Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 869

May 22, 201116 counties in Oklahoma; 20 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 22, 2011, 6:34 PM CDT for 16 counties in Oklahoma; 20 counties in Texas. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 6:34 PM CDT (23:34 UTC)
Expired
May 22, 2011, 7:30 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 36 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Seminole County, OK, Callahan County, TX, Clay County, TX, Collin County, TX, Cooke County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Stephens County, TX, Tarrant County, TX, Wise County, TX, Young County, TX

The radar

The Norman radar (KTLX), 147 km from the middle of the area, began a volume at 23:35 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

Fort Worth, TX (KFWD), launched 12:00Z, 11.6 hours before the alert went out and 132 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, Fort Worth, TX at 12:00Z on 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3761 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, Fort Worth, TX at 12:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 240 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
3761 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
534 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
240 m²/s²
0-3 km storm-relative helicity
224 m²/s²
Significant tornado parameter
3.3
Supercell composite
16.2

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 21, 7:08 PM CDTTornado WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Creek and 14 more3 hr
May 21, 8:31 PM CDTMesoscale DiscussionSPCLeFlore89 min
May 22, 12:42 PM CDTMesoscale DiscussionSPCCarter, Garvin, Jefferson, Johnston, Love, Marshall and 2 more2 hr
May 22, 1:06 PM CDTMesoscale DiscussionSPCCraig, Delaware, Mayes, Nowata, Osage, Ottawa and 3 more114 min
May 22, 1:27 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Craig, Creek, Delaware and 19 more8 hr
May 22, 1:47 PM CDTTornado WatchSPCAtoka, Bryan, Carter, Coal, Garvin, Hughes and 10 more7 hr
May 22, 3:47 PM CDTMesoscale DiscussionSPCCarter, Coal, Hughes, Johnston, Love, McIntosh and 5 more58 min
May 22, 3:48 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Delaware, Haskell, McIntosh and 9 more117 min
May 22, 6:10 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Delaware, Haskell, McIntosh and 9 more65 min
May 21, 7:34 PM CDTMesoscale DiscussionSPCBell, Blanco, Burnet, Coryell, Gillespie, Hamilton and 10 more86 min
May 22, 2:48 PM CDTSevere Thunderstorm WatchSPCBrewster, Brown, Callahan, Coke, Coleman, Concho and 25 more7 hr
May 22, 6:56 PM CDTMesoscale DiscussionSPCBrewster, Brown, Callahan, Coke, Coleman, Concho and 25 more64 min

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Oklahoma, 2011Every mesoscale discussion in 2011

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.