Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Sep 21 2025 02:13:53 AWUS01 KWNH 210210 FFGMPD MOZ000-ARZ000-OKZ000-KSZ000-210800- Mesoscale Precipitation Discussion 1112 NWS Weather Prediction Center College Park MD 1009 PM EDT Sat Sep 20 2025 Areas affected...Northeast OK...Southwest MO...Northwest AR...Far Southeast KS... Concerning...Heavy rainfall...Flash flooding possible Valid 210210Z - 210800Z SUMMARY...Increasing WAA from strengthening low-level jet intersecting pool of moist/unstable air. Favorable mid-level flow may support training and isolated back-building/cell mergers to support DISCUSSION...GOES-E WV suite shows a subtle shortwave feature moving along the central OK/KS boarder providing some mid-level DPVA and positive ascent profiles downstream, coincident with early evening low-level jet acceleration up to 20kt and eventually veering more southwest to northeast and into the 30kt range. This ascent is interacting with an old linger outflow boundary from this morning's activity that connects from the surface front just east of AVK toward SWO, MKO, FSM and more east across central AR.=20 Enhanced moisture of upper 60s to even mid 70s Tds with still some remaining higher surface temperatures maintains a pool of 2000-2500 J/kg of MLCAPE across NE OK. The ascent pattern convection has been pressing eastward into Osage county and isolated pre-cursory cells north of Tulsa have been fairly stationary in a 500-1000mb thickness ridge, that supports some upstream redevelopment. Stronger updrafts and low level moisture has made the cells fairly prolific/intense with hourly rates up to 2"/hr, with some localized observations over 3" near Collingsville. This activity is likely to become a bit more progressive with time, but localized totals may intersect areas saturated this morning and have lower FFG values of 1.5"/hr and less than 3"/3hrs, suggesting increased run-off is possible. Further northeast, the northeast edge of the LLJ combined with the northern edge of this morning's rain foot has concentrated flow/convergence to support a NW to SE oriented 925-850mb FGEN band. The convergence along which has sprouted some elevated convection along the northeast edge of the higher instability air. Deeper layer flow, here initially will support NW to SE cell motions allowing for some potential training across SW MO/NW AR.=20 Spots of 2-3" may be possible, but eventual backing of the deeper layer flow will reduce orthogonal ascent convergence and cells from NE OK, will slide northeast and meld/merge. Rates may trickle up to 1.75-2"/hr for these short-term mergers, but given more rugged terrain with low water crossings, there is some potential for possible incident or two of localized flash flooding through the overnight period here as well. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_xp65VQ2MNcpbph3TQEkY66KmhWeulAAQwOxxAycrLMAfmHAZREsooxCtV72-ZYUMn6W= wuxj_HVMHjB-3iXlzKTKUro$ for graphic product... ATTN...WFO...ICT...LZK...SGF...TSA... ATTN...RFC...KRF...ORN...TUA...NWC... LAT...LON 37469484 37159307 36649217 36029197 35679252=20 35869334 35979438 35819600 36279667 36859667=20 37239626=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .