Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 798

May 29, 202116 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 29, 2021, 1:34 AM CDT for 16 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 29, 2021, 1:34 AM CDT (06:34 UTC)
Expired
May 29, 2021, 4:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
40%

Counties Crockett County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Kimble County, TX, Kinney County, TX, La Salle County, TX, Maverick County, TX, Menard County, TX, Real County, TX, Schleicher County, TX, Sutton County, TX, Tom Green County, TX, Uvalde County, TX, Val Verde County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 53 km from the middle of the area, began a volume at 06:34 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 nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 6.6 hours before the alert went out and 46 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, Del Rio, TX at 00:00Z on 2021-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3576 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2021-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
3576 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
1255 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
166 m²/s²
Significant tornado parameter
3.0
Supercell composite
14.8

Open this sounding in Storm Lab

The text

As transmitted.

073 
ACUS11 KWNS 290635
SWOMCD
SPC MCD 290634 
TXZ000-290900-

Mesoscale Discussion 0798
NWS Storm Prediction Center Norman OK
0134 AM CDT Sat May 29 2021

Areas affected...Portions of the Edwards Plateau into south-central
TX

Concerning...Severe potential...Watch possible 

Valid 290634Z - 290900Z

Probability of Watch Issuance...40 percent

SUMMARY...Severe/damaging wind gusts may continue with a cluster of
storms. Watch issuance is possible.

DISCUSSION...An organized cluster of storms will probably continue
southeastward early this morning along the MLCAPE gradient present
across the Edwards Plateau. Although some convective inhibition is
present across this region, persistent 30-35 kt low-level
southeasterly winds indicated on the KDFX VWP will maintain a fetch
of moist boundary-layer air ahead of these storms. KE41 in west TX
recently gusted to 51 kt as the cluster moved through, and enhanced
outbound velocities have been observed from the KMAF radar. Strong
deep-layer shear will likely support continued organization with
this cluster in the short term, and the presence of steep mid-level
lapse rates observed on the 00Z DRT sounding are contributing to
substantial MUCAPE (2000-3000 J/kg) per latest mesoanalysis
estimates. Although it remains unclear how long the cluster will
persist since some MLCIN is present, a threat for at least isolated
severe/damaging winds will probably continue for a few hours early
this morning. A somewhat greater severe threat should remain
confined along and south of an outflow boundary from earlier
convection that is present across this region.

..Gleason/Grams.. 05/29/2021

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

ATTN...WFO...CRP...EWX...SJT...MAF...

LAT...LON   30780170 31050134 31650043 30909970 29379925 29059886
            28539876 28079932 28020007 28380040 29040074 29380110
            29680144 29770172 30640207 30780170

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 28, 11:22 PM CDTMesoscale DiscussionSPCCrane, Pecos, Reeves, Upton, Ward, Winkler113 min
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.