Alert archive / Delaware / Areal Flood Advisories in 2020

Areal Flood Advisory 166, NWS Philadelphia/Mount Holly

August 29, 2020Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 29, 2020, 8:16 AM EDT for Kent County, Sussex County, Delaware. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Aug 29, 2020, 8:16 AM EDT (12:16 UTC)
Expired
Aug 29, 2020, 12:15 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 7 km from the middle of the area, began a volume at 12:17 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, 0.3 hours before the alert went out and 107 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 2020-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 886 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2020-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 square meters per square second.193958Sfc1 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
886 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
555 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.0
Supercell composite
48.8

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 29, 6:57 AM EDT, 1 hour 19 minutes earlier.

Area forecast discussion, Aug 29, 6:57 AM EDT, 1 hour 19 minutes before
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Hazardous weather outlook, Aug 29, 3:34 AM EDT, 4 hours 42 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
334 AM EDT Sat Aug 29 2020

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-013-015>023-027-
PAZ054-055-060>062-070-071-101>106-300745-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Southeastern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
334 AM EDT Sat Aug 29 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.

Showers and thunderstorms will produce heavy rain, and enhanced
rainfall rates may result in local flash flooding. In addition, some
thunderstorms could be severe with locally damaging winds the main
threat.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ004-NJZ014-024>026-300745-
Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-
334 AM EDT Sat Aug 29 2020

This Hazardous Weather Outlook is for southern Delaware, central
New Jersey and southern New Jersey.

.DAY ONE...Today and tonight.

There is a moderate risk for the development of dangerous rip
currents.

Showers and thunderstorms will produce heavy rain, and enhanced
rainfall rates may result in local flash flooding. In addition, some
thunderstorms especially this afternoon could be severe with locally
damaging winds the main threat.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

ANZ430-431-450>455-300745-
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-
334 AM EDT Sat Aug 29 2020

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

.DAY ONE...Today and tonight.

Some thunderstorms may produce locally strong winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

In the hours before

Local storm report, Aug 29, 5:46 AM EDT, 2 hours 30 minutes before
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Local storm report, Aug 29, 5:49 AM EDT, 2 hours 27 minutes before
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Local storm report, Aug 29, 5:53 AM EDT, 2 hours 23 minutes before
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Local storm report, Aug 29, 5:55 AM EDT, 2 hours 21 minutes before
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Local storm report, Aug 29, 5:57 AM EDT, 2 hours 19 minutes before
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Local storm report, Aug 29, 5:59 AM EDT, 2 hours 17 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 9:59 AM EDTAreal Flood AdvisoryPHICamden, Gloucester, Salem4 hr
Aug 29, 11:58 AM EDTFlash Flood WarningPHICamden, Gloucester, Salem4 hr
Aug 29, 12:15 PM EDTAreal Flood AdvisoryPHIBurlington, Camden4 hr
Aug 29, 12:36 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean4 hr
Aug 29, 2:27 PM EDTAreal Flood AdvisoryPHIOcean3 hr
Aug 29, 2:46 PM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland3 hr
Aug 29, 3:04 PM EDTSmall Craft AdvisoryPHI15 hr
Aug 29, 3:53 PM EDTAreal Flood WarningPHIGloucester, Salem4 hr
Aug 29, 6:26 PM EDTSevere Thunderstorm WarningPHIWarren64 min
Aug 29, 7:16 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren59 min
Aug 29, 5:34 PM EDTSpecial Weather StatementPHICarbon, Monroe56 min
Aug 29, 6:08 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Northampton67 min
Aug 29, 6:50 PM EDTSpecial Weather StatementPHIBerks55 min
Aug 29, 12:58 AM EDTSpecial Weather StatementPHISussex32 min
Aug 29, 2:02 PM EDTAreal Flood AdvisoryPHIKent, Sussex3 hr
Aug 29, 2:38 PM EDTSevere Thunderstorm WarningPHISussex26 min
Aug 29, 2:49 PM EDTSpecial Weather StatementPHINew Castle41 min

Nearby

Areal Flood Advisories in Delaware, 2020Every 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.