Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Mar 25 2023 01:36:03 AWUS01 KWNH 250135 FFGMPD OHZ000-KYZ000-INZ000-ILZ000-250715- Mesoscale Precipitation Discussion 0126 NWS Weather Prediction Center College Park MD 935 PM EDT Fri Mar 24 2023 Areas affected...Lower Ohio River Valley... Concerning...Heavy rainfall...Flash flooding possible Valid 250135Z - 250715Z SUMMARY...Prolonged moderate rainfall and localized totals of 1-2" crossing saturated grounds likely to result in localized flooding concerns with low end possibility of rapid inundation/flashy conditions due to high runoff. DISCUSSION...Squall line continues to advance across the central Mississippi River Valley into the Tennessee River Valley with strong storms continuing to ingest and rob the remaining instability for activity to the north. Surface analysis depicts the eastward extending warm/stationary front has been suppress a tad south of expected forecast and resides across southern Kentucky, perhaps just a few miles north of the KY/TN border.=20 Still, the breadth and strength of the moisture flux within the 50-60kt LLJ remains favorably oriented to the boundary for strong upglide. Combined with nearly opposite 850mb flow (north-northeast seen across central IND/OH), the slope and convergence along and south of the 850mb boundary will continue to support fairly efficient upglide/shield precipitation across the Lower Ohio River Valley. Weak embedded convective elements still exist where MUCAPEs remain above 100-250 J/kg which is generally south of the Ohio River in W KY, this is expected to continue into central KY, and support .75"/hr rates, slowly decreasing to .5"/hr along and north of the Ohio River.=20 The concern for flooding, perhaps even occasional rapid inundation/flashy conditions may occur along the interface of significantly reduced FFG values and higher upper soil saturation ratios denoted along and north of the Ohio River. Broad areas of 2-4" last evening have reduced hourly values between .5-1.5" and 3hr values between .75-2" across the area of concern. The length of the isentropic ascent and .5"/hr rates should allow for a broad swath of 1-2" totals. Even as rates and totals continue to fall after 06z and toward the Tri-state area of IND/OH/N KY...FFG values fall to lower values to keep pace for risk of exceedance.=20 As such flooding is considered likely especially in the vicinity of urban centers like Evansville, Owensboro, Louisville and Cincinnati...though flash flooding is only considered possible and limited to low end Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7M8fKFLk91E4NFcjKG5NuSNK4kgCI-VTCRDgDsfSclADAuNvM_Z5e34S2OeKjDY7Q_mp= o2ahpEX1FpTnfg-aV9pprJ0$ for graphic product... ATTN...WFO...ILN...ILX...IND...LMK...PAH... ATTN...RFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 40258386 39968289 38888305 38318441 37708609=20 37248731 36768863 37258916 38088935 38538856=20 39228744 39808594=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .