Alert archive / Missouri / Tornado Watches in 2008

Tornado Watch 776

July 30, 20084 states

The Storm Prediction Center issued this tornado watch at Jul 30, 2008, 5:21 PM CDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 30, 2008, 5:21 PM CDT (22:21 UTC)
Expired
Jul 30, 2008, 9:57 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 66 counties

Alexander County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jefferson County, IL, Johnson County, IL, Massac County, IL, Monroe County, IL, Perry County, IL, Pope County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Gibson County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Carlisle County, KY, Crittenden County, KY, Daviess County, KY, Henderson County, KY, Livingston County, KY, McCracken County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Oregon County, MO, Ozark County, MO, Perry County, MO, Reynolds County, MO, Ripley County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Scott County, MO, Shannon County, MO, Stoddard County, MO, Taney County, MO, Texas County, MO, Washington County, MO, Wayne County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 124 km from the middle of the area, began a volume at 22:25 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
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 30, 5:29 PM CDTSevere Thunderstorm WarningPAHPerry34 min
Jul 30, 7:14 PM CDTSevere Thunderstorm WarningPAHJackson, Williamson22 min
Jul 30, 7:21 PM CDTFlash Flood WarningSGFTexas, Webster, Wright6 hr
Jul 30, 7:43 PM CDTSevere Thunderstorm WarningPAHCape Girardeau47 min
Jul 30, 8:47 PM CDTSevere Thunderstorm WarningSGFBarry, Christian, Stone, Taney41 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

Lincoln, IL (KILX), launched 12:00Z, 10.4 hours before the alert went out and 304 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, Lincoln, IL at 12:00Z on 2008-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 78 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, Lincoln, IL at 12:00Z on 2008-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
78 J/kg
Mixed-layer CIN
-156 J/kg
Mixed-layer LCL
1609 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
42 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
Jul 29, 7:05 PM CDTMesoscale DiscussionSPCChampaign, DeKalb, Douglas, DuPage, Ford, Grundy and 10 more85 min
Jul 30, 4:44 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Jackson, Johnson, Monroe, Perry and 5 more91 min
Jul 30, 2:57 PM CDTMesoscale DiscussionSPCAdair, Bell, Breathitt, Casey, Clay, Clinton and 20 more93 min

Nearby

Tornado Watches in Missouri, 2008Tornado Watches in Illinois, 2008Tornado Watches in Kentucky, 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.