Alert archive / Texas / Mesoscale Discussions in 2019

Mesoscale Discussion 710

May 20, 201924 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 20, 2019, 5:50 PM CDT for 24 counties in Texas. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
May 20, 2019, 5:50 PM CDT (22:50 UTC)
Expired
May 20, 2019, 7:45 PM CDT
In force
115 min
Issued by
the Storm Prediction Center
All 24 counties

Borden County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Donley County, TX, Fisher County, TX, Floyd County, TX, Garza County, TX, Glasscock County, TX, Hall County, TX, Howard County, TX, Kent County, TX, King County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Motley County, TX, Scurry County, TX, Stonewall County, TX, Wheeler County, TX

The radar

The Lubbock radar (KLBB), 85 km from the middle of the area, began a volume at 22:53 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 10.8 hours before the alert went out and 201 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, Amarillo Airport, TX at 12:00Z on 2019-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 812 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, Amarillo Airport, TX at 12:00Z on 2019-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 404 square meters per square second.1939587897Sfc1 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
812 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
637 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
404 m²/s²
0-3 km storm-relative helicity
461 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.5

Open this sounding in Storm Lab

The text

As transmitted.

876 
ACUS11 KWNS 202250
SWOMCD
SPC MCD 202250 
OKZ000-TXZ000-210045-

Mesoscale Discussion 0710
NWS Storm Prediction Center Norman OK
0550 PM CDT Mon May 20 2019

Areas affected...Southeast Texas Panhandle...Eastern Texas South
Plains...Portions of Permian Basin

Concerning...Tornado Watch 197...

Valid 202250Z - 210045Z

The severe weather threat for Tornado Watch 197 continues.

SUMMARY...The tornado threat will continue within WW 197. Given the
strength of the low-level shear expected, tornadoes will be possible
with all storm modes. However, significant tornadoes will remain
possible with any storm that can remain discrete.

DISCUSSION...Several discrete/semi-discrete supercell thunderstorms
are ongoing across WW 197. So far, tornadic activity has been
limited by the number of storms ongoing in relative close proximity.
Nevertheless, very strong deep-layer shear (60-70 kts) and strong
low-level veering ahead of these storms, particularly in northwest
Texas and into southwest Oklahoma, will continue to support strong
low-level rotation. As the low-level jet continues to increase this
evening, the tornado threat should also increase. The threat for
strong tornadoes will generally be modulated by storm mode. Any
storm that can remain discrete will continue to pose a threat for a
significant tornado. However, given the very strong low-level shear,
tornadoes will remain possible within linear segments.

..Wendt.. 05/20/2019

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

ATTN...WFO...OUN...SJT...LUB...AMA...MAF...

LAT...LON   34630113 35500060 35590001 34619991 33759995 33110014
            32410063 31570148 31310245 31880254 34630113

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 7:21 PM CDTMesoscale DiscussionSPCHarrison, Panola84 min
May 19, 11:56 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Bailey, Briscoe, Carson, Castro and 21 more2 hr
May 20, 1:57 AM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Carson, Castro, Cochran, Dallam and 21 more8 hr
May 20, 6:14 AM CDTMesoscale DiscussionSPCHemphill, Lipscomb, Ochiltree, Roberts2 hr
May 20, 10:41 AM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Castro, Childress and 34 more3 hr
May 20, 11:17 AM CDTMesoscale DiscussionSPCHardeman, Wichita, Wilbarger2 hr
May 20, 12:36 PM CDTTornado Watch PDSSPCArmstrong, Borden, Briscoe, Childress, Collingsworth, Cottle and 34 more9 hr
May 20, 1:37 PM CDTMesoscale DiscussionSPCBriscoe, Childress, Collingsworth, Cottle, Crosby, Dickens and 11 more53 min
May 20, 1:37 PM CDTTornado Watch PDSSPCArcher, Baylor, Clay, Foard, Hardeman, Knox and 2 more8 hr
May 20, 2:15 PM CDTMesoscale DiscussionSPCDallam, Hansford, Hartley, Hutchinson, Lipscomb, Moore and 4 more90 min
May 20, 5:08 PM CDTMesoscale DiscussionSPCCrane, Crockett, Glasscock, Midland, Reagan, Terrell and 1 more2 hr

Nearby

Mesoscale Discussions in Texas, 2019Every mesoscale discussion in 2019

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.