Alert archive / Oklahoma / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 176

April 15, 20124 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 15, 2012, 6:38 AM CDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2012, 6:38 AM CDT (11:38 UTC)
Expired
Apr 15, 2012, 11:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 26 counties

Benton County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Madison County, AR, Sebastian County, AR, Washington County, AR, Cherokee County, KS, Barry County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Adair County, OK, Cherokee County, OK, Craig County, OK, Delaware County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, Mayes County, OK, McIntosh County, OK, Muskogee County, OK, Ottawa County, OK, Pittsburg County, OK, Sequoyah County, OK

The radar

The Tulsa radar (KINX), 74 km from the middle of the area, began a volume at 11:38 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
40%
One or more gusts of 65 knots or more
30%
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

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

IssuedProductOfficeCountiesLasted
Apr 15, 6:41 AM CDTSevere Thunderstorm WarningSGFBourbon, Cherokee, Crawford49 min
Apr 15, 7:21 AM CDTSevere Thunderstorm WarningSGFCherokee, Crawford39 min
Apr 15, 8:55 AM CDTFlash Flood WarningSGFCherokee6 hr
Apr 15, 9:13 AM CDTSevere Thunderstorm WarningTSABenton, Washington62 min
Apr 15, 9:16 AM CDTTornado WarningTSAAdair, Cherokee29 min
Apr 15, 9:42 AM CDTTornado WarningTSABenton, Washington33 min
Apr 15, 10:13 AM CDTSevere Thunderstorm WarningTSABenton, Carroll, Washington24 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

Springfield, MO (KSGF), launched 00:00Z, 11.6 hours before the alert went out and 103 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 00:00Z on 2012-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 532 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 00:00Z on 2012-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 294 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
532 J/kg
Mixed-layer CIN
-182 J/kg
Mixed-layer LCL
1275 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
294 m²/s²
0-3 km storm-relative helicity
443 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 15, 6:35 AM CDTMesoscale DiscussionSPCBenton, Crawford, Madison, Sebastian, Washington85 min
Apr 15, 9:25 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 22 more95 min
Apr 15, 10:51 AM CDTTornado WatchSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 18 more7 hr
Apr 15, 1:38 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 18 more97 min
Apr 15, 3:44 PM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Hempstead, Lafayette, Miller and 3 more91 min
Apr 15, 4:22 PM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clay, Cleburne, Cleveland and 29 more83 min
Apr 15, 4:25 PM CDTTornado WatchSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 49 more6 hr
Apr 14, 7:15 PM CDTMesoscale DiscussionSPCButler, Chase, Dickinson, Geary, Harper, Harvey and 7 more60 min
Apr 14, 10:37 PM CDTMesoscale DiscussionSPCButler, Chase, Clay, Coffey, Dickinson, Douglas and 19 more83 min
Apr 14, 11:48 PM CDTMesoscale DiscussionSPCCoffey, Douglas, Franklin, Johnson, Leavenworth, Lyon and 2 more87 min
Apr 15, 1:37 AM CDTTornado WatchSPCAtchison, Brown, Butler, Chase, Chautauqua, Coffey and 26 more5 hr
Apr 15, 4:32 AM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 13 more88 min
Apr 14, 11:28 PM CDTMesoscale DiscussionSPCPutnam92 min
Apr 15, 4:42 PM CDTTornado WatchSPCAudrain, Boone, Butler, Callaway, Carter, Cole and 35 more6 hr
Apr 14, 10:29 PM CDTSevere Thunderstorm WatchSPCComanche, Cotton, Tillman6 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Arkansas, 2012Severe Thunderstorm Watches in Missouri, 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.