High surf advisory

Coconuts · Post by **Coconuts** » Thu Mar 27, 2014 7:22 am

That storm that mostly missed the mid-Atlantic and New England yesterday is very powerful, and moving rapidly off into the northern Atlantic Ocean. Its very intense low pressures and strong winds generated large swells, though, which will be arriving in the VI tonight through Saturday night before subsiding. These swells will make for large breaking waves on North Shore beaches. Anyone on island may want to choose south shore beaches instead. Here is a link to the National Weather Service's High Surf Advisory:

http://forecast.weather.gov/wwamap/wwat ... 20advisory

You can watch the swells approach on this buoy 120 miles north of the VI. It shows very low swells now (3'), but this will spike this evening.

http://www.ndbc.noaa.gov/show_plot.php? ... _label=AST

Compared to exposed coastline in Puerto Rico, Jost Van Dyke and the islands to the north of Pillsbury Sound shelter St. John from the worst of these swells, but the wording of the advisory is strong and worth noting:

WAVES AND SURF: BREAKING WAVES OF 10 TO 14 FEET.

PERSONS ON THE BEACH SHOULD BE VIGILANT FOR LARGE BREAKING WAVES
SURGING UPON THE SHORE...WHICH CAN CARRY PEOPLE OF ALL SIZES INTO
THE OCEAN. YOU SHOULD AVOID BEING NEAR THE SHORE LINE AND STAY
OFF OF ROCK FORMATIONS.

All the best,

Kevin

Barb Y · Post by **Barb Y** » Thu Mar 27, 2014 8:28 am

Be safe everyone!

Agent99 · Post by **Agent99** » Thu Mar 27, 2014 9:08 am

Wow. I bet the surfers are out in force at Cane Garden Bay.

ArkieLovesSTJ · Post by **ArkieLovesSTJ** » Fri Mar 28, 2014 7:18 am

Trying to decide if South Shore beaches would be ok today. First time we have been here with this type of advisory. We are staying in Coral Bay so we are close to Lameshur and Little Lameshur. Anybody got advise on what to do?

Coconuts · Post by **Coconuts** » Fri Mar 28, 2014 7:22 am

At 8 PM last night, the large swells arrived right on schedule, and at the size that was predicted. Fourteen foot swells in deep water would make for some remarkable waves on unprotected north-facing coastlines. Fortunately, as per the original post, St. John is spared the worst by islands to its north, but even with that protection, exposed beaches on the North shore will be pretty wild, with knock you over waves for the next few days. Trunk Bay Beach will certainly be flying red flags and closed to swimming.

: Right on schedule

Edit: Arkie: Anything on the South Shore will be fine. Protected, west facing beaches such as Francis or Caneel, and maybe Maho, may also be calm enough.

All the best,

Kevin

ArkieLovesSTJ · Post by **ArkieLovesSTJ** » Fri Mar 28, 2014 7:37 am

Thanks, Kevin! Sounds like it is time to load up and head south...

Muhaha · Post by **Muhaha** » Fri Mar 28, 2014 11:54 am

Interesting to watch the Peter Bay webcam and the waves breaking over the reef on the point.

BillVT · Post by **BillVT** » Fri Mar 28, 2014 6:02 pm

The surf washed across the road at Big Maho. The south shore was better but still rockin' out by the points. Not a good day to deep water snorkel.

ArkieLovesSTJ · Post by **ArkieLovesSTJ** » Fri Mar 28, 2014 7:08 pm

Stopped by Trunk Bay this afternoon. I was shocked at the waves. You could hear the roar of the water in the parking lot.

augie · Post by **augie** » Fri Mar 28, 2014 8:36 pm

At noon today the Jumbie parking lot was empty. Went to Cinnamon and enjoyed watching the waves breaking. Stopped by the (also empty) Peace Hill parking lot and walked down to Denis - there were some dramatic looking breakers!

2beachbums · Post by **2beachbums** » Sun Mar 30, 2014 12:27 pm

Has everything settled down? Is there any damage or major loss of beach?

Coconuts · Post by **Coconuts** » Sun Mar 30, 2014 2:25 pm

2beachbums: "Has everything settled down? Is there any damage or major loss of beach?"
Paradoxically, it is precisely large but far away winter storms of this type that originally created and continue to enlarge St. John's beaches. New coral "sand" is created in the reef by mechanical wave action, and when fish such as parrotfish gnaw at the coral. Those milky plumes that parrotfish emit capture this process in action. If all of this new sand stayed in the reef, it would choke it, but the large swells from far away winter storms such as this one, called ground seas, transport sand from the reef onto the beach. Maho Bay was once the deepest beach on St. John, but much of its sand was removed to make concrete during the buildout of Cruz Bay. Natural ways that beach sand is lost include winds that blow it inland, and large tropical storms that move sand out into the deeper sea.

The onset of the big waves was rapid, and the decay slow, but wave heights should be back to normal by this time tomorrow:

: Getting back to normal

On the above beach creation theme, it usually gets a start out of newbies when they remark on how beautiful and fine the beach sand is, compared to the crushed quartz sand of the Atlantic coast. "Yeah", you reply, "parrotfish poop".

All the best,

Kevin

2beachbums · Post by **2beachbums** » Sun Mar 30, 2014 3:47 pm

SWEET! I do love me some Parrotfish poop! This will be our 6th trip back to the rock. I'm just to fuzzy from all the pre-trip work stuff of being self employed to think about how it all works! Thanks for the info!

Cheers!

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