Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 733

May 25, 2021Choctaw County, McCurtain County, Pushmataha County, Oklahoma; 31 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 25, 2021, 12:32 PM CDT for Choctaw County, McCurtain County, Pushmataha County, Oklahoma; 31 counties in Texas. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
May 25, 2021, 12:32 PM CDT (17:32 UTC)
Expired
May 25, 2021, 2:30 PM CDT
In force
118 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 34 counties

Choctaw County, OK, McCurtain County, OK, Pushmataha County, OK, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Leon County, TX, Limestone County, TX, McLennan County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 131 km from the middle of the area, began a volume at 17:35 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 nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 5.5 hours before the alert went out and 130 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 2021-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 668 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 12:00Z on 2021-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 square meters per square second.1939Sfc1 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
668 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
164 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

919 
ACUS11 KWNS 251733
SWOMCD
SPC MCD 251732 
ARZ000-TXZ000-OKZ000-251930-

Mesoscale Discussion 0733
NWS Storm Prediction Center Norman OK
1232 PM CDT Tue May 25 2021

Areas affected...far southeast OK into northeast TX

Concerning...Severe potential...Watch unlikely 

Valid 251732Z - 251930Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong gusts are possible through the afternoon
across far southeast OK into northeast TX.

DISCUSSION...Strong heating during the morning and early afternoon
has allowed temperatures to warm into the upper 70s and low 80s amid
upper 60s to low 70s surface dewpoints. This is aiding in weak to
moderate destabilization across the region, and new convective
development has been noted in radar and satellite imagery ahead of a
remnant MCS and associated MCV across north Texas. Deep layer flow
is not particularly strong, and effective shear is expected to
remain modest. Nevertheless, adequate instability coupled with high
PW values and the influence of the eastward-advancing MCV near the
Red River, should support isolated to widely scattered strong
convection. This activity could produce wind gusts to around 40-45
kt through the afternoon. Low level shear also will remain weak, but
backed low level flow ahead of the MCV is resulting in small, but
favorably curved low level hodographs. Given the moist low level
environment and moderate low level instability, a brief tornado also
could occur with any stronger/better organized cell. Overall, the
lack of stronger shear should limit a more organized threat, with
stronger cells being somewhat transient in nature. A watch is not
expected at this time.

..Leitman/Guyer.. 05/25/2021

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

ATTN...WFO...LZK...SHV...TSA...HGX...FWD...OUN...

LAT...LON   32849650 33659628 34289592 34389579 34529543 34539468
            34229438 33449430 32449444 31629495 31099584 30809682
            30989721 31299736 31489734 31929674 32849650

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 4:08 PM CDTSevere Thunderstorm WatchSPCBeckham, Greer, Harmon, Jackson, Roger Mills7 hr
May 24, 8:56 PM CDTMesoscale DiscussionSPCBorden, Briscoe, Crosby, Dawson, Dickens, Floyd and 12 more94 min
May 24, 11:43 PM CDTMesoscale DiscussionSPCBaylor, Foard, King, Knox2 hr
May 25, 2:02 PM CDTMesoscale DiscussionSPCBrewster, Crane, Pecos, Terrell, Upton, Ward118 min
May 25, 2:56 PM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Crosby, Dawson and 15 more94 min

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Oklahoma, 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.