Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Mar 12 2023 20:04:46 AWUS01 KWNH 122004 FFGMPD CAZ000-130200- Mesoscale Precipitation Discussion 0101 NWS Weather Prediction Center College Park MD 403 PM EDT Sun Mar 12 2023 Areas affected...central to northern CA Concerning...Heavy rainfall...Flash flooding possible Valid 122003Z - 130200Z Summary...Localized areas of flash flooding will be possible across portions of central to northern CA during the afternoon and evening. Showers and thunderstorm coverage will likely increase through 00Z with rain occasionally peaking near 1 in/hr. Discussion...GOES West visible imagery over the past 3 hours has shown mostly overcast skies over the Sacramento into the northern San Joaquin Valley, while clear to scattered conditions have been in place to the south. The increased solar insolation, mainly south of MER, has allowed surface temperatures to increase roughly 10 degrees over the past 3 hours compared with only a 2-5 degree increase to the north. 700-500 mb lapse rates were sampled at 6.5 to 7 C/km on area 12Z skew-T diagrams, similar to Saturday. Precipitable water values were also similar to yesterday at this time but a bit higher to the north and lower to the south. A loosely organized thunderstorm was observed to be moving northeastward over northern Madera County at 19Z, a testament to increasing instability and decreasing inhibition. 19Z RAP analysis soundings across the Valley indicated that further daytime heating will increase MLCAPE into the 500-1000 J/kg range by mid-afternoon with sufficient effective bulk shear to support a few organized cells. Storm motions should be toward the east to southeast at 20-30 kt with limited upstream development. However, high rain rates within individual cells/cell mergers could allow for peak rain rates near 1 in/hr and storm totals in the 1 to 2+ inch range. Added forcing from upstream shortwave activity off of the northern CA coast and left exit region divergence aloft from a GOES West DMW sampled 100+ kt jet streak (centered near 35N 128W) will likely favor central and northern locations of the MPD area in terms of rainfall coverage but perhaps lower intensity, but higher instability as far south as PTV may support a localized stronger cell or two for southern locations of the MPD area. Given saturated soils in many locations, susceptibility to flash flooding and renewed areas of areal flooding will be a concern. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5C_AWyTZsWYuNBJGxSsJbydIlD7IgmXtXF89xdrhwe3cUlrQn9XO0IgBxcAhpOffPW3f= P0n6Nx6fSaOk__ESgG799PE$ for graphic product... ATTN...WFO...HNX...STO... ATTN...RFC...CNRFC...NWC... LAT...LON 39712085 39652058 39022029 38502009 37681966=20 37031907 36481866 36041857 35881903 35981942=20 36752025 37342090 37972144 38632166 39182147=20 39592114=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) .