Alert archive / Pennsylvania / Areal Flood Advisories in 2018

Areal Flood Advisory 147, NWS Philadelphia/Mount Holly

July 24, 2018Salem County, New Jersey; 7 counties in Pennsylvania; Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 24, 2018, 4:56 AM EDT for Salem County, New Jersey; 7 counties in Pennsylvania; Kent County, New Castle County, Delaware. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Jul 24, 2018, 4:56 AM EDT (08:56 UTC)
Expired: Jul 24, 2018, 9:00 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Kent County, DE, New Castle County, DE, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 93 km from the middle of the area, began a volume at 08:58 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, 8.9 hours before the alert went out and 204 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: 791 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 722 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.2

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 Jul 24, 3:53 AM EDT, 1 hour 3 minutes earlier.

Area forecast discussion, Jul 24, 3:53 AM EDT, 1 hour 3 minutes before

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Hazardous weather outlook, Jul 24, 3:59 AM EDT, 57 minutes before

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      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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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
Jul 23, 9:14 PM EDT	Rip Current Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	48 hr
Jul 24, 12:56 AM EDT	Areal Flood Advisory	PHI	Cumberland, Gloucester, Salem	4 hr
Jul 24, 1:34 AM EDT	Flash Flood Warning	PHI	Berks, Chester, Lehigh, Montgomery	8 hr
Jul 24, 10:03 AM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Chester, Lehigh, Montgomery	2 hr
Jul 24, 12:50 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Jul 24, 1:02 PM EDT	Special Weather Statement	PHI	Chester	28 min
Jul 24, 1:22 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Monroe, Montgomery, Northampton	3 hr
Jul 24, 1:24 PM EDT	Special Weather Statement	PHI	Berks, Chester	36 min
Jul 24, 1:40 PM EDT	Areal Flood Advisory	PHI	Berks, Chester	4 hr
Jul 24, 3:03 AM EDT	Areal Flood Advisory	PHI	Kent	3 hr
Jul 24, 3:24 AM EDT	Flash Flood Warning	PHI	Kent, New Castle	3 hr
Jul 24, 12:45 PM EDT	Special Weather Statement	PHI	Sussex	30 min

Nearby

Areal Flood Advisories in Pennsylvania, 2018 Areal Flood Advisories in Delaware, 2018 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.