ZCZC SPCSWOMCD ALL
ACUS11 KWNS 261930 
SPC MCD 261930 
NEZ000-SDZ000-COZ000-WYZ000-262200-

Mesoscale Discussion 1592
NWS Storm Prediction Center Norman OK
0230 PM CDT Fri Jul 26 2019

Areas affected...Parts of far southeast Wyoming into far northeast
Colorado...Nebraska Panhandle...and northern Nebraska

Concerning...Severe potential...Watch unlikely 

Valid 261930Z - 262200Z

Probability of Watch Issuance...20 percent

SUMMARY...Scattered storm development is expected, with at least
isolated large hail and damaging winds possible with the more
mature, organized storms. A WW issuance is not currently
anticipated.

DISCUSSION...Convective initiation is expected within the next
couple of hours, with a rapid increase in instability (2000+ J/kg
MLCAPE) noted, and with gradual erosion of convective inhibition.
Deep-layer ascent is largely absent, as a large-scale upper-level
ridge is impinging on the region from the west. Nonetheless,
continued surface heating west of a northwest-to-southeast
differential heating boundary has led to low-level parcels
approaching their convective temperatures. With further warming of
the boundary layer, convective initiation is expected to take place,
with multiple attempts at initiation noted around Sheridan/Garden
Counties in Nebraska over the past 2 hours. The most likely time for
initiation will be around 2000-2100 UTC (based on trends in
satellite data, 1200 UTC HREF guidance and the last few runs of the
HRRR). Storms will most likely initiate across the Pine Ridge, into
Garden County in northern Nebraska, then propagate southeastward and
intensify as the storms move into a moister airmass, delineated by
multiple differential moisture boundaries.  

Deep-layer speed shear is in place within a 700-400 mb layer,
contributing to 35-45 knots of effective bulk shear across Nebraska.
Latest RAP PFCs indicate mainly straight hodographs, indicative of
multicellular clusters and perhaps splitting supercells, the
stronger of which may be capable of producing severe hail and
perhaps a few damaging gusts. Given the isolated nature of the
severe threat, a WW issuance is not expected.

..Squitieri/Hart.. 07/26/2019

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

ATTN...WFO...GID...LBF...UNR...BOU...CYS...

LAT...LON   40470303 41420404 42630454 42980343 43020178 42890058
            42639963 42119918 41599926 41089927 40659980 40590012
            40450136 40470303 

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