Alert archive / Delaware / Areal Flood Advisories in 2020

Areal Flood Advisory 196, NWS Philadelphia/Mount Holly

November 12, 2020Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood advisory at Nov 12, 2020, 10:15 AM EST for Sussex County, Delaware. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued: Nov 12, 2020, 10:15 AM EST (15:15 UTC)
Expired: Nov 12, 2020, 3:38 PM EST
In force: 5 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 18 km from the middle of the area, began a volume at 15:17 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 84 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: 870 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 210 m²/s²
0-3 km storm-relative helicity: 293 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 Nov 12, 9:25 AM EST, 50 minutes earlier.

Area forecast discussion, Nov 12, 9:25 AM EST, 50 minutes before

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Hazardous weather outlook, Nov 12, 3:17 AM EST, 6 hours 58 minutes before

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
317 AM EST Thu Nov 12 2020

DEZ001>004-MDZ012-015-019-020-NJZ001-007>010-012>027-PAZ054-055-
060>062-070-071-101>106-130830-
New Castle-Kent-Inland Sussex-Delaware Beaches-Kent MD-Queen Annes-
Talbot-Caroline-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Eastern Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
317 AM EST Thu Nov 12 2020

This Hazardous Weather Outlook is for central Delaware, northern
Delaware, southern Delaware, northeast Maryland, central New
Jersey, northern New Jersey, northwest New Jersey, southern New
Jersey, east central Pennsylvania, northeast Pennsylvania and
southeast Pennsylvania.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ430-431-450>455-130830-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
317 AM EST Thu Nov 12 2020

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, Nov 12, 5:07 AM EST, 5 hours 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
507 AM EST THU NOV 12 2020

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

0430 AM     FLOOD            2 NNW SEABROOK FARMS    39.53N 75.24W
11/12/2020                   CUMBERLAND         NJ   DEPT OF HIGHWAYS

            NJ 77 NORTHBOUND CLOSED DUE TO FLOODING.

&&

SFJ

Local storm report, Nov 12, 6:26 AM EST, 3 hours 49 minutes before

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Local storm report, Nov 12, 6:37 AM EST, 3 hours 38 minutes before

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Local storm report, Nov 12, 7:42 AM EST, 2 hours 33 minutes before

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Local storm report, Nov 12, 8:17 AM EST, 1 hour 58 minutes before

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Local storm report, Nov 12, 9:16 AM EST, 59 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
Nov 12, 4:20 AM EST	Areal Flood Advisory	PHI	Atlantic, Cape May	3 hr
Nov 12, 4:51 AM EST	Areal Flood Advisory	PHI	Cumberland, Salem	48 min
Nov 12, 5:39 AM EST	Areal Flood Warning	PHI	Cumberland, Salem	11 hr
Nov 11, 8:32 PM EST	River Flood Warning	PHI	New Castle	56 min
Nov 11, 9:03 PM EST	River Flood Warning	PHI	New Castle	6 hr
Nov 11, 10:54 PM EST	Areal Flood Advisory	PHI	Sussex	3 hr
Nov 12, 1:43 AM EST	Areal Flood Advisory	PHI	Kent, New Castle	2 hr
Nov 12, 4:16 AM EST	Areal Flood Advisory	PHI	Sussex	110 min
Nov 12, 6:06 AM EST	Areal Flood Warning	PHI	Sussex	4 hr

Nearby

Areal Flood Advisories in Delaware, 2020 Every areal flood advisory in 2020

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.