Alert archive / Virginia / Flash Flood Watches in 2017

Flash Flood Watch 1, NWS Wakefield, VA

July 27, 201712 counties in Virginia; 9 counties in North Carolina; 4 counties in Maryland

NWS Wakefield, VA issued this flash flood watch at Jul 27, 2017, 3:20 PM EDT for 12 counties in Virginia; 9 counties in North Carolina; 4 counties in Maryland. It took effect at Jul 28, 2017, 1:05 PM EDT. It was in force for 20 hr.

The area

The counties it named.

The facts

Issued: Jul 27, 2017, 3:20 PM EDT (19:20 UTC)
In effect from: Jul 28, 2017, 1:05 PM EDT
Expired: Jul 29, 2017, 9:33 AM EDT
In force: 20 hr
Issued by: NWS Wakefield, VA
Flood severity: None

All 25 counties

Dorchester County, MD, 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, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Accomack County, VA, Caroline County, VA, Essex County, VA, Gloucester County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northumberland County, VA, Richmond County, VA, Westmoreland County, VA

The radar

The Norfolk radar (KAKQ), 59 km from the middle of the area, began a volume at 19:22 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, 7.3 hours before the alert went out and 199 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 669 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 117 m²/s²
0-3 km storm-relative helicity: 110 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 Jul 27, 2:05 PM EDT, 1 hour 15 minutes earlier.

Area forecast discussion, Jul 27, 2:05 PM EDT, 1 hour 15 minutes before

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Hazardous weather outlook, Jul 27, 5:58 AM EDT, 9 hours 22 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
Jul 27, 4:30 PM EDT	Special Weather Statement	AKQ	Lunenburg, Prince Edward	45 min
Jul 27, 5:17 PM EDT	Special Weather Statement	AKQ	Lunenburg, Nottoway	43 min
Jul 27, 6:01 PM EDT	Special Weather Statement	AKQ	Mecklenburg	44 min
Jul 27, 6:10 PM EDT	Special Weather Statement	AKQ	Brunswick, Dinwiddie, Greensville, City of Emporia	50 min
Jul 27, 4:02 PM EDT	Coastal Flood Statement	AKQ	Dorchester, Wicomico	15 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.