Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 232

March 22, 202159 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 22, 2021, 8:25 PM CDT for 59 counties in Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Mar 22, 2021, 8:25 PM CDT (01:25 UTC)
Expired
Mar 22, 2021, 9:30 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 45
All 59 counties

Archer County, TX, Baylor County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Brown County, TX, Burnet County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Foard County, TX, Gillespie County, TX, Hamilton County, TX, Haskell County, TX, Hill County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Knox County, TX, Lampasas County, TX, Limestone County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Milam County, TX, Mills County, TX, Montague County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Robertson County, TX, Runnels County, TX, San Saba County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Travis County, TX, Wichita County, TX, Wilbarger County, TX, Williamson County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 70 km from the middle of the area, began a volume at 01:27 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.4 hours before the alert went out and 142 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, Fort Worth, TX at 00:00Z on 2021-03-23Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2021-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 404 square meters per square second.1939587897Sfc1 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
679 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
404 m²/s²
0-3 km storm-relative helicity
672 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

209 
ACUS11 KWNS 230126
SWOMCD
SPC MCD 230125 
TXZ000-OKZ000-230230-

Mesoscale Discussion 0232
NWS Storm Prediction Center Norman OK
0825 PM CDT Mon Mar 22 2021

Areas affected...northern and central Texas

Concerning...Severe Thunderstorm Watch 45...

Valid 230125Z - 230230Z

The severe weather threat for Severe Thunderstorm Watch 45
continues.

SUMMARY...The severe threat continues across WW 45.  Additional
convection west of the WW may pose a severe risk over the next
couple hours or so.

DISCUSSION...Scattered convective cells and bands continue across
central Texas currently, with one supercell over Coryell County
responsible for 1.5 inch hail over the past half hour.  Additional
convection has developed west of the WW in Taylor County, and
redevelopment has also occurred on the southwestern flank of the
ongoing central Texas cluster near Mason County.  These cells are in
a weakly to moderately unstable environment (characterized by around
1000-1500 J/kg MUCAPE) with strong low-level shear that has recently
improved due to increasing 850mb flow.  The reinvigoration of
western-most convection is indicative of steepening mid-level lapse
rates and lift associated with an upstream mid-level wave over the
Texas South Plains.  Meanwhile, near 60F dewpoints will likely be
maintained over the course of the evening due to the strong
low-level flow, and near-surface-based convection appears probable
for at least the next couple hours.  Large hail (especially within
rotating updrafts) and damaging wind gusts are possible, and a
tornado cannot be completely ruled out.

..Cook/Guyer.. 03/23/2021

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

ATTN...WFO...HGX...FWD...OUN...EWX...SJT...LUB...

LAT...LON   33240000 33880010 34189987 34079881 33759728 33299652
            32379649 31689627 30939628 30329703 30079822 30209927
            30469972 31160017 31920019 32770024 33240000

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 22, 10:21 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bell, Bexar, Blanco, Bosque and 52 more54 min
Mar 22, 10:44 PM CDTMesoscale DiscussionSPCDelta, Fannin, Franklin, Hopkins, Hunt, Kaufman and 6 more61 min
Mar 22, 11:10 PM CDTSevere Thunderstorm WatchSPCAustin, Bandera, Bastrop, Bexar, Blanco, Brazos and 29 more5 hr
Mar 23, 1:29 AM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bexar, Brazos and 29 more91 min
Mar 23, 3:19 AM CDTMesoscale DiscussionSPCAngelina, Austin, Colorado, DeWitt, Fayette, Fort Bend and 20 more56 min

Nearby

Mesoscale Discussions in Texas, 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.