Alert archive / Delaware / Areal Flood Advisories in 2009

Areal Flood Advisory 75, NWS Philadelphia/Mount Holly

August 22, 2009Kent County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 22, 2009, 8:12 AM EDT for Kent County, Delaware. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Aug 22, 2009, 8:12 AM EDT (12:12 UTC)
Expired: Aug 22, 2009, 11:15 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 12:14 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, 0.2 hours before the alert went out and 130 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: 1451 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 643 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 40 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 Aug 22, 6:03 AM EDT, 2 hours 9 minutes earlier.

Area forecast discussion, Aug 22, 6:03 AM EDT, 2 hours 9 minutes before

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Hazardous weather outlook, Aug 22, 3:15 AM EDT, 4 hours 57 minutes before

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In the hours before

Local storm report, Aug 22, 2:44 AM EDT, 5 hours 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
244 AM EDT SAT AUG 22 2009

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

0228 AM     FLASH FLOOD      3 S SOMERDALE           39.80N 75.02W
08/22/2009                   CAMDEN             NJ   AMATEUR RADIO

            FLASH FLOODING MINNETONKA RD IN HI-NELLA 3 FT OR WATER ON
            THE ROAD

&&

RNS

Local storm report, Aug 22, 4:20 AM EDT, 3 hours 52 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 22, 1:28 AM EDT	Flash Flood Warning	PHI	Camden, Cumberland, Gloucester, Salem	4 hr
Aug 22, 1:40 AM EDT	Areal Flood Advisory	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 1 more	3 hr
Aug 22, 3:36 AM EDT	Flash Flood Warning	PHI	Somerset	4 hr
Aug 22, 4:26 AM EDT	Areal Flood Advisory	PHI	Atlantic, Camden, Cape May, Cumberland, Gloucester, Salem	6 hr
Aug 22, 5:42 AM EDT	Areal Flood Advisory	PHI	Camden, Cumberland, Gloucester, Salem	3 hr
Aug 22, 9:01 AM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland	3 hr
Aug 22, 6:02 PM EDT	Flash Flood Warning	PHI	Mercer	4 hr
Aug 22, 6:21 PM EDT	Flash Flood Warning	PHI	Hunterdon, Warren	3 hr
Aug 22, 6:32 PM EDT	Flash Flood Warning	PHI	Camden, Gloucester	3 hr
Aug 22, 7:32 PM EDT	River Flood Warning	PHI	Mercer	19 hr
Aug 21, 10:14 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Aug 21, 10:49 PM EDT	Flash Flood Warning	PHI	Chester	55 min
Aug 22, 1:51 AM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	77 min
Aug 22, 6:03 AM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	3 hr
Aug 22, 7:00 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Aug 22, 2:19 AM EDT	Areal Flood Advisory	PHI	Kent	6 hr
Aug 22, 6:02 PM EDT	Flash Flood Warning	PHI	Kent, New Castle, Sussex	4 hr

Nearby

Areal Flood Advisories in Delaware, 2009 Every areal flood advisory in 2009

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.