Alert archive / Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 937

May 24, 201117 counties in North Carolina; 19 counties in Virginia; McDowell County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 7:33 PM EDT for 17 counties in North Carolina; 19 counties in Virginia; McDowell County, West Virginia. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
May 24, 2011, 7:33 PM EDT (23:33 UTC)
Expired
May 24, 2011, 8:30 PM EDT
In force
57 min
Issued by
the Storm Prediction Center
All 37 counties

Alamance County, NC, Alleghany County, NC, Ashe County, NC, Caswell County, NC, Durham County, NC, Forsyth County, NC, Granville County, NC, Guilford County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wake County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Bland County, VA, Carroll County, VA, Charlotte County, VA, City of Danville, VA, City of Galax, VA, City of Martinsville, VA, City of Radford, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, McDowell County, WV

The radar

The Roanoke radar (KFCX), 37 km from the middle of the area, began a volume at 23:34 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, 11.6 hours before the alert went out and 91 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, Greensboro/Hi Pt, NC at 12:00Z on 2011-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 451 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, Greensboro/Hi Pt, NC at 12:00Z on 2011-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.193958Sfc1 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
451 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1350 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

260 
ACUS11 KWNS 242334
SWOMCD
SPC MCD 242333
NCZ000-VAZ000-WVZ000-TNZ000-250030-

MESOSCALE DISCUSSION 0937
NWS STORM PREDICTION CENTER NORMAN OK
0633 PM CDT TUE MAY 24 2011

AREAS AFFECTED...PORTIONS OF S-CNTRL/SWRN VA...NWRN NC

CONCERNING...TORNADO WATCH 361...

VALID 242333Z - 250030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 361 CONTINUES.

AT 2330Z...REGIONAL RADAR IMAGERY INDICATED A BROKEN LINE OF CELLS
FROM 25 NW OF DAN TO 30 NNW HKY...WITH WEAKER ACTIVITY OCCURRING IN
ITS WAKE NEAR THE TN/NC BORDER AND SWRN VA. SURFACE TEMPERATURES
OVER WRN NC HAVE BEGUN TO COOL SLIGHTLY DURING THE LAST HR...WITH
MLCAPE VALUES NOW AROUND 500 J/KG. THE STABILIZING BOUNDARY LAYER
MAY EVENTUALLY LEAD TO A REDUCED SVR WEATHER THREAT DURING THE NEXT
FEW HRS...THOUGH IN THE SHORT TERM...THE THREAT FOR DAMAGING
WINDS/LARGE HAIL AND PERHAPS AN ISOLATED TORNADO WILL CONTINUE.

..GARNER.. 05/24/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AKQ...RAH...RNK...RLX...GSP...MRX...

LAT...LON   37428183 37047850 35737849 36128184 37428183

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 8:34 AM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Caldwell and 13 more116 min
May 24, 10:00 AM EDTSevere Thunderstorm WatchSPCAlleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more7 hr
May 24, 12:15 PM EDTMesoscale DiscussionSPCAlamance, Bertie, Camden, Caswell, Chowan, Durham and 24 more90 min
May 24, 12:42 PM EDTSevere Thunderstorm WatchSPCAlamance, Bertie, Camden, Chowan, Currituck, Durham and 20 more5 hr
May 24, 3:33 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Bertie and 30 more87 min
May 24, 4:43 PM EDTTornado WatchSPCAlamance, Alleghany, Ashe, Caswell, Forsyth, Guilford and 8 more5 hr
May 24, 7:01 AM EDTSevere Thunderstorm WatchSPCLee, Russell, Scott, Washington, Wise, City of Bristol and 1 more8 hr
May 24, 12:55 PM EDTMesoscale DiscussionSPCLee, Scott, Wise, City of Norton65 min
May 24, 1:57 PM EDTSevere Thunderstorm WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more6 hr
May 24, 4:27 PM EDTMesoscale DiscussionSPCBuchanan, Dickenson, Lee, Russell, Scott, Tazewell and 4 more63 min
May 24, 7:46 PM EDTMesoscale DiscussionSPCLee, Russell, Scott, Washington, Wise, City of Bristol and 1 more59 min
May 23, 8:07 PM EDTMesoscale DiscussionSPCBrooke, Hancock83 min
May 23, 8:31 PM EDTSevere Thunderstorm WatchSPCBrooke, Cabell, Calhoun, Doddridge, Gilmer, Hancock and 15 more3 hr

Nearby

Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in West Virginia, 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.