Alert archive / Mississippi / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 285

May 9, 200936 counties in Mississippi

The Storm Prediction Center issued this severe thunderstorm watch at May 9, 2009, 5:53 PM CDT for 36 counties in Mississippi. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2009, 5:53 PM CDT (22:53 UTC)
Expired
May 9, 2009, 10:23 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 36 counties

Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 83 km from the middle of the area, began a volume at 22:53 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 9, 6:12 PM CDTSevere Thunderstorm WarningJANIssaquena, Sharkey48 min
May 9, 6:31 PM CDTSevere Thunderstorm WarningJANHumphreys, Sharkey44 min
May 9, 6:37 PM CDTSevere Thunderstorm WarningJANCarroll, Montgomery53 min
May 9, 6:43 PM CDTFlash Flood WarningJANHolmes, Humphreys, Sharkey, Washington, Yazoo2 hr
May 9, 6:44 PM CDTTornado WarningJANHolmes, Humphreys, Yazoo52 min
May 9, 7:03 PM CDTSevere Thunderstorm WarningJANAttala42 min
May 9, 7:14 PM CDTSevere Thunderstorm WarningJANChoctaw27 min
May 9, 7:30 PM CDTSevere Thunderstorm WarningJANAttala, Holmes, Madison, Yazoo45 min
May 9, 8:05 PM CDTSevere Thunderstorm WarningJANSmith40 min
May 9, 8:06 PM CDTSevere Thunderstorm WarningJANAttala, Leake, Madison, Scott39 min
May 9, 8:35 PM CDTSevere Thunderstorm WarningJANJasper, Smith40 min
May 9, 8:41 PM CDTSevere Thunderstorm WarningJANLeake, Neshoba38 min
May 9, 9:05 PM CDTSevere Thunderstorm WarningJANClarke, Jasper, Lauderdale, Newton55 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

Jackson, MS (KJAN), launched 12:00Z, 10.9 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, Jackson, MS at 12:00Z on 2009-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 615 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, Jackson, MS at 12:00Z on 2009-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 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
615 J/kg
Mixed-layer CIN
-185 J/kg
Mixed-layer LCL
610 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 12:33 PM CDTMesoscale DiscussionSPCBolivar, Washington57 min
May 9, 3:25 PM CDTMesoscale DiscussionSPCBolivar, Washington65 min
May 9, 5:31 PM CDTMesoscale DiscussionSPCAttala, Calhoun, Carroll, Chickasaw, Choctaw, Clay and 28 more89 min

Nearby

Severe Thunderstorm Watches in Mississippi, 2009Every severe thunderstorm watch in 2009

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.