Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 586

May 10, 20218 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 10, 2021, 6:05 PM CDT for 8 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 10, 2021, 6:05 PM CDT (23:05 UTC)
Expired: May 10, 2021, 8:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Bee County, TX, Dimmit County, TX, Duval County, TX, Jim Wells County, TX, La Salle County, TX, Live Oak County, TX, McMullen County, TX, Webb County, TX

The radar

The Corpus Christi radar (KCRP), 108 km from the middle of the area, began a volume at 23:09 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 nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 11.1 hours before the alert went out and 126 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: 1226 J/kg
Mixed-layer CIN: -331 J/kg
Mixed-layer LCL: 1021 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

529 
ACUS11 KWNS 102305
SWOMCD
SPC MCD 102305 
TXZ000-110130-

Mesoscale Discussion 0586
NWS Storm Prediction Center Norman OK
0605 PM CDT Mon May 10 2021

Areas affected...South-central Texas

Concerning...Severe potential...Watch possible 

Valid 102305Z - 110130Z

Probability of Watch Issuance...40 percent

SUMMARY...A severe threat will likely develop across parts of
south-central Texas this evening. Large hail and wind damage will be
possible. Weather watch issuance may be needed as cell coverage
increases over the next few hours.

DISCUSSION...The latest radar imagery from Del Rio, Texas shows a
cluster of strong to severe thunderstorms to the east of the Sierra
Madre Oriental mountain range. These storms are moving through far
northern Mexico and will cross the international border over the
couple of hours. The airmass near and to the east of the lower Rio
Grande Valley is strongly unstable, with the RAP estimating MLCAPE
in the 3500 to 4500 J/k range. Surface dewpoints are near 70 F. This
thermodynamic environment also includes steep lapse rates in the
mid-levels, approaching 8.0 C/km according to the RAP. This will be
favorable for large hail. Forecast models suggest that supercells
with a left-moving tendency will be possible. As the cells move into
south-central Texas later this evening, the wind-damage threat could
increase, especially if a cold pool can organize. Weather watch
issuance may be needed under this scenario.

..Broyles/Hart.. 05/10/2021

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

ATTN...WFO...CRP...EWX...

LAT...LON   28739801 28649767 28389753 27919756 27689776 27549840
            27399939 27709991 28250013 28569956 28739801

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 9, 8:06 PM CDT	Mesoscale Discussion	SPC	Anderson, Bell, Blanco, Bosque, Burnet, Comal and 32 more	114 min
May 10, 10:28 AM CDT	Mesoscale Discussion	SPC	Delta, Fannin, Grayson, Lamar, Red River	92 min
May 10, 1:04 PM CDT	Mesoscale Discussion	SPC	Edwards, Kinney, Real, Terrell, Val Verde	116 min
May 10, 1:48 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bexar, Crockett, Dimmit, Edwards and 14 more	10 hr
May 10, 2:07 PM CDT	Mesoscale Discussion	SPC	Grimes, Houston, Madison, Polk, San Jacinto, Trinity and 2 more	113 min
May 10, 5:47 PM CDT	Mesoscale Discussion	SPC	Brazos, Grimes, Jasper, Montgomery, Polk, San Jacinto and 2 more	88 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.