Mesoscale Discussion 242

Issued

Mar 24, 2021, 3:22 PM CDT (20:22 UTC)

Expired

Mar 24, 2021, 5:45 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch likely

Chance of a watch

80%

The Dallas/Ft Worth radar (KFWS), 102 km from the middle of the area, began a volume at 20:24 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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• Tornado Watch 47Mar 24, 4:40 PM CDT
• Severe Thunderstorm Watch 48Mar 24, 5:00 PM CDT

925 
ACUS11 KWNS 242022
SWOMCD
SPC MCD 242022 
TXZ000-242245-

Mesoscale Discussion 0242
NWS Storm Prediction Center Norman OK
0322 PM CDT Wed Mar 24 2021

Areas affected...Central/North-Central TX

Concerning...Severe potential...Watch likely 

Valid 242022Z - 242245Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorm development is anticipated this evening
across western portions of central and north-central TX. Threat for
large hail, damaging wind gusts, and perhaps a tornado or two will
accompany this storms as they move northeastward into more of
central and north-central TX. Trends are being monitored for
possible watch issuance.

DISCUSSION...Recent surface analysis places a weak low just
southeast of BWD in central TX. A warm front extends eastward from
this low, demarcated well by both the 56 deg F isodrosotherm and the
edge of the cloud shield in visible satellite imagery. A surface
trough also extends southwestward from this low before arcing back
northwestward south of SJT into the TX Permian Basin. 

The air mass south of the warm front also continues to destabilize,
particularly over the TX Hill County in the vicinity of the low.
Recent mesoanalysis suggests MLCAPE around 500 J/kg near the low,
increasing to over 1000 J/kg over in the region between Del Rio and
San Antonio. Continued destabilization is expected as the warm front
continue to move northward. 

At the same time, persistent low-level convergence in the vicinity
of the low and its associated surface trough is expected to result
in eventual convective initiation. Visible satellite imagery has
shown several attempts at deep convection, although none have
succeeded thus far. Current attempt is underway over McCulloch
County. In addition to this mesoscale forcing, large-scale forcing
for ascent is gradually increasing across the region as a shortwave
trough approaches from the west.

Once convective initiation is realized, the environment is favorable
for maturation into supercells. Primary hazard throughout the
evening will be large hail while some damaging downburst winds are
also possible. Gradually strengthening low-level could also result
in a tornado or two.

..Mosier/Hart.. 03/24/2021

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

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

LAT...LON   30770016 31639962 33039660 33209548 32909500 31919523
            31119689 29929940 30770016

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

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.