Toledo weather mon jun 22 2015

spc ac 220558

day 1 convective outlook
nws storm prediction center norman ok
1258 am cdt mon jun 22 2015

valid 221200z - 231200z

...there is an enh risk of svr tstms from the mid-upper ms valley
ewd into lower mich...

...there is a slgt risk of svr tstms over a large portion of the
midwest and great lakes...

...there is a mrgl risk of svr tstms from ern ks into the
northeastern u.s....

...there is a mrgl risk of svr tstms over nrn parts of fl into the
wrn carolinas...

...summary...
scattered severe storms are likely across parts of the upper
mississippi valley and great lakes regions...some of which should be
intense...mainly from midday through the evening on monday. the
threat for large to very large hail and a strong tornado appear to
be greatest over southern wisconsin and northern illinois.

...upper ms valley/great lakes...
considerable uncertainty remains regarding the forecast evolution of
a severe mcs across the nrn plains into the upper ms valley prior to
the start of the period. as a result...confidence for this severe
forecast is tempered owing to several potentially critical variables
1) longevity/severity of early morning mcs from the ms valley into
the great lakes 2) preferred storm mode /supercell and/or bow echo/.
given relatively high uncertainty...will defer substantial changes
to the next outlook.

the primary shortwave trough will move from the nrn plains to lake
superior during the day while a potential convectively-generated mcv
evolves from squall line activity leading into the day 1 period. in
the low levels...a reservoir of rich moisture over the lower to mid
mo valley will advect n/newd into the mid ms valley/wrn great lakes
during the morning owing partially to strong low-level waa. while
it is possible for the early morning storms to continue ewd from the
mid-upper ms valley into the cntrl great lakes...lessening buoyancy
with ewd extent should serve to weaken this activity. a strong
influx of low-level moisture /characterized by 16-18 g per kg lowest
100 mb mean mixing ratios/ will likely move into nrn il/wi vicinity
along and to the s of trailing outflow and ahead of the approaching
cold front.

it is probable storm redevelopment /sctd coverage/ will occur later
in the afternoon near the residual boundary over the wrn great lakes
or along the front located over cntrl wi sw into ern ia. the
strength of the deep layer shear vector /50-70 kt/ and its
orientation to the boundary coupled with a very strong to extremely
buoyant /3000-4500 j per kg mlcape/ boundary layer would promote
explosive updraft development and a supercellular mode early in the
storm lifecycle. all severe hazards would be possible with this
activity...including significant hail/wind/tornado. further storm
development along the front will favor a transition to a mixed mode
and probably yield a wind/hail threat becoming predominate with
time. storms should move downstream and into the srn and lower
great lakes states overnight with the primary risk being isold large
hail/wind.

...parts of the sern u.s...
a flattened mid-level anticyclone will persist off the se u.s. and
diurnally-driven storms will likely develop during the afternoon. a
very weak wind profile will result in slow-moving pulse storms which
will likely propagate on convective outflow. steepened low-level
lapse rates owing to strong diabatic heating coupled with pw
1.75-2.0 inches will promote water loading with the more intense
cores. wet microbursts capable of pockets of wind damage will be
the primary threat and this activity will diminish during the early
evening.

..smith/rogers.. 06/22/2015

click to get wuus01 ptsdy1 product

note: the next day 1 outlook is scheduled by 1300z

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