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Sunday, December 5, 2021

12/5/21v Report - $600,000 Found By Plumber in Church Wall. Surf Forecasts: Accuracy and Usefulness.

 

Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.


HOUSTON (AP) — For more than seven years, no one has known what happened to $600,000 in checks and cash that was stolen from a safe at Pastor Joel Osteen’s Houston megachurch, which has one of the largest congregations in the country.

Now, there’s a possible plot twist in the case: The money might never have left the church and a plumber could have helped solve the mystery.

Houston police are investigating whether cash and checks discovered by a plumber during repair work that was being done at Lakewood Church is connected to the money that was stolen in 2014.

Here is that link.

Plumber's find possibly tied to 2014 Texas megachurch theft | AP News

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I give you the surf forecast from MagicSeaWeed in almost every post.  While there are several factors you will want to consider when deciding when and where to metal detect, for me the surf forecast is among the most useful.   

Like other forecasts, the surf forecasts are not 100% accurate, but it is a matter of probabilities.  If a 2 - 3 foot surf is predicted, you might actually get a 4 or 5-foot surf, but not likely an 8-foot surf.  And that makes a big difference.  Although there are other factors involved, you have a much better chance of finding good beach conditions after an 8 foot surf than after a 2-foot surf.  I've proved that to my own satisfaction for sure.   You can find something good at any time, but sometimes it is much more difficult and you'll spend a lot more time for meagre results.  You can detect every day for months during a summer like the one we just had with no storms or much of anything to stir things up, and you'd be lucky to find much of anything old.  It is no coincidence that most good old things are found after rough seas or a good northeaster, as history proves. 

A foot or two of surf might not mean a whole lot for metal detecting, but several feet can definitely make a big difference.  As a result, a small forecast error is not very important.  I tend to divide the surf into a few categories; small, medium and large, and maybe very large.   That would be something like 1 - 3 feet, 4 - 6 feet, and 7 - 9 feet and up.  Then the tides should be considered, as should the wind direction and other things which can either increase or decrease the effect and your chances.  And some locations will be affected more than other areas due to things like the angle of the beach, the starting conditions and nearshore reefs or shoaling. 

But how accurate are the surf forecasts?  It isn't as easy to answer that question as you might think.  To determine the accuracy of the forecasts you have to compare the forecast with what actually happened, which isn't as easy as you might think.  You might measure the forecast size and periods with data from buoys, but buoys generally provide open ocean data while what surfers and detectorists are interested in nearshore data.  

There is a big and serious business.   Commercial shipping, the military, and oil exploration companies pay a lot of money for surf forecasts.  They take the data seriously.   Ben Freeston, Surfline's VP of Data Science said, The nuts and bolts of it is, we want to know things — how big the waves will be, how they’re going to break, what type of conditions to expect — and to dig that stuff out, we have to take huge sets of data that weren’t created for surfers and transform them. In many cases, this information was created for oil exploration, commercial shipping or military use. So our goal is to take these data sets that exist for other purposes and turn it all into something relevant to surfers. This means ingesting massive amounts of information from satellites, ocean wave models, sensors and reporters to help us on the journey to producing surf forecasts.

Freeston, who works for a competitor to MagicSeaWeed, has several articles online about measuring and improving the accuracy of surf forecasts.   

(Source: How Surfline is Redefining Surf Forecast Accuracy -- And What Comes Next - Surfline)

You might remember me commenting several times on what I thought was a systematic error in the MagicSeaWeed forecasts.  Large surfs predicted multiple days out very often disappeared over time.  I also mentioned that they seemed to correct that to some extent.

Below is a brief excerpt from an article on MagicSeaWeed.

The bulk of our forecasts start life as the output of the NWW3 Model. This computer model is a third generation swell forecast model. That's to say it's the third in a series of attempts by meteorologists to forecast swell mathematically from observed conditions using a forecast of surface winds around the globe. It's very sophisticated in the way it does this and is fed every six hours by thousands of actual observations from satellites, buoys, ships, weather stations and aeroplanes as the starting point for it's predictions. It's regarded as one of the most sophisticated models of its kind and is routinely used for shipping forecasts for both commercial and military planning. The full 'validation' giving a wealth of technical reports on the percentage errors etc. can be found here:

http://polar.ncep.noaa.gov/waves/validation.html\

Here is another excerpt from the same source.

Recently we've started improving many of our forecasts with the addition of a complex nearshore modelling tool that allows us to take this open ocean data and predict how it will be transformed right up to the beach, giving an accurate idea of the size of the swell coming right into the surf zone. This allows us to take the highly accurate (see link above) NWW3 model and make the results immediately relevant to a surf session. We're currently building our own accuracy statistics from this compared to certain key wave buoys located just outside the surf zone and so far the results are impressive.

And finally.

The second issue is range and detail of the forecasts. For about the first three days the forecast is at it's most accurate. During this period you can with some confidence use the data as part of the information required to plan trips and travel and the three hour details are quite relevant. As you move into 3-5 days the predictions will start to change more as time progresses and to expect the three hour details to be accurate is less and less reasonable. Between 5-8 days the forecast enters its 'experimental' stage. This means that small errors creeping into the model will mean it's likely that the actual conditions vary more widely from the forecast - it becomes more inaccurate...

Here is link to another article by Freeston in which he discusses how they are measuring forecast accuracy and improving their forecasts.

Surf Forecast Accuracy. Building an accurate surf forecast… | by Ben Freeston | Surfline Labs | Medium

And here is a chart showing the average error for over a six-day period at one location - less than one foot six days out.

Of course they are not going to present something that makes them look good relative to their competition.


From Surfline Labs.

So, are the surf forecasts accurate?  Not totally, but accurate enough that I find them very helpful, especially when considered along with other factors.\

Like all data, it is most useful when you learn to use it effectively.

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Happy hunting,

TreasureGuide@comcast.net