Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 827

May 28, 201515 counties in Oklahoma; 31 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2015, 2:56 PM CDT for 15 counties in Oklahoma; 31 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 28, 2015, 2:56 PM CDT (19:56 UTC)
Expired
May 28, 2015, 4:30 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 46 counties

Bryan County, OK, Carter County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pontotoc County, OK, Stephens County, OK, Archer County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Hamilton County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, McCulloch County, TX, Mills County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, San Saba County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 126 km from the middle of the area, began a volume at 19:58 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, 7.9 hours before the alert went out and 204 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 2015-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 2015-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 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
39 J/kg
Mixed-layer CIN
-204 J/kg
Mixed-layer LCL
1310 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
121 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
May 28, 2:50 AM CDTMesoscale DiscussionSPCCaddo, Carter, Comanche, Cotton, Garvin, Grady and 11 more2 hr
May 28, 10:37 AM CDTMesoscale DiscussionSPCLeFlore, McCurtain, Sequoyah53 min
May 28, 2:18 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Texas7 hr
May 28, 3:26 PM CDTSevere Thunderstorm WatchSPCCaddo, Canadian, Carter, Cleveland, Comanche, Cotton and 13 more8 hr
May 28, 5:33 PM CDTMesoscale DiscussionSPCBeaver, Cimarron, Harper, Texas87 min
May 28, 11:45 AM CDTMesoscale DiscussionSPCAndrews, Borden, Cochran, Cottle, Crosby, Dawson and 28 more90 min
May 28, 12:44 PM CDTTornado WatchSPCAndrews, Bailey, Baylor, Borden, Brewster, Callahan and 58 more7 hr
May 28, 2:04 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bee, Bell, Bexar and 30 more56 min
May 28, 3:42 PM CDTMesoscale DiscussionSPCAndrews, Bailey, Baylor, Borden, Brewster, Cochran and 55 more63 min
May 28, 6:57 PM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Coke, Comal, Concho and 28 more2 hr

Nearby

Mesoscale Discussions in Texas, 2015Mesoscale Discussions in Oklahoma, 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.