607
ACUS03 KWNS 120729
SWODY3
SPC AC 120729

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Wed Jun 12 2024

Valid 141200Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS AND NORTHEAST...

...SUMMARY...
Scattered severe storms with large hail and severe wind gusts will
be possible from Friday afternoon into the overnight period across
parts of the central Plains. Thunderstorms associated with severe
wind gusts will also be possible in parts of the Northeast.

...Central Plains...
An upper-level ridge is forecast to move eastward into the central
and northern Plains on Friday. Behind the ridge, a
northwest-to-southeast corridor of moderate instability will likely
be in place by afternoon. Model forecasts are in good agreement that
scattered thunderstorms will develop Friday afternoon to the west of
the ridge axis from far northeast Colorado and far northern Kansas
into central Nebraska. These storms are forecast to move
east-northeastward across Nebraska and could impact southeastern
South Dakota during the late evening or overnight period. MCS
development will be possible across parts of the central Plains.

Strong instability appears likely to develop by afternoon from
northern Kansas into western Nebraska, where model consensus has
MLCAPE peaking in the 3000 to 4000 J/kg range. Forecast soundings
near the instability axis for North Platte, NE at 00Z/Saturday have
substantial amount of directional shear in the low-levels, with 0-6
km shear near 50 knots. This should support severe storm development
during the late afternoon. Supercells with isolated large hail will
be possible. However, temperatures near 700 mb are very warm, and
generally above 12C. This could temper the hail threat some. Severe
wind gusts will also be possible, especially if an cluster can
organize, or if a linear MCS can develop during the evening.

...Northeast...
An upper-level trough is forecast to move eastward into the
Northeast on Friday, as a cold front moves southeastward across the
region. Surface dewpoints ahead of the front are forecast to be in
the mid 60s F, which will result in a narrow corridor of instability
in the central and northern Appalachians. As surface temperatures
warm, thunderstorms will likely form in the higher terrain around
midday, with several small clusters moving eastward into the lower
elevations during the afternoon.

There is some disagreement concerning how much instability will
develop across the northeast on Friday. More aggressive solutions
suggest that moderate instability could be in place ahead of the
front by mid afternoon. Forecast soundings that show moderate
instability, have veered winds and steep lapse rates at low-levels,
and moderate to strong deep-layer shear. These soundings would
support a severe threat with either large hail or wind damage
possible. The severe threat would be concentrated near and after
peak heating as instability maximizes during the late afternoon.

..Broyles.. 06/12/2024

$$