Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 540

May 7, 20154 counties in Oklahoma; 25 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2015, 8:49 PM CDT for 4 counties in Oklahoma; 25 counties in Texas. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 7, 2015, 8:49 PM CDT (01:49 UTC)
Expired
May 7, 2015, 10:15 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
All 29 counties

Atoka County, OK, Bryan County, OK, Choctaw County, OK, Pushmataha County, OK, Bosque County, TX, Collin County, TX, Comanche County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 30 km from the middle of the area, began a volume at 01:49 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 nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 1.8 hours before the alert went out and 11 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 00:00Z on 2015-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1673 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, Fort Worth, TX at 00:00Z on 2015-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 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
1673 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
942 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
380 m²/s²
Significant tornado parameter
4.1
Supercell composite
18.6

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 7, 11:05 PM CDTMesoscale DiscussionSPCChoctaw, McCurtain, Pushmataha85 min
May 8, 12:22 PM CDTMesoscale DiscussionSPCCaddo, Comanche, Cotton, Greer, Harmon, Jackson and 4 more83 min
May 8, 12:51 PM CDTTornado WatchSPCBeckham, Caddo, Canadian, Carter, Cleveland, Comanche and 22 more8 hr
May 8, 2:12 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cleveland, Coal, Comanche and 22 more93 min
May 8, 3:45 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Carter, Cleveland, Comanche, Cotton and 11 more90 min
May 8, 5:24 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Creek, Delaware, Haskell and 15 more96 min
May 8, 6:50 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 7 more85 min
May 8, 8:57 AM CDTMesoscale DiscussionSPCBailey, Briscoe, Castro, Childress, Cottle, Crosby and 18 more93 min
May 8, 9:31 AM CDTTornado WatchSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Callahan and 40 more7 hr
May 8, 2:48 PM CDTMesoscale DiscussionSPCBailey, Borden, Cottle, Crosby, Dawson, Dickens and 18 more87 min
May 8, 3:26 PM CDTMesoscale DiscussionSPCCoke, Crockett, Edwards, Glasscock, Irion, Kinney and 8 more94 min
May 8, 3:50 PM CDTTornado WatchSPCAndrews, Borden, Callahan, Coke, Crane, Crockett and 27 more8 hr
May 8, 5:15 PM CDTMesoscale DiscussionSPCBell, Brazos, Burleson, Falls, Freestone, Grimes and 8 more90 min
May 8, 6:13 PM CDTMesoscale DiscussionSPCBaylor, Borden, Callahan, Coke, Concho, Crane and 31 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.