Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 243

March 24, 202137 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2021, 6:10 PM CDT for 37 counties in Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Mar 24, 2021, 6:10 PM CDT (23:10 UTC)
Expired
Mar 24, 2021, 7:15 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 47
All 37 counties

Bell County, TX, Bosque County, TX, Brown County, TX, Burnet County, TX, Comanche County, TX, Concho County, TX, Coryell County, TX, Dallas County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Johnson County, TX, Kaufman County, TX, Kerr County, TX, Kimble County, TX, Lampasas County, TX, Limestone County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Mills County, TX, Navarro County, TX, Rains County, TX, Rockwall County, TX, San Saba County, TX, Somervell County, TX, Tarrant County, TX, Van Zandt County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 115 km from the middle of the area, began a volume at 23:13 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 12:00Z, 11.2 hours before the alert went out and 153 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 12:00Z on 2021-03-24Temperature 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 12:00Z on 2021-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 182 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
1705 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
182 m²/s²
0-3 km storm-relative helicity
362 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

543 
ACUS11 KWNS 242310
SWOMCD
SPC MCD 242310 
TXZ000-250015-

Mesoscale Discussion 0243
NWS Storm Prediction Center Norman OK
0610 PM CDT Wed Mar 24 2021

Areas affected...portions of central and north-central Texas

Concerning...Tornado Watch 47...

Valid 242310Z - 250015Z

The severe weather threat for Tornado Watch 47 continues.

SUMMARY...The severe threat continues across WW 47.

DISCUSSION...Scattered cellular convection, including a few
supercells, have evolved near/just east of the DFW metro area over
the past hour.  Additionally, a longer-lived supercell over San
Saba/Mills/Hamilton counties has recently produced 1.5-1.75 inch
hail.  Additional shallow convection has deepened in the past 15
minutes along the I-35 corridor between Waco and Hillsboro.  The
storms are in a favorable environment for updraft rotation, with
southeasterly low-level flow veering strongly with height amid weak
to moderate instability.  Additionally, the cells just east of DFW
appear to be interacting favorably with a warm front lifting
northward along the I-20 corridor in that area.  As gradual
low-level moistening continues, surface-based convection is expected
to continue to pose a risk for tornadoes in addition to hail
(potentially significant near supercells).  A greater tornado risk
may evolve after the 00Z time frame pending backing of low-level
wind fields due to cyclogenesis along the Rio Grande/Big Bend area.

..Cook.. 03/24/2021

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

ATTN...WFO...SHV...FWD...EWX...SJT...

LAT...LON   31569956 32179905 32709797 33069657 33049602 32809556
            32249539 31659587 31029687 30349821 30049936 30160000
            30490018 31140019 31569956

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 3:22 PM CDTMesoscale DiscussionSPCAnderson, Bell, Bosque, Brown, Burnet, Comanche and 32 more2 hr
Mar 24, 4:38 PM CDTTornado WatchSPCBell, Bosque, Brown, Burnet, Comanche, Coryell and 21 more5 hr
Mar 24, 4:59 PM CDTSevere Thunderstorm WatchSPCCamp, Collin, Cooke, Dallas, Delta, Denton and 18 more5 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; radar from the NEXRAD Level II archive.