they use different forecasting models, when they agree it usually happens, when they are dif, lean towards bom being more right.

superlizard said...

what i don't get is that seabreeze was showing 20-22 knots in "Live weather readings" the other day,

Which graph? I'm guessing Rotto? Rotto, being offshore is generally lots winder because there are no terrain obstructions out in the water...only a short ferry ride if you wanted to get in those conditions!

Regards which forecast is right, sometimes it leans towards BoM, sometimes Seabreeze. Sometimes they're both wrong!!

With forecasting, you have to take a punt on which direction a weather system will travel, and at what speed .. that's one of the many reasons why they can differ.

You can't beat educating yourself on the basics of a synoptic chart to add that little bit of extra knowledge to interpret the weather to find out why each is predicting what.

If you click on the 7 day forecast, you'll see it takes you to the synoptic chart when you can see why the forecast is what it is.

Here's a primer, which hopefully wets your appetite for reading weather charts:

www.seabreeze.com.au/info/wind.asp

Enjoy!

how exactly is the website updated laurie? you don't sit in front of your computer all day and change the graphs manually do you? i have know idea how this sort of stuff works.

Seabreeze wind graphs are the first tool I use, BOM coastal waters forecast next, combine them with local knowledge and calibration of rustling leaves outside the window.
After looking at Seabreeze vs WhatActuallyHappened for a few years, I think I've got a local formula for when to trust the arrows and when to tell em they're dreaming.
Often Seabreeze will accurately forecast what it will blow a few km offshore, but what we get at the beach here can be quite different.
Overall I think the Graphs are the most useful weather tool for Australian kiters.

Laurie, I have often thought that it would be interesting to see some historical wind data on the site, like averages by month, wind roses or better yet some historical wind readings from days with a similar graph forecast eg-
Last time our forecast for _________ looked like this, here's a few examples of what actually happened.

Another very cool model to watch is Stormsurf's wave model- www.stormsurfing.com/cgi/display.cgi?a=spac_height

Have a look at this link, it show graphically the wind direction and speed over the country (1-7day forecast). Then you can see how the wind forecast can differ depending on where on the water you are.

www.bom.gov.au/marine/wind.shtml

harry potter said...

IMO the BOM's new forecasting model ...( I believe new as of late last year ) is no where near as good as the previous one... Her in Vic we are regularly getting 10 -15knot differences in the forecast and the actual winds. Which is a hell of a lot when you consider they are forecasting 10 knots and it ends up being 25+ or the worst case scenario they forecast 20 - 25 and you end up with 10knots ....this sort of disparity is occuring regularly. The previous model was waaaaay more accurate..perhaps the new one needs some dialing in

IMHO the BOM are staffed by fishermen who take great delight in forecasting 20knots all weekend when they know it is going to be 5knots. They do this to keep the other fishermen from planning to go fishing (resulting in uncrowded fishing spots).
They neither know, nor care, about the anguish this causes us wind junkies as we plan and scheme to get time on the water, only to have no wind again!

It's a good thing that Laurie would never stoop so low

So, start with graphs, but put more trust in trees & flags.
Put even more trust in your kite, if you listen, she will tell you when there is enough wind

Forums are hard, many opinions!! Weather and modelling sytems have dramatically evolved over the last 10 years: ie computer age.
Here is my 2 cents worth on this thread. I work with the weather, for 25 years now, in wave, wind and air. Seabreeze (USA) and BOM (AUST) differ due to the fact that they employ different computerised models. My best advice is look at both, read books like "understand the sky", by Denis Pagen and finally, look outside and feel the micro changes that occur in your area. Remember, the weather is dynamic and it changes....

Thanks for all the info!!! i will endeavour to learn how to read synoptic charts, weather models, stones and observe leaves as the old timers did and of course pay attention to what's happening outside..............
Can we freeze the seabreeze forecast for Easter Saturday/Sunday/Monday/Tuesday for Perth right now cause its looking GOOD!!!

Thank You for sharing your knowledge

I work on the Great Barrier Reef as a marine bio, taking groups of people snorkelling and diving, so have to get the call right on the weather.

I found the best service is Buoyweather ( www.buoyweather.com ) which I think uses the NOAA data and models. Accuracy wise, it leaves BOM for dead.

Worth its weight in gold to be a subscriber, and get access to the full 14 days predictive charts.

You can also overlay all sorts of data on the local map of your area (wave height, sea temp, wind, precipitation, cloud cover) which really lets you learn about all the various factors involved in the weather, rather than just the wind.

But fellas, if "that" tree outside my house rustles in a certain way......then I'm down the beach ASAP regardless of the forecast!

superlizard said...

what i don't get is that seabreeze was showing 20-22 knots in "Live weather readings" the other day, and then i came to the beach, and everyone was stalling with their kites at 12 sitting in the water.... i waited ten minutes but nothing changed and didn't look like it was gonna pick up... then i came back home and the seabreeze was still showing around 20 knots...

I found fawkner's accuracy depends largely on the wind direction. unless it has west in it, it over reads by a fair margin. On the up side, now you know why people claim 40 knots on their 9m kites.

Here's an article I wrote about how forecasting even got to the point we are today, where so many crew still "expect" accuracy.

Interest rates, stock markets & weather .. imagine if we could forecast them all, 100% accurate all the time .. ?

www.seabreeze.com.au/Articles/Miscellaneous/A-history-of-weather-discovery_1216853.aspx

Hi Guys

I guess I consider myself a professional wind user as my business and livelyhood depend on accurate wind predictions.

I usually check Seabreeze and see what Lozza reckons, if the 7 day wind forecast looks like a typical pattern then I look no further. If I feel it's a bit suss, I check on the BOM's forecast. If they are the same, then I go no further. If they differ, then I click onto the Synoptic Charts and generally make my own call.

To date I've had a very good stretch at picking it correctly when the forecasts are mismatching, then again, WA wind is a bit of a no brainer usually.

I studied Marine Meteorology at TAFE many years ago and learned heaps. For anyone interested, it's a great course and went for 22 weeks, one night a week about 20 years ago. At the end of the course there was no exam. I was told it was an imperfect science so no exam was appropriate.

Forecasting accurate wind any more than 1 day ahead is at best a guess, two days ahead, a big guess, three days ahead, a wild guess.

Interesting topic.

Good winds,

Hi Laurie,

I'm guessing there are times when the forecasts are more confident than others. Any chance of including that info?

Eg, esp when there's light winds, I assume you're less sure which way they'll blow. Frontal systems passing overhead. Etc.

By the way, I'm very impressed by Seabreeze - well done!

laurie said...

superlizard said...

what i don't get is that seabreeze was showing 20-22 knots in "Live weather readings" the other day,

Which graph? I'm guessing Rotto? Rotto, being offshore is generally lots winder because there are no terrain obstructions out in the water...only a short ferry ride if you wanted to get in those conditions!

Regards which forecast is right, sometimes it leans towards BoM, sometimes Seabreeze. Sometimes they're both wrong!!

With forecasting, you have to take a punt on which direction a weather system will travel, and at what speed .. that's one of the many reasons why they can differ.

You can't beat educating yourself on the basics of a synoptic chart to add that little bit of extra knowledge to interpret the weather to find out why each is predicting what.

If you click on the 7 day forecast, you'll see it takes you to the synoptic chart when you can see why the forecast is what it is.

Here's a primer, which hopefully wets your appetite for reading weather charts:

www.seabreeze.com.au/info/wind.asp

Enjoy!

GreenPat said...

Hey Loz, can you put that Northwester back on Monday? I was hoping to try my new board in it.

Hey look, it's Easterly Sunday.

Forget Forecasting, we're into requesting here...

Laurie, if you can't help, do you know anyone who can?

I normally call 13 4839 for my requests. Payments methods accepted: burning boards and the odd virgin.

EDIT: That was a joke... 13 HUEY. Don't call it please, it may belong to someone legit.... hmm, maybe I should try it in case the big man picks up! [}:)]