494 FXUS66 KLOX 120543 AAA AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 1043 PM PDT Fri Oct 11 2019 updated aviation and fire weather discussions .SYNOPSIS...11/809 PM. Persisting dry, breezy conditions will keep the fire danger over much of Ventura and LA Counties area through Saturday. Afternoon temperatures remain warm for Saturday, but will begin cooling off Sunday. Despite the warm daytime temperatures, the Antelope Valley will see low overnight temperatures in the upper 20s and 30s through Sunday morning. && .SHORT TERM (FRI-MON)...11/807 PM. ***UPDATE*** Offshore gradients have diminished but were still -4.2 mb LAX-DAG at 03Z...a _2.5 mb increase in 24 hours. This has helped to maintain breezy NE winds in the favored areas of the VTU/L.A. County mtns and vlys this evening, with gusts up to 34 mph noted at Warm Springs. Otherwise, winds were in the 10 to 20 mph range with local gusts to 30 mph in a lot of these areas. Not much change in the winds can be expected overnight. Skies will be clear in all areas thru the night as well. Temps will become quite cold in the wind-sheltered interior areas overnight, with lows expected to fall into the mid to upper 30s. Temps should fall into the mid to upper 20s late tonight for the central and northern Antelope Vly, and a Freeze Warning remains in effect for this area from 2 AM to 8 AM PDT Saturday. ***From Previous Discussion*** Offshore gradients are weakening and trends are positive as well which confirms that this Santa Ana event is in its final stages. However, the Red Flag Warning for the valleys and mountains will continue until 6pm Sat. And it's important to keep in mind that there will still be some gusty winds in the favored areas and extremely low humidities into tomorrow. The remainder of the forecast remains more or less the same as it has been. It will still be very warm and dry Saturday but with less wind. Then Sunday and Monday onshore flow returns as a weak trough moves through the West Coast. This will cool temps quite a bit back to normal levels or even slightly below normal by Monday, raise humidities, and bring a return to the marine layer to coast and valley areas. .LONG TERM (TUE-FRI)...11/220 PM. Models in better agreement on the pattern for next week agreeing that onshore flow will at least be weakening following Monday's trough passage, leading to a warming trend and less marine layer. The ECMWF continues to be more aggressive with the offshore trends but nothing close to what we're seeing today. So odds certainly favor at least a modest warming trend through mid week, bringing temps back up to near normal or slightly above normal. Then likely some cooling later in the week as another trough arrives along the coast. Otherwise pretty quiet weather through the period. && .AVIATION...12/0540Z. At 0530Z...there was a surface-based inversion at KLAX. The top of the inversion was at 1100 ft with a temperature of 25 deg C. High confidence in VFR at all airfields through the period, except for MVFR FU at times near any fires, especially KBUR and KVNY. KLAX...High confidence in VFR through Sat evening, then there is a 50%-60% chance of IFR cigs developing by 10Z late Sat night. KBUR...High confidence in VFR through Sat evening. Periodic MVFR vsby due to smoke will be possible through the period. && .MARINE...11/808 PM. Northeast wind gusts will diminish and shift to the east and southeast overnight. The area nearshore between Ventura Harbor and Malibu could see local gusts to 20 knots, otherwise easterly winds should stay below 15 knots. After Saturday morning, high confidence in winds and seas staying below SCA everywhere through Sunday. NW winds with gusts around 20 kt possible Monday and Tuesday for the waters off the Central Coast with SCA winds possible Wednesday across the outer waters and portions of the waters nearshore. && .FIRE WEATHER...11/1042 PM. For tonight and Saturday morning, northeast winds are expected to be gusting between 20 and 30 mph across the wind prone mountains and valleys of Los Angeles and Ventura counties, then switch to onshore on Saturday afternoon. With the continuation of widespread single digit humidities, warm temperatures, and breezy conditions, the Red Flag Warning remains in effect for the Los Angeles and Ventura county mountains, Santa Clarita Valley, Ventura county valleys, and San Fernando Valley through 6 PM Saturday. Warmer temperatures are on track for Saturday, with highs in the 80s to around 90 degrees across many coastal and valley areas. Much of San Luis Obispo and Santa Barbara counties will continue to see elevated to brief critical fire weather conditions due to locally breezy offshore conditions and widespread single digit humidities. Rapid fire spread and extreme fire behavior are still possible with any existing fires and new ignitions. This is a dangerous situation, with critical fire weather and fuel conditions. If a new fire were to start, the environment will still be favorable for very rapid fire spread, long range spotting, and extreme behavior. The public should be urged to use extreme caution with any potential fire ignition sources. Past fires have begun from things like discarded cigarettes, metallic hedge trimmers, welding activities, and campfires. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Freeze Warning in effect from 2 AM to 8 AM PDT Saturday for zone 59. (See LAXNPWLOX). Red Flag Warning in effect until 6 PM PDT Saturday for zones 244>246-253-254-288-547. (See LAXRFWLOX). PZ...NONE. && .HAZARD POTENTIAL OUTLOOK (MON-FRI). No significant hazards expected. && $$ PUBLIC...MW/Sirard AVIATION...Sirard MARINE...Smith FIRE...Gomberg/Sirard SYNOPSIS...Phillips weather.gov/losangeles