spc ac 170730
day 3 convective outlook
nws storm prediction center norman ok
0230 am cdt wed aug 17 2022
valid 191200z - 201200z
...there is a marginal risk of severe thunderstorms across parts of
the central plains into the upper midwest...
isolated severe thunderstorms appear possible friday across parts of
the central plains into the upper midwest.
...central plains into the upper midwest...
a positively tilted upper trough should evolve into a closed low
while moving slowly southeastward over the upper midwest on friday.
at the surface, a weak low should also be present beneath the upper
low, with a cold front forecast to advance southeastward across the
northern/central plains and upper midwest through the period.
diurnal heating of a modestly moist low-level airmass should foster
at least weak destabilization across parts of the central plains
into ia by friday afternoon.
low-level convergence along the front and weak large-scale ascent
associated with the upper trough/low should aid in thunderstorm
development across these areas through the afternoon and continuing
into the early evening. even though mid/upper-level flow is not
forecast to be particularly strong, there should be enough
strengthening of the wind field with height to support around 25-35
kt of deep-layer shear, with locally stronger shear possible across
parts of ks and vicinity. some updraft organization is anticipated,
and isolated severe thunderstorms appear possible along the length
of the front from central ia into northwestern mo and eastern ks
through friday evening.
multiple rounds of convection will occur prior to friday along/south
of a weak front that should be present across parts of the
southeast. it remains rather unclear whether sufficient instability
will develop south/east of this boundary friday afternoon to support
robust convection. deep-layer shear also appears only marginally
supportive of organized convection across this region, as a
large-scale upper trough and modest mid-level winds persist across a
majority of the eastern conus. will continue to monitor for small
zones of potentially damaging winds wherever sufficient instability
can develop. but, at this point there is too much uncertainty to
include low severe wind probabilities across any portion of the
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note: the next day 3 outlook is scheduled by 0730z