Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Feb 03 2025 02:14:14 AWUS01 KWNH 030213 FFGMPD CAZ000-030700- Mesoscale Precipitation Discussion 0015 NWS Weather Prediction Center College Park MD 913 PM EST Sun Feb 02 2025 Areas affected...Redding Area of Shasta County Concerning...Heavy rainfall...Flash flooding possible Valid 030212Z - 030700Z SUMMARY...Heavy rain associated with a convergence band over Shasta County, CA will continue into tonight. Flash flooding will be possible in addition to the ongoing areal flooding. DISCUSSION...An impressive WSW-ENE convergence band that set up at the head of the Sacramento Valley near Redding and Anderson, CA continues to be the source of heavy rain this evening. A strong southerly low level jet (LLJ) with winds of over 40 kts at 850 mb continues along the Sacramento Valley, with surface stations south of the band reporting winds as high as 20 kts south of the band. The band had been nearly stationary over Anderson, CA or just south of Redding, but trends have been for the band to crawl northward with time. Guidance shows very little if any instability, so this band is likely being forced by the strong convergence in the area from the combination of the strong southerly flow with the LLJ hitting a stationary front in that same area, as well as localized upslope as the terrain of the Sacramento Valley forms an arc, or upside down U, allowing for southerly flow to become focused and converge in the Redding area. Surface observations show there has been over 1.7 inches of rain in the last 3 hours, and 2.5 inches of rain in the last 6. HiRes guidance is in good agreement that the front and convergence band will remain in place for at least the next several hours, if not throughout the overnight (HRRR). With rates as high as an inch per hour possible, expect continued areal flooding and possible flash flooding in those areas where the convergence band interacts with the terrain to focus the rain water into narrow streams, creeks, and channels. Urban areas in and around Redding may also locally increase the flash flooding threat. Wegman ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9eS4LoJC5rkLYwpzCDlGSmDkq3NN8Fuul9JOKPgas3J0LLhDLgP0FQpPCjCFg8iwYp73= zgSNm_NPyE4BnVj4BcMxRqs$ for graphic product... ATTN...WFO...EKA...STO... ATTN...RFC...CNRFC...NWC... LAT...LON 40792205 40692191 40492197 40422224 40402259=20 40332288 40452290 40542276 40662255 40742235=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .