Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 665

May 17, 202119 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 17, 2021, 10:35 PM CDT for 19 counties in Texas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
May 17, 2021, 10:35 PM CDT (03:35 UTC)
Expired
May 18, 2021, 12:00 AM CDT
In force
85 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...severe thunderstorm watch likely
Chance of a watch
95%

Counties Andrews County, TX, Borden County, TX, Brewster County, TX, Crane County, TX, Crockett County, TX, Dawson County, TX, Ector County, TX, Glasscock County, TX, Howard County, TX, Irion County, TX, Martin County, TX, Midland County, TX, Pecos County, TX, Reagan County, TX, Schleicher County, TX, Sterling County, TX, Terrell County, TX, Upton County, TX, Val Verde County, TX

The radar

The Midland/Odessa radar (KMAF), 119 km from the middle of the area, began a volume at 03:34 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

Midland Regional, TX (KMAF), launched 00:00Z, 3.6 hours before the alert went out and 120 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, Midland Regional, TX at 00:00Z on 2021-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 953 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, Midland Regional, TX at 00:00Z on 2021-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
953 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1920 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted.

324 
ACUS11 KWNS 180336
SWOMCD
SPC MCD 180335 
TXZ000-180500-

Mesoscale Discussion 0665
NWS Storm Prediction Center Norman OK
1035 PM CDT Mon May 17 2021

Areas affected...Southwest TX

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 180335Z - 180500Z

Probability of Watch Issuance...95 percent

SUMMARY...Redevelopment of severe thunderstorms is possible later
tonight. Severe thunderstorm watch issuance is likely by 04Z.

DISCUSSION...As a low-level jet becomes focused into southwest TX
late tonight, redevelopment of strong thunderstorms is expected. The
renewed convection will likely be somewhat elevated, but very
favorable buoyancy and shear will favor a threat of very large hail
with initial development, with some upscale growth potentially
leading to a greater damaging wind risk late tonight. A tornado
cannot be ruled with any supercell that can become surface based,
though any such threat is highly conditional. A severe thunderstorm
watch will be issued prior to 04Z to cover the overnight severe
threat.

..Dean/Grams.. 05/18/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...EWX...SJT...LUB...MAF...

LAT...LON   29660332 31150305 31590288 32130278 33010216 32710125
            31770067 31270054 30960047 30390058 30120089 29850115
            29810157 29600294 29660332

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 7:04 PM CDTMesoscale DiscussionSPCArcher, Bosque, Brown, Clay, Comanche, Eastland and 15 more86 min
May 17, 7:23 PM CDTMesoscale DiscussionSPCCarson, Dallam, Gray, Hansford, Hartley, Hemphill and 8 more2 hr
May 17, 7:32 PM CDTTornado WatchSPCBrown, Callahan, Coke, Coleman, Concho, McCulloch and 4 more3 hr
May 17, 7:37 PM CDTMesoscale DiscussionSPCCallahan, Coke, Coleman, Glasscock, Howard, Jones and 6 more83 min
May 17, 8:04 PM CDTSevere Thunderstorm WatchSPCArcher, Clay, Comanche, Eastland, Erath, Hamilton and 11 more5 hr
May 17, 8:34 PM CDTMesoscale DiscussionSPCAtascosa, Dimmit, Frio, La Salle, McMullen, Maverick and 2 more116 min
May 17, 9:28 PM CDTMesoscale DiscussionSPCCarson, Collingsworth, Donley, Gray, Hansford, Hemphill and 7 more2 hr
May 17, 9:44 PM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Childress, Collingsworth, Cottle and 15 more91 min
May 17, 10:23 PM CDTMesoscale DiscussionSPCArcher, Brown, Callahan, Clay, Coke, Coleman and 16 more97 min
May 17, 10:58 PM CDTSevere Thunderstorm WatchSPCAndrews, Borden, Brown, Coke, Coleman, Concho and 22 more7 hr
May 17, 11:37 PM CDTMesoscale DiscussionSPCBosque, Brown, Comanche, Denton, Eastland, Erath and 9 more83 min
May 18, 1:02 AM CDTMesoscale DiscussionSPCBrooks, Duval, Jim Hogg58 min
May 18, 1:29 AM CDTMesoscale DiscussionSPCCoke, Concho, Crane, Crockett, Ector, Glasscock and 13 more91 min
May 18, 5:07 AM CDTMesoscale DiscussionSPCCoke, Concho, Irion, Reagan, Runnels, Schleicher and 2 more53 min
May 18, 1:18 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bexar, Brazos, Burleson and 28 more117 min
May 18, 1:57 PM CDTMesoscale DiscussionSPCBailey, Castro, Deaf Smith, Parmer, Randall, Swisher3 hr
May 18, 2:29 PM CDTTornado WatchSPCAnderson, Atascosa, Austin, Bastrop, Bexar, Blanco and 30 more7 hr
May 18, 2:30 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 12 more2 hr
May 18, 3:51 PM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 11 more5 hr
May 18, 3:52 PM CDTMesoscale DiscussionSPCBastrop, Caldwell, Colorado, Fayette, Gonzales, Guadalupe and 2 more83 min
May 18, 5:10 PM CDTMesoscale DiscussionSPCLa Salle, McMullen, Webb95 min
May 18, 5:39 PM CDTMesoscale DiscussionSPCBowie, Cass, Gregg, Harrison, Marion, Morris and 1 more2 hr
May 18, 6:07 PM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Castro, Cochran and 17 more113 min
May 18, 6:13 PM CDTMesoscale DiscussionSPCAustin, Brazos, Burleson, Colorado, DeWitt, Fayette and 14 more92 min

Nearby

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

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.