textproduct: Los Angeles

SYNOPSIS

27/1109 PM.

Beach impacts from Tropical Cyclones well south of the region are expected through Tuesday in the form of high surf, beach erosion, and possible coastal flooding. A significant warming trend is expected to begin Tuesday with increasing heat concerns through at least the following weekend.

LONG TERM (THU-SUN)

28/220 AM.

High pressure will remain draped over Srn CA through the Thu-Sun xtnd period. Hgts will be around 590 dam through the period. The big question will revolve around the sfc gradients. There will likely be offshore flow from both the N and E in the morning, but there is quite a bit of disagreement on how strong the offshore push will be. Similarly in the afternoon there is disagreement with the EC showing weak offshore flow continuing in the afternoon while the GFS shows weak onshore flow. In the past the actual values have mostly come in in between the two.

Regardless of the exact magnitude of the offshore push the forecast will very likely be one of minimal or zero morning clouds and very warm temperatures. Max temps will mostly be in the 80s across the coasts and in the 90s in the vlys. There is a 40 percent chc that the warmest vly temps will reach triple digits Friday or Saturday. Heat advisories are almost a certainty for many areas and warnings may be necessary as well. Stay tuned to the NWS for the latest on this developing heat risk.

Of note: the AI enhanced version of the EC shows above to well above normal temps continuing into the middle of next month.

The National Hurricane Center (NHC) is tracking the newly formed Tropical Storm Rachel in the Eastern Pacific Ocean. The latest NHC track brings a Hurricane nearing our swell window by Friday. If this west to northwest track holds, it could enter our swell window by early next week. The potential surf or coastal flood impacts would probably occur after October 4th.

AVIATION

28/1101Z.

At 0822Z at KLAX, the marine layer was around 900 ft deep. The top of the inversion was at 1900 feet with a temperature of 22 Celsius.

High confidence in TAFs for KBUR, KVNY, KWJF, and KPMD.

Moderate confidence in TAFs for KSBP/KSMX low cloud arrival timing may be off by 2 hours and cig hgt may be off by +/- 300 ft.

Good confidence in TAFs for KSBA, KOXR and KCMA with a 10 percent chc of MVFR cigs 13Z-16Z.

Moderate confidence in TAFs for KSMO, KLAX and KLGB with a 15 percent chc of MVFR cigs 13Z-16Z.

KLAX...Fair confidence in TAF. There is a 15 percent chance BKN012 conds 13Z-17Z. High confidence in no significant east wind component.

KBUR...High confidence in TAF.

MARINE

28/235 AM.

High confidence in Small Craft Advisory (SCA) winds and steep seas affecting the outer waters through late least Tuesday night. Local Gale Force gusts will be possible at times, especially this afternoon and evening across the outer waters south of Point Conception. There is a 25% chance for a Gale Warning to be issued for that time period. Nearshore along the Central coast will see SCA winds and steep seas each afternoon and evening through Tuesday.

For the nearshore waters south of Point Conception, SCA winds are expected across the entirety of the Santa Barbara Channel and portions of the inner waters adjacent to Los Angeles and Orange Counties on today, with moderate chances Tuesday.

Southerly swells from Hurricanes Odalys (SSW) and Polo (SSE) will continue to affect the region through Tuesday. These swells will create larger waves and surf nearshore, which could impact some harbor entrances.

Conditions are likely to improve to below SCA levels Wednesday into next weekend, except for occasional northwest SCA winds near Point Conception in the afternoon/evening hours.

LOX WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory in effect until 5 PM PDT Tuesday for zones 87-354-362-366. (See LAXCFWLOX). High Surf Advisory in effect until 5 PM PDT Tuesday for zones 87-354-362-366. (See LAXCFWLOX). Beach Hazards Statement in effect through Wednesday afternoon for zones 349-350. (See LAXCFWLOX). Wind Advisory in effect from 6 PM this evening to 6 AM PDT Tuesday for zones 349>353-376>378. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 11 PM PDT this evening for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until midnight PDT tonight for zones 650-655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX).