Alert archive / Virginia / Flood Watches in 2011

Flood Watch 1, NWS Blacksburg, VA

January 1, 2011Grayson County, Smyth County, Tazewell County, Virginia; Alleghany County, Ashe County, Watauga County, North Carolina; Mercer County, Summers County, West Virginia

NWS Blacksburg, VA issued this flood watch at Jan 1, 2011, 3:50 AM EST for Grayson County, Smyth County, Tazewell County, Virginia; Alleghany County, Ashe County, Watauga County, North Carolina; Mercer County, Summers County, West Virginia. It took effect at Jan 1, 2011, 10:00 AM EST. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Jan 1, 2011, 3:50 AM EST (08:50 UTC)
In effect from
Jan 1, 2011, 10:00 AM EST
Expired
Jan 2, 2011, 4:00 AM EST
In force
18 hr
Issued by
NWS Blacksburg, VA
Flood severity
None

Counties Alleghany County, NC, Ashe County, NC, Watauga County, NC, Grayson County, VA, Smyth County, VA, Tazewell County, VA, Mercer County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 95 km from the middle of the area, began a volume at 08:50 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

Roanoke, VA (KRNK), launched 00:00Z, 8.8 hours before the alert went out and 167 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-pSkew-T log-p diagram, Roanoke, VA at 00:00Z on 2011-01-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 00:00Z on 2011-01-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1360 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 1, 3:51 AM ESTWind AdvisoryRNKBland, Smyth, Tazewell12 hr
Jan 1, 1:05 PM ESTDense Fog AdvisoryRNKCarroll, Floyd, Franklin, Grayson, Patrick, City of Galax14 hr

Nearby

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