Areas affected…Portions of southeastern WY…northeastern CO…and
the western NE Panhandle
Concerning…Severe Thunderstorm Watch 607…
Valid 210000Z – 210130Z
The severe weather threat for Severe Thunderstorm Watch 607
continues.
SUMMARY…Mainly an isolated large hail threat continues across
Severe Thunderstorm Watch 607 this evening.
DISCUSSION…Persistent easterly low-level upslope flow has
encouraged scattered thunderstorms to form across southeastern WY
and northeastern CO early this evening. Although flow through mid
levels remains generally modest per area VWPs (less than 30 kt), it
does veer substantially. This veering wind profile is supporting
around 35-40 kt of effective bulk shear, which is sufficient for
updraft organization and supercells. Given the generally discrete
mode observed thus far and the presence of very steep mid-level
lapse rates across this region, large hail will likely remain the
primary severe threat in the short term with ongoing storms this
evening. The low-level easterly flow is forecast to gradually
strengthen over the next couple of hours, particularly across the
western NE Panhandle and southeastern WY. Storm mergers and eventual
clustering may result in a greater wind threat with eastward extent
across Severe Thunderstorm Watch 607 later this evening.
..Gleason.. 08/21/2019
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…BOU…CYS…
LAT…LON 41060522 42480527 43240587 43300421 42900404 42880297
41010296 40030350 39870430 39990478 40960525 41060522