000
ACUS11 KWNS 130142
SWOMCD
SPC MCD 130141
NEZ000-KSZ000-130315-

Mesoscale Discussion 1486
NWS Storm Prediction Center Norman OK
0841 PM CDT Sat Aug 12 2017

Areas affected...Parts of central/southwest Nebraska...northwest
Kansas

Concerning...Severe Thunderstorm Watch 449...

Valid 130141Z - 130315Z

The severe weather threat for Severe Thunderstorm Watch 449
continues.

SUMMARY...A risk for severe weather may continue with isolated
stronger storms another couple of hours.  This activity could
progress just east of the remaining watch area before diminishing
later this evening.

DISCUSSION...Strongest lingering thunderstorm development (near
Broken Bow, North Platte and Imperial) appears aided by large-scale
forcing for ascent associated with low/mid-level warm advection.
This is generally focused near the southerly 850 mb jet axis, which
has strengthened some (to 30-40 kt) during the past hour or two.
Only a very gradual veering of this feature is expected into late
evening, and this could continue to provide support for the
maintenance of ongoing storms another couple of hours, before waning
instability/increasing inhibition associated with boundary layer
cooling finally result in storm dissipation.  Until then, a slow
south/southeastward propagation of storms should continue, with a
risk for severe hail and locally strong surface gusts.

..Kerr.. 08/13/2017

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

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

LAT...LON   40250100 41040037 41520008 41779934 41519868 40429932
            39879997 39720084 40250100