Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 736

May 25, 202121 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 25, 2021, 2:56 PM CDT for 21 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: May 25, 2021, 2:56 PM CDT (19:56 UTC)
Expired: May 25, 2021, 4:30 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 60%

All 21 counties

Armstrong County, TX, Borden County, TX, Briscoe County, TX, Carson County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hockley County, TX, Hutchinson County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Randall County, TX, Swisher County, TX, Terry County, TX

The radar

The Lubbock radar (KLBB), 56 km from the middle of the area, began a volume at 20:02 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 7.9 hours before the alert went out and 135 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2701 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 135 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

366 
ACUS11 KWNS 251956
SWOMCD
SPC MCD 251956 
TXZ000-252130-

Mesoscale Discussion 0736
NWS Storm Prediction Center Norman OK
0256 PM CDT Tue May 25 2021

Areas affected...portions of the TX Panhandle and South Plains
vicinity

Concerning...Severe potential...Watch possible 

Valid 251956Z - 252130Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated to widely scattered thunderstorms are expected in
the next couple of hours. Locally strong gusts and hail are possible
with the strongest storms.

DISCUSSION...A broad area of cumulus over parts of the TX
Panhandle/South Plains vicinity has shown signs of deepening over
the past 30-60 minutes per visible satellite loops. This activity is
developing within an axis of moderate instability, and near a
modified outflow boundary and weak surface trough. Latest
mesoanalysis as a 19z RAOB from AMA indicates little inhibition
remains over the region. Isolated to widely scattered thunderstorms
are likely to develop within the next 1-2 hours. Effective shear
remains weak across the region, with only around 20-25 kt indicated
in forecast soundings. While this may limit overall longevity of
organized cells, degree of instability combined with steep midlevel
lapse rates should support a least a couple of strong to severe
cells. Steep low level lapse rates, with a well-mixed sub-cloud
layer will promote strong downdraft and gusty outflow winds are
possible in addition to hail. Convective trends will be monitored
for possible watch issuance within the next couple of hours.

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

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

ATTN...WFO...LUB...AMA...MAF...

LAT...LON   33140081 32640108 32480146 32470181 32470198 32600234
            32780243 32980246 33460241 34330217 35170192 35370182
            35750156 35920123 35890096 35700064 35460047 35100040
            34110053 33800060 33140081

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, 2:02 PM CDT	Mesoscale Discussion	SPC	Brewster, Crane, Pecos, Terrell, Upton, Ward	118 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.