MD 1320 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR EAST CENTRAL MINNESOTA INTO NORTHWESTERN WISCONSIN
Mesoscale Discussion 1320
NWS Storm Prediction Center Norman OK
0309 PM CDT Wed Jun 28 2023
Areas affected...east central Minnesota into northwestern Wisconsin
Concerning...Severe potential...Watch possible
Valid 282009Z - 282215Z
Probability of Watch Issuance...60 percent
SUMMARY...A rapidly developing supercell or two appears possible by
5-7 PM CDT, before storms begin to consolidate into an organizing
cluster. This will be accompanied by a risk for large hail and
perhaps a tornado, before strong wind gusts becomes the more
prominent hazard this evening.
DISCUSSION...Downstream of a developing low over central Minnesota,
a focused new area of thunderstorm development to the southwest of
Duluth appears largely rooted within ascent associated with
lower/mid-tropospheric warm advection. Models suggest that this
will generally be maintained through the remainder of the afternoon,
as the leading edge of a narrow plume of more substantive low-level
moisture return occurs on south-southwesterly flow across
southwestern through east central Minnesota. It appears that this
will become supportive of rapid boundary-layer destabilization
characterized by mixed-layer CAPE increasing in excess of 2000 J/kg,
on the southwestern periphery of the initial elevated storm
development.
While this also may tend to coincide with warming and increasingly
capping mid-level air advecting from southwest to northeast across
the upper Mississippi Valley vicinity, it appears that a window of
opportunity may exist for rapidly intensifying boundary-based
thunderstorm development. Beneath 30-50 kt westerly mid-level flow,
this may include an isolated supercell or two. Before subsequently
tending to grow upscale into an organizing cluster, this activity
may pose a risk for large hail and perhaps a tornado.
..Kerr/Guyer.. 06/28/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...MPX...
LAT...LON 46019320 46029230 45699128 45379125 44649146 44779238
45009338 46019320
