Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 1826

October 10, 2021Little River County, Polk County, Sevier County, Arkansas; 7 counties in Oklahoma; 41 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 10, 2021, 10:16 PM CDT for Little River County, Polk County, Sevier County, Arkansas; 7 counties in Oklahoma; 41 counties in Texas. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Oct 10, 2021, 10:16 PM CDT (03:16 UTC)
Expired
Oct 10, 2021, 11:15 PM CDT
In force
59 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 518
All 51 counties

Little River County, AR, Polk County, AR, Sevier County, AR, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Johnston County, OK, McCurtain County, OK, Pushmataha County, OK, Anderson County, TX, Bell County, TX, Bosque County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Grayson County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lampasas County, TX, Limestone County, TX, Marion County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River 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), 112 km from the middle of the area, began a volume at 03:19 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 00:00Z, 3.3 hours before the alert went out and 105 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 2021-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1814 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 2021-10-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.1939587897117Sfc1 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
1814 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1524 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
253 m²/s²
Significant tornado parameter
1.5
Supercell composite
11.2

Open this sounding in Storm Lab

The text

As transmitted.

951 
ACUS11 KWNS 110316
SWOMCD
SPC MCD 110316 
ARZ000-TXZ000-OKZ000-110415-

Mesoscale Discussion 1826
NWS Storm Prediction Center Norman OK
1016 PM CDT Sun Oct 10 2021

Areas affected...north and northeast Texas...southeast
Oklahoma...and far southwest Arkansas

Concerning...Tornado Watch 518...

Valid 110316Z - 110415Z

The severe weather threat for Tornado Watch 518 continues.

SUMMARY...A line of severe thunderstorms continues to move east
across north Texas and southeast Oklahoma this evening. Very strong,
damaging winds, large hail, and tornadoes remain possible.

DISCUSSION...Thunderstorms continue to move east across north Texas
and south Oklahoma this evening. These thunderstorms have a history
of producing severe, damaging winds, with several measured wind
reports of 60-70 mph across the greater Dallas-Fort Worth metro,
including a 70 mph wind at DFW, were recorded within the last hour.
The strong wind fields conducive to these severe thunderstorm winds
will also be capable of producing tornadoes along the leading edge
of the squall line, especially where kinks in the line occur. Given
the very moist, unstable airmass and strong kinematic fields across
the area, the severe threat will continues. 

Farther east, across northeast Texas and southwest Arkansas, more
uncertainty exists as to the magnitude of the severe potential.
Here, instability is weaker than farther west and will be farther
removed from the stronger influence of the lifting mid-level trough.
However, the level of organization of the ongoing storms, and a
couple more hours of theta-e advection may support an extension of
the severe risk into this area. Conditions here, downstream of
Tornado Watch #518, continue to be monitored for possible watch
issuance this evening.

..Marsh.. 10/11/2021

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

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

LAT...LON   31209831 32089755 33189713 34169671 34819657 34929613
            34809418 34169412 32629404 32239454 31639559 30739704
            31209831

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 10, 9:24 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more5 hr
Oct 10, 11:07 PM CDTTornado WatchSPCHempstead, Howard, Lafayette, Little River, Logan, Miller and 6 more5 hr
Oct 10, 11:32 PM CDTMesoscale DiscussionSPCBenton, Crawford, Polk, Scott, Sebastian, Sevier and 1 more118 min
Oct 11, 12:58 AM CDTMesoscale DiscussionSPCHempstead, Howard, Lafayette, Little River, Logan, Miller and 5 more92 min
Oct 11, 1:26 AM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more64 min
Oct 10, 7:19 PM CDTMesoscale DiscussionSPCNowata, Washington86 min
Oct 10, 8:11 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Coal, Johnston, Love and 1 more64 min

Nearby

Mesoscale Discussions in Texas, 2021Mesoscale Discussions in Oklahoma, 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; radar from the NEXRAD Level II archive.