Alert archive / Oklahoma / Mesoscale Discussions in 2018

Mesoscale Discussion 237

April 13, 20185 states

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2018, 12:39 PM CDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 13, 2018, 12:39 PM CDT (17:39 UTC)
Expired
Apr 13, 2018, 2:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 71 counties

Benton County, AR, Allen County, KS, Bourbon County, KS, Chautauqua County, KS, Cherokee County, KS, Crawford County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Barton County, MO, Jasper County, MO, McDonald County, MO, Newton County, MO, Adair County, OK, Atoka County, OK, Bryan County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Marshall County, OK, Mayes County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK, Bosque County, TX, Collin County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Fannin County, TX, Freestone County, TX, Grayson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Limestone County, TX, McLennan County, TX, Navarro County, TX, Rains County, TX, Rockwall County, TX, Tarrant County, TX, Van Zandt County, TX

The radar

The Norman radar (KTLX), 136 km from the middle of the area, began a volume at 17:41 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 5.7 hours before the alert went out and 138 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, Norman, OK at 12:00Z on 2018-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 960 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, Norman, OK at 12:00Z on 2018-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 577 square meters per square second.1939587897Sfc1 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
960 J/kg
Mixed-layer CIN
-283 J/kg
Mixed-layer LCL
758 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
577 m²/s²
0-3 km storm-relative helicity
755 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 13, 12:41 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Conway and 24 more2 hr
Apr 13, 1:20 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more9 hr
Apr 13, 1:50 PM CDTTornado Watch PDSSPCBaxter, Boone, Bradley, Calhoun, Clark, Cleburne and 43 more8 hr
Apr 13, 3:43 PM CDTMesoscale DiscussionSPCBenton, Washington92 min
Apr 13, 5:53 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 63 more97 min
Apr 13, 6:50 PM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Desha, Drew115 min
Apr 13, 2:06 PM CDTMesoscale DiscussionSPCAnderson, Atchison, Brown, Chase, Coffey, Doniphan and 17 more2 hr
Apr 13, 2:19 PM CDTTornado WatchSPCAnderson, Atchison, Brown, Coffey, Doniphan, Douglas and 12 more7 hr
Apr 13, 5:08 PM CDTMesoscale DiscussionSPCBenton, Camden, Carter, Christian, Cole, Dallas and 23 more2 hr
Apr 13, 5:27 PM CDTTornado WatchSPCBollinger, Butler, Camden, Cape Girardeau, Carter, Crawford and 33 more8 hr
Apr 13, 5:31 PM CDTMesoscale DiscussionSPCAtchison29 min
Apr 13, 11:04 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Coal, Hughes, Johnston and 5 more56 min
Apr 13, 4:49 PM CDTMesoscale DiscussionSPCBastrop, Bell, Blanco, Brazos, Burleson, Burnet and 14 more2 hr

Nearby

Mesoscale Discussions in Oklahoma, 2018Mesoscale Discussions in Texas, 2018Mesoscale Discussions in Kansas, 2018Every mesoscale discussion in 2018

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.