Alert archive / Missouri / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 201

April 27, 20094 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 27, 2009, 12:47 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 27, 2009, 12:47 PM CDT (17:47 UTC)
Expired
Apr 27, 2009, 7:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 73 counties

Benton County, AR, Carroll County, AR, Washington County, AR, Allen County, KS, Bourbon County, KS, Cherokee County, KS, Crawford County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Barry County, MO, Barton County, MO, Benton County, MO, Camden County, MO, Cedar County, MO, Christian County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Jasper County, MO, Laclede County, MO, Lawrence County, MO, Maries County, MO, McDonald County, MO, Miller County, MO, Morgan County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, Shannon County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Vernon County, MO, Webster County, MO, Wright County, MO, Adair County, OK, Cherokee County, OK, Cleveland County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Hughes County, OK, Lincoln County, OK, Logan County, OK, Mayes County, OK, McClain County, OK, McIntosh County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Payne County, OK, Pottawatomie County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Tulsa radar (KINX), 71 km from the middle of the area, began a volume at 17:48 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
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 27, 1:07 PM CDTSevere Thunderstorm WarningOUNLogan, Payne38 min
Apr 27, 1:24 PM CDTSevere Thunderstorm WarningOUNPayne51 min
Apr 27, 1:35 PM CDTSevere Thunderstorm WarningTSAOsage40 min
Apr 27, 1:37 PM CDTSevere Thunderstorm WarningTSAPawnee53 min
Apr 27, 2:17 PM CDTSevere Thunderstorm WarningTSAOsage, Pawnee46 min
Apr 27, 2:27 PM CDTSevere Thunderstorm WarningTSAOsage63 min
Apr 27, 2:40 PM CDTFlash Flood WarningICTChautauqua, Montgomery, Wilson6 hr
Apr 27, 3:04 PM CDTFlash Flood WarningICTNeosho6 hr
Apr 27, 3:05 PM CDTSevere Thunderstorm WarningTSANowata, Osage, Washington40 min
Apr 27, 3:13 PM CDTSevere Thunderstorm WarningTSANowata, Osage, Washington30 min
Apr 27, 4:57 PM CDTFlash Flood WarningSGFBourbon, Cherokee, Crawford6 hr

Discussions around it

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

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 5.8 hours before the alert went out and 125 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, Springfield, MO at 12:00Z on 2009-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 118 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, Springfield, MO at 12:00Z on 2009-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 448 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
118 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
720 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
448 m²/s²
0-3 km storm-relative helicity
496 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 9:28 AM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more12 hr
Apr 27, 12:32 PM CDTMesoscale DiscussionSPCBenton88 min
Apr 27, 1:14 PM CDTMesoscale DiscussionSPCHempstead, Lafayette, Little River, Miller91 min
Apr 27, 2:24 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 19 more66 min
Apr 27, 2:57 PM CDTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 22 more6 hr
Apr 27, 3:28 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Washington2 hr
Apr 27, 5:08 PM CDTMesoscale DiscussionSPCClay, Craighead, Cross, Greene, Independence, Jackson and 5 more97 min
Apr 27, 6:03 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Washington27 min
Apr 26, 8:21 PM CDTMesoscale DiscussionSPCAnderson, Atchison, Brown, Chase, Coffey, Doniphan and 16 more54 min
Apr 26, 8:42 PM CDTMesoscale DiscussionSPCAllen, Barber, Butler, Chase, Chautauqua, Comanche and 16 more2 hr
Apr 26, 11:15 PM CDTMesoscale DiscussionSPCAdair, Bates, Carroll, Cass, Chariton, Henry and 10 more60 min

Nearby

Severe Thunderstorm Watches in Missouri, 2009Severe Thunderstorm Watches in Oklahoma, 2009Severe Thunderstorm Watches in Kansas, 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.