Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 1346

July 25, 20217 counties in Oklahoma; 19 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2021, 4:57 PM CDT for 7 counties in Oklahoma; 19 counties in Texas. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jul 25, 2021, 4:57 PM CDT (21:57 UTC)
Expired
Jul 25, 2021, 6:30 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 26 counties

Beaver County, OK, Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Roger Mills County, OK, Armstrong County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Donley County, TX, Floyd County, TX, Gray County, TX, Hall County, TX, Hansford County, TX, Hardeman County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Motley County, TX, Ochiltree County, TX, Roberts County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 115 km from the middle of the area, began a volume at 22:00 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 10.0 hours before the alert went out and 114 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, Amarillo Airport, TX at 12:00Z on 2021-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 769 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 12:00Z on 2021-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -59 square meters per square second.1939Sfc1 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
769 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
1898 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-59 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

401 
ACUS11 KWNS 252158
SWOMCD
SPC MCD 252157 
OKZ000-TXZ000-252330-

Mesoscale Discussion 1346
NWS Storm Prediction Center Norman OK
0457 PM CDT Sun Jul 25 2021

Areas affected...Oklahoma and Texas Panhandles...far western
Oklahoma...and extreme northwest Texas

Concerning...Severe potential...Watch unlikely 

Valid 252157Z - 252330Z

Probability of Watch Issuance...5 percent

SUMMARY...Thunderstorms will continue across the area this
afternoon. Extreme instability will support brief potential for
severe hail and wind with the strongest thunderstorm updrafts. Weak
shear should limit the overall severe threat. A watch is not
expected.

DISCUSSION...Showers and thunderstorms continue to develop within a
band of low-level convergence associated with the lee trough.
Extreme instability, most-unstable CAPE in excess of 3500 J/kg, may
support brief, isolated large hail and gusty thunderstorm outflows
with the strongest updraft pulses. However, weak effective-layer
shear -- between 10-15 knots -- will limit overall thunderstorm
organization to storm-scale processes. Thunderstorm intensity should
wane later this evening with the loss of diurnal heating. The
overall disorganized nature of the threat should preclude the need
of a watch.

..Marsh/Grams.. 07/25/2021

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

ATTN...WFO...OUN...LUB...AMA...

LAT...LON   36800127 36950094 36959975 36709946 35609948 34659950
            34109971 33510045 33850150 34990158 36190138 36800127

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Oklahoma, 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.