


Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
458 FXUS66 KLOX 040933 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 233 AM PDT Sat Oct 4 2025 .SYNOPSIS...03/621 PM. An upper-level trough of low pressure will continue to exit the region through Saturday. Skies will continue to clear with gusty northerly winds expected in portions of Santa Barbara, Ventura, and Los Angeles Counties into early Saturday. Cooler than normal conditions will linger into late next week as broad troughing remains over the West. A warming trend is possible for late next week. && .SHORT TERM (TDY-MON)...04/232 AM. Overall, 00Z models in good synoptic agreement through the short term period. At upper levels, low will continue to move across the Great Basin today then another low develops off the Central California coast Sunday/Monday. Near the surface, weak diurnal flow prevails today/Sunday then onshore flow strengthens on Monday. Forecast-wise, no significant issues are expected in the short term. Northerly winds from last evening across the Santa Ynez Range and I-5 Corridor have begun to diminish as flow will turn weakly northeasterly this morning. Given current trends, will let the WIND ADVISORIES expire at 500 AM this morning for these areas. For the balance of today and Sunday, weak diurnal flow will prevail with only isolated locations flirting with advisory level offshore winds. So, no additional advisories are anticipated. By Monday, weak onshore flow will prevail throughout the day. As for sky conditions, low clouds will be very limited this morning, confined to the Central Coast as well as interior sections of the area (due to the weak northeasterly flow). For tonight/Sunday morning, HREF indicates bit more widespread stratus/fog across the Central Coast as well as the LA county coast. With the onshore flow returning on Sunday night and lowering H5 heights, inversion will deepen and stratus/fog should be much more widespread and push into the Santa Clarita Valley by Monday morning. Other than this stratus/fog, skies are expected to remain mostly clear through Monday. As for temperatures, expect 4-8 degrees of warming for most areas today. For Sunday, there may be an additional degree or two of warming. By Monday, the increased marine influence will bring some cooling to the coastal plain, but little change across the valley and interior sections. .LONG TERM (TUE-FRI)...04/233 AM. For the extended, 00Z models start out in decent agreement, but gradually deviate later on in the period. So, confidence in the forecast details drops off noticeably by Thursday/Friday. For Tuesday/Wednesday, both the GFS and ECMWF weaken the upper low off the Central Coast and move it inland. With this pattern, no significant issues are expected. Marine layer stratus/fog will continue across the coasts and valleys, but should diminish in areal coverage from night-to-night. As for temperatures, areas west of the mountains will remain rather persistent, but interior sections will exhibit some slight warming. For Thursday/Friday, the potential for much more interesting weather remains along with a much lower confidence in the forecast details. Essentially, a potent upper level low is forecast to develop somewhere offshore from the Pacific Northwest/Northern California while likely tropical storm Priscilla move up off the Baja Mexico coast. The operational ECMWF seems to be the odd model out, bringing Priscilla up to around Bahia Tortuga by Friday, while most other guidance (GFS, ensemble means of GFS/ECMWF and even the ECWMF AI) move Priscilla out to sea west of Cabo San Lucas. Either way, there will be some increase in PWATs as moisture from Priscilla is advected northward across the area. So, there will be a threat of some convective precipitation for the area Thursday/Friday, based on a decent number of various model ensemble members. So, current forecast has slight chances for all areas during the Thursday-Friday time frame which is good for now, given the uncertainty in how the pattern develops. && .AVIATION...04/0540Z. At 0526Z at KLAX, the marine layer was 800 ft deep, with a weak inversion up to around 1300 ft with a maximum temperature of 19 C. High confidence in VFR TAFs for KSMX, KSBP, KSBA, KOXR, KCMA, KPMD, and KWJF. Low confidence in TAF for KPRB. There is a 50% chance of MVFR cigs from 10Z through 17Z. Moderate confidence in remaining TAFs. 10-20% chance of brief MVFR cigs developing between 10Z-17Z for LA County sites, highest at KLGB. There is a 40% chance no north winds impact KVNY tonight, and a 20% chance they do surface at KBUR through 10Z. KLAX...Moderate confidence in TAF. There is a 15% chance of BKN008-BKN018 cigs from 12Z-17Z Sat. Between 08Z and 17Z, there is a 30% chance of an east wind component reaching 8 kts. KBUR...Moderate confidence in TAF. 20% chance for north winds up to 10 kts through 10Z. There is a 10% chance of BKN010-BKN025 cigs from 10Z-17Z. && .MARINE...04/140 AM. High confidence in Small Craft Advisory (SCA) level winds across the outer waters and nearshore waters along the Central Coast through early Sunday morning, with lulls nearshore through this afternoon. Localized Gale Force wind gusts may occur in the southwestern outer waters through early this morning. Seas will be between 8 to 11 feet through this morning before decreasing. Then conditions are likely to remain sub advisory through mid- week. High confidence in winds decreasing through this morning this morning across the Southern California Bight, although localized Gale Force winds may occur along the southwestern Santa Barbara County coastline as northerly Sundowner winds have made their way downslope the Santa Ynez range all the way to the coast. Seas will remain steep and choppy through this morning, especially beyond 5 NM from shore. SCA level winds will fill the Santa Barbara Channel again this afternoon and evening and seas will be choppy. The waters adjacent to Los Angeles and Orange counties will calm down through this morning. Thereafter, conditions generally look to remain below SCA criteria through mid-week. Hazardous boating conditions will linger into later today, but confidence is high in improving conditions relative to Friday. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT early this morning for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Sunday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Sunday for zones 673-676. (See LAXMWWLOX). && $$ PUBLIC...Thompson AVIATION...Lewis MARINE...Lewis SYNOPSIS...Hall weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox