Mesoscale Discussion 963

Issued

Jun 13, 2021, 8:39 PM MDT (02:39 UTC)

Expired

Jun 13, 2021, 10:45 PM MDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely 268

Chance of a watch

20%

Counties Arthur County, NE, Cherry County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, McPherson County, NE, Sheridan County, NE

The North Platte radar (KLNX), 107 km from the middle of the area, began a volume at 02:39 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.

322 
ACUS11 KWNS 140240
SWOMCD
SPC MCD 140239 
NEZ000-140445-

Mesoscale Discussion 0963
NWS Storm Prediction Center Norman OK
0939 PM CDT Sun Jun 13 2021

Areas affected...Western Nebraska

Concerning...Severe potential...Watch unlikely 268...

Valid 140239Z - 140445Z

Probability of Watch Issuance...20 percent

SUMMARY...The threat for severe wind and hail will continue across
portions of western Nebraska for the next 1-2 hours, but the
duration of the threat after 04 UTC is uncertain.

DISCUSSION...Thunderstorms ongoing across western and northwestern
NE continue to produce instances of measured severe wind gusts as
well as hail up to 1.5 inches. The convection that developed within
the warm frontal zone near the NE/SD border has been slow to grow
upscale with only recent cold pool organization noted in KLNX
velocity data. This activity will continue to migrate to the
southeast and interact with a broken line of storms moving eastward
out of the NE Panhandle. This interaction should maximize
convergence to the west/northwest of the KLNX area and provide
sufficient lift for continued development (and a continued severe
threat) in the near term given nearly 2000 J/kg MLCAPE in place.

The severe potential becomes less certain by (and after) 04 UTC as
the storms move towards the KLNX area. The 00Z North Platte sounding
revealed around -130 J/kg MLCIN, and decreasing low-level moisture
to the east of KLNX suggests capping may be stronger with eastward
extent. Storms will likely struggle to maintain intensity in this
environment in the absence of more organized mesocyclones (which is
unlikely given the limited deep-layer shear). Recent hi-res guidance
supports this idea, suggesting that the severe threat should
diminish after 04 UTC.

..Moore.. 06/14/2021

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

ATTN...WFO...LBF...CYS...

LAT...LON   41620295 42420291 42810230 42900192 42990146 42920100
            42570046 41950087 41510113 41200147 41260188 41410284
            41620295

Mesoscale Discussions in Nebraska, 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.