- Day Three
acus03 kwns 050720
Storm Prediction Center ac 050719
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0219 am CDT Sat Sep 05 2015
Valid 071200z - 081200z
..there is a marginal risk of severe thunderstorms from the Central Plains into
the lower MO valley...
A few strong to isolated severe thunderstorms will be possible
Monday afternoon and evening over parts of the Central Plains into
the lower Missouri River valley.
An upper low is forecast to move eastward across the Canadian prairie
provinces with weakly cyclonic flow spreading eastward across the upper
Midwest. At the surface...a cold front will settle southward from the
Great Lakes into the Central Plains...although convective outflow
from storms late Sunday night/Monday morning may result in multiple
mesoscale boundaries to focus redevelopment of storms during the
afternoon peak-heating period over the Central Plains into the lower
..Central Plains into the lower MO valley...
Early storms are expected to gradually weaken during the morning but
the effects of remnant cloud cover may delay onset of stronger
diabatic heating over some areas. Ample low-level moisture and
pockets of stronger heating will promote diurnal destabilization
with maximum MLCAPE of 2000-2500 j/kg expected during the afternoon.
Weak convergence along the front and other mesoscale boundaries
coupled with low-level heating will weaken the cap sufficiently for
strong storms to develop during the afternoon and evening. With the
stronger flow aloft displaced to the north over the Dakotas and
Minnesota...the effective shear over the discussion area will be modest
/25-30 knots/ suggesting potential for primarily weakly organized
multicell storms. This is expected to limit the overall severe
threat although isolated severe cells capable of producing hail and
strong wind gusts will be possible during the afternoon and evening.