Marine Weather and Tide Forecast for Pismo Beach, CA

.SHORT TERM (TDY-TUE)...28/1231 PM.

Surface pressure gradients have finally turned onshore this afternoon and looks to stay onshore through Monday. This fact, combined with the high pressure ridge breaking down will bring steady cooling each day through Monday, when temperatures will be a hair above normal with highs between 65 and 75 common. Slight warming likely to follow on Tuesday.

The cooling will be enhanced on Monday by a weak low pressure system that will take an inside slider path Monday into Tuesday.
While there might be a few light rain showers on the north slopes, this system will make it biggest impression through winds. Look for west to northwest winds Sunday Night into early Monday focused over the coastal, mountains and desert areas. Most areas should stay below Wind Advisory levels, except maybe southwest Santa Barbara County. The winds increase during the day and evening on Monday as they shift to more northerly. A few localized Wind Advisories are possible. The winds will weaken on Tuesday as they turn northeasterly.

With the flow trending onshore after a warm and dry spell, one has to anticipate some smatterings of dense fog developing Sunday morning. Exactly where it forms one the first day is always one of the hardest things to predict in this business, but the highest chances are on the Central Coast and southern Los Angeles County.
Low clouds and fog will likely expand on Monday, but with a weak inversion from the passing low pressure system, any clouds may not be very organized or blanketing. The winds should help decrease any coverage Monday Night into Tuesday.

.LONG TERM (WED-SAT)...28/105 PM.

Another inside slider system will dive through California Wednesday Night through Tuesday. This system has more energy than the Monday system and thus a higher potential for widespread impactful winds, but it also has more uncertainty. As usual, the exact path of this system will determine a few key details. If it takes a bit more of a westerly track over eastern California (like the 12Z ECMWF show and about half of the ensembles) the winds will be more localized and light showers will be more common over the mountains and maybe even eastern LA County. If it stays more to the east (like the 12Z GFS and the other half of the ensembles) then winds will be more widespread and any showers will be confined to the Kern/Ventura County borders. With that said, either scenario will bring at least moderate winds to the coastal waters and the mountains - with hazardous seas, roads, and potential for downed trees and power outages. If the windier solution plays out, then those concerns will be enhanced and spread out over a larger area which includes many coastal and some valley areas.

Regardless of which scenario plays out, temperatures will remain fairly steady and hover slightly above normal. Low clouds and fog will likely be minimal.

After Thursday, most of the projections have the low retrograding back towards southern California to close the week. While there is still a range of outcomes, one scenario does bring rather strong northeast (offshore) winds to the region.

AVIATION
28/1736Z.

At 1632Z at KLAX, there was no marine layer. There was a surfaced based inversion with a top at 1900 ft and a temperature of 25 C.

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

Moderate confidence for remaining sites. Marine layer stratus will return to some coastal sites overnight into Sunday morning. VLIFR to LIFR conditions will be common. Timing of CIG/VSBY restrictions may be off +/- 3 hours and flight minimums off by one cat - if CIGs arrive. Sites with highest chances that CIGs do not arrive: KCMA (50+%), KSBA (40%), KOXR (35%), KSMO (25%). All other sites with CIGs forecasted have a greater than 70% chance of verifying.

KLAX...Moderate confidence in TAF. Arrival and clearing times of CIGs may be off +/- 3 hours from current forecast. There is a 30% chance of conditions falling to VLIFR (OVC001-002 with 1/4SM) from 01/08Z to 01/16Z. No significant east wind component expected.

KBUR...High confidence in VFR TAF. No wind impacts expected.

MARINE
28/141 PM.

For the Outer Waters, Small Craft Advisory (SCA) level NW winds will develop across the waters between Point Conception and San Nicolas island Saturday evening. These winds will continue and increase some through the weekend. This trend will persist into Monday, resulting in a moderate chance (30-40%) of Gale Force wind gusts near the Channel islands during the afternoon and evening. By Tuesday, the axis of SCA level NW winds will shift westward and expand including the northern waters. These winds will strengthen significantly bringing very hazardous conditions Wednesday into Friday morning. There is a likely chance (60-70%)
of GALES during this timeframe.

For the nearshore waters along the Central Coast, conditions will remain below SCA levels through at least Sunday morning. There is a 30% chance of SCA level NW winds that afternoon and evening.
SCA winds are very likely (60-90%) Monday thru at least Thursday.
There is a moderate chance (30-40%) for GALES Wednesday/Thursday.

For the inner waters south of Point Conception, winds may briefly reach SCA levels (21kts) this evening through Sunday morning across western and southern portions of the Santa Barbara Channel.
By Sunday afternoon, SCA level W of 20-25 kt will become widespread across the channel. These winds will strengthen into the nighttime.
Strongest Monday afternoon and evening with a moderate chance (30-40%) of GALE Force wind gusts across western/southern portions.
Reduction of winds to possible sub-SCA is possible Tuesday morning.
SCA winds will likely stay confined to western portions through early Wednesday morning. Thereafter through Friday morning SCA winds are likely across most if not all of the channel. There is a moderate chance (30%) for GALES across western/southern portions during this timeframe. Moderate chances for SCA conditions across at least western portions of PZZ655 Sunday and Monday, & possible more widespread on Thursday. A lull below SCA levels looks likely Tuesday morning through Wednesday morning.

LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...Small Craft Advisory in effect from noon Sunday to 3 AM PST Monday for zone 650. (See LAXMWWLOX).
Small Craft Advisory in effect from 3 PM Sunday to 3 AM PST Monday for zone 655. (See LAXMWWLOX).
Small Craft Advisory in effect from 9 PM this evening to 3 AM PST Monday for zones 673-676. (See LAXMWWLOX).