Alert archive / Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 267

March 23, 201129 counties in North Carolina; 37 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 23, 2011, 10:26 PM EDT for 29 counties in North Carolina; 37 counties in Virginia. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Mar 23, 2011, 10:26 PM EDT (02:26 UTC)
Expired
Mar 23, 2011, 11:30 PM EDT
In force
64 min
Issued by
the Storm Prediction Center
All 66 counties

Alamance County, NC, Bertie County, NC, Camden County, NC, Caswell County, NC, Chatham County, NC, Chowan County, NC, Davidson County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Pasquotank County, NC, Perquimans County, NC, Person County, NC, Randolph County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wilson County, NC, Amelia County, VA, Brunswick County, VA, Charles City County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Williamsburg, VA, Dinwiddie County, VA, Gloucester County, VA, Greensville County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Nottoway County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Raleigh/Durham radar (KRAX), 81 km from the middle of the area, began a volume at 02:26 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, 2.4 hours before the alert went out and 146 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 2011-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 47 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, Roanoke, VA at 00:00Z on 2011-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.1939587897117136Sfc1 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
47 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
968 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 23, 8:39 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 22 more66 min
Mar 23, 9:21 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Haywood, Jackson, Macon and 1 more24 min
Mar 23, 9:41 PM EDTTornado WatchSPCAvery, Buncombe, Burke, Caldwell, Cherokee, Clay and 11 more2 hr
Mar 23, 8:13 PM EDTMesoscale DiscussionSPCAlbemarle, Arlington, Culpeper, Fairfax, Fauquier, Greene and 16 more92 min

Nearby

Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 2011Every mesoscale discussion 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.