142 
ACUS11 KWNS 262026
SWOMCD
SPC MCD 262025 
PAZ000-WVZ000-OHZ000-MIZ000-262200-

Mesoscale Discussion 0292
NWS Storm Prediction Center Norman OK
0325 PM CDT Thu Mar 26 2026

Areas affected...much of Ohio into western Pennsylvania

Concerning...Severe potential...Watch likely 

Valid 262025Z - 262200Z

Probability of Watch Issuance...80 percent

SUMMARY...Gradual convective development should support an
increasing risk for supercells late this afternoon into this
evening. Hail, damaging gusts are likely, with a couple of tornadoes
possible.

DISCUSSION...Afternoon visible and radar imagery showed an area of
showers and weak convection gradually intensifying across southern
Lower MI into northwestern OH. Located along and south of a
front/lake breeze intersection, warming and moistening of the air
mass across much of OH and PA this afternoon has resulted in weak to
moderate buoyancy. Area VADs show very strong mid-level flow with
elongated and veering hodographs. This will favor a mix of
supercells and linear segments as the primary storm mode. Given the
sufficient buoyancy and strong low/deep-layer shear, hail and severe
gusts are likely. Tornadoes are also possible given ESRH of 300-400
m2/s2. Additional vertical vorticity near the lake breeze boundary
could also support a locally greater tornado risk given favorable
storm motions parallel to the lake shore.

Recent CAM guidance and satellite trends regarding the ongoing
shallow convection/showers over northwest OH and Lower MI show them 
gradually deepening as continued heating and mid-level ascent erode
inhibition. This should support an increase in the severe risk late
this afternoon into the evening. A Tornado Watch will likely be
needed.

..Lyons/Smith.. 03/26/2026

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

ATTN...WFO...CTP...PBZ...RLX...CLE...ILN...DTX...IWX...

LAT...LON   41748249 42038144 42058046 41617949 41077934 40447956
            39768013 39258145 39148316 39458405 39838433 40468450
            41188445 41648424 41758388 41768347 41748249 

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS11/20260326T2026.txt



252 
ACUS11 KWNS 261948
SWOMCD
SPC MCD 261948 
MIZ000-OHZ000-INZ000-ILZ000-262145-

Mesoscale Discussion 0291
NWS Storm Prediction Center Norman OK
0248 PM CDT Thu Mar 26 2026

Areas affected...Portions of Illinois...northern Indiana...into
southern lower Michigan and northwest Ohio

Concerning...Severe potential...Watch likely 

Valid 261948Z - 262145Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorm development appears likely over the next
couple of hours along a surface cold front and various lake breeze
boundaries. Ample buoyancy and vertical shear for supercells and
line segments will support an increasing severe risk for all
hazards. A WW is likely.

DISCUSSION...As of 1945 UTC, visible imagery showed a deepening
cumulus field across portions of northern IL into northern IN, Lower
MI and northwestern OH. Mid-level ascent from a shortwave trough and
strong flow aloft north of a subtropical ridge has begun to erode
remnant inhibition from west to east. Amid strong diurnal heating,
dewpoints in the upper 50s to low 60s F are supporting 500-1500 J/kg
of MLCAPE. Continued destabilization is likely over the next couple
of hours, with a favorable cape/shear parameter space for supercells
and line segments. Hail, some very large, is likely with
supercellular elements, given steep mid-level lapse rates > 8 C/km.
A fairly quick transition to more linear structures appears likely
given the frontal forcing. This would favor a risk for
severe/damaging gusts as well.

The tornado threat, especially to the west, remains more uncertain.
Stronger heating/mixing has resulted in nearly 30 degree
temperature/dewpoint spreads over parts of IL, with veered low-level
flow. Still, elongated hodographs will favor supercells along the
frontal zone with hail and damaging gusts likely. The tornado threat
appears highest where low 60s F surface dewpoints hold, and stronger
low-level hodograph curvature is present. Primarily across IN/OH,
closer to the front.

Storms may develop across multiple areas of the surface front and
lake breeze this afternoon into this evening before rapidly
increasing in coverage. Given the expected increase in severe
potential a WW is likely needed this afternoon.

..Lyons/Smith.. 03/26/2026

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

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

LAT...LON   42148522 42108469 41668423 41218419 40118451 39658502
            39608510 38858825 38999023 39439082 39889086 40629010
            41298926 41638787 41768688 42088590 42148522 

MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS11/20260326T1948.txt