHI		97 min
Aug 19, 3:31 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Ocean	101 min
Aug 19, 4:11 AM EDT	Areal Flood Warning	PHI	Ocean	4 hr
Aug 19, 10:00 AM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	110 min
Aug 19, 2:05 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	8 hr
Aug 18, 9:49 PM EDT	Special Weather Statement	PHI	Kent	26 min
Aug 19, 1:11 AM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr

Nearby

Areal Flood Advisories in New Jersey, 2018 Every areal flood advisory in 2018

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.