Mesoscale Discussion 1066

Issued

Jun 22, 2021, 9:51 PM CDT (02:51 UTC)

Expired

Jun 22, 2021, 10:45 PM CDT

In force

54 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

5%

Counties Butler County, NE, Clay County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Jefferson County, NE, Merrick County, NE, Polk County, NE, Saline County, NE, Seward County, NE, Thayer County, NE, York County, NE

The Grand Island radar (KUEX), 84 km from the middle of the area, began a volume at 02:50 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.

389 
ACUS11 KWNS 230252
SWOMCD
SPC MCD 230251 
NEZ000-230345-

Mesoscale Discussion 1066
NWS Storm Prediction Center Norman OK
0951 PM CDT Tue Jun 22 2021

Areas affected...east-central Nebraska

Concerning...Severe potential...Watch unlikely 

Valid 230251Z - 230345Z

Probability of Watch Issuance...5 percent

SUMMARY...Lingering strong/severe storms may pose an isolated risk
for severe hail over the next couple hours.

DISCUSSION...North of the previous severe convection across
southeastern Nebraska, two elevated supercells have recently evolved
in the warm advection regime across York, Polk, and Butler Counties.
An uptick in lightning and radar reflectivity over the last 20
minutes suggests these storms may strengthen temporarily over the
next hour. This redevelopment is likely a result of increased
forcing associated with the nocturnal low-level jet. SPC
mesoanalysis indicates these storms are ongoing near the
southeastern edge of a plume of 500-1000 J/kg of MUCAPE. Vertical
shear profiles remain supportive of supercells with 40 kts of
effective shear observed by the 00z OAX sounding. The severe risk
with these storms will likely be short lived as they continue to
move south into an increasingly stable airmass. Over the next hour
or two, isolated severe hail will remain possible before storms
permanently weaken below severe limits.

..Lyons/Grams.. 06/23/2021

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

ATTN...WFO...OAX...GID...

LAT...LON   40029761 40059799 40579809 40959812 41279811 41429786
            41489737 41129701 40309661 40089668 40029722 40029761

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.