Marine Weather and Tide Forecast for Rossmoor, CA

.SHORT TERM (THU-SUN)...07/919 PM.

***UPDATE***

High temperatures warmed well over the region today, with many locations seeing 5-10 degrees of warming, and about 1-4 degrees near the coasts. Low 90s were common throughout the interior as high pressure strengthens over the region. Expecting similar temperatures for Friday, however areas that see marine layer clouds and fog could end up a few degrees cooler. Expecting a more significant warm up over the weekend.

Tonight, satellite imagery reveals a far more substantial marine layer than we have seen in days, supported by a strong inversion.
Better confidence in low clouds and fog reaching the coasts and coastal plains tonight into tomorrow morning, especially for the Central Coast, Ventura County Coast and the LA Basin. As high pressure builds, the marine layer will compress, leading to a greater potential for dense fog towards the end of the weekend.
The current forecast looks on track with no significant changes needed.

***From Previous Discussion***

Advisory level winds have developed tonight, lasting into the overnight hours across the SW SB coast/western Santa Ynez range.
Wind advisories may be needed again for that timeframe on Friday.

Expecting more low clouds tonight into tomorrow morning across the same areas. There is a better chance for marine layer stratus across the LA Basin tomorrow morning. This is due to increasing onshore flow indicated by a 1 mb pressure rise (LAX-DAG). In addition, a weak to moderate Catalina Eddy is expected to develop overnight. Whether or not low clouds arrive into the San Fernando Valley is dependent on its strength. This is currently forecasted.
However, there is a 30% chance clouds do not arrive.

On Friday, high temperatures will be somewhat similar maybe a couple degrees warmer or cooler depending on the evolution of marine layer stratus in the morning hours. This is especially true for areas south of Point Conception.

The combination of strongest ridging and weak onshore flow will result in Sunday (Mother's Day) and Monday being the warmest days for this warm spell. The exact magnitude of the pressure gradients will determine how much the sea breeze will influence max temperatures across the csts and vlys. Most ECWMF ensembles support enough influence to keep the csts in the 70s-80s, and the valleys in the mid 90s. However, there is a handful of solutions that would support heat advisory across some of the valleys (20% chance). Temperatures could also reach 100 F across the Antelope Valley.

.LONG TERM (MON-THU)...07/1211 PM.

The latest trend across the majority of models (except for GFS)
has been for a "kicker" trof to push out the ridge to the east.
This would solidify a cooling trend to begin on Tuesday. Above normal temperatures likely to continue across the interior through the middle of next week. Increasing onshore flow should bring back marine layer stratus which will keep coastal locations relatively cool (near normal).

AVIATION
08/0152Z.

At 2333Z at KLAX, the marine layer was about 800 ft deep. The top of the inversion was around 3500 ft with a temperature of 21 C.

High confidence in desert TAFs, moderate to low confidence in remaining TAFs. There is a 40% chance of no cigs at KVNY and KBUR, and a 30% chance for no cigs at KSMO, KLAX, KCMA, and KLGB.
Timing of flight cat changes could be off by +/- 2 hours. Clearing times may be 2-3 hours later than forecast.

KLAX...Moderate to low confidence in TAF. Timing of flight cat changes could be off by +/- 2 hours. There is a 20% chance for brief east wind component of 6-9 kts around significant east wind component expected.

KBUR...Low confidence in TAF. There is a 30-40% chance of VFR conds remaining through the period. Cigs may only last one hour.STDAFDLOX

MARINE
07/841 PM.

SCA level NW winds are expected to strengthen each day through Saturday for the outer waters. Winds may approach Gale Force levels Friday (20% chance), with GALES likely (40-60% chance)
Saturday afternoon and evening over the northern two zones, near and NW of Point Conception. For the southern outer zone PZZ676, SCA winds are likely through early Sunday morning.

For the nearshore waters, SCA level winds are likely during the late afternoon into evening hours along the Central Coast and into at least western portions of the Santa Barbara Channel and near the Channel Islands on Friday and possible again Saturday afternoon and evening.

Short period seas will build during this timeframe especially across the outer waters - reaching around 10 feet Friday through Saturday night.

Winds and seas should diminish throughout the day on Sunday. By Monday, conditions should be much calmer and likely below SCA levels.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Wind Advisory remains in effect until 3 AM PDT Friday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX).