Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 27 2024 06:00:37 AWUS01 KWNH 270600 FFGMPD MNZ000-NDZ000-271100- Mesoscale Precipitation Discussion 0742 NWS Weather Prediction Center College Park MD 200 AM EDT Sat Jul 27 2024 Areas affected...Northwest Minnesota...Eastern North Dakota... Concerning...Heavy rainfall...Flash flooding possible Valid 270600Z - 271100Z SUMMARY...Continuing upstream redevelopment along favorable training profile/track to allow for localized rainfall totals of 3-4" and possible incidents of flash flooding through the overnight period. DISCUSSION...GOES-E 10.3um EIR loop along with regional RADAR has shown cycling clusters of thunderstorms across northwest MN for the last few hours. Convection has been aligned along a low-level convergence zone/stationary front from the Northwest Angle back toward Grand Forks. However, GOES-E WV suite shows shortwave/MCV from earlier convective cluster is moving out of western SD into the region and starting to provide further mid to upper level ascent forcing via DPVA and increasing exposure to the right entrance region of the northern stream jet streak over south-central Canada. Additionally, deep layer moisture pooling has reached total PWat values in the 1.75" range but with 30kts of slightly veering/convergence streamlines have maintained solid flux into the parallel frontal zone. As such, rain rates have steadily increased with rates of 1.5-2"/hr seen across NW MN. RAP analysis shows fairly unstable air feeding with that low level flow and while capped, the forcing/convergence into the boundary is sufficient for the 2000 J/kg of MLCAPE to maintain stronger thunderstorms across the area. There is reduction of instability forecast with time, but should be sufficient (1000-1500 J/kg) to further enhance/maintain upstream convection across central NDak into the low level stationary frontal zone. As such, a profile for further convective training is expected to maintain over the next few hours. A few spots of 2"+ values have been observed and so additional 2-3" and expanding spots of 2-5" and should overcome naturally higher FFG values in the region. So all considered, flash flooding is possible across NW MN and may even intersect with urban locales around Grand Forks over the next few hours as the shortwave/MCV moves through. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8J8YRNNsTlehXvbOSKQvE5Z-3pcGcDHkd-lWYlWZviQ6UFEjzQHhBQ7jPjrZsu0GZi9E= Lkh3NmqX9NASNa_61p19HwM$ for graphic product... ATTN...WFO...FGF... ATTN...RFC...NCRFC...NWC... LAT...LON 48979550 48939468 48429450 47969537 47319734=20 47269802 47569840 47899823 48319759 48529706=20 48749650=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .