Mesoscale Discussion 410

Issued

Apr 23, 2021, 5:26 PM CDT (22:26 UTC)

Expired

Apr 23, 2021, 7:30 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Tornado watch 100

Counties Cotton County, OK, Jackson County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Foard County, TX, Hardeman County, TX, Knox County, TX, Wichita County, TX, Wilbarger County, TX

The Altus AFB radar (KFDR), 37 km from the middle of the area, began a volume at 22:28 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.

• Severe Thunderstorm Watch 103Apr 23, 8:00 PM CDT

546 
ACUS11 KWNS 232227
SWOMCD
SPC MCD 232226 
TXZ000-OKZ000-240030-

Mesoscale Discussion 0410
NWS Storm Prediction Center Norman OK
0526 PM CDT Fri Apr 23 2021

Areas affected...Northwest Texas and southwest Oklahoma

Concerning...Tornado Watch 100...

Valid 232226Z - 240030Z

The severe weather threat for Tornado Watch 100 continues.

SUMMARY...A tornado threat will persist through at least 7 PM
associated with a trio of discrete supercells, though large hail
will remain the primary concern. To the northwest across the Texas
Panhandle, developing thunderstorms will pose a wind/hail threat
over the next couple of hours.

DISCUSSION...A trio of discrete supercells have become established
as they move off the dryline and toward the Red River. Radar and
satellite trends suggest the more robust northern supercell is
likely taking advantage of enhanced low-level helicity along and
just north of a warm frontal boundary that is draped along the Red
River. This cell has also exhibited notable right deviant motion,
likely the result of a strengthening mesocyclone and propagation
along the warm front/instability gradient to the east. This cell
should continue on an eastward trajectory over the next 1-2 hours
and will primarily pose a large hail threat. However, given ambient
surface vorticity along the boundary (and backed easterly flow just
north of the boundary), the tornado threat will persist. The
neighboring storms to the south/southeast may intensify in the
coming hours, especially if they can become rooted along the
boundary. Upscale growth into a cluster is still expected later this
evening after 00Z as storms continue to move east. 

To the northwest, thunderstorm development along the dryline has
been underway with a few stronger updrafts noted. This activity is
occurring on the northwestern periphery of richer boundary layer
moisture where dewpoint remain in the 50s. Sufficient instability
(around 1000 J/kg MLCAPE) along with favorable effective bulk shear
(35-45 knots) roughly off the dryline should continue to support
semi-discrete storms capable of producing severe hail and wind.

..Moore.. 04/23/2021

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

ATTN...WFO...FWD...OUN...LUB...

LAT...LON   33449978 33810008 34380024 34709988 34799934 34619882
            34439831 34199795 33849781 33529819 33419905 33449978

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