Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed May 10 2023 23:22:22 AWUS01 KWNH 102322 FFGMPD NEZ000-COZ000-WYZ000-110330- Mesoscale Precipitation Discussion 0253 NWS Weather Prediction Center College Park MD 721 PM EDT Wed May 10 2023 Areas affected...Northeast CO...Far Southeast WY...Far Southwest NEB Panhandle... Concerning...Heavy rainfall...Flash flooding possible Valid 102320Z - 110330Z SUMMARY...Training cells may merge into a larger complex across areas of lower flash flood guidance, resulting in a few possible incidents of localized flash flooding. DISCUSSION...GOES-WV suite denotes negative tilt trof across N NM with embedded jet streak rotating around the left edge increasing in diffluence across much of northeastern CO. Strong thunderstorms with a history of severe hail are starting to slide off the higher terrain of the Front Range to the east of the Denver Metro. These cells are starting to align more favorably to the deep mean steering flow to allow for training. While each individual cell has been quick moving, the duration of multiple cores has resulted in a few observations of up to 1" across the south and southeast suburbs of Denver. However, surface and RAP analysis denote a wedge of enhanced moisture rotating north over the dry slot residing in SE CO, with TDs in the low to mid-50s across the South Platte River Valley along easterly to northeasterly winds. Above average moisture continues through low depths into the 700mb layer (5-6C). Through sfc to 700mb, the winds are also highly convergent both in speed and direction, and while it is converging with the dry slot air, the cells appear to be riding just west with likely lesser dry air entrainment.=20 Still, increased moisture flux should increase rainfall efficiency over the next hour or so and allow for rates to steadily increase. Rates of .2"/5 min were observed and likely to increase slowly to support 1.5-1.75"/hr rates. Given potential for 1-2 hours of repeating similar rates, isolated pockets of 2-2.5" are possible across areas of relatively lower FFG in northeast CO into far SE WY and SW NEB Panhandle. To compound matters into WY/NEB, left moving updrafts from the complex over NW KS are likely to merge locally enhancing rainfall rates to over 2"/hr (or 1"/15 minutes) as supported by some of the WoFS members that indicate some interaction/mergers. While the overall area is not likely to see flash flooding, a few incidents are considered possible within the area of concern based on those mergers and ideal training corridors over the next few hours. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-k-2e-jOBrndj6tsGldC2bKN9Hp80cBIW_5vqE7mCUk-u8pdTBVA4enjyAlNYRvjLru1= SZnXmUxBOSco02bDu3uO2Oc$ for graphic product... ATTN...WFO...BOU...CYS... ATTN...RFC...ABRFC...MBRFC...NWC... LAT...LON 41960380 41920314 41500280 40820305 40170347=20 39670373 39270404 39130426 39210497 39770498=20 39900492 40640476 41590439=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) .