Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 15 2023 17:13:03 AWUS01 KWNH 151712 FFGMPD MOZ000-ARZ000-OKZ000-KSZ000-152310- Mesoscale Precipitation Discussion 0300 NWS Weather Prediction Center College Park MD 112 PM EDT Mon May 15 2023 Areas affected...Southwest and South-Central MO...Far Northwestern AR and Southeastern KS...Northeastern OK Concerning...Heavy rainfall...Flash flooding likely Valid 151710Z - 152310Z Summary...Localized intense downpours may result in 2"+ totals in an hour or less, with 3-6 hour totals as high as 3-5". Isolated to scattered instances of flash flooding are likely, and an instance or two of significant flash flooding is possible. Discussion...A relatively weak low pressure system will slowly translate northeastward this afternoon across southwestern MO (currently located near the MO/KS/AR/OK border region), bringing slow moving, localized heavy downpours that will be capable of causing flash floods. The current mesoscale enviornment is characterized by surface-based CAPE of 1000-2000 J/kg (and progged to increase by another 500-1000 J/kg, particularly across cloud-free areas of southern MO/northern AR), precipitable water values of 1.4-1.8 inches (near record territory, per SGF sounding climatology), and limited effective bulk shear of 15-25 kts. While this enviornment is fairly lacking in upper-level support (with marginal upper divergence and forcing being dislocated to the northwest), this is expected to be made up for on the mesoscale via modest low-level frontogensis/warm air advection in an impressively moist tropospheric column with relatively slow storm motions (10-20 kts) and localized training potential. This should result in a proliferation of pulse-like convection, which will likely prevent individual updrafts from maintaining heavy rainfall on the order of 1-2"+/hr rates. However, downpours are expected to be quite intense locally, as evidenced by rather impressive HRRR sub-hourly (15-min) precipitation output of 1"+. These short-term rates (with localized 2"+ totals in an hour or less) will alone be capable of producing flash flooding (with 1-hr FFG as low a 1.0-1.5" across much of the region), but with relatively high coverage of this pulse-like convection there will likely be localized totals (over the next 6 hours) that reach the 3-5" range (with associated 6-hr FFG of 2-3"). The area most favored for localized totals in excess of 3" extends from far northeast OK and southeast KS into southwest and south-central MO (per HREF 40-km neighborhood exceedance probabilities of 30-70%). Similarly, the area with best spatial agreement for >1" (per HREF Ensemble Agreement Scale 10-100 km neighborhood probabilities of 30-70%) is solely across southwestern MO (including but not limited to Joplin, Springfield, and Branson). While overall storm organization is expected to be fairly underwhelming, isolated to scattered instances of flash flooding are considered to be likely (with an instance or two of significant flash flooding possible). Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5sOKTVrJ1gQ2uq8T7MAipS_cj1S9t1cjaJIY-D0aXPA9bPMBeB3qfTuTL04XG7fj1DeO= s0DlSUaIY3myiyzkDAJHM7Y$ for graphic product... ATTN...WFO...ICT...LSX...LZK...OUN...PAH...SGF...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...NWC... LAT...LON 38019385 38009189 37539073 36559095 36469206=20 36299285 35509446 34889549 34699645 34979688=20 35879665 36929634 37589600 37949529=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) .