Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 638

May 16, 20217 counties in New Mexico; 18 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 16, 2021, 2:16 PM MDT for 7 counties in New Mexico; 18 counties in Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
May 16, 2021, 2:16 PM MDT (20:16 UTC)
Expired
May 16, 2021, 4:15 PM MDT
In force
119 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
80%
All 25 counties

Curry County, NM, De Baca County, NM, Guadalupe County, NM, Harding County, NM, Quay County, NM, Roosevelt County, NM, San Miguel County, NM, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Cochran County, TX, Deaf Smith County, TX, Floyd County, TX, Hale County, TX, Hartley County, TX, Hutchinson County, TX, Lamb County, TX, Moore County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Swisher County, TX

The radar

The Cannon AFB radar (KFDX), 18 km from the middle of the area, began a volume at 20:18 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, 8.3 hours before the alert went out and 172 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 2021-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -57 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1470 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-57 m²/s²
0-3 km storm-relative helicity
-16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

028 
ACUS11 KWNS 162016
SWOMCD
SPC MCD 162016 
TXZ000-NMZ000-162215-

Mesoscale Discussion 0638
NWS Storm Prediction Center Norman OK
0316 PM CDT Sun May 16 2021

Areas affected...Eastern NM...Western/Central TX Panhandle...TX
South Plains

Concerning...Severe potential...Watch likely 

Valid 162016Z - 162215Z

Probability of Watch Issuance...80 percent

SUMMARY...Increasing thunderstorm coverage anticipated, with an
attendant threat for large hail and damaging wind gusts. A Severe
Thunderstorm Watch will likely be needed to cover this threat.

DISCUSSION...Visible satellite imagery shows cumulus continuing to
deepen along the dryline across central NM. Mesoanalysis estimates
that convective inhibition has now eroded downstream across much of
east-central NM, and the expectation is for the deepening to
continue, with eventual convective initiation. This activity, along
with the storms developing across far northeast NM and southeast CO
(discussed in MCD 636), is expected to move eastward over time into
the more moist and unstable air mass over the TX Panhandle. 
Additionally, cumulus has started to build in the vicinity of a
remnant outflow boundary which stretches from near DHT southeastward
to north of CDS. 19Z AMA sounding sampled a weakly capped
environment near this boundary, and there is at least some potential
for thunderstorm development along this boundary as well.

Overall expectation is for thunderstorm coverage to gradually
increase over the next few hours. The environment is weakly sheared,
but steep low/mid-level lapse rates coupled favorable low-level
moisture will still result in enough buoyancy for strong to severe
storms. Hail is possible with initial, more cellular development and
as a result of updraft intensification due to cell mergers. High
storm bases and a deeply mixed boundary layer will also promote
strong outflow. Some amalgamation of this outflow is possible later
this evening.

..Mosier/Guyer.. 05/16/2021

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

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

LAT...LON   33570527 35600480 36090393 36200265 35860098 33810127
            33460386 33570527

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 16, 1:23 PM MDTMesoscale DiscussionSPCUnion2 hr
May 16, 2:43 PM MDTSevere Thunderstorm WatchSPCCurry, Harding, Quay, Union7 hr
May 15, 8:09 PM MDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Castro, Crosby, Floyd and 11 more96 min
May 15, 8:32 PM MDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 11 more88 min
May 16, 11:15 AM MDTMesoscale DiscussionSPCAnderson, Bastrop, Bell, Brazos, Burleson, Cherokee and 22 more2 hr
May 16, 2:46 PM MDTMesoscale DiscussionSPCArcher, Clay, Cooke, Jack, Montague, Wichita and 1 more89 min
May 16, 4:52 PM MDTMesoscale DiscussionSPCGlasscock, Howard, Irion, Midland, Reagan, Sterling53 min
May 16, 5:12 PM MDTMesoscale DiscussionSPCArmstrong, Briscoe, Carson, Castro, Childress, Deaf Smith and 7 more93 min
May 16, 5:35 PM MDTSevere Thunderstorm WatchSPCBorden, Coke, Crockett, Dawson, Fisher, Glasscock and 12 more4 hr

Nearby

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