Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 797

May 28, 20216 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2021, 11:22 PM CDT for 6 counties in Texas. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
May 28, 2021, 11:22 PM CDT (04:22 UTC)
Expired
May 29, 2021, 1:15 AM CDT
In force
113 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 220...222

Counties Crane County, TX, Pecos County, TX, Reeves County, TX, Upton County, TX, Ward County, TX, Winkler County, TX

The radar

The Midland/Odessa radar (KMAF), 107 km from the middle of the area, began a volume at 04:22 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

Midland Regional, TX (KMAF), launched 00:00Z, 4.4 hours before the alert went out and 107 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 2021-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2460 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, Midland Regional, TX at 00:00Z on 2021-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
2460 J/kg
Mixed-layer CIN
-89 J/kg
Mixed-layer LCL
1075 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
267 m²/s²
Significant tornado parameter
2.7
Supercell composite
18.5

Open this sounding in Storm Lab

The text

As transmitted.

145 
ACUS11 KWNS 290422
SWOMCD
SPC MCD 290422 
TXZ000-290615-

Mesoscale Discussion 0797
NWS Storm Prediction Center Norman OK
1122 PM CDT Fri May 28 2021

Areas affected...Parts of the Texas South Plains into southwestern
Texas

Concerning...Severe Thunderstorm Watch 220...222...

Valid 290422Z - 290615Z

The severe weather threat for Severe Thunderstorm Watch 220, 222
continues.

SUMMARY...It is not certain a new severe weather watch will be
issued at current Midnight watch expiration, but trends are being
monitored for this possibility.  At least isolated strong to severe
storm development may persist into the overnight hours, mainly near
the Pecos River into the higher terrain to the southwest.

DISCUSSION...The south-southeastward propagating convective system
has undergone substantive weakening across parts of the Texas South
Plains, as low-level inflow has generally become progressively less
unstable.  However, 55-65+ kt inbound velocities have been evident
in the lowest 1-2 km on Midland radar, associated with convective
outflow tending to surge out ahead of the weakening convective line.
 This should begin to weaken across and southeast of the Midland
area as convection continues to weaken.  However, upslope flow into
the higher terrain across and southwest of the Pecos River could
maintain or support additional vigorous thunderstorm development
through 06-07Z. This is where steep lapse rates associated with
capping elevated mixed-layer air continues to support large CAPE. 
In the presence of strong shear (largely due to pronounced veering
of lower to mid tropospheric wind fields with height), isolated to
widely scattered supercell development remains possible, posing a
risk for large hail and locally damaging wind gusts.

..Kerr.. 05/29/2021

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

ATTN...WFO...SJT...MAF...

LAT...LON   31710410 31950284 31680197 30860161 30860177 30250189
            30450287 30680313 31190377 31710410

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 7:18 PM CDTMesoscale DiscussionSPCCrane, Crockett, Ector, Kimble, Reagan, Schleicher and 4 more87 min
May 28, 7:40 PM CDTSevere Thunderstorm WatchSPCAndrews, Bailey, Borden, Castro, Cochran, Crosby and 16 more6 hr
May 28, 7:58 PM CDTMesoscale DiscussionSPCBandera, Bexar, Comal, Gonzales, Guadalupe, Medina and 2 more2 hr
May 28, 9:12 PM CDTMesoscale DiscussionSPCAndrews, Gaines, Hockley, Lubbock, Lynn, Terry93 min
May 28, 10:15 PM CDTMesoscale DiscussionSPCBee, Brazoria, Calhoun, Fort Bend, Goliad, Jackson and 5 more90 min
May 29, 1:34 AM CDTMesoscale DiscussionSPCCrockett, Dimmit, Edwards, Frio, Kimble, Kinney and 10 more2 hr
May 29, 10:09 AM CDTMesoscale DiscussionSPCBrooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Starr and 1 more96 min
May 29, 2:51 PM CDTMesoscale DiscussionSPCCulberson, Hudspeth, Jeff Davis, Loving, Presidio, Reeves114 min
May 29, 6:30 PM CDTMesoscale DiscussionSPCDallam, Hartley, Moore90 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.