645
ACUS11 KWNS 181721
SWOMCD
SPC MCD 181720
MNZ000-WIZ000-SDZ000-181915-

Mesoscale Discussion 1317
NWS Storm Prediction Center Norman OK
1220 PM CDT Tue Jun 18 2024

Areas affected...most of MN

Concerning...Severe potential...Tornado Watch likely

Valid 181720Z - 181915Z

Probability of Watch Issuance...80 percent

SUMMARY...While initially elevated thunderstorms may pose an
isolated severe hail threat, scattered surface-based storms will
likely develop by mid to late afternoon from across most of
Minnesota. All severe hazards are possible. A tornado watch will
probably be needed by 19Z.

DISCUSSION...17Z surface analysis placed a 997 mb cyclone near the
northeast SD/west-central MN border with a warm front gradually
advancing north into northern MN and a cold front arcing
south-southwest into central NE. Initially elevated convection north
of the front may pose some risk for isolated severe hail in the
near-term. Latest SPC mesoanalysis indicates MLCIN has become weak
with MLCAPE of 1500-2500 J/kg within the plume of pervasive low 70s
boundary-layer dewpoints ahead of the cold front. Morning CAM
guidance is insistent on scattered to eventually widespread
convective development from northern MN building southward later
this afternoon.

While the mid to upper-level bulk shear will be modest with much of
the stronger flow displaced west of the front, low-level hodographs
will remain enlarged across the MN portion of the warm-moist sector.
A rather messy convective mode is anticipated to evolve quickly
given this wind profile. But with rich boundary-layer moisture and
enhanced SRH, tornado potential is a concern from the warm frontal
zone southward. A mix of outflow-dominated clusters with embedded
and largely transient supercells is expected. These should yield
potential for a few tornadoes, scattered wind gusts of 55-70 mph,
and isolated large hail from 1-1.75 inches in diameter.

..Grams/Gleason.. 06/18/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON   45579650 46179613 47179439 47959296 48119199 47809152
            46619217 45619290 44329384 43669474 43649620 44379653
            45579650