Alert archive / Oklahoma / Mesoscale Discussions in 2021

Mesoscale Discussion 934

June 12, 202112 counties in Oklahoma; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2021, 2:58 AM CDT for 12 counties in Oklahoma; 4 counties in Texas. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Jun 12, 2021, 2:58 AM CDT (07:58 UTC)
Expired: Jun 12, 2021, 4:30 AM CDT
In force: 92 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Caddo County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Kiowa County, OK, McClain County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Archer County, TX, Clay County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 70 km from the middle of the area, began a volume at 08:00 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

Norman, OK (KOUN), launched 00:00Z, 8.0 hours before the alert went out and 104 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3394 J/kg
Mixed-layer CIN: -216 J/kg
Mixed-layer LCL: 1175 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 225 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

443 
ACUS11 KWNS 120758
SWOMCD
SPC MCD 120758 
OKZ000-TXZ000-120930-

Mesoscale Discussion 0934
NWS Storm Prediction Center Norman OK
0258 AM CDT Sat Jun 12 2021

Areas affected...portions of southwest OK into north TX

Concerning...Severe potential...Watch unlikely 

Valid 120758Z - 120930Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong wind gusts around 50-60 mph will accompany storms
shifting southward across parts of southwest Oklahoma into northwest
Texas early this morning.

DISCUSSION...The western portions of an MCS across central OK has
shows some recent intensification with measured wind gusts from the
Oklahoma Mesonet around 50-60 mph. One stronger gust to 73 mph was
measured at Acme near the apex of the bowing segment. The downstream
airmass is characterized by low 70s dewpoints and strong DCAPE,
along with steep 2-6 km lapse rates. This is likely supporting some
stronger, near-severe level wind gusts despite strong low level
inhibition and warm 850-700 mb temperatures and weak low level jet.
Some strong gusts around 50-60 mph are expected to continue over the
next couple of hours as the line of storms shifts generally
southward toward the Red River at around 40 kt. While some strong
gust are expected, with an isolated gust greater than 60 mph
possible, overall severe/widespread damaging wind potential is
expected to remain sporadic/limited and a watch is not expected at
this time.

..Leitman/Thompson.. 06/12/2021

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

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

LAT...LON   35249761 35229733 35039714 34649717 34029748 33689776
            33529833 33539881 33639924 33999940 34479942 34999923
            35339902 35399884 35319839 35219787 35249761

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 9:20 PM CDT	Mesoscale Discussion	SPC	Garfield, Grant, Kay, Noble, Osage, Pawnee and 1 more	115 min
Jun 11, 11:37 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Garfield, Grant, Kay, Kingfisher, Lincoln and 4 more	113 min
Jun 12, 3:09 PM CDT	Mesoscale Discussion	SPC	Bailey, Cochran, Deaf Smith, Hartley, Oldham, Parmer	2 hr

Nearby

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