Alert archive / Virginia / Flood Watches in 2011

Flood Watch 5, NWS Blacksburg, VA

November 28, 201119 counties in Virginia; 5 counties in North Carolina

NWS Blacksburg, VA issued this flood watch at Nov 28, 2011, 11:42 AM EST for 19 counties in Virginia; 5 counties in North Carolina. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued: Nov 28, 2011, 11:42 AM EST (16:42 UTC)
Expired: Nov 29, 2011, 6:00 AM EST
In force: 18 hr
Issued by: NWS Blacksburg, VA
Flood severity: None

All 24 counties

Alleghany County, NC, Ashe County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Amherst County, VA, Bedford County, VA, Botetourt County, VA, Carroll County, VA, City of Buena Vista, VA, City of Galax, VA, City of Lexington, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Wythe County, VA

The radar

The Roanoke radar (KFCX), 9 km from the middle of the area, began a volume at 16:43 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 12:00Z, 4.7 hours before the alert went out and 112 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: 64 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 700 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 201 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 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 flood watch went out at Nov 28, 10:37 AM EST, 1 hour 5 minutes earlier.

Area forecast discussion, Nov 28, 10:37 AM EST, 1 hour 5 minutes before

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Hazardous weather outlook, Nov 28, 4:18 AM EST, 7 hours 24 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
Nov 28, 11:52 AM EST	High Wind Warning	RNK	Bland, Smyth, Tazewell	16 hr
Nov 28, 5:06 PM EST	Special Weather Statement	RNK	Carroll, Grayson, Smyth, City of Galax	84 min
Nov 28, 5:27 PM EST	Flash Flood Warning	RNK	Carroll, Grayson, Patrick, City of Galax	12 hr

Nearby

Flood Watches in Virginia, 2011 Flood Watches in North Carolina, 2011 Every 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.