Storm Prediction Center Mesoscale Discussion 1816

   Mesoscale Discussion 1816
   NWS Storm Prediction Center Norman OK
   1231 PM CDT Sat Aug 01 2026

   Areas affected...portions of southern Indiana and Ohio into central
   Kentucky and middle Tennessee

   Concerning...Severe potential...Watch possible 

   Valid 011731Z - 012000Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered thunderstorms are expected to develop ahead of a
   cold front and surface cyclone this afternoon across the OH/TN
   Valleys. A mixed mode of clusters and supercell structures could
   pose a risk for damaging gusts and a couple of tornadoes. A WW is
   possible, but uncertain.

   DISCUSSION...As of 1730 UTC visible and radar imagery showed showers
   and incipient thunderstorms intensifying along a broad frontal zone
   over the lower OH valley. Diffuse heating amid lingering clouds
   ahead of the front and occluded surface cyclone have raised surface
   temperatures into upper 70s to low 80s F in a very moist surface air
   mass. While overall lapse rate profiles are modest, the heating and
   weak ascent from the associate upper low overspreading the area is
   supporting continuing destabilization this afternoon with MLCAPE of
   1000-2000 J/kg expected. Storm coverage is forecast to increase from
   IN, southward across KY and into parts of OH and middle TN this
   afternoon.

   A belt of stronger westerly flow aloft is supporting 30-35 kt of
   effective shear and modest low-level hodograph curvature evident on
   area VADs. This suggests a mix of organized multicells and transient
   supercell structures is likely. The high PWATs will favor
   water-loading of the downdrafts and some damaging gusts potential,
   especially for cells that can cluster.

   The tornado risk is less clear, but focused low-level buoyancy,
   plentiful ambient vertical vorticity and 0-500m SRH of 75-150 m2/s2
   could support a couple of tornadoes with any potential supercells.
   This could be locally focused where the most robust surface heating
   is occurring, and where low-level flow remains backed along portions
   of the OH river in southern IN northern KY and southwest OH.

   Given the expected increase in thunderstorms with some risk for
   damaging gusts and a couple tornadoes, a WW is being considered.
   However, the lingering cloud cover and nebulous forcing lend low
   confidence on timing and where the greatest threat may occur.

   ..Lyons/Mosier.. 08/01/2026

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

   ATTN...WFO...MRX...JKL...ILN...LMK...OHX...IND...HUN...PAH...

   LAT...LON   36858729 37988686 39268683 39898709 40288654 40148524
               39888472 39588406 39168359 38728340 37508392 36758446
               36118485 35668535 35308604 35128680 35078728 35308773
               35548775 36858729 

   MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH