Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 813
The Storm Prediction Center issued this mesoscale discussion at May 30, 2021, 5:37 PM CDT for 22 counties in Texas. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- May 30, 2021, 5:37 PM CDT (22:37 UTC)
- Expired
- May 30, 2021, 7:00 PM CDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 80%
All 22 counties
Bailey County, TX, Briscoe County, TX, Castro County, TX, Cochran County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Floyd County, TX, Garza County, TX, Hale County, TX, Hall County, TX, Hockley County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Parmer County, TX, Swisher County, TX, Terry County, TX, Yoakum County, TX
The radar
The Lubbock radar (KLBB), 26 km from the middle of the area, began a volume at 22:38 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, 10.6 hours before the alert went out and 159 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.
- Mixed-layer CAPE
- 64 J/kg
- Mixed-layer CIN
- -307 J/kg
- Mixed-layer LCL
- 1320 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 188 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
014
ACUS11 KWNS 302238
SWOMCD
SPC MCD 302237
TXZ000-310000-
Mesoscale Discussion 0813
NWS Storm Prediction Center Norman OK
0537 PM CDT Sun May 30 2021
Areas affected...portions of Texas South Plains
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 302237Z - 310000Z
Probability of Watch Issuance...80 percent
SUMMARY...Severe potential is expected to increase over the next few
hours as storms within Severe Thunderstorm Watch #225 move into
western Texas from eastern New Mexico. Large hail and damaging winds
are the main threats with these storms, though a brief tornado
cannot be ruled out.
DISCUSSION...Discrete to semi-discrete supercells, with 50+ dBZ
echoes exceeding 45 kft (per latest MRMS mosaic radar data) are
gradually progressing eastward towards the eastern bounds of Severe
Thunderstorm Watch #225 in southeast New Mexico, and are poised to
moved into western Texas within the next couple of hours. MRMS
mosaic MESH suggests that severe hail (perhaps briefly reaching 2.0
inches in diameter) has been occurring with these storms, which are
progressing into a 7.5 C/km low and mid-level lapse rate
environment, where 1500 J/kg MLCAPE and 40+ kts effective bulk shear
are present. As such, the potential for large hail and perhaps a
brief tornado is expected to continue with these storms while they
remain at least partially discrete. However, latest high-resolution
guidance suggests that upscale growth into linear segments is likely
given cold pool mergers in a relatively weak low-level shear
environment. Damaging gusts would then become the main concern with
storms that become more linear with time.
..Squitieri/Guyer.. 05/30/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LUB...AMA...MAF...
LAT...LON 32930298 33890303 34590292 34770249 34790138 34760057
34500020 34100012 33570016 33010057 32790131 32790196
32930298SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 29, 7:28 PM CDT | Severe Thunderstorm Watch | SPC | Dallam, Hartley, Oldham, Sherman | 8 hr |
| May 29, 9:20 PM CDT | Mesoscale Discussion | SPC | Dallam, Hartley, Sherman | 85 min |
| May 29, 11:59 PM CDT | Mesoscale Discussion | SPC | Dallam, Hartley, Moore, Oldham, Potter, Sherman | 61 min |
| May 30, 2:00 AM CDT | Mesoscale Discussion | SPC | Castro, Deaf Smith, Oldham, Parmer, Potter, Randall | 60 min |
| May 30, 3:52 PM CDT | Mesoscale Discussion | SPC | Armstrong, Briscoe, Carson, Castro, Childress, Collingsworth and 20 more | 113 min |
| May 30, 4:42 PM CDT | Tornado Watch | SPC | Armstrong, Carson, Dallam, Deaf Smith, Donley, Gray and 10 more | 7 hr |
| May 30, 6:03 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Bailey, Borden, Briscoe, Castro, Childress and 30 more | 7 hr |
| May 30, 6:04 PM CDT | Mesoscale Discussion | SPC | Dallam, Hansford, Hartley, Hemphill, Hutchinson, Moore and 3 more | 86 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.