Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 07 2023 09:49:01 AWUS01 KWNH 070948 FFGMPD TXZ000-OKZ000-KSZ000-COZ000-071400- Mesoscale Precipitation Discussion 0650 NWS Weather Prediction Center College Park MD 548 AM EDT Fri Jul 07 2023 Areas affected...Kansas, Oklahoma Concerning...Heavy rainfall...Flash flooding possible Valid 070947Z - 071400Z Summary...Clusters of thunderstorms are likely to expand through the morning and train to the southeast. Rainfall rates of 2-3"/hr are likely which may produce 2-3" of rain with locally higher amounts. Flash flooding is possible. Discussion...The regional radar mosaic centered around Kansas/Oklahoma reveals two modes of convection early this morning. The first is with a leading MCS and developing MCV which emerged out of Colorado last night and is still potent while it tracks southeast into Oklahoma. This MCS has produced a stripe of 2-4" of rainfall in the last 6 hours according to MRMS, with recent rain rates estimated by KDDC still reaching 2.5"/hr. North of this feature, renewed and fresh convection is developing in an arc draped NW to SE along the nose of a LLJ measured by regional VWPs of 30-35 kts. The environment surrounding this development remains extremely favorable for heavy rainfall noted by GPS measured PWs of around 1.5 inches, and RAP analyzed MUCAPE of 1000-1500 J/kg. The flash flood threat developing in the next few hours will likely emerge in two regimes. The first will be associated with the MCS/MCV which is progged to rotate southeast through central OK. This feature will move into a region with still impressive MUCAPE, and a resupply of favorable thermodynamics on the slowly veering 30 kt LLJ. The veering of this LLJ will also be important due to the inflow then becoming more orthogonal to the trailing outflow boundary noted on radar, suggesting more intense upglide atop it. This could result in more linear/training convection upstream of the MCS as it digs southward. With rainfall rates progged by both the HREF and HRRR sub-hourly fields to approach 3"/hr, could result in 2-3" of rain or locally higher amounts in a short period of time. The second area of flash flood concern will develop along the nose of the LLJ across Kansas. While mesoscale forcing may be modestly weaker here, again the veering of the LLJ will resupply favorable thermodynamics northward, while at the same time converging efficiently to drive ascent. It is also possible that the aforementioned MCV may help squeeze moisture as 850-700mb flow turns more easterly to converge across KS. Although storm motions here are likely to remain progressive on 25kts of 0-6km mean wind, and rainfall rates may be less intense than across OK, persistent training is possible which could also result in locally 2-3" of rainfall. Soils are somewhat vulnerable across the region due to 14-day rainfall that in some places has been above 200% of normal resulting in 1-hr FFG around 1-1.5 inches, for which the HREF has some modest exceedance probabilities. Although confidence is not extremely high in evolution due to relatively poor model initialization of ongoing convection, it is possible some of this training heavy rain could result in instances of flash flooding this morning. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-Z_PBxekK8dkOxcTMa3sNMVUO_6WOZWk2_hS_hYBY2E8M9LU1WvjpWldh1VD2plx32KS= NpsZDNc1U8H_bvTESm93dM0$ for graphic product... ATTN...WFO...AMA...DDC...GID...GLD...ICT...OUN... ATTN...RFC...ABRFC...MBRFC...NWC... LAT...LON 39980207 39860090 39640012 38919899 38049809=20 36869730 35889693 35449698 35219729 35049787=20 34949841 35019892 35319955 35770035 36510114=20 37560169 37560169 38470201=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) .