- Day Three
acus02 kwns 311723
Storm Prediction Center ac 311722
Day 2 convective outlook
National Weather Service Storm Prediction Center Norman OK
1222 PM CDT Friday Jul 31 2015
Valid 011200z - 021200z
..there is a slight risk of severe thunderstorms across northestern Nebraska...Southeastern
South Dakota...IA...srn Minnesota...
..there is a marginal risk of severe thunderstorms from South Dakota/Nebraska into WI and Illinois...
..There is a marginal risk of severe thunderstorms across northern New England...
Severe storms capable of hail and wind are expected mainly from
Nebraska into Iowa during the late afternoon and evening...with more
isolated activity into South Dakota...Minnesota and Wisconsin. A few
severe storms with hail may also occur over a portion of New
An upper trough will move across the northestern states during the day with
a weak cold front supporting a few strong storms across northern New
England. To the west...a secondary shortwave trough will sink southward
across the northern plains and upper MS valley later in the day...with
surface low developing across the eastern Dakotas southeastward into WI. Pockets of
60s f dewpoints and heating will lead to cluster of storms across
the region focused near the cold front with hail and wind possible.
..ern Nebraska...IA...sern South Dakota...southern Minnesota...
a surface high to the S of the area as well as boundary layer mixing
should lead to only lower to middle 60s f dewpoints across the warm
sector by afternoon...but cool temperatures aloft will aid
instability levels. Severe hail and wind is expected to initiate
across southern South Dakota into Nebraska during the late afternoon where heating will
be strongest and closer to the surface trough/front. Additional storms
are expected farther north along the front into western Minnesota as well. The northwesterly
flow pattern as relatively large T/dew point spreads should favor some
upscale growth as storms develop southeastward across Minnesota and Iowa...with severe
wind and hail possible. With time...the low-level jet will veer to
westerly...and will focus lift eastward into WI possibly supporting a few
severe storms. There is some concern about capping across Minnesota/WI as
storms move away from the low-level lapse rate plume...and some
models do not indicate very strong quantitative precipitation forecast signals into these
areas...thus will maintain a marginal threat at this time.
..nrn New England...
A shortwave trough will swing through the area during the day with
scattered thunderstorms developing near a cold front/wind shift by
early afternoon. Cool temperatures aloft along with heating will
support development with long/straight hodographs supporting
cellular activity capable of large hail. Wind threat is expected to
be largely mitigated by cellular storm Mode.