Mesoscale Discussion 703

Issued

May 22, 2021, 1:34 PM MDT (19:34 UTC)

Expired

May 22, 2021, 3:30 PM MDT

In force

116 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 193

Counties Phillips County, CO, Sedgwick County, CO, Washington County, CO, Arthur County, NE, Deuel County, NE, Keith County, NE

The Goodland radar (KGLD), 171 km from the middle of the area, began a volume at 19:34 UTC, the scan nearest the moment this went out.

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• Severe Thunderstorm Watch 195May 22, 2:55 PM MDT

775 
ACUS11 KWNS 221935
SWOMCD
SPC MCD 221934 
NEZ000-COZ000-222130-

Mesoscale Discussion 0703
NWS Storm Prediction Center Norman OK
0234 PM CDT Sat May 22 2021

Areas affected...Parts of northeastern Colorado into southwestern
Nebraska

Concerning...Tornado Watch 193...

Valid 221934Z - 222130Z

The severe weather threat for Tornado Watch 193 continues.

SUMMARY...Thunderstorm development appears likely to continue to
increase, potentially evolving into an organizing cluster of storms
across northeastern Colorado into southwestern Nebraska through 4-6
PM MDT.  A new severe weather watch will likely be needed northeast
of Tornado Watch 193.

DISCUSSION...The slow moving/stalling cold front across northeastern
Colorado into the Nebraska Sand Hills may become a focus for
increasing and intensifying thunderstorm development.  Thunderstorms
have already initiated southwest of Akron, perhaps aided by forcing
associated with a weak, north-northeastward migrating MCV. 
Differential surface heating has contributed to strengthening of the
frontal zone, and frontogenetic forcing may contribute to
increasingly widespread thunderstorm development along the corridor
northeastward toward the Nebraska Sand Hills through 22-00Z. 

In the presence of steep lower/mid tropospheric lapse rates,
boundary-layer moisture along and south of the front appears to have
contributed to CAPE on the order of 1500 J/kg, with at least some
further increase still possible.  Beneath 35-60+ kt southerly flow
in the 500-300 mb layer, deep-layer shear is strong, and the
environment appears conducive to the potential evolution of an
upscale growing and organizing cluster of storms by early evening.  

Initial stronger storms probably will pose a risk for severe hail,
with some risk for a brief tornado, before strong surface wind gusts
become the more prominent potential severe hazard.

..Kerr.. 05/22/2021

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

ATTN...WFO...LBF...GLD...BOU...CYS...

LAT...LON   41140250 41720209 41880128 41400124 40160247 39470340
            39690379 40260355 41140250

Mesoscale Discussions in Colorado, 2021Mesoscale 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.