Alert archive / Virginia / Flash Flood Watches in 2011

Flash Flood Watch 10, NWS Blacksburg, VA

July 8, 201131 counties in Virginia; 5 counties in North Carolina; Mercer County, Monroe County, Summers County, West Virginia

NWS Blacksburg, VA issued this flash flood watch at Jul 8, 2011, 3:58 AM EDT for 31 counties in Virginia; 5 counties in North Carolina; Mercer County, Monroe County, Summers County, West Virginia. It took effect at Jul 8, 2011, 12:00 PM EDT. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued: Jul 8, 2011, 3:58 AM EDT (07:58 UTC)
In effect from: Jul 8, 2011, 12:00 PM EDT
Expired: Jul 8, 2011, 10:56 PM EDT
In force: 11 hr
Issued by: NWS Blacksburg, VA
Flood severity: None

All 39 counties

Alleghany County, NC, Ashe County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, City of Buena Vista, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Lynchburg, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, Mercer County, WV, Monroe County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 18 km from the middle of the area, began a volume at 08:02 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 8.0 hours before the alert went out and 128 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: 1612 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1191 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 8 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 Blacksburg, VA wrote its last area forecast discussion before this flash flood watch went out at Jul 8, 3:46 AM EDT, 12 minutes earlier.

Area forecast discussion, Jul 8, 3:46 AM EDT, 12 minutes before

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Hazardous weather outlook, Jul 7, 11:39 PM EDT, 4 hours 19 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 1:13 PM EDT	Special Weather Statement	RNK	Franklin	62 min
Jul 8, 2:07 PM EDT	Special Weather Statement	RNK	Franklin	23 min
Jul 8, 2:33 PM EDT	Special Weather Statement	RNK	Campbell	27 min
Jul 8, 3:11 PM EDT	Special Weather Statement	RNK	Campbell	34 min
Jul 8, 3:34 PM EDT	Severe Thunderstorm Warning	RNK	Appomattox, Campbell, Charlotte	23 min
Jul 8, 4:37 PM EDT	Special Weather Statement	RNK	Bedford, Franklin	53 min
Jul 8, 5:07 PM EDT	Special Weather Statement	RNK	Charlotte	53 min
Jul 8, 5:31 PM EDT	Special Weather Statement	RNK	Fluvanna	14 min
Jul 8, 5:33 PM EDT	Special Weather Statement	RNK	City of Danville	57 min
Jul 8, 5:44 PM EDT	Special Weather Statement	RNK	Botetourt, Craig	61 min
Jul 8, 5:55 PM EDT	Severe Thunderstorm Warning	RNK	Bedford, Botetourt, Craig, Roanoke	30 min
Jul 8, 6:06 PM EDT	Severe Thunderstorm Warning	RNK	Halifax, Pittsylvania, City of Danville	54 min
Jul 8, 6:12 PM EDT	Special Weather Statement	RNK	Cumberland	63 min
Jul 8, 7:07 PM EDT	Special Weather Statement	RNK	Charlotte	53 min
Jul 7, 8:43 PM EDT	Special Weather Statement	RNK	Rockingham	32 min
Jul 7, 9:00 PM EDT	Flash Flood Warning	RNK	Rockingham	38 min

Nearby

Flash Flood Watches in Virginia, 2011 Flash Flood Watches in North Carolina, 2011 Flash Flood Watches in West Virginia, 2011 Every flash flood watch in 2011

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.