Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Dec 03 2022 20:26:40 AWUS01 KWNH 032026 FFGMPD CAZ000-040600- Mesoscale Precipitation Discussion 1142 NWS Weather Prediction Center College Park MD 325 PM EST Sat Dec 03 2022 Areas affected...Central Coastal Ranges of California... Concerning...Heavy rainfall Valid 032030Z - 040600Z SUMMARY...Modest Atmospheric River Continues... DISCUSSION...GOES-W WV suite depicts deep closed low centered just north of 40N and 130W, starting to tilt/shift southwestward as internal center matures spurring mean deep layer trof from positive to neutral orientation over the next several hours.=20 Visible imagery along with VWP winds have seen some backing over the past few hours slowing eastward progression but also changing the angle of orientation of the low to mid-level moisture plume toward reducing orthogonality to the coast line and strongest angle for best orographic ascent. Still, this is delaying eastward propagation of the moisture plume, while CIRA LPW suite denotes deeper surge just a bit offshore. Expectation is for the core of the moisture plume, expected to total around 1.25". IVT values will increase with tighter gradient and winds up to 40-45kts; values from 350-400 to near 600 kg/m/s to increase the ..15-.25"/hr rates currently estimated/observed toward .3-.4"/hr rates particularly along the near the southern coastal Santa Lucia Range. At peak, generally between 00-03z, some modest moisture may help to increase totals through the Diablo Range of SE Monterrey county perhaps expanding concern for some isolated flooding there as well...likely with best timing of right entrance strengthening of the upglide/slantwise slope of atmospheric river stream.=20 The duration along the coast range of 4-6hrs at those higher intensities should support isolated additional 1.5-2" totals resulting in increased runoff and potential flooding in prone areas or some of the older burn scars that have not fully recovered yet across the region. By 03-06z, upstream height-falls should start to spur eastward propagation of the moisture stream axis toward SLO county and points eastward after 06z. Shorter duration of modest rates are likely to limit flooding concerns with time thereafter.=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_PSkuWL3T0ArVd6U0UpMUoqk3kTz-NKmGGbGPCWg9y6tfucyGHh3wlddF-RmOezmdf7f= 4jNyPSZcQk6jxx_gViXKyKE$ for graphic product... ATTN...WFO...LOX...MTR... ATTN...RFC...CNRFC...NWC... LAT...LON 36642169 36442134 36182097 35932060 35552028=20 35212021 34942029 34692043 34622060 34832078=20 35002082 35342102 35702124 36042166 36562199=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .