Alert archive / Virginia / Mesoscale Discussions in 2011
Mesoscale Discussion 920
The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 8:34 AM EDT for 5 states. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 8:34 AM EDT (12:34 UTC)
- Expired
- May 24, 2011, 10:30 AM EDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
All 114 counties
Bell County, KY, Breathitt County, KY, Clay County, KY, Floyd County, KY, Harlan County, KY, Jackson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, Letcher County, KY, Magoffin County, KY, Martin County, KY, McCreary County, KY, Owsley County, KY, Perry County, KY, Pike County, KY, Wayne County, KY, Whitley County, KY, Alamance County, NC, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Caldwell County, NC, Caswell County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Madison County, NC, Mitchell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Cumberland County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, Morgan County, TN, Pickett County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Washington County, TN, Alleghany County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buchanan County, VA, Carroll County, VA, City of Bristol, VA, City of Buena Vista, VA, City of Covington, VA, City of Danville, VA, City of Galax, VA, City of Lexington, VA, City of Martinsville, VA, City of Norton, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Dickenson County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Henry County, VA, Lee County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Greenbrier County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Raleigh County, WV, Summers County, WV, Wyoming County, WV
The radar
The Knoxville radar (KMRX), 64 km from the middle of the area, began a volume at 12:38 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 0.6 hours before the alert went out and 297 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
428
ACUS11 KWNS 241234
SWOMCD
SPC MCD 241234
VAZ000-NCZ000-WVZ000-TNZ000-KYZ000-241430-
MESOSCALE DISCUSSION 0920
NWS STORM PREDICTION CENTER NORMAN OK
0734 AM CDT TUE MAY 24 2011
AREAS AFFECTED...MIDDLE/EASTERN TN AND SOUTHERN/EASTERN KY TO
SOUTHERN WV AND VA/NORTHERN NC
CONCERNING...SEVERE THUNDERSTORM WATCH 352...
VALID 241234Z - 241430Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 352
CONTINUES.
SEVERE TSTM WATCH 352 CONTINUES UNTIL 18Z...WITH A RISK OF SEVERE
HAIL AND AN INCREASING POTENTIAL FOR DAMAGING WINDS THROUGH MID/LATE
MORNING. CURRENT THINKING IS THAN AN ADDITIONAL WATCH WILL LIKELY BE
NEEDED THIS MORNING FOR PORTIONS OF SOUTHERN WV AND VA/NORTHERN NC.
A FORWARD PROPAGATING TSTM CLUSTER/MCS CONTINUES TO STEADILY
PROGRESS EAST-NORTHEASTWARD ACROSS NORTHERN TN/SOUTHEAST KY EARLY
THIS MORNING...AND ADDITIONAL UPSCALE GROWTH/EXPANSION OF THIS MCS
SEEMS LIKELY THIS MORNING. SEVERE HAIL AND DAMAGING WINDS WILL
REMAIN A CONCERN...WITH THE DAMAGING WIND POTENTIAL EXPECTED TO ONLY
BECOME MORE WIDESPREAD THIS MORNING INTO A QUICKLY
HEATING/DESTABILIZING BOUNDARY LAYER. ALONG THESE LINES...A MEASURED
42 KT WIND GUST WAS RECENTLY NOTED AT MONTICELLO/EKQ IN KY.
CURRENT THINKING IS THAT AN ADDITIONAL SEVERE TSTM WATCH WILL LIKELY
BE NEEDED FOR PORTIONS OF SOUTHERN WV AND WESTERN/SOUTHERN VA AND
NORTHERN NC THIS MORNING...WHERE 12Z OBSERVED SOUNDINGS REFLECT
STEEP LAPSE RATES ALOFT/POTENTIAL FOR AMPLE HEATING COINCIDENT WITH
A BELT OF MODERATE WESTERLY FLOW ALOFT.
..GUYER.. 05/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LWX...RAH...RNK...RLX...GSP...MRX...JKL...LMK...
OHX...
LAT...LON 35478564 36728501 37458404 37798307 38037917 35977929
35478564SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 8:31 PM EDT | Severe Thunderstorm Watch | SPC | Bath, Boyd, Carter, Elliott, Fleming, Greenup and 6 more | 3 hr |
| May 23, 8:47 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Butler, Caldwell, Christian and 21 more | 58 min |
| May 24, 6:24 AM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Casey, Clay and 18 more | 96 min |
| May 24, 7:01 AM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Casey and 38 more | 8 hr |
| May 24, 12:55 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 15 more | 65 min |
| May 24, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 14 more | 6 hr |
| May 24, 3:33 PM EDT | Mesoscale Discussion | SPC | Harlan | 87 min |
| May 24, 4:27 PM EDT | Mesoscale Discussion | SPC | Bell, Harlan, Letcher, Whitley | 63 min |
| May 24, 10:00 AM EDT | Severe Thunderstorm Watch | SPC | Alleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more | 7 hr |
| May 24, 12:15 PM EDT | Mesoscale Discussion | SPC | Alamance, Bertie, Camden, Caswell, Chowan, Durham and 24 more | 90 min |
| May 24, 12:42 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Bertie, Camden, Chowan, Currituck, Durham and 20 more | 5 hr |
| May 24, 4:43 PM EDT | Tornado Watch | SPC | Alamance, Alleghany, Ashe, Caswell, Forsyth, Guilford and 8 more | 5 hr |
| May 24, 7:33 PM EDT | Mesoscale Discussion | SPC | Alamance, Alleghany, Ashe, Caswell, Durham, Forsyth and 11 more | 57 min |
| May 24, 7:46 PM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 26 more | 59 min |
| May 23, 8:07 PM EDT | Mesoscale Discussion | SPC | Brooke, Hancock | 83 min |
Nearby
Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 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.