Mesoscale Discussion 1565 NWS Storm Prediction Center Norman OK 0139 PM CDT Tue Jul 09 2024 Areas affected...western/central Kentucky and adjacent portions of southeastern Illinois/southern Indiana Concerning...Severe potential...Watch likely Valid 091839Z - 092045Z Probability of Watch Issuance...95 percent SUMMARY...Potential for supercells posing a risk for tornadoes appears likely to increase through 5-7 PM EDT, particularly near the Ohio River from Evansville/Owensboro through the Greater Louisville area. DISCUSSION...Beryl's remnant surface low is currently in the process of migrating east-northeastward across southeastern Missouri into the lower Ohio Valley, with a zone of strengthening differential surface heating becoming better defined near the Ohio River downstream toward the Greater Cincinnati area. South of this zone, boundary-layer destabilization is ongoing, supported by both insolation and slowly increasing moisture. The increasingly buoyant low-level environment is supporting the development of showers and isolated to widely scattered weak thunderstorms, but this is occurring beneath a notably warm and warming mid-level environment, which will tend to slow, if not suppress, intensifying convective development. Into the 21-23Z time frame, in the peaking boundary-layer instability, latest Rapid Refresh suggests that a relatively minimum in mid-level inhibition may linger near the Ohio River, roughly from Evansville IN/Owensboro Ky through the Greater Louisville area, near the nose of the stronger southerly flow around 850 mb associated with Beryl. Although this jet streak is forecast to weak some, speeds on the order of 30+ kt appear likely to still contribute to sizable clockwise-curved low-level hodographs, particularly along or just south of the differential heating zone. Given dynamic forcing associated with occasionally strengthening low-level mesocyclones, and the near-surface buoyancy associated with the high boundary-layer dew points (increasing to 75+ F), low-level upward accelerations may become increasingly conducive to tornadic potential in evolving supercell structures. ..Kerr/Guyer.. 07/09/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILN...LMK...OHX...IND...PAH... LAT...LON 37748853 38258783 38588668 38588480 37518524 36938580 36488720 36598814 37748853
Storm Prediction Center Mesoscale Discussion 1565

09
Jul