Alert archive / Virginia / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 1, NWS Blacksburg, VA

February 11, 20099 counties in Virginia; 5 counties in North Carolina; Mercer County, Monroe County, Summers County, West Virginia

NWS Blacksburg, VA issued this severe thunderstorm warning at Feb 11, 2009, 5:47 PM EST for 9 counties in Virginia; 5 counties in North Carolina; Mercer County, Monroe County, Summers County, West Virginia. It was in force for 240 days. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Feb 11, 2009, 5:47 PM EST (22:47 UTC)
Expired: Oct 9, 2009, 9:30 PM EDT
In force: 240 days
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon

Counties Alleghany County, NC, Ashe County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Bland County, VA, Carroll County, VA, City of Galax, VA, Giles County, VA, Grayson County, VA, Pulaski 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), 73 km from the middle of the area, began a volume at 22:50 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, 10.8 hours before the alert went out and 137 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: 890 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 208 m²/s²
0-3 km storm-relative helicity: 258 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 severe thunderstorm warning 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 severe thunderstorm warning went out at Feb 11, 3:20 PM EST, 2 hours 27 minutes earlier.

Area forecast discussion, Feb 11, 3:20 PM EST, 2 hours 27 minutes before

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Hazardous weather outlook, Feb 11, 5:15 PM EST, 32 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
Feb 11, 4:40 AM EST	High Wind Warning	RNK	Alleghany, Amherst, Bath, Bedford, Bland, Botetourt and 21 more	35 hr
Feb 11, 4:40 AM EST	Wind Advisory	RNK	Alleghany, Amherst, Appomattox, Bath, Bedford, Bland and 29 more	43 hr
Feb 11, 3:04 PM EST	Fire Weather Watch	RNK	Appomattox, Buckingham, Campbell, Charlotte, Halifax, Henry and 4 more	15 hr
Feb 11, 6:39 PM EST	Severe Thunderstorm Warning	RNK	Alleghany, Bath, City of Covington	81 min
Feb 11, 6:59 PM EST	Severe Thunderstorm Warning	RNK	Bland, Carroll, Giles, Grayson, Pulaski, Smyth and 2 more	46 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2009 Severe Thunderstorm Warnings in North Carolina, 2009 Severe Thunderstorm Warnings in West Virginia, 2009 Every severe thunderstorm warning 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.