Alert archive / North Carolina / Mesoscale Discussions in 2005

Mesoscale Discussion 924

May 20, 20054 states

The Storm Prediction Center issued this mesoscale discussion at May 20, 2005, 12:56 AM EDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 20, 2005, 12:56 AM EDT (04:56 UTC)
Expired
May 20, 2005, 3:00 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 80 counties

Alamance County, NC, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Graham County, NC, Guilford County, NC, Haywood County, NC, Henderson County, NC, Iredell County, NC, Jackson County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mecklenburg County, NC, Mitchell County, NC, Montgomery County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Cherokee County, SC, Greenville County, SC, Pickens County, SC, Spartanburg County, SC, York County, SC, Blount County, TN, Carter County, TN, Cocke County, TN, Greene County, TN, Hamblen County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, Monroe County, TN, Sevier County, TN, Unicoi County, TN, Washington County, TN, Bland County, VA, Carroll 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, Wythe County, VA

The radar

The Greer radar (KGSP), 142 km from the middle of the area, began a volume at 04:56 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 00:00Z, 4.9 hours before the alert went out and 157 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 00:00Z on 2005-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1135 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 00:00Z on 2005-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 133 square meters per square second.1939Sfc1 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
1135 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
791 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
133 m²/s²
0-3 km storm-relative helicity
207 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.4

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
May 20, 12:58 AM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Buncombe and 39 more2 hr
May 20, 2:00 AM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Anson, Ashe, Avery and 33 more7 hr
May 20, 2:30 AM EDTSevere Thunderstorm WatchSPCBuncombe, Cherokee, Clay, Graham, Haywood, Henderson and 5 more8 hr
May 20, 5:18 AM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Jackson, Macon, Swain and 1 more57 min
May 20, 8:42 AM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Macon93 min
May 20, 3:45 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Macon, Swain60 min
May 20, 4:40 PM EDTMesoscale DiscussionSPCBrunswick, Columbus, New Hanover95 min
May 20, 5:52 AM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Calhoun, Edgefield and 7 more53 min
May 20, 9:40 AM EDTSevere Thunderstorm WatchSPCMcCormick7 hr
May 20, 1:16 PM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Colleton and 6 more29 min
May 20, 1:20 PM EDTSevere Thunderstorm WatchSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Calhoun and 9 more7 hr
May 20, 1:55 PM EDTMesoscale DiscussionSPCMcCormick65 min
May 20, 2:43 PM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Calhoun and 8 more62 min
May 19, 9:31 PM EDTMesoscale DiscussionSPCClaiborne, Clay, Fentress, Hancock, Jackson, Macon and 7 more89 min
May 19, 9:50 PM EDTSevere Thunderstorm WatchSPCCheatham, Davidson, Dickson, Henry, Houston, Montgomery and 3 more5 hr
May 19, 10:05 PM EDTSevere Thunderstorm WatchSPCAnderson, Campbell, Carter, Claiborne, Clay, Davidson and 21 more5 hr

Nearby

Mesoscale Discussions in North Carolina, 2005Mesoscale Discussions in Virginia, 2005Mesoscale Discussions in Tennessee, 2005Every mesoscale discussion in 2005

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.