Mesoscale Discussion 157

Issued

Mar 12, 2021, 5:40 PM CST (23:40 UTC)

Expired

Mar 12, 2021, 7:15 PM CST

In force

95 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

40%

Counties Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Oklahoma County, OK, Roger Mills County, OK, Washita County, OK

The Altus AFB radar (KFDR), 102 km from the middle of the area, began a volume at 23:41 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 18Mar 12, 8:35 PM CST

807 
ACUS11 KWNS 122340
SWOMCD
SPC MCD 122340 
OKZ000-TXZ000-130115-

Mesoscale Discussion 0157
NWS Storm Prediction Center Norman OK
0540 PM CST Fri Mar 12 2021

Areas affected...western-central Oklahoma

Concerning...Severe potential...Watch possible 

Valid 122340Z - 130115Z

Probability of Watch Issuance...40 percent

SUMMARY...Recent storm development/observations suggests some severe
threat may develop early this evening ahead of the main series of
storms across west Texas. A weather watch is being considered.

DISCUSSION...22z surface analysis showed a quasi-stationary front
located along the I-40 corridor through western and central
Oklahoma. To the south of the front, temperatures in the 70s with
dewpoints in the lower to middle 60s were supporting weak to
moderate destabilization (500-1000 J/kg of MLCAPE) across much of
Oklahoma. Recent RADAR trends have shown an increase in storm
coverage/intensity in western Oklahoma, likely driven by increasing
warm advection. Hi-res guidance and downstream observations suggest
some potential for severe weather may be developing early this
evening especially with two stronger cells across Beckham and Roger
Mills counties. Mid-level lapse rates near 8 C/km, and bulk shear
above 50 kts will favor supercellular updrafts capable of large hail
(possibly significant 2+ in) along and immediately north of the
boundary. Given the proximity of storms to the surface front, a
non-zero tornado threat may also exist given backed surface winds
near and south of the boundary. However, surface based development
across southwestern Oklahoma is much more uncertain. Trends will be
monitored for a possible weather watch early this evening. A more
robust severe threat is likely tonight with the ongoing
strong/severe convection moving out of far west Texas and into
Oklahoma overnight.

..Lyons/Hart.. 03/12/2021

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

ATTN...WFO...OUN...LUB...AMA...

LAT...LON   34580003 35510008 35939951 36299848 36249764 36029736
            35499727 35319744 35009776 34629841 34359984 34429989
            34580003

Mesoscale 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.