Mesoscale Discussion 775

Issued

May 27, 2021, 5:34 PM CDT (22:34 UTC)

Expired

May 27, 2021, 6:30 PM CDT

In force

56 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 215

Counties Caddo County, OK, Cleveland County, OK, Comanche County, OK, Garvin County, OK, Grady County, OK, McClain County, OK, Murray County, OK, Stephens County, OK

The Norman radar (KTLX), 72 km from the middle of the area, began a volume at 22:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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404 
ACUS11 KWNS 272234
SWOMCD
SPC MCD 272234 
OKZ000-272330-

Mesoscale Discussion 0775
NWS Storm Prediction Center Norman OK
0534 PM CDT Thu May 27 2021

Areas affected...Parts of central Oklahoma

Concerning...Tornado Watch 215...

Valid 272234Z - 272330Z

The severe weather threat for Tornado Watch 215 continues.

SUMMARY...The evolution of an increasingly organized cluster of
storms is possible through 7-9 PM CDT, along with a more substantive
increase in potential for strong surface gusts near and southwest
through south of the Oklahoma City area.

DISCUSSION...Vigorous thunderstorm development continues above
southward advancing convective outflow advancing into the Interstate
40 corridor of central Oklahoma.  More recent thunderstorm
initiation is ongoing west-northwest of the Oklahoma City area,
focused near the western-most flank of the outflow and the
northeastern edge of a more strongly heated environment across the
higher plains, beneath remnant elevated mixed-layer air.  

Low/mid tropospheric warm advection is focused along the periphery
of this elevated mixed-layer air, which is gradually becoming
suppressed southward and southwestward as troughing (most prominent
around the 700 mb level) slowly progresses across the central Great
Plains/middle Mississippi Valley region.  With steep lapse rates
near this boundary, coupled with seasonably high low-level moisture
content, contributing to large mixed-layer CAPE in excess of 3000
J/kg, synoptic and mesoscale forcing for ascent may contribute to
rapidly intensifying convection during the next few hours.

In the presence of strong deep-layer shear, a new, increasingly
organized, upscale growing cluster of storms may evolve through
00-02Z.  If/when this occurs, convective processes may contribute to
a more substantive increase in potential for strong surface gusts,
which may take on an increasingly southeastward forward propagation,
near/southwest through south of the Greater Oklahoma City area.

..Kerr.. 05/27/2021

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

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

LAT...LON   35629833 35069681 34499694 34289769 34849890 35449893
            35629833

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.