Marine Weather and Tide Forecast for Pasadena, CA

.SHORT TERM (TDY-SAT)...08/131 PM.

An upper level high pressure will continue to sit over the region through Friday, before starting to move NE on Saturday. 500 mb heights will range from 594 to 596 dam, which is 3 to 4 dam higher than normal for this time of year. There will be onshore flow to the east strongest in the afternoon, but a few mb weaker than it was earlier this week. There will be a mb or two of offshore flow from the north in the mornings turning weakly onshore to the north in the afternoons.

High temperatures continue to be the main concern through the forecast period. With rising 500mb heights through Thursday, lack of a solid marine layer, and only weak to moderate onshore flow in the afternoon, conditions will be warmer than normal for this time of year. High temperatures through Thursday will range 92-103 across the valleys and 75-92 across the coasts/inland coasts.
These temperatures are 5-10 degrees above normal for this time of year.

On Friday and over the weekend, 500 mb heights will decrease with a slight increase in onshore flow, leading to a few degrees of cooling. However, temperatures will remain above normal for the time of year. However, temperatures will start to increase again next week, even warmer than this week. Thus, The Heat Advisory for all the valleys, mountains, and Los Angeles Inland Coast has been extended through Tuesday morning (please see the product LAXNPWLOX for all details).

Advisory level Sundowner winds are expected again this evening and Thursday evening for Southwest Santa Barbara County, and a Wind Advisory is in effect late this afternoon into early Thursday morning. Elevated fire weather conditions are expected for this area as well.

.LONG TERM (SUN-WED)...08/139 PM.

As previously mentioned, the upper level high pressure will shift NE late Friday through Sunday, and eventually reach the Dakotas.
This northeastward shift will open the door for SE flow into Southern California. Meanwhile, at the surface, moderate to strong onshore flow will continue both to the north and east.

With the SE flow, monsoonal moisture will move into the region Sunday night, lasting through basically all of the next week.
While the moisture won't reach the region until Sunday night, there is still instability that will bring a 10-20% chance of dry thunderstorms on Sunday. However, once the moisture moves in Sunday night, PWATs will raise to 1-1.5 inches across most of the region (even up to Paso Robles) through at least Tuesday, bringing a 10-20% chance of showers and isolated thunderstorms to Southern California.

As for the heat, another warming trend will start up Tuesday through Thursday, with widespread Moderate HeatRisk, and a 30% chance of Major HeatRisk to most of the region during those days.
Thus, an Extreme Heat Watch has been issued for the majority of the region, with temperatures of 90-112 degrees possible away from the coast. Additionally, the monsoonal moisture will add to the discomfort of the heat.

AVIATION
08/1711Z.

At 1606z at KLAX, the marine layer was 800 ft deep. The top of the inversion was at 1400 ft deep with a temperature of 22 C.

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

Fair confidence in TAFs for KSBP and KSMX with a 25 percent chc of IFR conds redeveloping this evening around 5-7z and lasting through 16Z. VFR conds could occur +/- 1 hour from fcst.

Good confidence in TAFs for KOXR and KCMA with a 15 percent chc of IFR cigs 13Z-16Z.

Low confidence in TAFs for KSMO, KLAX, KPRB (40 percent chc of IFR cigs 10Z-17Z) and KLGB (40 percent chc of no cigs)

KLAX...Low confidence in TAF. There is a 40 percent chc of OVC008 conds 12Z-17Z). Good confidence that any east wind component will be AOB 5kt.

KBUR...High confidence in TAF.

MARINE
08/104 PM.

High confidence in Small Craft Advisory (SCA) level NW winds persisting through at least Friday morning across the Outer Waters. There is a 50-70% chance of Gale Force winds this afternoon and evening into Friday morning. Winds will likely be strongest near Point Conception and the Channel Islands, extending south to San Nicolas Island. Short- period, advisory level, choppy seas will gradually increase in height, reaching around 10 ft by mid- week and then subsiding below advisory levels Friday into the weekend.

SCA level NW-W winds will affect the inner waters along the Central Coast and the Santa Barbara Channel greatest during the afternoon and evening hours through at least Thursday. There is a 40% chance of Gales across the nearshore waters along the Central Coast and the Santa Barbara Channel in the afternoons/evenings through Thursday morning.

For the inner waters adjacent to Los Angeles County, moderate confidence in SCA level gusts through tonight. Otherwise, conditions are expected to remain below SCA levels.

BEACHES
08/104 PM.

A south to southwest swell will continue to affect the coastal waters through next week. With the swell, the potential for larger surf and greater risk for rip currents will continue.
High tides are expected to increase this weekend going into next week with Monday expected to be the highest tide of 7.0 to 7.6 ft above MLLW. There is the potential for some minor coastal flooding next week with the high tides and south swell. One thing that will need to be watched into next week will be the potential of a greater south to southwest swell from potential tropical development.

Thunderstorms are also possible starting Sunday and going through next week with a 10-20% chance.

LOX WATCHES/WARNINGS/ADVISORIES
CA...Heat Advisory now in effect until 10 AM PDT Tuesday for zones 38-88-343>345-353-368-372-373-375>380-548. (See LAXNPWLOX).
Extreme Heat Watch in effect from Tuesday morning through Thursday evening for zones 38-88-341>345-347>358-362-366>376-378>383-548. (See LAXNPWLOX).
Wind Advisory in effect until 8 AM PDT Thursday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 5 AM PDT Friday for zone 645. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Thursday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PDT this afternoon for zones 670-673-676. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Thursday for zones 670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect from 3 AM Thursday to 5 AM PDT Friday for zones 670-673-676. (See LAXMWWLOX).