Alert archive / Georgia / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 269

May 9, 201210 counties in Georgia; 7 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at May 9, 2012, 2:00 PM EDT for 10 counties in Georgia; 7 counties in South Carolina. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2012, 2:00 PM EDT (18:00 UTC)
Expired
May 9, 2012, 7:25 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Tattnall County, GA, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC, Jasper County, SC

The radar

The Charleston,SC radar (KCLX), 30 km from the middle of the area, began a volume at 18:02 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 9, 3:18 PM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Jasper57 min
May 9, 3:45 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Dorchester60 min
May 9, 4:40 PM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Jasper38 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

Charleston AFB, SC (KCHS), launched 12:00Z, 6.0 hours before the alert went out and 72 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, Charleston AFB, SC at 12:00Z on 2012-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 484 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, Charleston AFB, SC at 12:00Z on 2012-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
484 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
666 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 11:32 AM EDTMesoscale DiscussionSPCBurke, Richmond88 min
May 9, 12:59 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 49 more2 hr
May 9, 4:54 PM EDTMesoscale DiscussionSPCBryan, Chatham, Liberty, Long, McIntosh, Wayne96 min
May 9, 6:01 PM EDTMesoscale DiscussionSPCAtkinson, Bacon, Brantley, Brooks, Camden, Charlton and 6 more89 min
May 9, 7:04 PM EDTMesoscale DiscussionSPCBryan, Chatham, Effingham, Liberty, Long, McIntosh26 min

Nearby

Severe Thunderstorm Watches in Georgia, 2012Severe Thunderstorm Watches in South Carolina, 2012Every severe thunderstorm watch in 2012

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.