Alert archive / Texas / Mesoscale Discussions in 2021
Mesoscale Discussion 651
The Storm Prediction Center issued this mesoscale discussion at May 17, 2021, 1:11 PM MDT for 4 counties in New Mexico; 26 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 17, 2021, 1:11 PM MDT (19:11 UTC)
- Expired
- May 17, 2021, 3:15 PM MDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...tornado watch likely
- Chance of a watch
- 95%
All 30 counties
Curry County, NM, De Baca County, NM, Lea County, NM, Roosevelt County, NM, Andrews County, TX, Bailey County, TX, Borden County, TX, Castro County, TX, Cochran County, TX, Crane County, TX, Dawson County, TX, Ector County, TX, Gaines County, TX, Garza County, TX, Glasscock County, TX, Hale County, TX, Hockley County, TX, Howard County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Parmer County, TX, Swisher County, TX, Terry County, TX, Upton County, TX, Ward County, TX, Winkler County, TX, Yoakum County, TX
The radar
The Lubbock radar (KLBB), 145 km from the middle of the area, began a volume at 19:09 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 12:00Z, 7.2 hours before the alert went out and 166 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
- 1892 J/kg
- Mixed-layer CIN
- -22 J/kg
- Mixed-layer LCL
- 750 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 204 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 6.7
The text
As transmitted.
165
ACUS11 KWNS 171912
SWOMCD
SPC MCD 171911
TXZ000-NMZ000-172115-
Mesoscale Discussion 0651
NWS Storm Prediction Center Norman OK
0211 PM CDT Mon May 17 2021
Areas affected...Southeast/East-Central NM...TX South Plains...TX
Permian Basin
Concerning...Severe potential...Tornado Watch likely
Valid 171911Z - 172115Z
Probability of Watch Issuance...95 percent
SUMMARY...Thunderstorm initiation is anticipated with the next hour
or two across far southeast NM/far southwestern TX Panhandle/western
Permian Basin. Supercells capable of all severe hazards are possible
and a Tornado Watch will be issued to cover the severe threat.
DISCUSSION...Recent surface analysis places a low over about 45
miles northwest of ROW. A dryline extends southeastward from this
low through much of southeast NM before arcing back more southward
across the TX Trans Pecos. Northward returning low-level moisture
also results in an effective warm front, which extends from the
surface low northeastward through De Baca County NM and then back
southeastward through the TX South Plains. Deepen cumulus has been
observed within the area between these two boundaries, with a few
orphan anvils recently noted.
Expectation is for eventual convective initiation along the dryline
as it continues eastward/northeastward. Air mass across the region
has become moderately unstable, with mesoanalysis estimating 1000 to
1500 J/kg of MLCAPE is in place with little to no convective
inhibition. Effective deep layer shear is currently around 30 to 40
kt, with a gradual increase anticipated over the next few hours as
the shortwave trough moves through.
Overall environment supports initial supercells capable of all
severe hazards, including very large hail (i.e. greater than 2" in
diameter) and tornadoes. Some upscale growth is anticipated over
time, which will result in a transition to strong wind gusts as the
primary severe threat.
..Mosier/Guyer.. 05/17/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LUB...AMA...MAF...ABQ...
LAT...LON 31470323 32660376 33620409 34150526 34690498 34940358
34570160 32710115 31220165 31470323SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 17, 12:39 PM MDT | Mesoscale Discussion | SPC | Colfax, Harding, Mora, San Miguel, Santa Fe, Taos and 1 more | 2 hr |
| May 17, 1:39 PM MDT | Severe Thunderstorm Watch | SPC | Colfax, Guadalupe, Harding, Mora, San Miguel, Santa Fe and 2 more | 8 hr |
| May 17, 2:04 PM MDT | Tornado Watch | SPC | Curry, Quay, Roosevelt | 8 hr |
| May 17, 4:10 PM MDT | Mesoscale Discussion | SPC | Colfax, Guadalupe, Harding, Mora, Quay, San Miguel and 1 more | 2 hr |
| May 17, 4:36 PM MDT | Mesoscale Discussion | SPC | Curry | 84 min |
| May 16, 6:08 PM MDT | Severe Thunderstorm Watch | SPC | Cottle, Crosby, Dickens, Floyd, Garza, Hale and 8 more | 6 hr |
| May 16, 7:54 PM MDT | Mesoscale Discussion | SPC | Briscoe, Cottle, Foard, Hall, King, Knox and 1 more | 96 min |
| May 16, 8:38 PM MDT | Severe Thunderstorm Watch | SPC | Archer, Baylor, Clay, Foard, Hardeman, Haskell and 10 more | 4 hr |
| May 16, 9:46 PM MDT | Mesoscale Discussion | SPC | Baylor, Cottle, Dickens, Foard, Haskell, King and 3 more | 59 min |
| May 17, 12:09 AM MDT | Mesoscale Discussion | SPC | Archer, Baylor, Clay, Crosby, Dickens, Fisher and 17 more | 96 min |
| May 17, 8:18 AM MDT | Mesoscale Discussion | SPC | Jasper, Jefferson, Newton, Orange | 117 min |
| May 17, 11:47 AM MDT | Mesoscale Discussion | SPC | Austin, Bastrop, Bell, Blanco, Brazoria, Brazos and 29 more | 88 min |
| May 17, 3:44 PM MDT | Tornado Watch | SPC | Baylor, Childress, Cottle, Fisher, Foard, Hardeman and 10 more | 6 hr |
| May 17, 3:53 PM MDT | Mesoscale Discussion | SPC | Baylor, Callahan, Childress, Cottle, Fisher, Foard and 11 more | 97 min |
| May 17, 5:13 PM MDT | Mesoscale Discussion | SPC | Dimmit, La Salle, Webb | 92 min |
| May 17, 5:40 PM MDT | Severe Thunderstorm Watch | SPC | Dimmit, Frio, La Salle, Maverick, Webb, Zavala | 4 hr |
Nearby
Mesoscale Discussions in Texas, 2021Mesoscale Discussions in New Mexico, 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.