Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 799

May 29, 20217 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 29, 2021, 10:09 AM CDT for 7 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: May 29, 2021, 10:09 AM CDT (15:09 UTC)
Expired: May 29, 2021, 11:45 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Brooks County, TX, Cameron County, TX, Hidalgo County, TX, Jim Hogg County, TX, Kenedy County, TX, Starr County, TX, Willacy County, TX

The radar

The Brownsville radar (KBRO), 94 km from the middle of the area, began a volume at 15:10 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 3.2 hours before the alert went out and 96 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3154 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 544 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 6.6

Open this sounding in Storm Lab

The text

As transmitted.

162 
ACUS11 KWNS 291509
SWOMCD
SPC MCD 291509 
TXZ000-291645-

Mesoscale Discussion 0799
NWS Storm Prediction Center Norman OK
1009 AM CDT Sat May 29 2021

Areas affected...South TX

Concerning...Severe potential...Watch unlikely 

Valid 291509Z - 291645Z

Probability of Watch Issuance...20 percent

SUMMARY...An increase in thunderstorm intensity is possible over the
next few hours with a risk for isolated strong/severe wind gusts.  A
watch is not currently anticipated.

DISCUSSION...Latest KBRO reflectivity trends show thunderstorms
associated with a long-lived MCS continuing to move southeast, with
some intermittent increase in updraft intensity.  Despite
substantial MCS-associated high-level clouds extending downstream,
the presence of mid-upper 70s dew points has contributed to strong
surface-based instability.  Further, 25-30 kts of mid-level flow
will provide a favorable environment for continued
re-intensification of individual storms and perhaps some increase in
organization of the convective complex, which would increase the
risk for more concentrated damaging wind potential as the system
approaches the coast.

A watch is not anticipated, however trends will continue to be
monitored.

..Bunting/Hart.. 05/29/2021

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

ATTN...WFO...CRP...BRO...

LAT...LON   25949718 25879746 26049774 26079816 26259866 26409907
            26579913 26979921 27179878 27279806 27279751 27279742
            26499720 25949718

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 28, 7:18 PM CDT	Mesoscale Discussion	SPC	Crane, Crockett, Ector, Kimble, Reagan, Schleicher and 4 more	87 min
May 28, 7:40 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Bailey, Borden, Castro, Cochran, Crosby and 16 more	6 hr
May 28, 7:58 PM CDT	Mesoscale Discussion	SPC	Bandera, Bexar, Comal, Gonzales, Guadalupe, Medina and 2 more	2 hr
May 28, 9:12 PM CDT	Mesoscale Discussion	SPC	Andrews, Gaines, Hockley, Lubbock, Lynn, Terry	93 min
May 28, 10:15 PM CDT	Mesoscale Discussion	SPC	Bee, Brazoria, Calhoun, Fort Bend, Goliad, Jackson and 5 more	90 min
May 28, 11:22 PM CDT	Mesoscale Discussion	SPC	Crane, Pecos, Reeves, Upton, Ward, Winkler	113 min
May 29, 1:34 AM CDT	Mesoscale Discussion	SPC	Crockett, Dimmit, Edwards, Frio, Kimble, Kinney and 10 more	2 hr
May 29, 2:51 PM CDT	Mesoscale Discussion	SPC	Culberson, Hudspeth, Jeff Davis, Loving, Presidio, Reeves	114 min
May 29, 6:30 PM CDT	Mesoscale Discussion	SPC	Dallam, Hartley, Moore	90 min

Nearby

Mesoscale Discussions in Texas, 2021 Every 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.