SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Fri Apr 22 2022
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE SOUTHERN PLAINS TO THE MIDDLE MISSISSIPPI VALLEY AND LOWER
MICHIGAN...
...SUMMARY...
Isolated strong to severe thunderstorms are possible from portions
of the southern Plains into the Middle Mississippi Valley and Lower
Michigan on Sunday.
...Middle Mississippi Valley to Great Lakes Vicinity...
The compact upper low over the Upper Midwest Sunday morning will
gradually weaken as it shifts east/northeast into Ontario.
Meanwhile, a positive-tilt upper trough will pivot east from the
Four Corners/Southwestern Deserts to the central/southern High
Plains. Height falls will remain weak to neutral from the southern
Plains into the Midwest, but enhanced southwesterly deep-layer flow
will remain over the regions. An occluding surface low will weaken
as it shifts northeast in tandem with the mid/upper level low/trough
from the Upper Midwest to near James Bay by Monday morning. A cold
front is forecast to extend from eastern WI into central MO/OK and
western TX. Showers and thunderstorms likely will be ongoing
near/ahead of the front across WI into MO and eastern OK, and
perhaps central TX. This activity, along with cloud cover and
generally weak midlevel lapse rates will limit destabilization ahead
of the front, especially across the Middle Mississippi Valley/Great
Lakes vicinity. Nevertheless, strong vertical shear and at least a
few hundred J/kg MLCAPE may support sporadic strong gusts.
Furthermore, forecast soundings show favorably curved low-level
hodographs, which could support a tornado or two with linear
convective modes across parts of IL into Lower MI if the low levels
can destabilize sufficiently.
...TX/OK/AR...
Low-level south/southeasterly flow across TX into southeast OK/AR
will maintain northward transport of higher-quality Gulf moisture
ahead of the surface cold front. Surface dewpoints in the mid/upper
60s F are likely beneath modest midlevel lapse rates. Pockets of
stronger heating should allow for great destabilization compared to
further north/northeast, though morning convection, along with a
midlevel warm layer are resulting in quite a bit of uncertainty in
severe potential. Furthermore, weak surface cyclogenesis, in
conjunction with neutral to modest height falls and nebulous
large-scale ascent will keep severe potential focused near the
southward-sagging cold front. As a result, it is unclear how much
open warm sector convection may develop, and any storms that form
could remain near the boundary with storm motion toward the cool
side of the front. If warm sector storms develop, supercells capable
of all severe hazards will be possible, but uncertainty is too great
for more than unconditional Marginal risk-level probabilities at
this time.
..Leitman.. 04/22/2022
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