Alert archive / Virginia / Flash Flood Watches in 2017

Flash Flood Watch 4, NWS Wakefield, VA

August 28, 201720 counties in Virginia; 8 counties in North Carolina; Somerset County, Wicomico County, Worcester County, Maryland

NWS Wakefield, VA issued this flash flood watch at Aug 28, 2017, 3:36 AM EDT for 20 counties in Virginia; 8 counties in North Carolina; Somerset County, Wicomico County, Worcester County, Maryland. It took effect at Aug 29, 2017, 2:00 AM EDT. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued: Aug 28, 2017, 3:36 AM EDT (07:36 UTC)
In effect from: Aug 29, 2017, 2:00 AM EDT
Expired: Aug 29, 2017, 8:27 PM EDT
In force: 18 hr
Issued by: NWS Wakefield, VA
Flood severity: None

All 31 counties

Somerset County, MD, Wicomico County, MD, Worcester County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Pasquotank County, NC, Perquimans County, NC, Accomack County, VA, Charles City County, VA, City of Chesapeake, VA, City of Hampton, VA, City of Newport News, VA, City of Poquoson, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Gloucester County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Surry County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 55 km from the middle of the area, began a volume at 07:40 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

Newport, NC (KMHX), launched 00:00Z, 7.6 hours before the alert went out and 267 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: 1400 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -61 m²/s²
0-3 km storm-relative helicity: 174 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 flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Wakefield, VA wrote its last area forecast discussion before this flash flood watch went out at Aug 28, 1:28 AM EDT, 2 hours 8 minutes earlier.

Area forecast discussion, Aug 28, 1:28 AM EDT, 2 hours 8 minutes before

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Hazardous weather outlook, Aug 27, 4:43 PM EDT, 10 hours 53 minutes before

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The office that day

Everything else NWS Wakefield, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 4:03 AM EDT	High Surf Advisory	AKQ	Accomack, Northampton, City of Virginia Beach	51 hr
Aug 28, 4:11 AM EDT	High Wind Watch	AKQ	Accomack, Mathews, Northampton, City of Chesapeake, City of Hampton, City of Virginia Beach	25 hr
Aug 28, 10:39 AM EDT	Storm Watch	AKQ		19 hr
Aug 28, 2:58 PM EDT	Wind Advisory	AKQ	Accomack, Gloucester, Lancaster, Mathews, Middlesex, Northampton and 7 more	33 hr
Aug 28, 5:59 PM EDT	Coastal Flood Watch	AKQ	Gloucester, James City, Lancaster, Mathews, Middlesex, Northampton and 9 more	12 hr
Aug 28, 5:59 PM EDT	Coastal Flood Advisory	AKQ	Accomack, Gloucester, James City, Lancaster, Mathews, Middlesex and 11 more	40 hr

Nearby

Flash Flood Watches in Virginia, 2017 Flash Flood Watches in North Carolina, 2017 Flash Flood Watches in Maryland, 2017 Every flash flood watch in 2017

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.