Alert archive / Missouri / Tornado Watches in 2010

Tornado Watch 84

April 23, 201010 counties in Illinois; 23 counties in Missouri

The Storm Prediction Center issued this tornado watch at Apr 23, 2010, 7:06 PM CDT for 10 counties in Illinois; 23 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 23, 2010, 7:06 PM CDT (00:06 UTC)
Expired
Apr 24, 2010, 12:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
50 kt
All 33 counties

Adams County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Greene County, IL, Jersey County, IL, Morgan County, IL, Pike County, IL, Schuyler County, IL, Scott County, IL, Adair County, MO, Audrain County, MO, Boone County, MO, Callaway County, MO, Chariton County, MO, Howard County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Putnam County, MO, Ralls County, MO, Randolph County, MO, Saline County, MO, Schuyler County, MO, Shelby County, MO, Sullivan County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 175 km from the middle of the area, began a volume at 00:09 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
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 23, 7:24 PM CDTTornado WarningLSXLincoln, Warren51 min
Apr 23, 7:48 PM CDTFlash Flood WarningLSXBoone, Cole, Moniteau6 hr
Apr 23, 8:11 PM CDTTornado WarningLSXLincoln, Pike49 min
Apr 23, 8:51 PM CDTTornado WarningLSXCalhoun, Pike18 min

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.1 hours before the alert went out and 293 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 00:00Z on 2010-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 00:00Z on 2010-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 259 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
4 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
462 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
259 m²/s²
0-3 km storm-relative helicity
350 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 24, 7:35 AM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 12 more55 min
Apr 24, 11:08 AM CDTMesoscale DiscussionSPCMonroe67 min
Apr 24, 11:31 AM CDTTornado Watch PDSSPCAlexander, Franklin, Jackson, Johnson, Massac, Perry and 6 more8 hr
Apr 24, 1:17 PM CDTTornado Watch PDSSPCEdwards, Gallatin, Hamilton, Hardin, Jefferson, Wabash and 2 more8 hr
Apr 24, 2:01 PM CDTMesoscale DiscussionSPCAlexander, Hardin, Massac, Pope, Pulaski89 min
Apr 24, 2:52 PM CDTMesoscale DiscussionSPCBond, Clinton, Fayette, Jersey, Madison, Marion and 4 more53 min
Apr 24, 3:20 PM CDTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 45 more7 hr
Apr 24, 5:14 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 41 more61 min
Apr 24, 5:48 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 11 more57 min
Apr 23, 10:03 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Bates, Buchanan, Caldwell, Cass and 12 more27 min
Apr 23, 10:58 PM CDTTornado WatchSPCAndrew, Atchison, Buchanan, Caldwell, Carroll, Clay and 15 more5 hr
Apr 23, 11:40 PM CDTMesoscale DiscussionSPCDunklin, Pemiscot65 min
Apr 24, 2:44 AM CDTMesoscale DiscussionSPCDunklin, Pemiscot91 min
Apr 24, 3:15 AM CDTMesoscale DiscussionSPCCaldwell, Carroll, Daviess, Grundy, Livingston, Mercer and 1 more30 min
Apr 24, 6:00 AM CDTTornado Watch PDSSPCDunklin, Pemiscot6 hr
Apr 24, 9:31 AM CDTMesoscale DiscussionSPCDunklin, Pemiscot59 min
Apr 24, 1:29 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Gentry, Harrison, Holt, Mercer and 2 more91 min
Apr 24, 1:52 PM CDTMesoscale DiscussionSPCCamden, Christian, Crawford, Dallas, Dent, Douglas and 14 more53 min

Nearby

Tornado Watches in Missouri, 2010Tornado Watches in Illinois, 2010Every tornado watch in 2010

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.