FXUS66 KLOX 030802 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 1202 AM PST Mon Feb 3 2025 .SYNOPSIS...02/432 PM. Dry and warm conditions are expected through Monday, with fair skies aside from coastal low clouds during the night to morning hours. The Central Coast will have a chance of light rain through Monday, mostly across San Luis Obispo county. A couple of storms will bring widespread rain and gusty winds to the area Tuesday through at least Wednesday morning, with rain chances increasing again Thursday afternoon into Friday. && .SHORT TERM (MON-THU)...02/905 PM. ***UPDATE*** Temperatures today were several degrees warmer across the region, save for the coastal areas south of Point Conception which cooled a few degrees due to marine layer clouds hugging the coast the majority of the day. While the coasts were in the 50s to 60s, the areas away from the coasts were in the high 60s to the mid to high 70s. These temperatures were 5-15 degrees above normal for this time of year (except a few degrees below normal at the immediate coasts). The marine layer clouds made a quick return today, with patchy dense fog across the coasts and inland coasts. A dense fog advisory was issued for all these areas until 10am Monday. Widespread rain totals of 0.01 to 0.04 were reported across San Luis Obispo and western Santa Barbara Counties today as some moisture extended southward into the region. Rain chances will continue for the northwestern tip of SLO County through Monday. Additionally, higher level clouds will continue to expand across SLO and SBA counties through tomorrow, which will combine with decreasing 500 mb heights and increasing onshore flow to lower temperatures by a few degrees and bring high temps down to the lower 60s. As for Ventura and Los Angeles Counties, little change is expected for the highs tomorrow compared to today. One final note, the most recent NAM run is suggesting slightly higher rainfall totals for the first storm (which is finally fully in the forecast window) across the region and particularly Los Angeles County, so will need to see how the next run or two progresses before adjusting the forecasted totals. Adjusted the expanse of the marine layer clouds and issued a dense fog advisory for the coasts/inland coasts through 10am, otherwise forecast looks to be in shape and no major updates were needed. ***From Previous Discussion*** The atmospheric river well north of SoCal continues to bring precipitation to the upper half of California and Southern Oregon. Tonight and Monday, the southernmost portion of the storm system will just clip northwest San Luis Obispo County. This will result in light rain for San Luis Obispo County and possibly Santa Barbara County. Totals across the low levels will be very light, under 0.10 inch, with up to 0.5 inches possible for the Santa Lucia Mountains (Rocky Butte) in NW San Luis Obispo County. The rain and/or clouds will bring some cooling to San Luis Obispo and Santa Barbara Counties on Monday, however Ventura and Los Angeles Counties will see one more day of warmer temperatures (65-75 degrees), with increasing clouds. Tuesday through Friday the region will see an extended period of rain chances, with two distinct storm systems. The first system will begin impacting the region early Tuesday as a low pressure center spins off the coast of the PacNW. The stream of moisture currently focused over extreme northern California will weaken and sweep from north to south across the region Tuesday though Wednesday morning. This system will bring light to moderate stratiform rainfall, that will be most likely and strongest Tuesday afternoon through Wednesday morning. Southwest flow in the low levels will allow for orographic enhancement along the Santa Lucia Mountains. Overall rain totals will be the higher for San Luis Obispo, Santa Barbara, and Ventura Counties, where 0.75 to 2 inches of rain are expected (2-4 inches for the mountains, especially the Santa Lucias). Los Angeles County is likely to see lower totals, up to around 1 inch. The pattern of this storm lacks both an upper level low over the region and significant upper level jet diffluence, thus thunderstorms are not favored. Additionally the risk for convective showers creating pockets of heavier rain rates is on the low end as well. There is a 5-15% chance of reaching debris flow thresholds over 1st year burn scars with this system. The source of moisture for this storm is the ocean waters off the California Coast, thus the system is expected to be relatively warm with snow levels at 6500-8000 feet. Any accumulating snow will only be at the highest peaks, above most mountains passes including the Tejon Pass/I-5 Corridor. Tuesday and Wednesday, daytimes highs will be temperate due to the rain, generally in the upper 50s to low 60s. Gusty winds out of the south to southwest will impact the Central Coast and interior mountains areas, peaking Tuesday afternoon and evening. .LONG TERM (FRI-MON)...02/304 PM. Thursday morning rain chances will lower somewhat as the region will be in between storm systems. There is however a slight (10 percent) chance of thunderstorms or convective showers due to some upper level divergence. Thursday afternoon through Friday a second storm system will sweep across the region. This system will have a greater southerly flow component that will have a greater focus south of Point Conception. Widespread rain of 0.5 to 1 inches is expected, with orographic enhancement (rain totals up to 2 inches) possible for south- facing slopes south of Point Conception, including the Santa Barbara South Coast, Malibu, and the San Gabriel Foothills. Snow levels are again expected to be very high. Dry conditions are generally favored for next weekend. && .AVIATION...03/0801Z. At 0545Z at KLAX, the marine layer was 500 ft deep and the inversion was near 3300 feet deep with a temperature of 19 C. High confidence in TAFs for KBUR, KVNY, KPMD, and KWJF. Moderate confidence in the remainder of the TAFs with VLIFR conds likely through at least 14Z. Lower confidence after 14Z due to uncertainty in how cigs and vis will lift. There is a 20 percent chc of no clearing at any one site and a 30 percent chc of LIFR conds returning to any one site by 23Z. KLAX...Moderate confidence in TAF. There is a 25 percent chc that 1/2SM FG VV002 conds lasting until 17Z and a 25 percent chc of BKN008 conds lasting until 21Z and a 15 percent chc that they will last until 03Z. There is a 30 percent chc that BKN008 conds could arrive at 23Z. No significant east wind component expected. KBUR...High confidence in TAF. && .MARINE...02/830 PM. For the entire Outer Waters and Inner Waters along the Central Coast, relatively benign conditions are expected through Monday night. Then Monday night or early Tuesday morning, an approaching storm system will bring SW to S SCA level winds to the region, first developing in the northern waters, then spreading south. SCA level winds are expected (60-80% chance) through Wednesday morning, with a a 20-30% chance of GALES, especially for the Inner and Outer Waters off the Central Coast Tuesday afternoon through late night. A lull is then likely before a return of periods of SCA level winds, and potential GALES Friday into the weekend. For the Inner Waters south of Point Conception, sub advisory conds are expected through Tuesday. Tuesday evening through Wednesday morning, there is a 30-40% chance for SCA winds across the western portion of the Santa Barbara Channel. Chances for SCA winds in the southern Inner Waters off the LA and OC coasts is lower (10-20% chance). Confidence in extent of possible SCA level winds is low. Sub advisory conds are expected until NW winds enter the region early Friday morning, bringing a 30-40% chance for SCA level conds into the weekend. Dense fog will impact portions of the coastal waters tonight through Monday morning. Widespread light to moderate rain will impact the Coastal Waters as early as Tuesday morning through most of the work week. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Dense Fog Advisory in effect until 10 AM PST this morning for zones 340-341-346-347-349-350-354-355-362-366-368. (See LAXNPWLOX). PZ...NONE. && $$ PUBLIC...Schoenfeld/Lund AVIATION...Rorke MARINE...Lewis/Ciliberti SYNOPSIS...Schoenfeld/Ciliberti weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox