Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 130

February 25, 20214 counties in Arkansas; 19 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 25, 2021, 11:25 PM CST for 4 counties in Arkansas; 19 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Feb 25, 2021, 11:25 PM CST (05:25 UTC)
Expired
Feb 26, 2021, 1:30 AM CST
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 23 counties

Columbia County, AR, Lafayette County, AR, Miller County, AR, Union County, AR, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Dallas County, TX, Delta County, TX, Erath County, TX, Franklin County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Morris County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 5.4 hours before the alert went out and 151 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 2021-02-26Temperature 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°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 2021-02-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 264 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
889 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
264 m²/s²
0-3 km storm-relative helicity
476 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

288 
ACUS11 KWNS 260525
SWOMCD
SPC MCD 260525 
ARZ000-TXZ000-OKZ000-260730-

Mesoscale Discussion 0130
NWS Storm Prediction Center Norman OK
1125 PM CST Thu Feb 25 2021

Areas affected...North Texas...Southern Arkansas...Northern
Louisiana

Concerning...Severe potential...Watch unlikely 

Valid 260525Z - 260730Z

Probability of Watch Issuance...5 percent

SUMMARY...Marginally severe hail threat continues with convection.
Severe thunderstorm watch does not appear warranted at this time.

DISCUSSION...Low-amplitude short-wave trough is approaching the
southern High Plains late this evening. This feature should eject
into eastern OK/Northeast TX by sunrise. Latest radar trends suggest
the leading edge of this short wave is becoming increasingly
influential in convection/intensity along a corridor from west of
SEP-DFW-PRX-TXK-north of ELD. Latest forecast soundings suggest this
elevated convection is likely rooted between 750-800mb, with
cloud-layer lapse rates on the order of 7 C/km. While MUCAPE is not
particularly noteworthy, steep lapse rates within the cool mid
levels will likely contribute to some threat for hail, especially
where more discrete structures are maintained. Latest thinking is a
considerable amount of convection will likely continue along the
aforementioned corridor for the next several hours with a slow
east-southeast movement to this evolving complex. While shear
remains strong, severe hail should remain marginal in size and
likely rather isolated in coverage. For these reasons, a watch does
not appear warranted.

..Darrow/Grams.. 02/26/2021

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

ATTN...WFO...LZK...SHV...FWD...

LAT...LON   32509865 33139735 33509594 33679446 33659335 33479240
            33019258 33079408 32899572 32539689 31999810 32509865

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 25, 6:50 PM CSTMesoscale DiscussionSPCUnion115 min

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Arkansas, 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.