ZCZC SPCSWOMCD ALL
ACUS11 KWNS 021828 
SPC MCD 021828 
NEZ000-KSZ000-022030-

Mesoscale Discussion 1682
NWS Storm Prediction Center Norman OK
0128 PM CDT Thu Sep 02 2021

Areas affected...much of central Nebraska into northern Kansas

Concerning...Severe potential...Watch possible 

Valid 021828Z - 022030Z

Probability of Watch Issuance...60 percent

SUMMARY...Storms are expected to increase in intensity, possibly
becoming severe by 21Z near a surface trough from central Nebraska
into northwest Kansas. A few supercells will be possible, with a
brief tornado or two.

DISCUSSION...An area of rain and thunderstorms is expected to shift
east out of central NE and KS, with heating and destabilization
expected westward toward the surface trough. Convergence along this
trough is currently supporting a low-topped line of convection
across northern NE, but temperatures are currently cool extending
east of this activity.

Visible satellite imagery shows clearing across southwest NE into
western KS, and this will likely support initiation near the surface
trough after about 20-21Z. While surface winds are weak near the
trough, strong boundary-layer flow will persist to the east, along
with 30-40 kt 850 mb winds. Therefore, assuming air mass recovery
late this afternoon, sufficient SRH will support a supercell threat
with cells that form near the trough and proceed east. Objective
analysis currently indicates 0-1 km values over 200 m2/s2. A couple
tornadoes will be possible in a narrow zone where the surface warm
nose and SRH gradient interface. Otherwise, a few severe gusts or
low-end severe hail will be possible.

..Jewell/Grams.. 09/02/2021

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

ATTN...WFO...GID...LBF...GLD...

LAT...LON   39709889 39169964 39220045 39610082 40050101 40670089
            41470041 42479993 42729982 42899934 42839892 42619865
            42019853 40949865 39709889 

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