Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 1147

July 4, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2021, 1:36 PM MDT for 4 states. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jul 4, 2021, 1:36 PM MDT (19:36 UTC)
Expired
Jul 4, 2021, 3:30 PM MDT
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%
All 25 counties

Huerfano County, CO, Las Animas County, CO, Colfax County, NM, Curry County, NM, Harding County, NM, Mora County, NM, Quay County, NM, San Miguel County, NM, Union County, NM, Cimarron County, OK, Armstrong County, TX, Carson County, TX, Castro County, TX, Dallam County, TX, Deaf Smith County, TX, Hansford County, TX, Hartley County, TX, Hutchinson County, TX, Moore County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Sherman County, TX, Swisher County, TX

The radar

The Cannon AFB radar (KFDX), 149 km from the middle of the area, began a volume at 19:36 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.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 7.6 hours before the alert went out and 178 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 2021-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 997 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 2021-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.193958Sfc1 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
997 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
825 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.3

Open this sounding in Storm Lab

The text

As transmitted.

377 
ACUS11 KWNS 041936
SWOMCD
SPC MCD 041936 
TXZ000-OKZ000-COZ000-NMZ000-042130-

Mesoscale Discussion 1147
NWS Storm Prediction Center Norman OK
0236 PM CDT Sun Jul 04 2021

Areas affected...northeast New Mexico and southeast Colorado into
the Texas Panhandle

Concerning...Severe potential...Watch possible 

Valid 041936Z - 042130Z

Probability of Watch Issuance...60 percent

SUMMARY...Storms are expected to increase over the Sangre De Cristo
mountains, and within a surface trough extending east into the
Panhandles. Some of the storms may produce large hail and locally
damaging gusts.

DISCUSSION...Visible imagery shows the remnants of an MCV over
western OK and the TX Panhandle where a pockets of cooler
temperatures remain. Substantial CU is noted on satellite imagery
west of this feature and into northeast NM where temperatures
continue to warm. Meanwhile, convection is slow building over the
Sangre De Cristo mountains.

Continued heating and ample moisture will support scattered strong
to severe storms. Weak northwest flow aloft atop the surface
southerlies will elongate hodographs favorably for a few long-lived
cells. Supercells will be possible for cells moving due-south or
southwestward, maximizing the meager SRH.

..Jewell/Guyer.. 07/04/2021

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

ATTN...WFO...LUB...AMA...PUB...ABQ...

LAT...LON   35410553 35870531 36330515 36930490 37750507 37800462
            37370325 37010219 36730161 36410118 35740097 34770112
            34430164 34340269 34480357 34640430 35410553

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 2:37 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Crowley, El Paso, Huerfano, Kiowa and 4 more7 hr
Jul 4, 3:01 PM MDTSevere Thunderstorm WatchSPCCheyenne7 hr
Jul 4, 5:29 PM MDTMesoscale DiscussionSPCCurry91 min
Jul 4, 5:56 PM MDTMesoscale DiscussionSPCBeaver, Texas94 min

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in New Mexico, 2021Mesoscale Discussions in Colorado, 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.