891
ACUS02 KWNS 040557
SWODY2
SPC AC 040555

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Tue Jun 04 2024

Valid 051200Z - 061200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF EASTERN LOWER MI AND THE UPPER OH VALLEY...

...SUMMARY...
Thunderstorms are possible along a eastward-progressing cold front
from the Upper Great Lakes into the Ohio and Tennessee Valley.
Isolated damaging gusts are possible, particularly in eastern Lower
Michigan the the Upper OH Valley

...Lower MI and the OH Valley..
A mid-latitude cyclone is forecast to be over central/southern
Saskatchewan/Manitoba early Wednesday morning, with troughing
associated with the cyclone stretching across the Upper Midwest into
the Lower OH Valley. A shortwave trough is expected to move quickly
through the base of this cyclone, from the northern Plains into the
Upper Midwest/Upper Great Lakes with another closed mid-level
circulation developing over the Upper Great Lakes/eastern Ontario
late Wednesday evening/early Thursday morning. Strong mid-level flow
will accompany this shortwave, spreading into the Mid MS Valley and
OH Valley Wednesday afternoon and evening.

Evolution of this shortwave trough will encourage a more eastward
progression of a triple-point surface low expected to be in the
western Upper MI vicinity early Wednesday. A cold front will likely
extend southward from this low through central IL and southern MO As
the surface low moves eastward into central/eastern Ontario, the
associated front will progress eastward across MI and much of the TN
and OH Valleys. A moist low-level airmass will precede this front,
with dewpoints ranging from the low 70s from the Mid-South into
western KY and far southern IN to the mid 60s across much of Lower
MI and the OH Valley. Surface temperatures could reach in the upper
70s/low 80s ahead of the front, combining with the low-level
moisture to support moderate buoyancy (i.e. MLCAPE around 1000
J/kg). Moderate vertical shear is anticipated as well, with around
30 kt of deep-layer shear possible as the mid-level flow increases
over the region.  Thunderstorm are likely along and ahead of this
front, with the moderate buoyancy and shear supporting the potential
for a few strong to severe storms capable of damaging gusts.

...Lower MS Valley across the TX Coastal Plains into the TX Hill
Country...
Thunderstorms will likely be ongoing early Wednesday morning in the
Arklatex vicinity, with continued southeastward motion into the
Lower MS Valley likely as the storms gradually weaken. Outflow from
these storms could provide the impetus for additional thunderstorm
development during the afternoon from the Lower MS Valley across the
TX Coastal Plains into the TX Hill Country, within a strongly
buoyant but weakly sheared airmass. Some severe is possible, with
outflow-dominant storm structures contributing to the potential for
damaging gusts. However, uncertainty regarding convective evolution
of the early morning storms and resultant uncertainty regarding the
strength and location of its associated outflow as well as expected
limited coverage precludes introducing any probabilities with this
outlook.

...Upper Midwest...
Afternoon thunderstorm development is anticipated across the region,
supported by cold mid-level temperatures and large-scale ascent
associated with the mid-latitude cyclone drifting into the region.
Most updrafts will likely be shallow, but a few deeper updrafts
could result in small hail and a damaging gust or two. Severe
coverage is currently expected to be less than 5%.

..Mosier.. 06/04/2024

$$