Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 192

March 17, 202112 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2021, 2:20 AM CDT for 12 counties in Texas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Mar 17, 2021, 2:20 AM CDT (07:20 UTC)
Expired
Mar 17, 2021, 3:45 AM CDT
In force
85 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 23

Counties Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Eastland County, TX, Erath County, TX, Hamilton County, TX, McCulloch County, TX, Mills County, TX, Palo Pinto County, TX, San Saba County, TX, Stephens County, TX

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 7.3 hours before the alert went out and 181 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 2021-03-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1277 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, Fort Worth, TX at 00:00Z on 2021-03-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 158 square meters per square second.19395878Sfc1 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
1277 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
1084 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
237 m²/s²
Significant tornado parameter
0.6
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

376 
ACUS11 KWNS 170721
SWOMCD
SPC MCD 170720 
TXZ000-170845-

Mesoscale Discussion 0192
NWS Storm Prediction Center Norman OK
0220 AM CDT Wed Mar 17 2021

Areas affected...Portions of central TX

Concerning...Severe Thunderstorm Watch 23...

Valid 170720Z - 170845Z

The severe weather threat for Severe Thunderstorm Watch 23
continues.

SUMMARY...Mainly an isolated large hail and severe wind threat
continues across Severe Thunderstorm Watch 23 early this morning.

DISCUSSION...A small cluster of storms across part of central TX is
expected to move eastward over the next couple of hours. Hail up to
the size of golf balls occurred earlier with this convection, and
large hail will remain possible given around 50 kt of deep-layer
shear and the presence of steep mid-level lapse rates. Additional
upscale growth along an eastward-moving composite dryline/Pacific
cold front appears possible. Even though some MLCIN remains present
ahead of this activity per latest mesoanalysis estimates, a large
reservoir of instability (MLCAPE 2000-2500 J/kg) and steep lapse
rates aloft may also support an increasing severe wind gust threat,
particularly if convection becomes more linear with time.

..Gleason.. 03/17/2021

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

ATTN...WFO...FWD...SJT...

LAT...LON   31099963 31609935 32219944 32829919 33149891 33179805
            32399803 31549808 31119844 30979908 31099963

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 16, 7:49 PM CDTSevere Thunderstorm WatchSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Roberts and 1 more7 hr
Mar 16, 9:27 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Coke, Coleman and 30 more93 min
Mar 16, 10:26 PM CDTSevere Thunderstorm WatchSPCBell, Bosque, Brown, Callahan, Coke, Coleman and 44 more7 hr
Mar 17, 1:32 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 7 more118 min
Mar 17, 4:04 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 25 more86 min
Mar 17, 4:37 AM CDTSevere Thunderstorm WatchSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 30 more5 hr
Mar 17, 4:38 AM CDTMesoscale DiscussionSPCArmstrong, Carson, Dallam, Deaf Smith, Gray, Hansford and 11 more6 hr
Mar 17, 6:40 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Delta and 16 more95 min
Mar 17, 8:43 AM CDTTornado WatchSPCAngelina, Nacogdoches, Sabine, San Augustine, Shelby4 hr
Mar 17, 11:35 AM CDTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Galveston, Hardin, Harris and 10 more85 min
Mar 17, 11:53 AM CDTTornado WatchSPCHardin, Jasper, Jefferson, Newton, Orange, Tyler6 hr

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.