Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 26 2023 14:25:37 AWUS01 KWNH 261425 FFGMPD KSZ000-NEZ000-261723- Mesoscale Precipitation Discussion 0344 NWS Weather Prediction Center College Park MD 1024 AM EDT Fri May 26 2023 Areas affected...Western KS/NE border Concerning...Heavy rainfall...Flash flooding likely Valid 261423Z - 261723Z Summary...A couple bands of heavy rainfall continue near the western KS/NE border. Hourly rain totals to 2.5" with additional local amounts of 5" remain possible over the next few hours where flash flooding is ongoing. Discussion...Two well-defined MCVs across western NE are helping to focus one small primary band of convection with heavy rainfall stretching from Atwood KS east-northeast towards Danbury NE with attempts at backbuilding on the southwest portion of the complex.=20 As one would expect in a warm core setup, the low-level inflow well exceeds the mean 850-400 hPa wind in this area, which is allowing for greater than average rainfall efficiency. SPC mesoanalyses have shown a continued decrease of instability near and upstream, but there's been little evidence of such on radar imagery other than some reduction in scale of the thunderstorm pattern. Effective bulk shear remains ~25 kts, enough for thunderstorm organization. Precipitable water values remain ~1.25", sufficient for the High Plains. The divergence aloft is ideal between an upper low across the West and troughing across the Mid-MS Valley.=20=20 The forecast is tricky, as the guidance says the activity should be nearly gone, yet it still exists. The MCVs aloft are moving around each other, with the western one move east and the main vortex moving north across west-central NE. The low-level inflow into the region is not forecast to decrease, so the effective bulk shear should remain status quo. Instability is expected to increase again in an hour or two, which is of some concern. It could either fuel the ongoing activity or provide competition should separate discrete development occur nearby. Since flash flooding is ongoing and the primary band remains well organized while trying to reorient more west-east, and a second band keeps trying to solidify, the concern is that this activity could continue for another few hours in an organized manner. While there's uncertainty, flash flooding is ongoing, so Likely wording was chosen. Roth ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4mAfN9PKlK0U8eieCOTRGnaj5jPqgJHY3iBPgTm811foOdCmvg8F2WLLXdWg1gWgKMIR= s2kLr7DJ5O3v4uROpsvdmpU$ for graphic product... ATTN...WFO...GLD...LBF... ATTN...RFC...MBRFC...NWC... LAT...LON 40590089 40540049 40340027 40000030 39800059=20 39770105 39990122 40540141=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) .