As Tropical Depression Christobal tracks north.... The post-Tropical Cyclone will bring with it heavy rain and gusty winds. Brief spin-up tornadoes are possible as well, although the main threat remains flooding from heavy rains.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MIDWEST AND VICINITY...AND ACROSS PARTS OF SOUTHEAST
NEBRASKA/NORTHEAST KANSAS...
...SUMMARY...
Scattered strong to severe storms are expected Tuesday over parts of
the Missouri, mid Mississppi and Ohio Valleys and into the Upper
Great Lakes region, with a few tornadoes possible in addition to
localized wind damage. Hail is possible as well over parts of
Nebraska and Kansas.
...Synopsis...
Remnants of Cristobal are forecast to shift northeastward across the
mid Mississippi Valley vicinity toward the Upper Great Lakes through
the day Tuesday, ahead of an upper trough moving out of the Rockies
into the central U.S. through the period.
While Cristobal -- initially progged to be centered over the Ozarks
at the start of the period -- shifts northward with time, a cold
front is forecast to surge eastward/southeastward across the Plains.
By the end of the period, with remnants of Cristobal now deepening
as a synoptic low over the Upper Great Lakes, a trailing cold front
will likely have surged to a position from the low
south-southwestward across the mid Mississippi Valley to the Texas
Gulf Coast.
...Mid MS/mid and lower OH/TN Valleys to the Upper Great Lakes...
A large area of precipitation associated with Cristobal is expected
to reside across the Ozarks and mid MS/TN/lower OH valleys early in
the period, and will spread northward across the Midwest into the
Upper Great Lakes region through the end of the period. A very
moist low-level airmass, and backed low-level flow in the northeast
quadrant of the low, will result in a large/broad area of at least
low-end wind and tornado potential through the period.
At this time, it appears that a diurnal uptick in risk should occur
through the morning and into the afternoon as storms spread across
the mid MS and TN valleys into the IL/IN area. Weak lapse rates,
but very modest heating should combine with the strong veering with
height within the background wind field to support a relative
increase in overall severe-weather probability through the afternoon
and into the evening hours. At least some risk will likely linger
through the end of the period, as convection spreads across the
Upper Great Lakes region.
...Southeast Nebraska/northeast Kansas vicinity...
Afternoon heating within the warm sector of a surface low over the
eastern Kansas vicinity -- associated with an upper low moving
eastward out of the Rockies -- is expected to yield moderate
afternoon destabilization across parts of eastern Kansas/eastern
Nebraska. Scattered storms are expected to develop as a result,
with supercell potential evident given favorably veering/increasing
flow with height. Large hail and damaging winds will be possible,
along with potential for a tornado or two. Storms should diminish
during the evening, as diurnal stabilization commences
**All credits go to SPC**
Edited 6/9/2020 01:06:50
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