Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 21 2023 07:38:32 AWUS01 KWNH 210738 FFGMPD KSZ000-NEZ000-211337- Mesoscale Precipitation Discussion 0546 NWS Weather Prediction Center College Park MD 337 AM EDT Wed Jun 21 2023 Areas affected...Portions of the Central Plains Concerning...Heavy rainfall...Flash flooding possible Valid 210737Z - 211337Z SUMMARY...Showers and thunderstorms will be developing and expanding in coverage over the next several hours. Locally heavy rainfall rates may pose an isolated threat for flash flooding. DISCUSSION...GOES-16 WV satellite imagery shows a very well-defined mid-level shortwave trough and associated vort center advancing gradually east out across the central Plains. This energy over the next few hours will be providing sufficient large scale ascent in conjunction with strong elevated instability parameters to foster developing and expanding clusters of showers and thunderstorms. In fact, MUCAPE values across central to western KS are currently on the order of 3000 to 4000+ J/kg, and there is a southerly low-level jet of as much as 30 to 40+ kts as seen in VWP data. Some additional slight nocturnal enhancement of this low-level jet may occur over the next couple of hours which will strengthen the warm air advection pattern and help to yield further ascent in conjunction with the DPVA associated with the approaching shortwave energy. The channel of low to mid-level moisture as seen in conventional satellite imagery (WV suite) and CIRA-ALPW data is favoring at least modestly anomalous PWs across the MPD threat area, with values as much as 1 to 1.5 standard deviations above normal. The CIRA-ALPW data shows that the 850/700mb layer in particular has become considerably more moist over the last few hours, and this is a precursor to the expected convective development given a combination of strengthening vertical ascent and layered moisture transport. As convection develops and expands in coverage, some of the stronger cells will be capable of producing 1 to 2 inch/hour rainfall rates, and with the expectation of rather slow cell-motions, some rainfall totals going through the early morning hours may reach as much as 2 to 4 inches. This is consistent with the 00Z HREF guidance and recent runs of the HRRR. These rains coupled with relatively moist soil conditions (especially over western KS) may result in a threat for isolated instances of flash flooding. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5n1BMmhWtaRR-d79im3G1Q1WJYXhR9_709TAcHOif0lgNBjB4Pv3Pf01Dk_x--rwzl3H= wRE6UZTk9nwc0GZFs-xxQMo$ for graphic product... ATTN...WFO...DDC...GID...GLD...ICT...LBF...TOP... ATTN...RFC...ABRFC...MBRFC...NWC... LAT...LON 40709956 40319876 39439798 38379737 37759734=20 37389806 37679910 38890018 39800043 40430023=20 =20=20=20=20=20=20=20=20=20=20=20=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) .