Alert archive / Pennsylvania / Areal Flood Advisories in 2018

Areal Flood Advisory 352, NWS Philadelphia/Mount Holly

December 16, 2018Salem County, New Jersey; Chester County, Delaware County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood advisory at Dec 16, 2018, 12:28 PM EST for Salem County, New Jersey; Chester County, Delaware County, Pennsylvania; New Castle County, Delaware. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Dec 16, 2018, 12:28 PM EST (17:28 UTC)
Expired: Dec 16, 2018, 4:30 PM EST
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 17:31 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, 5.5 hours before the alert went out and 184 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 461 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 133 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Dec 16, 12:22 PM EST, 6 minutes earlier.

Area forecast discussion, Dec 16, 12:22 PM EST, 6 minutes before

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Hazardous weather outlook, Dec 16, 12:14 PM EST, 14 minutes before

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In the hours before

Local storm report, Dec 16, 7:04 AM EST, 5 hours 24 minutes before

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Local storm report, Dec 16, 10:05 AM EST, 2 hours 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1005 AM EST SUN DEC 16 2018

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

0924 AM     FREEZING RAIN    POCONO SUMMIT           41.11N 75.38W
12/16/2018  E0.10 INCH       MONROE             PA   TRAINED SPOTTER

&&

TCD

Local storm report, Dec 16, 10:28 AM EST, 2 hours before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1028 AM EST SUN DEC 16 2018

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

1000 AM     FREEZING RAIN    2 NW MOUNT POCONO       41.14N 75.38W
12/16/2018  E0.16 INCH       MONROE             PA   ASOS

            RADIAL MEASUREMENT. STORM TOTAL SO FAR. ASOS
            STATION MPO, POCONO MOUNTAINS MUNICIPAL
            AIRPORT. STATION ELEVATION: 1895 FT.

&&

SFJ

Local storm report, Dec 16, 11:33 AM EST, 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1133 AM EST SUN DEC 16 2018

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

1131 AM     FREEZING RAIN    3 SE MONTAGUE           41.28N 74.71W
12/16/2018  E0.05 INCH       SUSSEX             NJ   PUBLIC

            PICTURES SHARED ON SOCIAL MEDIA OF ICE
            ACCUMULATION ON TREES AND OTHER ELEVATED
            SURFACES. ICE ACCUMULATION AMOUNT ESTIMATED.

&&

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 16, 12:38 AM EST	Special Marine Warning	PHI		112 min
Dec 16, 1:29 AM EST	Coastal Flood Advisory	PHI	Ocean	16 hr
Dec 16, 1:39 AM EST	Special Weather Statement	PHI	Atlantic, Cape May, Cumberland	51 min
Dec 16, 2:22 AM EST	Special Weather Statement	PHI	Atlantic, Cape May	53 min
Dec 16, 2:24 AM EST	Special Marine Warning	PHI		96 min
Dec 16, 3:20 AM EST	Wind Advisory	PHI	Monmouth, Ocean	10 hr
Dec 16, 12:01 PM EST	Small Craft Advisory	PHI		42 hr
Dec 16, 3:56 PM EST	Gale Watch	PHI		12 hr
Dec 16, 5:09 PM EST	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland, Gloucester, Salem	3 hr
Dec 16, 7:25 AM EST	River Flood Warning	PHI	Chester	96 min
Dec 16, 3:41 PM EST	Areal Flood Warning	PHI	Chester	4 hr
Dec 16, 12:59 AM EST	Special Weather Statement	PHI	Sussex	46 min

Nearby

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