Alert archive / Virginia / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 30, NWS Wakefield, VA

April 12, 20118 counties in Virginia

NWS Wakefield, VA issued this severe thunderstorm warning at Apr 12, 2011, 1:16 PM EDT for 8 counties in Virginia. It was in force for 59 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 12, 2011, 1:16 PM EDT (17:16 UTC)
Expired
Apr 12, 2011, 2:15 PM EDT
In force
59 min
Issued by
NWS Wakefield, VA
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Essex County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Middlesex County, VA, New Kent County, VA, Richmond County, VA

The radar

The Norfolk radar (KAKQ), 79 km from the middle of the area, began a volume at 17:19 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.3 hours before the alert went out and 126 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, Wallops Is Stn, VA at 12:00Z on 2011-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 25 joules per kilogram.LCLLFCEL10008507005003002001001 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, Wallops Is Stn, VA at 12:00Z on 2011-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 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
25 J/kg
Mixed-layer CIN
-139 J/kg
Mixed-layer LCL
1296 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
187 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 12, 2:08 PM EDTSpecial Weather StatementAKQLancaster, Northumberland22 min
Apr 12, 3:06 PM EDTSpecial Weather StatementAKQNorthumberland39 min
Apr 12, 5:09 PM EDTSpecial Weather StatementAKQAmelia, Cumberland, Nottoway, Powhatan, Prince Edward66 min
Apr 12, 7:11 PM EDTSpecial Weather StatementAKQAmelia49 min
Apr 12, 7:15 PM EDTSpecial Weather StatementAKQLunenburg, Mecklenburg45 min
Apr 12, 7:48 PM EDTSpecial Weather StatementAKQPrince Edward42 min
Apr 12, 2:45 PM EDTSpecial Weather StatementAKQDorchester45 min
Apr 12, 3:13 PM EDTSpecial Weather StatementAKQSomerset62 min
Apr 12, 3:29 PM EDTSpecial Weather StatementAKQDorchester, Wicomico46 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2011Every severe thunderstorm warning 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.