Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 158

March 12, 2021Curry County, Roosevelt County, New Mexico; 27 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 12, 2021, 4:58 PM MST for Curry County, Roosevelt County, New Mexico; 27 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 12, 2021, 4:58 PM MST (23:58 UTC)
Expired
Mar 12, 2021, 7:00 PM MST
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Tornado watch 17
All 29 counties

Curry County, NM, Roosevelt County, NM, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Castro County, TX, Cochran County, TX, Cottle County, TX, Crosby County, TX, Deaf Smith County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Hale County, TX, Hall County, TX, Hockley County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Parmer County, TX, Randall County, TX, Stonewall County, TX, Swisher County, TX, Terry County, TX, Yoakum County, TX

The radar

The Lubbock radar (KLBB), 36 km from the middle of the area, began a volume at 00:02 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.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 12.0 hours before the alert went out and 157 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 2021-03-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 66 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 2021-03-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 345 square meters per square second.1939587897117Sfc1 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
66 J/kg
Mixed-layer CIN
-163 J/kg
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
81 kt
0-1 km storm-relative helicity
345 m²/s²
0-3 km storm-relative helicity
390 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

072 
ACUS11 KWNS 122359
SWOMCD
SPC MCD 122358 
TXZ000-NMZ000-130200-

Mesoscale Discussion 0158
NWS Storm Prediction Center Norman OK
0558 PM CST Fri Mar 12 2021

Areas affected...Eastern NM...TX South Plains

Concerning...Tornado Watch 17...

Valid 122358Z - 130200Z

The severe weather threat for Tornado Watch 17 continues.

SUMMARY...Severe threat continues across ww017.

DISCUSSION...Weak surface low is expected to become focused over
southeastern NM during the overnight hours in response to upper low,
currently over the lower CO River Valley, shifting east across AZ.
As a result, easterly low-level component will persist across the
southern High Plains assuring modest buoyancy will likely be
maintained. Scattered supercells have evolved across this region
with one longer-lived storm having already produced a tornado
northwest of LBB. Given the moist, unstable profiles noted across
this region, additional development is likely, especially if LLJ
strengthens after dark as would be expected ahead of the approaching
trough. Large hail and isolated tornadoes remain possible until
boundary layer cools enough for updrafts to become more elevated.

..Darrow.. 03/12/2021

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

ATTN...WFO...OUN...SJT...LUB...AMA...MAF...ABQ...

LAT...LON   33040314 35080386 35090050 33069989 33040314

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 12, 2:24 PM MSTTornado WatchSPCCurry, Quay, Roosevelt5 hr
Mar 12, 12:48 PM MSTMesoscale DiscussionSPCArmstrong, Briscoe, Castro, Childress, Collingsworth, Cottle and 15 more117 min

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.