Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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860 FXUS66 KLOX 281012 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 312 AM PDT Sun Apr 28 2024 .SYNOPSIS...28/227 AM. Some coastal low clouds and fog will be possible each night and morning through late next week, otherwise mostly clear skies with warmer temperatures can be expected during the period. Gusty west to north winds will prevail over the mountains and deserts at least through at least Monday. && .SHORT TERM (TDY-TUE)...28/256 AM. Not much going on in the short term other than some winds and a slow increase in the amount of night through morning low clouds. The main storm track is well north of the area and NW slightly cyclonic flow will be over the area today and Monday on Tuesday the flow will turn a little more westerly and a little more cyclonic. At the sfc a large high pressure system to the WNW of the Bay Area will bring strong NW winds to the waters and the Central Coast. A meso sfc high near Bakersfield will keep northerly offshore flow going across eastern SBA county, VTA county and western LA county. The strong WNW flow into western SBA county has produced some back building low clouds in the Santa Ynez vly back into western coastal plain. A weak eddy is forecast by the ensemble to bring low clouds to the KLAX-KLGB area around dawn there is a 40 percent chc that this will not happen. There will be low end advisory (45 mph) gusts across the western Antelope Vly, I-5 corridor and VTA county mtns. There will also be advisory level 45 mph gusts across western portion of the SBA south coast as the strong NW winds whip off of the Pacific and filter through passes and canyons of the western Santa Ynez range. Max temps today will respond nicely to the sunshine and offshore flow - look for 3 to 6 degrees of warming across the board. Most max temps will approach normals but will likely fall just short. Monday will be much like today just a little better low clouds coverage. The winds will continue through the afternoon. There is a decent chc (30-40 percent) that wind advisories will be need to be extended into Tuesday. Another 1 to 2 degrees of warming will bring max temps to normals or a degree above. The offshore flow from the north increases to 6mb on Tuesday morning. The canyon winds will likely extend down from the mtns and into the vlys and then the csts as it passes through various N/S passes and canyons. Short range high rez ensembles indicate only a low chc (25 percent) of advisory level winds across VTA/LA counties but a much higher chc (70 percent) across the western half of southern SBA county. .LONG TERM (WED-SAT)...28/310 AM. The EC and GFS mean ensembles and deterministic are in generally good agreement thru Thursday with broad pos tilt troffing on Wednesday giving way to NW flow on Thursday. There will only be minimal low clouds on Wednesday mostly across the LA county south coast. Lower hgts and stronger onshore flow will bring 2 to 4 degrees of cooling to most areas. High pressure is fcst to move into NV on Thursday morning and will set up offshore flow from both the N and E. A low end Santa Ana wind event will develop. There will be no low clouds and 3 to 6 degrees of warming. There is not much mdl agreement either in the deterministic side or ensemble side of things for the Friday and Saturday forecast. fortunately the consequences will not be great the EC fcst will be cooler with more marine layer clouds and the GFS fcst will trend warmer with less marine layer clouds. && .AVIATION...28/0559Z. At 0500Z at KLAX, the marine layer was 900 ft deep. The top of the of marine layer was 1600 ft with a temp of 16 C. High confidence in TAFs except for KSMO where there is a 30 percent chc of IFR cigs 11Z-17Z and KLAX and KLGB where there is a 30 percent chc of no cigs. KLAX...Moderate confidence in TAF. There is a 30 percent chance of no cigs. No significant easterly wind component is expected. KBUR...High confidence in TAF. && .MARINE...27/827 PM. With increasing confidence, have issued an extended period of Gale Warnings for the outer waters through Monday night, where peak gusts of 35 to 40 knots are expected. There is a 40-60% chance of gales will persist into Tue night, especially zones 673/676. Strongest winds expected each afternoon/evening. SCA winds are expected through Thu. In the inner waters N of Pt. Sal, SCA level winds are likely especially during the afternoon/eve hours thru Tue night. Seas are expected to be near SCA levels during the periods of weaker winds. There is a 25% chance of gale force winds during the afternoon/eve hours Sun and Mon. In the inner waters S Pt.Conception, a persistent eddy circulation will likely keep much of the inner waters below SCA level winds. However, western portions of the Santa Barbara Channel are expected to see at least SCA level winds during the afternoon/evening hours through Tuesday, with a 50 percent chance of Gale force winds late Sunday afternoon/evening. Due to the lower confidence, keeping the Gale Watch in effect for the western Santa Barbara Channel during that time period. Widespread strong to gale force winds will keep dangerous sea conditions across much of the coastal waters (particularly the outer waters) thru the weekend, with short-period, steep, and choppy waves. There may be dangerous breaking waves near west- facing harbors. Mariners should remain in safe harbor until conditions improve. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory now in effect until 3 PM PDT Monday for zones 349-351. (See LAXNPWLOX). Wind Advisory remains in effect until 3 PM PDT Monday for zones 376>378-381-383. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect from noon today to 3 AM PDT Monday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 PM PDT this afternoon for zone 670. (See LAXMWWLOX). Gale Warning in effect from 3 PM this afternoon to 3 AM PDT Wednesday for zone 670. (See LAXMWWLOX). Gale Warning in effect until 3 AM PDT Wednesday for zones 673-676. (See LAXMWWLOX). && $$ PUBLIC...Rorke AVIATION...Rorke MARINE...Gomberg/Schoenfeld SYNOPSIS...Sirard weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox