Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 355

April 18, 20157 counties in Kansas; 25 counties in Oklahoma; 29 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2015, 1:52 PM CDT for 7 counties in Kansas; 25 counties in Oklahoma; 29 counties in Texas. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Apr 18, 2015, 1:52 PM CDT (18:52 UTC)
Expired
Apr 18, 2015, 3:45 PM CDT
In force
113 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 61 counties

Barber County, KS, Clark County, KS, Comanche County, KS, Edwards County, KS, Ford County, KS, Kiowa County, KS, Pratt County, KS, Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Jefferson County, OK, Kingfisher County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Comanche County, TX, Eastland County, TX, Erath County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Hood County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 12 km from the middle of the area, began a volume at 18:55 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, 6.9 hours before the alert went out and 175 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 2015-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2015-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1320 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
-8 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 17, 7:06 PM CDTMesoscale DiscussionSPCBarber, Cheyenne, Clark, Comanche, Decatur, Edwards and 28 more84 min
Apr 17, 7:26 PM CDTMesoscale DiscussionSPCGrant, Morton, Stevens2 hr
Apr 17, 8:24 PM CDTMesoscale DiscussionSPCEllsworth, Lincoln, Mitchell, Osborne, Phillips, Russell and 1 more2 hr
Apr 17, 8:56 PM CDTMesoscale DiscussionSPCCheyenne, Clark, Comanche, Decatur, Edwards, Ellis and 28 more94 min
Apr 18, 12:45 PM CDTMesoscale DiscussionSPCBarber, Harper, Kingman, Pratt60 min
Apr 18, 2:43 PM CDTSevere Thunderstorm WatchSPCBarber, Barton, Butler, Clark, Comanche, Cowley and 27 more8 hr
Apr 18, 2:49 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Graham, Norton, Phillips, Rawlins and 3 more116 min
Apr 18, 3:08 PM CDTTornado WatchSPCCheyenne, Decatur, Gove, Graham, Greeley, Logan and 7 more6 hr
Apr 18, 4:07 PM CDTMesoscale DiscussionSPCButler, Chase, Chautauqua, Clay, Cowley, Dickinson and 9 more2 hr
Apr 18, 5:31 PM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Comanche, Edwards, Ellis and 24 more59 min
Apr 18, 6:07 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Gove, Logan, Rawlins, Sheridan and 3 more53 min
Apr 18, 2:27 PM CDTTornado WatchSPCAlfalfa, Beckham, Blaine, Caddo, Comanche, Cotton and 16 more6 hr
Apr 18, 6:03 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Comanche, Cotton and 13 more87 min
Apr 18, 6:21 PM CDTMesoscale DiscussionSPCCanadian, Carter, Cleveland, Garvin, Grady, Hughes and 11 more84 min
Apr 18, 6:31 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Atoka, Beckham, Blaine, Bryan, Caddo and 38 more6 hr
Apr 17, 7:39 PM CDTMesoscale DiscussionSPCChambers, Galveston, Jefferson96 min
Apr 17, 9:10 PM CDTMesoscale DiscussionSPCAransas, Brooks, Calhoun, Duval, Hidalgo, Jim Hogg and 7 more95 min
Apr 17, 9:13 PM CDTSevere Thunderstorm WatchSPCBrazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 4 more5 hr
Apr 17, 10:59 PM CDTMesoscale DiscussionSPCAransas, Brooks, Hidalgo, Kenedy, Kleberg, Nueces91 min
Apr 17, 11:31 PM CDTMesoscale DiscussionSPCChambers, Galveston, Jefferson, Orange59 min
Apr 18, 2:13 PM CDTSevere Thunderstorm WatchSPCBandera, Bastrop, Bexar, Blanco, Bosque, Brown and 58 more8 hr
Apr 18, 4:32 PM CDTMesoscale DiscussionSPCAtascosa, Bastrop, Bexar, Caldwell, Comal, Dimmit and 11 more2 hr
Apr 18, 4:48 PM CDTMesoscale DiscussionSPCHidalgo, Kenedy, Kleberg, Willacy2 hr
Apr 18, 5:23 PM CDTMesoscale DiscussionSPCCollin, Dallas, Ellis, Falls, Hill, Kaufman and 6 more3 hr
Apr 18, 5:46 PM CDTSevere Thunderstorm WatchSPCAnderson, Bell, Collin, Cooke, Dallas, Denton and 20 more5 hr
Apr 18, 6:40 PM CDTMesoscale DiscussionSPCBandera, Bell, Blanco, Bosque, Brown, Burnet and 48 more95 min

Nearby

Mesoscale Discussions in Texas, 2015Mesoscale Discussions in Oklahoma, 2015Mesoscale Discussions in Kansas, 2015Every mesoscale discussion in 2015

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.