Alert archive / South Carolina / Tornado Watches in 2008

Tornado Watch 329

May 20, 200821 counties in North Carolina; 23 counties in South Carolina

The Storm Prediction Center issued this tornado watch at May 20, 2008, 3:39 PM EDT for 21 counties in North Carolina; 23 counties in South Carolina. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 20, 2008, 3:39 PM EDT (19:39 UTC)
Expired
May 20, 2008, 11:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
70 kt
All 44 counties

Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Pitt County, NC, Robeson County, NC, Tyrrell County, NC, Washington County, NC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Morehead City radar (KMHX), 79 km from the middle of the area, began a volume at 19:38 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

57 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 20, 3:47 PM EDTSevere Thunderstorm WarningCAEAiken58 min
May 20, 3:58 PM EDTSevere Thunderstorm WarningMHXDuplin, Jones, Lenoir47 min
May 20, 4:17 PM EDTSevere Thunderstorm WarningCAEBarnwell58 min
May 20, 4:34 PM EDTSevere Thunderstorm WarningCAEBamberg56 min
May 20, 4:38 PM EDTSevere Thunderstorm WarningMHXCraven, Jones, Onslow52 min
May 20, 4:40 PM EDTSevere Thunderstorm WarningCAECalhoun, Lexington, Orangeburg65 min
May 20, 5:02 PM EDTSevere Thunderstorm WarningCAECalhoun, Clarendon, Richland, Sumter48 min
May 20, 5:04 PM EDTTornado WarningCAEBamberg, Barnwell41 min
May 20, 5:06 PM EDTSevere Thunderstorm WarningMHXMartin39 min
May 20, 5:15 PM EDTSevere Thunderstorm WarningCHSBerkeley, Dorchester45 min
May 20, 5:23 PM EDTTornado WarningCHSColleton, Dorchester37 min
May 20, 5:24 PM EDTSevere Thunderstorm WarningMHXCarteret, Craven, Pamlico51 min
May 20, 5:31 PM EDTSevere Thunderstorm WarningMHXTyrrell, Washington59 min
May 20, 5:43 PM EDTSevere Thunderstorm WarningMHXDare62 min
May 20, 5:48 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Colleton, Dorchester42 min
May 20, 5:50 PM EDTSevere Thunderstorm WarningMHXBeaufort, Hyde, Martin, Tyrrell, Washington55 min
May 20, 5:56 PM EDTTornado WarningCHSColleton, Dorchester34 min
May 20, 5:58 PM EDTSevere Thunderstorm WarningCHSBerkeley, Dorchester47 min
May 20, 6:17 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Dorchester43 min
May 20, 6:19 PM EDTSevere Thunderstorm WarningCAEBarnwell41 min
May 20, 6:23 PM EDTSevere Thunderstorm WarningMHXGreene, Pitt52 min
May 20, 6:27 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Colleton, Dorchester33 min
May 20, 6:31 PM EDTSevere Thunderstorm WarningCHSAllendale44 min
May 20, 6:36 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Dorchester24 min
May 20, 6:39 PM EDTTornado WarningCHSBerkeley, Charleston36 min
May 20, 6:41 PM EDTSevere Thunderstorm WarningMHXCraven, Lenoir49 min
May 20, 6:47 PM EDTSevere Thunderstorm WarningILMBladen, Robeson58 min
May 20, 6:56 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston34 min
May 20, 7:08 PM EDTTornado WarningCHSAllendale, Colleton, Hampton52 min
May 20, 7:14 PM EDTSevere Thunderstorm WarningCHSAllendale, Colleton, Hampton46 min
May 20, 7:18 PM EDTSevere Thunderstorm WarningCHSBerkeley, Colleton, Dorchester27 min
May 20, 7:23 PM EDTSevere Thunderstorm WarningMHXBeaufort, Pamlico52 min
May 20, 7:26 PM EDTSevere Thunderstorm WarningCHSAllendale, Hampton49 min
May 20, 7:43 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston47 min
May 20, 7:45 PM EDTSevere Thunderstorm WarningILMBladen45 min
May 20, 7:45 PM EDTTornado WarningMHXCraven, Jones, Lenoir30 min
May 20, 7:46 PM EDTTornado WarningCHSColleton, Dorchester29 min
May 20, 7:50 PM EDTSevere Thunderstorm WarningCHSAllendale, Beaufort, Colleton, Hampton, Jasper40 min
May 20, 7:56 PM EDTSevere Thunderstorm WarningMHXDuplin, Jones, Onslow64 min
May 20, 8:12 PM EDTTornado WarningCHSCharleston, Colleton, Dorchester33 min
May 20, 8:13 PM EDTSevere Thunderstorm WarningMHXCarteret, Craven, Pamlico47 min
May 20, 8:14 PM EDTSevere Thunderstorm WarningCHSAllendale, Hampton26 min
May 20, 8:17 PM EDTSevere Thunderstorm WarningCHSColleton13 min
May 20, 8:23 PM EDTSevere Thunderstorm WarningILMPender52 min
May 20, 8:23 PM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Hampton, Jasper39 min
May 20, 8:35 PM EDTTornado WarningCHSBeaufort, Charleston, Colleton25 min
May 20, 8:38 PM EDTSevere Thunderstorm WarningMHXCarteret, Onslow37 min
May 20, 8:38 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Colleton, Dorchester37 min
May 20, 8:42 PM EDTSevere Thunderstorm WarningCAECalhoun, Fairfield, Kershaw, Lee, Richland, Sumter46 min
May 20, 8:58 PM EDTSevere Thunderstorm WarningILMDarlington, Dillon, Marlboro27 min
May 20, 9:22 PM EDTSevere Thunderstorm WarningILMDarlington, Dillon, Florence, Marion38 min
May 20, 9:31 PM EDTSevere Thunderstorm WarningILMColumbus, Robeson42 min
May 20, 9:43 PM EDTSevere Thunderstorm WarningILMBladen, Pender28 min
May 20, 9:47 PM EDTSevere Thunderstorm WarningILMHorry, Marion43 min
May 20, 9:57 PM EDTSevere Thunderstorm WarningCHSAllendale, Hampton63 min
May 20, 10:12 PM EDTSevere Thunderstorm WarningCAEOrangeburg33 min
May 20, 10:59 PM EDTSevere Thunderstorm WarningCHSHampton, Jasper20 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Newport, NC (KMHX), launched 12:00Z, 7.7 hours before the alert went out and 78 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, Newport, NC at 12:00Z on 2008-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 558 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, Newport, NC at 12:00Z on 2008-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 325 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
558 J/kg
Mixed-layer CIN
-179 J/kg
Mixed-layer LCL
1420 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
325 m²/s²
0-3 km storm-relative helicity
377 m²/s²
Significant tornado parameter
0.1
Supercell composite
6.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 12:34 PM EDTMesoscale DiscussionSPCCaswell, Northampton, Person, Vance, Warren56 min
May 20, 1:09 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Anson, Bertie, Burke and 54 more7 hr
May 20, 2:59 PM EDTSevere Thunderstorm WatchSPCAvery, Buncombe, Cherokee, Clay, Graham, Haywood and 11 more7 hr
May 20, 3:23 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, Craven, Duplin, Greene and 7 more37 min
May 20, 4:38 PM EDTMesoscale DiscussionSPCAlamance, Bertie, Cabarrus, Camden, Chatham, Chowan and 22 more67 min
May 20, 7:19 PM EDTMesoscale DiscussionSPCAnson, Hoke, Richmond, Scotland, Union86 min
May 20, 2:23 PM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Calhoun, Clarendon and 10 more67 min

Nearby

Tornado Watches in South Carolina, 2008Tornado Watches in North Carolina, 2008Every tornado watch in 2008

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.