Seznam is a remarkable company. Their maps (http://mapy.cz) are second to none, my favourite feature are touristic maps which work at least within Europe.
Though for windsurfing I find windguru.cz is more useful (also Czech(!)) and for flying its hard to beat ForeFlight.
It should also be clarified that Seznam is one of the few companies to beat Google in searches with the Latin alphabet. Local search engines are still beating Google in Chinese, Korean, Japanese and Cyrillic alphabets.
But the one specific rule is that players can't use their phones to check the weather, and even more specifically the wind direction. Wind makes a huge difference on the course, and being able to know the exact direction of the wind where the ball is flying would be really helpful. Other part is being able to know if the wind shifts during the round. Before you start you can check the wind direction, but if that changes, you could be out of luck. This seems like a perfect golf aide, so much to the point where it's a penalty in a tournament.
It'd be easy enough to look at the forecast for a 3km model like the HRRR, but the challenging part would be guessing at how the various features on a course interact with that forecast.
And yes, trees and hills totally have an impact, but the main impact is the difficulty of having a very in tune knowledge of where the wind above the trees and hills is blowing. If you're hitting a normal full shot, the ball flight will be (usually) only affected by the standard wind direction.
Again of course, there are gusts that make that difficult to time a shot, and ball flight and shot type make a difference as well, but knowing and trusting the overall direction would be really helpful.
Electronically, in most classes of boats you're allowed to get any information that's available to anyone (i.e. you can hit any public website, but you can't call your local weatherman to ask his opinion). But really, there's not that much information available for day races (long distance races are a different animal)
One of the things that's become common over the last 10 years or so it to use a forecasting service. Basically you talk with a meterologist each morning or perhaps a few days in advance and they let you know what they expect to happen. You end up with statements like, "If you see big puffy clouds coming in, you should expect the wind to shift to the right of about 30 degrees shortly. But if the clouds don't come in, or you see flat ones, you won't get the shift until the puffy clouds fill in."
They're pretty good at forecasting what will happen over a large area or a day, but for really small areas (a few square miles) or really short periods, they can't be that accurate because the movement of the systems varies in speed and direction too much over short periods.
But try a forecasting service, it really can be helpful to know what's happening around you. Around $100 a day is reasonable last time I did this.
The key part of this site seems like I'd be able to check back every few holes to see if it's shifted enough to change the arrow. When checking for a local course, I can see enough to where I'd trust it, but then again, having more correct wind information would be better.
When I did tournaments we would look at the flagstick, trees and also release blades of grass.
I could see near exact speeds helping (could make the difference between putting for birdie vs chipping from off the green) but not any more of an advantage than a rangefinder. Do they let you use a rangefinder in your tournaments or no?
Ever since tile maps have become the norm, most of the weather radar services are unbearably slow on my DS(Hel)L connection. This loads fast.
I wonder what they are doing right.
I noticed Windy.com took me straight to this spot due to my location near the approaching storm, so in case you're in a part of the world with a little less going on right now, check out the winds coming to Texas.
I have a 100 Mbps connection and tile weather radar maps are some of the poorest experiences on the web with that speed, too. Why can high-resolution, high-framerate video load fast, but not a map?
It can be sourced back to Cameron Beccario's project getting some exposure in late 2013 after launch as open source. https://github.com/cambecc/earth
It's cited as direct motivation by windy: https://community.windy.com/topic/4/about-windy
For the record: windy, launched as windity in late 2014, this was 1 1/2 years before ventusky:
"ventusky is owned by InMeteo, built to compete with windyty, which was originally a copy of my site's open source repo"
"if you're curious: http://hint.fm/wind launched Mar? 2012, e.n.n Dec 2013, windyty Nov 2014, and ventusky Jul 2016"
I also recommend his talks at "The Graphical Web" 2014: https://www.youtube.com/watch?v=QXNODLWhSbw
and openvis 2015: https://www.youtube.com/watch?v=OLSmNZm1e0k
Does that thing where you hit back and it cancels the loading scripts and site actually runs
They get their data from https://www.meteoblue.com/ .
Small criticism: Every time you move it creates new page entry in the back button list, so once you have moved around a bit you can't use browser back button to easily go back to previous website.
Btw I think they use Riot.js on their front end?
While the big spinning mass offshore is the headline, the subtitle is that everything east of I-35 is going to get somewhere between a foot and two feet of rain. Not snow, water.
I would hope FEMA does better this time but recent track record of that agency still is not good.
Which is very cool to track ocean sailing.
I have made several trackers to follow around the world sailing races/adventures.
They have since pivoted to something similar, as AFAIK they didn't get enough traction.
"The Roaring Forties are strong westerly winds found in the Southern Hemisphere, generally between the latitudes of 40 and 50 degrees."
(Especially after pressing the "play" button in the lower left).