On Thursday (4/26) Northern CA surf was chest to head high and clean. South facing breaks were waist to chest high with some bigger sets. Central California was waist high with some chest high sets. Southern CA breaks from Santa Barbara to just north of LA were up to waist high. The LA area southward into Orange County was waist high with some chest high plus sets. Southward to San Diego waves were waist high with bigger sets. The North Shore of Oahu was chest to head high. The South Shore was up to waist high. The East Shore was up to waist high.
things were proceeding about as expected, though the west swell in North California was coming up a little bit earlier than expected. Over the coming days small northwest windswell expected for Oahu's North Shore with southern hemi swell scheduled for the South Shore over the weekend. A different Southern Hemi swell is also expected for California this weekend. See details below...
SHORT- TERM FORECAST
Current marine weather and wave analysis plus forecast conditions for the next 72 hours
On Thursday (4/28) the jetstream was weak flowing almost flat from west to east. The last vestiges of a strong ridge was fading fast over the Gulf of Alaska. 2 small pockets of somewhat stronger energy were flowing over California and the other over the dateline. There were no indications of anything capable of supporting storm development (animation here). Over the next 72 hours through Sunday (5/1) it is to weaken even more. Possibly a bit of a trough to develop in the Gulf, but not much.
At the surface today two weak low pressure systems were tracking east with one north of Hawaii and the other over the dateline. Strongest winds were confirmed in the 30 kt range. The dateline low actually formed the day before well off North Japan (Wednesday AM) tracking fast towards the dateline. Winds were confirmed up to 50 kts for 16 hrs with seas building to 24 ft Wednesday PM, but it all quickly decayed late night down to 30 kts by Thursday AM (4/28) as indicated above. Windswell potential for Hawaii with even less energy reaching California (animation here). both these system to fade fast.
Over the next 72 hours another weak low is to form north of Hawaii (on Sunday 5/1) but only a brief bit of 20-25 kt winds expected aimed south towards the Islands, good for some short period windswell.
More model data here
On Thursday (4/28) in the South Pacific a split jet pattern continued to dominate the upper level picture, severely hampering storm development. Most energy was traveling in the northern branch with the southern branch appearing cut off from any solid energy. This did not support development of any solid storms (animation here). Over the next 72 hours through Sunday (5/1) there was no indication of any major change on the charts.
At the surface today a mixed pattern of mild high and low pressure was present over the broader South Pacific, but no indications of any real storm or fetch suggested. Under Tasmania a 972 mb low was present with 45-50 kts west winds confirmed by the QuikSCAT satellite at 57S 152E aimed up the 218 degree path to California but shadowed from Hawaii by New Zealand (animation here). Over the next 72 hours this system is to slide up the eastern side of New Zealand with a consistent fetch of 40-45 kts winds aimed continuously at California up the 218 degree path and pushing well up the 195 degree path to Hawaii too, fading Friday morning (4/29). Seas expected at 28-30 ft through the period.
Current data suggests that a nice shot of fun sized swell should push north right up the great circle paths to both Hawaii and California, with Hawaii getting the most size due to it's close proximity to the fetch (minimizing swell decay). Most size likely in the 14-15 sec period bands.
More model data here
On Thursday AM (4/21) a tiny 988 mb low developed in the northeastern reaches of the South Pacific with 40-45 kt south winds imaged at 42S 138W. It slid slowly east with pressure dropping to 984 mbs on Friday (4/22) while seas built to 29 ft over a tiny area centered at 37S 135W. This system faded late Friday into Saturday AM (4/23) with winds dropping to 35 kts or less. This system was well to the north of usual, reducing swell travel time and decay, but the fetch area was tiny with only a very limited sea generation window. This system had the potential to generate a small background swell (but rideable at best South and North California breaks) coming from 190-195 degrees arriving Friday night (4/29). No real fetch was aimed at Hawaii.
New Zealand Storm
On Thursday (4/21) a 956 mb low was tracking east in the deep South Pacific under New Zealand while high pressure at 1028 mbs held over the Tasman Sea. This was generating a gradient between the two with 40-45 kt west winds centered near 60S 160E. Even on Wednesday night (4/20) the QuikSCAT satellite confirmed winds of 50-55 kts over a tiny area positioned well southwest of New Zealand at 60S 148E. These winds were aimed well at California up the 213-215 degree great circle paths and moving into the Hawaiian swell window from behind the New Zealand shadow at 210 degrees. The fetch bloomed Thursday evening as pressure in the low dropped to 952 mbs while the high over the Tasman Sea increased to 1032 mbs. Winds were confirmed at 45-50 kt blowing from the west over a broad area centered at 60S 165E. They were aimed about 25 degree east of the 211 degree path to South CA and 45 degrees east of the 197 degree path to Hawaii. Seas were modeled at 29 ft centered at 60S 162E.
On Friday AM (4/22) the low pushed southeast away from the high some, and as a result the fetch started to fade down to 40-45 kts in the AM (at 59S 168E) and even less in the evening. Stronger winds at 50 kts were blowing right off the Ross Ice Shelf aimed towards California, but this was essentially and new fetch and no seas were associated with it yet. Seas in the original fetch were 35 ft (at 59S 171E) but down to 31 ft by evening (at 57S 180E).
On Saturday (4/23) the low was diving southeast over Antarctica and the fetch dissipated. No fresh seas were generated.
This was a rather small system that was short lived and positioned a long ways from both Hawaii (5107 nmiles) and California (6645 nmiles). Based on this confirmed data a small 16-17 sec period swell appears is likely for California starting 10.4 days out (Monday PM 5/2) with sideband energy moving up to Hawaii starting 8 days away (Saturday AM 4/30). But the long travel distance will ensure that swell decay and inconsistency will be major negative factors. Still, something rideable is expected.
More New Zealand Energy
On Tuesday PM (4/26) a new low was pushing under New Zealand with pressure at 972 mbs while high pressure at 1028 mbs held over the Tasman Sea. The difference in pressure produced fetch of 40-50 kt southwest winds confirmed near 56S 162E. Seas were modeled at 29-30 ft centered near 58S 153E.
By Wednesday AM (4/27) the low continued east turning the fetch angle to the northeast. But the fetch stretched and lost momentum, with winds confirmed down to 35-40 kts aimed northeast up the great circle tracks to Hawaii and California. Seas remained in the 29 ft range at 56S 165E. By evening things started to consolidate better on the east side of New Zealand. A solid fetch of 40 to near 50 kts was confirmed at 44S 173W aimed northeast up the 217 degree path to California and 190 degree path to Hawaii. Seas had faded but then started to rebound.
On Thursday AM (4/28) the low held near 970 mbs with 40-45 kts southwest winds aimed like before, just a bit more to the east. Seas were modeled in the 27 ft range near 43S 168W. In the evening the system is to back off some with winds down in the 35 kt range aimed northeast. Seas were forecast at 28-29 ft near 40S 170W. The gale is to remain sitting in a hole between the two branches of the jetstream with not enough energy aloft to enable it to do much.
On Friday (4/29) through Tuesday (5/3) is to to drift slowly east traveling on the 40S line with 30-40 kt fetch and 23-25 ft seas aimed continuously northeast spraying moderate energy focused on Tahiti but covering from Hawaii to California in to Central America. this system is to fade thereafter.
Of most interest is not this systems strength, but it's position very far to the north (40S). This will cut alot of travel distance out of the swell moving towards Tahiti and California, reducing swell decay. Unfortunately Tahiti will likely be too close to the fetch, meaning the swell will be raw, and poor local winds conditions are expected (south wind 15 kts as the peak of the swell arrives Saturday AM through Tuesday 5/4). California to see some small+ sized 14 sec energy from this systems if all develops as forecast. In all Hawaii might do well starting Wednesday (5/4) with solid energy expected in the days beyond. Will monitor.
California Offshore Forecast
Thursday mornings local charts (4/28) depicted moderate high pressure at 1022 mbs nestled along the US west up into the Gulf of Alaska coast with a weak 1006 mb low north of Hawaii pushing east and expected to fade. None of it is to survive long enough to reach California. A new series of lows is expected to develop early next week north of Hawaii tracking northeast into the Gulf, with the potential to generate some windswell for late week.
Today's infrared satellite imagery depicted no real clouds near California. A solid signature was echoed north of Hawaii in association with the weak surface low there. QuikSCAT imagery indicated a light offshore flow from Monterey Bay northward with light west winds (5-10 kts) south to Pt Conception . No Southern CA data available. Buoy and nearshore reports indicated variable winds 8 kts with seas 5-6 ft @ 16 secs. In Southern CA winds were southwest at 6 kts with seas 5 ft @ 7 secs.
The 5 Day local overview looks like this:
- On Friday (4/29) near calm winds early turning northwest 10 kts in the afternoon.
- On Saturday (4/30) light northwest winds all locations early building to 10 kts in the afternoon.
- On Sunday (5/1) light northwest winds all locations all day, except building to 15 kts Southern CA in the afternoon.
- On Monday (5/2) same thing.
- On Tuesday (5/3) light northwest winds early but building to 15-20 kts all locations in the afternoon.
See QuikCAST's for swell details.
Marine weather and forecast conditions 3-10 days into the future
Thursdays upper level models (4/28) indicate that beyond 72 hours out a weak zonal jetstream pattern is to continue. Perhaps a bit of a trough is to develop north of Hawaii mid-next week, but that's all.
At the surface a reasonably solid low is forecast over the dateline next Tuesday (5/3) generating 30-35 kt northwest winds aimed well at Hawaii and somewhat at California. It is to move fully into the Gulf of Alaska on Thursday (5/4). 18-20 ft seas suggested, but all this seems most optimistic.
Thursday upper level models (4/28) indicated that beyond 72 hours out the split jetstream pattern that has dominated the South Pacific is to continue, even getting worse with the 2 streams taking up almost parallel tracks across the southern hemisphere. No indications of any large scale storm development.
At the surface virtually no fetch of interest is forecast. Get whatever you can fro the energy that's already tracking north.
Southern Oscillation Index
Also of real long-term interest is the Southern Oscillation Index. This is an indicator of developing El Nino or La Ninas. Back in February through early March it went very negative, the most it had done in over a decade for that tome of year. This was a signal that a major pulse of the Madden Julian Oscillation was in effect, and that is what produced the string of solid swells in the North Pacific at that time. It also produce a major eastward moving Kelvin Wave (warm water pool) that is about to impact the South America coast on the equator within the next week or so. These sorts of signals are indicative of El Nino.
This all faded in mid-March, but the SOI index has again dropped well into the negative range (-25 to -35 daily starting 4/13 and continuing in the -10 to -20 range 4/25 to present). We suspect the MJO is firing up again. This is not so much going to have any affect on producing North Pacific storms (though it might jump start the typhoon cycle in the far West Pacific) but is a second good push towards an El Nino for the coming winter. We would want to see a series of these cycles through the summer. Nothing conclusive yet, but this is much more encouraging than anything we've seen in years since the last big El Nino of 97/98.
Details to follow...
Big Florida Swell: A strong gale pushed off Cape Hatteras on 4/15 generating solid seas and a 70 ft rogue wave that hit a cruise ship before proceeded south to make solid waves for the Southeast US coast. Matt Kechele was there to catch it. Take a look here: http://www.stormsurf.com/page2/forecast/forecast/kechele.html
Stormsurf Weather Models Updated Again: Yes, we've been at it again this weekend getting another batch of weather models running. Global coverage is now provided for jetstream forecasts and surface pressure and winds. Zoomed in data is also available for such locations as the Mentawai Islands to Western Australia corridor, Tahiti, South America, Europe and Norwegian Sea. So now you can get local wind forecasts for these and more locations with one click. Take a look here: http://www.stormsurf.com/mdls/menu.html
WaveWatch.com - New Surf Forecast Website: Read this teaser about something new on the scene. http://surfermag.com/features/onlineexclusives/ww_qna/
Wave and Weather Models We've updated our set of Wavewatch III and GFS weather models to include the Indian Ocean and South Pacific in preparation for the coming Southern Hemi big wave surf season. Take a look here or click 'Models' on the navigation bar at the top of every page: http://www.stormsurf.com/mdls/menu.html
Ghost Tree 3/9/05: Check out the pics of Don Curry and others on Monster Swell #16 in Monterey. http://www.stormsurf.com/page2/forecast/forecast/ghost_tree.shtml
SURFRIDER Web Site: The San Mateo County Chapter of SURFRIDER can be found at: http://surfridersanmateoco.org Take a minute to visit and find out what's happening to your coast.
Surf Height-Swell Height Correlation Table