Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 734

May 25, 20216 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 25, 2021, 2:02 PM CDT for 6 counties in Texas. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: May 25, 2021, 2:02 PM CDT (19:02 UTC)
Expired: May 25, 2021, 4:00 PM CDT
In force: 118 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

Counties Brewster County, TX, Crane County, TX, Pecos County, TX, Terrell County, TX, Upton County, TX, Ward County, TX

The radar

The Midland/Odessa radar (KMAF), 182 km from the middle of the area, began a volume at 19:02 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.

Severe Thunderstorm Watch 204May 25, 4:05 PM CDT

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.0 hours before the alert went out and 182 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: 2087 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 217 m²/s²
0-3 km storm-relative helicity: 278 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

As transmitted.

337 
ACUS11 KWNS 251902
SWOMCD
SPC MCD 251902 
TXZ000-252100-

Mesoscale Discussion 0734
NWS Storm Prediction Center Norman OK
0202 PM CDT Tue May 25 2021

Areas affected...southwest Texas

Concerning...Severe potential...Watch possible 

Valid 251902Z - 252100Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated strong wind gusts and hail are possible this
afternoon across parts of southwest Texas near/east of the Davis
Mountains.

DISCUSSION...Isolated convection is developing near the Davis
Mountains/Marfa vicinity in southwest Texas this afternoon. While
capping is still an issue across the region per latest mesoanalysis
and regional forecast soundings, as the dryline continues to mix
eastward over the next couple of hours, this should aid in
weakening/erosion of the cap. Steep midlevel lapse rates greater
than 8 C/km are aiding in moderate destabilization across the
region. While this will aid in development of robust updrafts,
overall shear remains weak across the region. As storms develop and
move off of the higher terrain to the south of the Midland vicinity,
a couple of strong to severe cells are possible. Steep low level
lapse rates and well-mixed sub-cloud layer will aid in strong gust
potential, and steep midlevel lapse rates/sufficient instability
could result in a few instances of large hail. Given then weak shear
environment and potential for some weak inhibition to remain, storms
may have trouble remaining intense for a long period of time. As
such, a watch is not immediately anticipated, but may become
necessary depending on convective trends.

..Leitman/Guyer.. 05/25/2021

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

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

LAT...LON   30050173 29510216 29050298 29050344 29410385 29840401
            30360412 30940401 31310371 31530327 31640265 31530213
            31290183 30770171 30050173

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 24, 8:56 PM CDT	Mesoscale Discussion	SPC	Borden, Briscoe, Crosby, Dawson, Dickens, Floyd and 12 more	94 min
May 24, 11:43 PM CDT	Mesoscale Discussion	SPC	Baylor, Foard, King, Knox	2 hr
May 25, 12:32 PM CDT	Mesoscale Discussion	SPC	Anderson, Bowie, Camp, Cass, Cherokee, Delta and 25 more	118 min
May 25, 2:56 PM CDT	Mesoscale Discussion	SPC	Armstrong, Borden, Briscoe, Carson, Crosby, Dawson and 15 more	94 min
May 25, 4:08 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Borden, Briscoe, Callahan, Carson, Castro and 54 more	7 hr

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.