Valid 010100Z – 011200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
…SUMMARY…
Organized severe thunderstorms appear unlikely through the remainder
of this evening and overnight.
…01Z Update…
Isolated strong to severe storms that formed earlier today along a
weak surface boundary across parts of KY, WV, and far western VA
will continue to weaken this evening with the loss of diurnal
heating and gradual reduction in instability. While occasional
strong/gusty downdraft winds may be possible for the next hour or
two, overall severe potential is expected to continue decreasing.
Have therefore removed 5% hail/wind probabilities from this region.
Weak low-level warm advection may encourage isolated storms to form
across southeastern SD and vicinity later this evening and
continuing through the overnight hours. Although northwesterly winds
are forecast to strengthen through mid and upper-levels, mid-level
lapse rates should remain modest. This will limit MUCAPE available
to any elevated convection that forms, with minimal severe hail
threat anticipated.
Isolated to scattered showers and storms should develop this evening
and overnight across parts of the mid MS Valley into the Midwest as
a weak shortwave trough moves eastward across these areas. Although
some modest enhancement to the mid-level flow will exist,
instability will be weak, and storms will probably remain elevated
above a stable boundary layer.
A robust storm that developed earlier this evening across far
northern CO in a weak low-level upslope flow regime has since
weakened. Upper ridging remains prominent across the Rockies, and
any additional storms that form in this environment will likely
weaken with southward extent as convective inhibition rapidly
increases with the onset of nocturnal cooling.
Elsewhere, isolated to scattered convection may continue this
evening and into the overnight hours across parts of the Southeast
and southern High Plains. Weak shear across these regions should
greatly limit any organized severe storm potential.
..Gleason.. 09/01/2019
$$