Marine Weather and Tide Forecast for Rancho Palos Verdes, CA

.SHORT TERM (TDY-MON)...09/800 AM.

***UPDATE***

A 2000 foot marine layer has clouds socked in across all coastal and lower valley areas. There's even been drizzle in some areas.
However, pressure gradients are trending weaker this morning by 1-2mb and that should help clear the stratus a little earlier and allow highs today to warm up between 1 and 3 degrees over Friday's highs.

Still expecting several degrees of warming Sunday and again Monday, which will be the warmest day. The marine layer will shrink to the coast but not disappear completely. There is a still around a 20-30 percent chance that heat advisories will be needed in isolated areas Monday. Almost no chance on Sunday.

***From Previous Discussion***

Weather a little more like August rather than May on tap for the short term. At the upper levels an upper high will move into the area from the west today, pass through the state on Sunday and will move into AZ on Mon. Hgts will raise from 583 to 584 dam today, but will increase further to 586 dam on Sunday. Even higher 588 dam hgts are forecast for Monday. Fortunately for the coastal community the offshore flow that was forecast last week did not come to fruition and there will be onshore flow both to the east and north through the period. This will set up the classic August pattern of warm but not hot across the coasts but quite hot in the vlys and inland away from the marine layer.

Today look for highs at the beaches to be in the lower 70s with mid 70s to mid 80s across the rest of the coastal area. The vlys will warm into the mid 80s to lower 90s while the lower mtn elevations will peak in the lower to mid 90s. Temps will warm 1 to 2 degrees further across the csts/vlys on Sunday with 2 to 4 degrees further inland. Another 1 to 3 degrees of warming is on tap for Monday with triple digit heat likely for the Antelope Vly and a 30 percent chc of a 100 degree reading at Woodland Hill and other vly hot spots. Saturday's max temps will be 6 to 12 degrees over normal with Monday's readings coming in 10 to 20 degrees above normal. While very warm, these temps are coming in just under heat advisory criteria, but if temps end up a little higher than fcst advisories may be needed on Sunday and esp Monday.

A strong marine inversion coupled with a weak eddy will bring night through morning low clouds and fog to the area. The low clouds will be most extensive tonight and will shrink both Sunday and Monday mornings as the hgts increase and the marine layer is smooshed down. There will be an increased chc of dense fog Sunday and esp Monday mornings.

.LONG TERM (TUE-FRI)...09/248 AM.

The upper high will pull further to the east on Tuesday and hgts will fall through the day. There will be a big increase in the onshore flow as well (~8 mb to the east and ~6 mb to the north).
Look for plenty of morning low clouds pushing into the vlys with slow clearing. There may be some advisory level winds in the Antelope Vly as well. Max temps will plummet 5 to 10 locally 15 degrees. Look for 70s across the coasts and lower to mid 80s in the vlys.

Not the best mdl agreement for the Wed to Fri period as there is confusion on how to handle an upper low that will traverse the northern portion of the state sometime during the period. The forecast, however, will likely not vary too much with any of the solutions. There will likely be plenty of night through morning low clouds and fog. Cool both Wed and Thu and then a tad warmer Friday as onshore flow relaxes a little. Thursday will be the coolest day of the next 7 with max temps right near normal.

AVIATION
09/1735Z.

At 1625Z at KLAX, the marine layer was 1800 ft deep. The top of the inversion was at 3400 ft with a temperature of 21 C.

High confidence in VFR TAFs for desert airfields (KPMD & KWJF).

Moderate confidence in remaining TAFs. Timing of CIG/VSBY restrictions may be off +/- 3 hours and cig hgt by +/- 200 ft.

KLAX...Moderate confidence in TAF. MVFR CIGs around 015 should scatter 19-20Z Sat. 30% chance CIGs remain 20Z-02Z or at least periodic BKN conditions. Thereafter, CIGs expected lower to IFR 006 (+/- 200ft). Fair confidence in clearing time, but with 30% chance CIGs linger thru end of fcst pd. No significant east wind component expected.

KBUR...Moderate confidence in TAF. Arrival and clearing times of CIGs should be accurate within +/- 2 hours. Low clouds may be as low as OVC003.

MARINE
09/744 AM.

GALE Warnings go in effect this afternoon across the Outer Waters to the west and north of Point Conception. These conditions should last through the evening hours - may linger past midnight across PZZ670. Short period seas peaking 10 to 13 feet are expected through tonight. In addition, Strong Small Craft Advisory (SCA)
winds are expected nearshore along the Central coast during this timeframe.

Winds and seas should diminish throughout the day on Sunday. By Monday, conditions should be much calmer and are expected to remain below advisory levels through Tuesday. From Wednesday through Friday, chances for SCA level winds will increase each day especially across the outer waters.

LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...Small Craft Advisory in effect from 2 PM this afternoon to 3 AM PDT Sunday for zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect until 2 PM PDT this afternoon for zones 670-673. (See LAXMWWLOX).
Gale Warning in effect from 2 PM this afternoon to 9 PM PDT this evening for zones 670-673. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Sunday for zone 676. (See LAXMWWLOX).