SPC MD 1345

MD 1345 CONCERNING TORNADO WATCH 432… FOR EASTERN IL…WESTERN/NORTHERN IN…FAR SOUTHWEST LOWER MI

Mesoscale Discussion 1345
NWS Storm Prediction Center Norman OK
1057 AM CDT Wed Jun 18 2025

Areas affected...eastern IL...western/northern IN...far southwest
Lower MI

Concerning...Tornado Watch 432...

Valid 181557Z - 181800Z

The severe weather threat for Tornado Watch 432 continues.

SUMMARY...Severe threat should increase substantially through
mid-afternoon as an arc of storms intensifies to the east-northeast
from central Illinois. A few tornadoes, scattered damaging winds,
and isolated severe hail will remain possible. Downstream tornado
watch issuance is anticipated to the northeast of Ww 432.

DISCUSSION...While the primary surface cyclone and attendant MCV are
centered near the northeast MO/west-central IL border area, a
downstream arc of increasing deep convection is expected to
strengthen across central IL. With mid 70s surface dew points common
across southern IL/IN, a pronounced MLCAPE gradient is setting up
from south to north. A compact belt of strong 700-500 mb
southwesterlies in the LSX VWP, recently sampled by the ILX VWP as
well, should support a broken band of supercells within this leading
arc as it spreads northeast. The potential for tornadoes has
increased and a 10 percent tornado probability will be added in the
1630Z D1 Outlook. The LSX VWP also indicates low-level SRH
diminishing behind this leading arc, but some tornado threat should
linger near the immediate MCV/surface low.

..Grams/Hart.. 06/18/2025

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

ATTN...WFO...IWX...GRR...IND...LOT...ILX...LSX...DVN...

LAT...LON   38828765 38718868 38918905 39628955 39998986 40269003
            40668975 41248906 41698817 42238631 42058597 41788572
            41378574 40628592 40218623 39618689 38828765 

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

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