Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 08 2025 03:53:59 AWUS01 KWNH 080353 FFGMPD VAZ000-WVZ000-OHZ000-KYZ000-INZ000-080900- Mesoscale Precipitation Discussion 0396 NWS Weather Prediction Center College Park MD 1153 PM EDT Sat Jun 07 2025 Areas affected...Central and southeast IND...Southwest OH...Northeast KY...Western WV... Concerning...Heavy rainfall...Flash flooding possible Valid 080355Z - 080900Z SUMMARY...Scattered, focused but very intense warm cloud tropical showers capable of quick 1.5-1.75"/hr and totals up to 2.5" may result in possible flash flooding.=20 DISCUSSION...GOES-E WV suite shows a pair of smaller scale shortwave features moving through the Ohio Valley at the eastern edge of the larger cyclonic synoptic trough over the Great Lakes. A stronger mid to upper level jet swings through the Lower Ohio into the TN River Valley, the short-wave axis continues to elongate/shear but also act as a deep layer speed convergence trof fro northwest IND across SW OH toward NE KY, with the base of the shear axis rotating eastward quicker. Deep layer moisture through the Ohio Valley remains well above average near 1.6-1.8" PWat. As the broad 20-25kt 850mb LLJ under-cuts, it is also advecting some weak mid-level drying to slightly steepen mid-level lapse rates and increase available instability toward 750-1000 J/kg in proximity to speed convergence axis. As such, smaller embedded fairly narrow updraft cores have been sprouting through the cirrus shield where some right entrance ascent/outflow has been increasing as the speed max exits to the northeast. Throughout the evening these shallow updrafts have been very efficient even with the above average moisture perhaps with some enhanced nucleation from ingested smoke particles in the warm cloud layer.=20 Cells within the shear axis have also shown relatively slow cell motion with some remaining stationary for over an hour resulting in recent hourly observations of 1.25-1.5".=20 Slow eastward shift of the shear axis with the base swinging through E KY/SW WV a bit quicker, may result in some very isolated spots seeing a repeating of these embedded shallow convective cells. As such, it cannot be ruled out a spot or t increase, with even recent hourly observations of 1.25-1.5" noted.wo of 2-2.5" totals may be possible. Still, the overall coverage is likely at the limit of inducing more than a few isolated incidents of flash flooding. However, hourly FFG of 1-1.5" and 3hr FFG values less than 2" dot the of concern and so there is sufficient potential for at least one or two possible incidents through early morning in/along the shear axis, particularly in narrow gullies/complex terrain within the Cumberland Plateau into central Appalachians. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_gHfN-X6UUolexQKvZLsszhNO-116VBf3HBuRFWqzcXkenLAXpKheQWLI5i2ceK8MMW7= gm5InkTNatx5bKGJKuK3uUI$ for graphic product... ATTN...WFO...ILN...IND...IWX...JKL...LMK...LOT...RLX... ATTN...RFC...MSR...TIR...NWC... LAT...LON 40958648 40858545 40488475 39868323 39608228=20 39378156 38968077 38658067 37718115 37258201=20 37348292 37598374 38108539 38318656 38898728=20 39998751 40558743 40938706=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .