Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jan 05 2023 08:32:29 FOUS30 KWBC 050832 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 331 AM EST Thu Jan 05 2023 Day 1 Valid 12Z Thu Jan 05 2023 - 12Z Fri Jan 06 2023 ....THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS OF CALIFORNIA... A strong cold front and atmospheric river continues to bring periods of heavy rain to a good chunk of California this morning. That rain will continue through much of the day today as various waves of rainfall move inland and sweep northwest to southeast across the state. The most consistent and heaviest rain is with this initial round of rain moving across the Central Valley and approaching southern CA. CAMs guidance shows a renewed round of occasionally heavy rain moving into the northern CA coast later this morning, followed by off and on shower activity through much of the day. A short break from the rain is expected overnight tonight statewide. This second round of rain is expected to impact the Central Valley north and not make it significantly into SoCal. The threat in SoCal is the nearly orthogonal flow of the rainfall into the Transverse Ranges especially, but with some impact into the Peninsular Ranges as well. Wegman Day 2 Valid 12Z Fri Jan 06 2023 - 12Z Sat Jan 07 2023 ....THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR COASTAL NORTHERN CALIFORNIA AND SOUTHWEST OREGON... The next round of rain into northern California and southwest Oregon is expected to begin Friday afternoon after a break in the rain from Thursday night. It's a similar setup from Thursday...a second strong low will approach Vancouver Island, and its trailing cold front will drape south into the coast Friday afternoon. While northern areas should see a quick hit of rain before it dissipates, the portion of the front aimed at the Slight Risk area is expected to persist much longer as the long axis of the front aligns orthogonal to the coast and coastal mountains. It is in this area that this front will largely stall...allowing for a prolonged period of heavy rain out of the subtropical Pacific aimed once again at northern California and southwest Oregon. Most notably, the latest guidance has become significantly wetter with the axis of heaviest rain than runs just 24 hours ago, and has also been trending south down the coast. There has been some consistency the past run or two, but further adjustments may be necessary if the guidance hasn't consolidated on this solution. Peak rainfall amounts into northern California's coastal mountains could exceed 4 inches during this period into very late Friday night. Wegman Day 3 The Day 3 outlook will be updated by 0830Z. Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6907P66EJK3G83cTWTsbDHJjWl7uXgCzmYnxKEZNM94k= ekIYpr4dgLUswCWn7_Uw7U5MROURYFMpnnvcynZzl7GzUDg$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6907P66EJK3G83cTWTsbDHJjWl7uXgCzmYnxKEZNM94k= ekIYpr4dgLUswCWn7_Uw7U5MROURYFMpnnvcynZzpb5qpYc$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6907P66EJK3G83cTWTsbDHJjWl7uXgCzmYnxKEZNM94k= ekIYpr4dgLUswCWn7_Uw7U5MROURYFMpnnvcynZzATeuAxM$=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) .