Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 14 2023 03:30:33 AWUS01 KWNH 140330 FFGMPD OKZ000-140900- Mesoscale Precipitation Discussion 0921 NWS Weather Prediction Center College Park MD 1130 PM EDT Sun Aug 13 2023 Areas affected...West-central to Northeast Oklahoma... Concerning...Heavy rainfall...Flash flooding likely Valid 140330Z - 140900Z SUMMARY...Line of convection starting to fill in across Oklahoma along/ahead of a southern stream shortwave. Rates of 2-2.5"/hr and periods of training (especially across NE OK) are becoming increasingly probable. Axis of 3-5" by 07z and accompanying instances of flash flooding are becoming likely. DISCUSSION...While confluence of streams is likely to be much more significant in rainfall intensity and duration across NE OK into southern MO/northern AR, thunderstorms are starting to fill in upstream along a southern/sub-tropical stream frontal zone that bisects the state generally along the axis of I-44. 03z surface analysis shows the cold front from the northern stream is surging southward at the southwest push of the very strong closed low over the Dakota dropping south. Deep layer return/confluent flow can be seen through the Rio Grande Valley then extending eastward across TX, OK, while typical summer return/southerly flow and Tds of 70+ (east of I-35) help to increase total PWAT values of 2-2.5" along and between the two frontal zones.=20 A subtle southern stream shortwave, enhanced by late afternoon convection has been progressing through the TX panhandle into OK, providing mid-level DPVA broad scale enhancement and strengthening of the confluent low level jet into the deeper moisture channel.=20=20 This shortwave will progress eastward but also help to maintain a favorable latitude of redevelopment of the convective line across central to northeast OK. Given ascent, flux and solid instability of 2000-3500 J/kg of MLCAPE...rainfall efficiency will be impressive with 2-3"/hr rates likely. Duration of those efficient cores remains the greatest uncertainty over the next few hours.=20 But 00z HRRR even suggests rainfall totals of 2"/15 minutes is possible, especially with the leading edge of convergence ahead of the aforementioned shortwave feature. Along the line, rates of 2"/hr are more likely. Given 2-4 hours, spots of 5"+ are possible likely toward the Northeast of the highlighted area. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7wSajQiZDn78fUJsCttv6F2XyT0ZWkT9cexefxvxl9f-5cYT9F8wyVOWU-bmf-a-trr2= 3laegalb1mZU4Oyh0zSRpsA$ for graphic product... ATTN...WFO...OUN...TSA... ATTN...RFC...ABRFC...NWC... LAT...LON 36859527 36479465 35749472 35439565 35199725=20 35329837 36139831 36529699 36729626=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) .