Where Does the Wind (forecast) Come From ?

"It don't take a weatherman to know which way the wind blows." You're making my brain hurt. "There is what we know, what we don't know, and what we don't know we don't know." Go figure. Any other questions?

 

I've seen the disparities and often wondered the same..who is the "official" authority on wind, and where do the disparities originate?

*sisurfdog, you seem to get headaches frequently, maybe you should get the ole' noggin checked out.

 

This may not be what you were looking for but heres my best shot... Winds are caused by pressure differences in the atmosphere (Pressure gradient) The way winds blows is associated with a front. Low fronts associate with stormy weather while High fronts usually bring clear skies. About how sites predict the surf forecast and winds is all based on models and computers, this changes daily due to storms and the unpredictability of the fronts. Usually sites (SI,MSW,Surfline) can have an in the ball park estimate of a swell about a week in advance but like i said the weather is so unpredictable it can change instantly, but as the desired date gets closer the report becomes more accurate because the front is more solidified and the computer scans basically have the data spot on. Waves are usually best after storms because of the prevailing west winds as the low front moves out and the high pushes in as well as the windswell produced at sea by the storm or ground swell

 

Disparities in temperature between air masses as well as air pressure predict winds. Cool air is heavier than warm air so when a mass of cool air converges with a mass of warm air the masses slide across one another creating wind (This is the same way ocean currents occur, but then we are getting into convection cells which also occur in wind). Obviously, air flows from areas of high pressure to low pressure, also contributing to wind. In reality though, there are too many factors and we yet lack the technology to predict wind with any real degree of certainty.

 

Thanks Dikipedia!

 

i wish i could answer that question because i am usually scrambiling to find out my local spots forecast and i see 3 different forecasts each with a different wind prediction.. My guess is they either bull**** it (unlikely) use their own instruments (may not be up to date) or NOAA or someother top of the line predicting instruments which are the closest thing we have so far.

 

I don't think anybody really knows what the wind will be, it's only a "forecast" which I equate to an educated guess, not a sure thing. The hardest part to predict is the LOCAL wind, If you look at the weather predictions you can get an idea of what it may be within the vecinity, but to get specific to the actual beach / break is near impossible. Too many variables at play, Mother nature isn't something we can predict with 100% accuracy, we can only make educated guesses. Just to give you an example, last week when I spent 5 days in Melbourne, the wind was forecasted to be 15-20 all day every day at most spots on the Space Coast, but almost every morning it was dead calm at the spot I surfed, only one day that was a little wonky out there, but other than that it was so much better than predicted.

 

I wonder the same thing Yankee, i've found weather.com to be pretty decent when looking at wind, if you go to the marine forecast and break it down by the hour a day or two before you head out it may help. What I tend to do is check SI.com, SL.com, and then Weather.com, if you add them up and and divide by three maybe it'll come up with an average that is closer to the truth?

 

Man, EVERYONE is bro'ing out today on SI.

I can just hear the music in the background... "Wouldn't it be nice?"

Erock, you ready to chest bump mid-air? My only fear of burying all these hatchets at once is that I'll never be able to find them if I need one again.

 

I'd guess (and sorry it's just a guess) is that the data source must be the issue explaining the variation...and no, I don't know what source they use (which is why I think the admin/Swellinfo model engineer needs to inform you). I imagine that some wind source data is predictive and some models will utilize that as an input, while other services/models might use historical data. Obviously, historical data would probably yield less accurate predictions because conditions change so rapidly and randomly. I don't pay for any surf subscription forecast sites, so I can't say if they are usually more accurate than the free ones, but if they are it might be that those costs are sunk into getting more accurate data (from, say, whatever radar the news stations use and broadcast every few minutes, rather than free data published by the national weather service or something).

A completely unbased hypothesis that still doesn't answer where it comes from...just agreeing with your suspicion that different services prob use different data sources.

 

I have a paid script with SL.com, they are no more accurate than SI.com when it comes to forecasts on regular run-of-the-mill type of days, BUT when there is a major swell event, SL is all over it and they are much more accurate than on the regular days, but still not 100%.

 

Good to know. I'd bet that SI and SL are just superior algorithms to everything else...just that one is free and the other isn't. Difference coming into play is that the SL models are being studied closer during major events, while SI is prob just on autopilot.

Again, totally guessing, but that's the conclusion I'm left with, considering this site is free.

 

Sounds about right my man