MD 1736 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR WESTERN PORTIONS OF THE LOWER MICHIGAN PENINSULA
Mesoscale Discussion 1736
NWS Storm Prediction Center Norman OK
0651 PM CDT Sun Aug 28 2022
Areas affected...western portions of the lower Michigan Peninsula
Concerning...Severe potential...Watch unlikely
Valid 282351Z - 290145Z
Probability of Watch Issuance...20 percent
SUMMARY...The threat for a few severe gusts and perhaps a brief
tornado may accompany an approaching line of storms currently over
Lake Michigan. It is unclear how widespread the severe threat will
be though, so a WW issuance is not currently anticipated.
DISCUSSION...A QLCS has maintained some organization while moving
northeast across Lake Michigan and is poised to reach the Lower
Michigan Peninsula shoreline in the next hour or so. Ahead of the
QLCS, temperatures are in the lower 80s, with at/near 70F surface
dewpoints contributing to over 1500 J/kg MLCAPE. Increasing speed
shear through the depth of the troposphere is supporting 30-40 kts
of effective bulk shear, and the GRR VAD has been consistently
displaying modestly curved, elongated hodographs in the lowest 3 km
for the past hour, with the hodograph size only increasing with
time. As such, at least an isolated severe threat is expected to
accompany the approaching QLCS for a couple of hours before
nocturnal cooling sets in and diminishes instability. Strong to
potentially severe gusts are possible. Any line segments that can
become more northwest-southeast oriented will have the best chance
to produce severe gusts or perhaps a line-embedded tornado since
these segments would be oriented orthogonal to the deep-layer shear
vectors.
Nonetheless, buoyancy is confined to tall-skinny CAPE profiles given
mediocre lapse rates, and the region is past peak heating. Questions
remain how long-lasting the severe threat will be and what coverage
may be expected should severe occur given the aforementioned lapse
rates. Current thinking is that the severe threat, though existent,
should remain more isolated, so a WW issuance is not currently
planned.
..Squitieri/Grams.. 08/28/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...APX...GRR...
LAT...LON 42318633 42788620 43288641 43588650 44078650 44258603
44108540 43758493 43288471 42898476 42518497 42298533
42178563 42168588 42318633
