Marine Weather and Tide Forecast for Marina del Rey, CA

.SHORT TERM (TDY-SAT)...12/821 AM.

***UPDATE***

Latest satellite and surface observations indicate clear skies across the area this morning. A shallow, surface-based, inversion is in place. Some northeasterly winds, gusting around 30 MPH, are currently observed in the usual Santa Ana wind-prone spots.

Forecast-wise for the immediate short term, the main concern will be the heat. Looking at morning parameters in TEMP STUDY database, boundary layer temperatures and surface pressure gradients all indicate an extremely warm day across Southwestern California.
Current forecast highs for today look very much on track with the 25+ year database in TEMP STUDY. Heat Risk calculations indicate widespread moderate to locally major heat risk across most coastal and coastal valley areas today. So, current HEAT ADVISORIES are still very valid across these areas today.

Other than temperatures, no significant issues are expected today. There will be some bump up in offshore winds this morning, but any advisory-level gusts should remain very localized and the winds will diminish this afternoon.

Overall, current forecast has great handle on the immediate short term. So, no significant updates are expected.

***From Previous Discussion***

Today and Friday will be all about the heat. A 591 dam upper high a hundred miles SW of LAX will bring 590 dam hgts to the area today. These hgts are beyond the 95th percentile for the month of March. At the sfc there will be about 3 mb of offshore flow from the E and 5 to 6 mb from the N. There is no marine layer and skies are clear. The offshore flow, sunny skies and near record hgts will all combine to bring 10 to 15 degrees of warming to the csts and vlys while the interior will see about 3 to 6 degree warmer temps. This warming will bring max temps in the upper 80s to the mid 90s for all of the csts and vlys or 20 to 22 degrees warmer than normal. Heat Advisories (See LAXNPWLOX for details) are in effect for all of the csts/vlys for SLO/SBA/VTA/LA counties.
The offshore flow will bring northerly canyon winds to LA/VTA counties, some NE winds across SLO county and local north winds to the SBA south coast. There will be isolated advisory level gusts (35 to 45 mph) but nothing widespread enough to warrant an advisory.

There will be a little better onshore push in the afternoon on Friday and this will bring 1 to 3 degrees of cooling to the area, but nowhere near enough to eliminate the heat threat.

On Saturday the ridge will flatten out and some energy form the NW pushes into the west coast. Hgts fall to 580 dam. More importantly there will be 1 mb of onshore flow to the east increasing to 4 mb in the afternoon. There will still be offshore flow from the north but will only be half as strong as it will be today and Friday.
The falling hgts and quick reversal of the E/W gradient will likely bring some marine layer clouds to the LA south cst and SBA west coast. Max temps will fall 5 to 10 degrees over the csts/vlys with much lesser amounts across the far interior. Max temps will end up in the mid 70s at the beaches, the upper 70s to lower 80s across the rest of the csts and in the mid and upper 80s in the vlys. While these max temps are 10 to 15 degrees above normal they will not necessitate a heat advisory.

.LONG TERM (SUN-WED)...12/258 AM.

The ridge will begin to reform on Sunday, but the day will also start off with a decent sized marine layer cloud deck across the csts and lower vlys. Offshore trends in the afternoon will ensure good clearing and when combined with slightly higher hgts will bring 1 to 3 degrees of warming.

Another heat wave will take aim at Srn CA starting Monday and lasting through at least Wednesday. The east PAC high will push into and over srn CA and is forecast to bring fairly extraordinary 500mb hgts between 590 and 593 dams. Looking at records dating back to 1948 the highest previously recorded 500 mb hgt for March is 591 dam. Look for 3 to 4 locally 5 and 6 degrees of warming each day Mon and Tue with only a small retreat in temps on Wed.
Tuesday's highs will be reaching towards 100 degree in the vlys and even 100 may be too low in the warmest vly locations. Another round of widespread Heat Advisories are a near certainty. Both daily and monthly records could fall esp on Tue. As mentioned in the earlier discussion: the Antelope Valley could break a record for the earliest 90 degree day in the calendar year.

A little more cooling is forecast Thursday but max temps will remain 15 to 22 degrees over normal.

Given the unprecedented length and magnitude of this extreme heat wave, heat stress will be a real threat each day, especially in areas that aren't used to the heat, like the coastal areas, where people may not have methods to cool off their homes. Try to complete outdoor activities early in the day or in the evening, and don't leave people or pets in cars.

Dry weather looks to continue for a while yet. Both the EC-AI and the GFS-AI do not show any rain all the way through the 26th.

AVIATION
12/1122Z.

At 0842Z at KLAX, there was no marine layer. There was a sfc based inversion with a top of the marine inversion was around 1600 feet with a temp of 24 deg C.

High confidence in CAVU TAFs.

KLAX...High confidence CAVU TAF. Any easterly winds should remain less than 7 knots.

KBUR...High confidence CAVU TAF.

MARINE
12/822 AM.

High confidence in northwest to north winds between 20-30 knots impacting the Outer Waters through at least Sunday night, with relative lulls possible today. There is a 50% chance of low end Gale Force winds (roughly 35 knots) across the waters beyond 30 NM from shore late Friday through Saturday morning. Seas will increase during this period, moderate confidence in seas reaching at least 10 feet across aforementioned areas. Conditions are likely to improve early next week, with relatively small seas expected.

Small Craft Advisory (SCA) level winds will approach the western edge of the Inner Waters along the Central Coast, but chances for these winds to reach nearshore areas are low.

Inside the Southern California Bight, conditions are expected to remain below SCA levels for the foreseeable future, except for hyper-localized SCA level winds across the far northwestern portion of the Santa Barbara Channel Saturday.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Heat Advisory remains in effect until 8 PM PDT Friday for zones 88-340>342-346>352-354>358-362-366>375-548. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673. (See LAXMWWLOX).
Small Craft Advisory in effect from midnight tonight to 3 AM PDT Saturday for zone 676. (See LAXMWWLOX).