MD 1621 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PARTS OF CENTRAL/SOUTHERN MN INTO WESTERN WI
Mesoscale Discussion 1621
NWS Storm Prediction Center Norman OK
0420 PM CDT Sun Jul 31 2022
Areas affected...Parts of central/southern MN into western WI
Concerning...Severe potential...Watch possible
Valid 312120Z - 312315Z
Probability of Watch Issuance...40 percent
SUMMARY...Severe risk could be increasing across parts of
central/southern Minnesota into western Wisconsin this
afternoon/early evening. The primary concerns are locally severe
gusts and sporadic large hail. Trends are being monitored for a
possible watch.
DISCUSSION...In the wake of earlier warm-advection-driven elevated
convection, pockets of diurnal destabilization are evident in
visible satellite imagery across parts of central/southern MN into
western WI -- characterized by a transition from stable billow
clouds to horizontal convective rolls. Given this gradual
destabilization of a moist boundary layer (upper 60s/lower 70s
dewpoints), new convective development will be possible along/ahead
of a cold front across west/central MN. The plume of warm advection
is contributing to modest low-level hodograph curvature (near 100
m2/s2 SRH), and effective bulk shear of 30-40 kt would conditionally
support organized convective structures including supercells.
If convection can maintain residence time in the pockets of
surface-based instability across the warm sector, locally severe
gusts and sporadic large hail would be possible, and a brief tornado
cannot be ruled out owing to the modest boundary-layer streamwise
vorticity. Convective trends are being monitored for a possible
watch issuance.
..Weinman/Hart.. 07/31/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...ARX...MPX...FSD...
LAT...LON 46139452 45649498 44799541 44489551 43879537 43579521
43579478 43549425 43559294 43649233 44119190 44929171
45989192 46399224 46539412 46139452
