SoCal Forecast
Updated most Sundays, Tuesdays, and Thursdays

Sunday August 1, 2021 6:20 AM
By Nathan Cool


Surf Charts for SoCal

Rincon | Ventura, C-St. | County Line | Malibu | Hermosa | Huntington Beach
Trestles | Old Mans | Oceanside | Beacons | Sunset Cliffs

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At a glance:
Today (Sunday) is a very small day for surf in SoCal, but waves are on the way. Southern hemi ground swell builds Monday, peaking Tuesday. Hurricane swell overlaps that into Wednesday. NW wind swell also comes into the mix by midweek. There's a chance for more swell from the tropics later this week. Sizable hurricane swell is possible by the second half of next week. And moderate southern hemi is being watched for the 17th. Condition-wise: onshore flow increases during the second half of the week; tide levels are moderate now but swing wide later in the week; water temps have dropped in some spots and further cooling could occur by the end of the week.

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Current Conditions:
Early this morning, periods were primarily running 13 seconds from 175-185° and 5-8 seconds from 300-315°.

Most breaks were running knee to waist high.

Buoys in the outer waters off SoCal were running 2-3'. Nearshore buoys were running 1.8-2.0'.

Tide levels are moderate over the next few days, but we will see a swing get underway by the weekend as we approach a New Moon Sunday the 8th. Today we have a 2.8' low around 6:00 AM that'll barely dip to a slackwater low of 2.4' around 10:00 AM. We'll see a 4.7' high around 5:00 PM and a 1.1' low after midnight.

Water temps continue to drop in SoCal, and we may see further cooling later in the week as outer water winds increase in a few days. Yesterday, much of SD and OC was running 61-64°. LA was varied with Cabrillo and Zuma 58-59° but Hermosa 67°. Santa Monica buoy has been running 61-65°. In VC, Channel Islands Harbor reported 59° yesterday. SB nearshore readings remain unavailable but water temps in the channel have dropped from 65° a couple days ago to 62° this morning.

Surf Forecast:
Today is one of the smallest days in the surf forecast. Although southern hemisphere ground swells are on the charts, the tropics are lighting up and NW wind swell is in the forecast as well. There's a lot to get to this morning, so let's start from the top.

Monday the 2nd (building day) into Tuesday the 3rd (peak day) should see SW swell from this system that broke off Antarctica near the French Poly longitudes almost ten days ago (model by FNMOC):

As you may recall from last week's reports, this one moved on an ideal, northeasterly course, relatively close for a southern hemi (about 4,900 nautical miles from SoCal), so we're looking at chest high surf at south facing breaks Tuesday the 3rd, with some pluses on the better set waves at standouts. Monday the 2nd, being a building day, should start out smaller (waist high). Swell should be angled from 195° with periods 16 seconds.

Hurricane swell should overlap with the FPoly swell from that tropical activity last week, which is now officially Hurricane Hilda (model generated by XyGrib from NFCENS data):

Models across the board agree on this somewhat-wobbly course that, with Hilda's 15-25' seas (varying widely at times), should send initially waist to chest high waves to SoCal arriving Tuesday the 3rd into Wednesday the 4th from 180° with periods 13 seconds. This would then increase to a more solid chest high Wednesday the 4th into Thursday the 5th. Pluses from combined seas (constructive interference) from the FPoly swell are possible both days.

Overlapping with Hilda and the tail end of the FPly swell should be an increase in NW wind swell, which will likely also bring a slight shift in our weather and winds, and possibly cool water temps by the end of the week. Today we're sittin' pretty under high pressure, but not for long (models by NOAA MAG):

High pressure (blue circle) is bathing most of the American West in summertime sunshine, but a large area of low pressure (red circle) is waiting in the wings. By the middle of the week that will shift with high pressure shrinking and retreating as low pressure advances into the region.

Once that trough nears our area, its interaction with the retreating high should increase winds (and wind swell) along the coast, especially off SoCal. Although NW wind swell should build somewhat Tuesday the 3rd (knee to waist at west facing spots), this should build more on Wednesday the 4th, peaking Thursday the 5th in the chest high range at west facing breaks, lingering with similar size Friday the 6th before backing down over the weekend.

Taking all three swells into account, the one day they all overlap with their max energies should be Thursday the 5th — chest high everywhere with pluses possible at standouts. But, with an onshore flow underway from that hefty trough, winds may pick up earlier and become strong in wind-prone spots in the afternoon, mostly north of LA. Upwelling becomes likely as well, so we could see a dip in water temps by the weekend. Coastal eddies become a possibility too, so there is a chance of thicker AM marine layer by Thursday and Friday with some eddy texture breezes for early AM sessions.

Friday the 6th into Saturday the 7th has a chance of seeing another Hurricane swell; however, this might be an outlier (model by FNMOC):

That FNMOC NAV model may have gone rogue as it conflicts with four other models I looked through this morning. This puts this hurricane in the 10-20% chance category (for now). If the NAV has it right though, then we could see head high swell from this Friday into Saturday; HOWEVER, it's too early to call given that most models say otherwise. Good news is that this is out on the medium range models, so I should be able to put a bow on this in my next report (on Tuesday).

If that hurricane swell doesn't pan out then we'd be looking at a small weekend ahead, about waist max everywhere from fading NW wind swell and minor southern hemi activity. The weekend forecast is highly reliant on that potential hurricane...I'll know more in a couple days.

Wednesday the 11th and/or Thursday the 12th (or even Friday the 13th) will very likely see hurricane swell; it's now a matter of timing as models differ on what to expect. As you may recall from last week's reports, some extended long range models showed a hefty storm making its way well into our swell window (see earlier model here). Now that we're in the extended range of many other models, consensus is forming; in fact, here's how many models are showing it this morning (model generated by XyGrib from NFCENS data):

That scenario is a later arrival (by the 13th), but other models show something a day or two earlier (some models still say nay). Either way, seas in that fetch measure 35' at just 860 nautical miles from SoCal — that's close, especially for that strength. In that model the swell angle would be tough at 165°. But, models continue that fetch on a course with only slightly weaker seas farther to the northwest, entering our swell window from a more ideal 180°, sending decent sized swell to all of SoCal's south facing breaks. If that becomes the case, then we could be looking at sets running head high to 3' overhead by the 11th or 12th or 13th (depending on the model one chooses to use from the deck this morning). Although this one has my attention and I excitedly slammed a bright red pin into my charts this morning, it's still too early to call. I'm on it though, and I'll keep you posted.

The last swell in my forecast this morning is a potential SW swell from the Tasman Sea that'd arrive around the 17th (model by FNMOC):

That FNMOC NAV model is the most bullish of the bunch, with some models showing this being a lesser system that'd ride up the east coast of New Zealand. Swell ETA either way is nearly the same. As for size, this has potential for chest max surf at SoCal's south facing breaks, angled from 220° with periods 16-18 seconds. Tasman Sea swells tend to be spotty for SoCal with few waves per set and long lulls between sets. But, it's too early to call either way — for now.

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Here's how the day-to-day is breaking down so far:

Monday the 2nd should see southern hemi swell start to fill in, running mostly waist high at south facing spots.

Tuesday the 3rd should run chest high at south facing breaks and waist high at west facing spots.

Wednesday the 4th looks about chest high with pluses at south facing breaks and waist to chest high at west facing spots.

Thursday the 5th looks about chest high with pluses at south facing breaks and chest high at west facing spots.

Friday the 6th looks about chest high at west facing breaks and waist high at south facing spots. However, there is a chance for hurricane swell around this time as well (10-20% chance right now).

Saturday the 7th, so far, looks about waist max everywhere; however, there is a 10-20% chance for hurricane swell.

Sunday the 8th, so far, also looks about waist high at south facing spots, smaller at west facing breaks.

Monday the 9th, so far, looks similar.

Tuesday the 10th, so far, looks about waist high at south facing breaks and knee high at west facing spots.

Wednesday the 11th will likely see hurricane swell start to fill in. This is still too early to call today. I'll have more in my next report.

 

Weather Outlook:
High pressure weakens during the second half of the week as a trough of low pressure pushes south toward SoCal, which will shift our weather to a stronger onshore flow, more so by the end of the week and weekend.

Today through Tuesday should see AM marine layer with an early burn-off and max beach temps in the mid 70s. Wednesday through Friday should see a later burn-off, around late morning, with max beach temps in the low 70s.

The weekend, so far, is looking at burn-offs late morning or early afternoon with max beach temps in the upper 60s to right around 70°.

Wind Outlook:
Winds at 6:00 AM were light and variable most everywhere. Afternoon onshores are expected to reach 15 mph. No major change is expected through Tuesday. Wednesday through Friday have a chance of seeing early AM eddy texture (more so Thursday and Friday), with onshores picking up earlier, but topping out around 15 mph, possibly stronger though north of LA.

 

Until my next report (Tuesday), take care, be safe, and smile in the lineup!

—Nathan

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