Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 13 2023 09:05:47 AWUS01 KWNH 130905 FFGMPD MOZ000-ARZ000-OKZ000-KSZ000-131430- Mesoscale Precipitation Discussion 0917 NWS Weather Prediction Center College Park MD 504 AM EDT Sun Aug 13 2023 Areas affected...Southeast KS...Southwest to South-central MO...Northern AR and far Northeast OK... Concerning...Heavy rainfall...Flash flooding possible Valid 130905Z - 131430Z SUMMARY...Highly efficient convective cluster likely to expand as it progresses across recently wet grounds. Short-term rates over 2"/hr near lower FFG in the area, triggering possible flash flooding DISCUSSION...Recent GOES-E 10.3 EIR loop shows a cluster of expanding/cooling cloud tops with overshooting tops below -80C, being spurred on by favorable DPVA from shortwave crossing central KS as well as strong moisture flux convergence at leading edge of deeper than normal WAA LLJ. VWP at KINX shows fairly deep unidirectional flow of 15-30kts from 925 to 700mb across NE OK.=20 This is also at the leading edge of a elongated higher Theta-E/moisture axis from south-central KS across northeast OK into northern AR (per CIRA LPW). Greatest overlap of the lower layers results in 2-2.25" total PWAt at the nose of the LLJ in northeast OK. Given the MUCAPE of 3000 J/kg across this axis, the isentropic/deep layer convergence supports these stronger cells.=20 Deeper than average warm cloud layer supports efficient rainfall production of 2-2.5"/hr in spots; which is supported by a few backyard weather observations in proximity to the Grand Lake o'the Cherokees, denoting 1.8"/30 minutes and 1.7" in 45 minutes.=20=20 A limiting factor is likely to be duration given forward cell motions of greater than 30kts; however, the strength of inflow from the southwest supports a favorable back-building regime, though source region will become slightly drier over a few hours as upstream mid-level moisture is a bit less in central OK into Northern TX. As such, duration of 1-2 hours suggests spots of 2-4" are probable across NE OK into SW MO and northern AR. There is some uncertainty toward northwest-ward expansion of the line.=20 Much of the Hi-Res CAMs are bullish toward this expansion, but have also struggled at evolution/timing of this cluster already.=20 Still, given DPVA and available instability toward the northwest, there is solid potential, though additionally this moves into areas of higher FFG and recent drier soil conditions. As such, area of concern has been limited in size/scope to align with recently wet grounds (last few days-week per AHPS precip anomalies) and lower FFG, rougher terrain of SW MO/N AR. Still, confidence is not particularly high overall and so localized flash flooding is considered possible through day-break. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_vhcraSVu7dld_3fwIPZcW0y3Ho8AleRC1havtMiGGQ246pqdeTXWUVJu748WK54s98U= 2wCDgjM8GGF28gqUqv0fB60$ for graphic product... ATTN...WFO...EAX...ICT...LZK...SGF...TOP...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC... LAT...LON 38279436 38139319 37719208 37189138 36689122=20 36179126 35659187 35699317 35909433 36159528=20 36839577 37829564 38189503=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) .