Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri Aug 16 2019 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY... ...SUMMARY... Scattered severe storms are expected to continue into tonight from the central Plains into the Lower Missouri Valley with very large hail and damaging winds as the primary threats. ...Central High Plains... Widely scattered storms that developed within the upslope flow regime over the higher terrain intensified as they moved into the moderately unstable environment across eastern CO through western NE and where effective shear from 40-50 kt is sufficient for supercells. It remains possible that a cluster of storms might organize and continue east through western KS and or southwest NE. However, there has been a trend for some storms to diminish over northeast CO as they move toward lower elevations where a very warm EML (16C at 700 mb) will result in strong surface based convective inhibition as the boundary layer begins to cool. This lowers confidence in future evolution of the storms moving off the higher terrain and into western KS but will maintain a SLGT risk for this possibility. ...Central Plains into the Lower Missouri Valley... A quasi-stationary front extends from northern MO through central and southwest KS and into southeast CO. The atmosphere is strongly unstable (3000-4000) J/kg MUCAPE) in vicinity of and south of this boundary where a plume of very steep (8-8.5 C/km) mid-level lapse rates have overspread the moist sector. However, the warm air at the base of an elevated mixed layer has also resulted in a substantial cap over much of this region, except in southwest KS and northwest OK where deep mixing has eroded the inversion, resulting in a few high-based severe storms. A substantial increase in storm coverage is expected later this evening into tonight from northern KS, southern NE into northern MO and possibly southern IA. This will be supported by increasing forcing for ascent along and north of the stationary front on nose of a strengthening southwesterly low-level jet. Most of these storms will probably be slightly elevated, but the thermodynamic environment and 30-40 kt effective bulk shear will support some supercell structures capable of large to very large hail and isolated damaging wind as the primary threats. Storms may eventually grow upscale with damaging wind becoming the main threat. ..Dial.. 08/17/2019Read more
from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_0100.html
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