• How should I use the forecast? (limitations)

• Observation Information

• How do I print the forecast?

• Station X has disappeared from the maps is there a problem?

• Can you add a new arrow for location X?

• What was the wind strength at location X last Thursday?

• Look at the size of that arrow! That's never right!

• Do you mind if I put a link from my site to WindMapper?

• Can I use your images and data on my website?

 

How should I use the forecast? (limitations)

The data used to produce the WindMapper forecast is from a high quality numerical weather prediction model run by the United States government (GFS). The output from this model gives forecast data in the form of a grid of points at ½ degree (50km) intervals. WindMapper then interpolates this information to give a forecast for each location. You should be aware that at this resolution the forecast will not be able to fully model topographical effects at the scales depicted. This means that in coastal areas localised effects such as sea breezes will not be fully incorporated into the prediction and that wind speeds in elevated areas will be given as if taken at a height of 10 meters above sea level. Also beware that the forecast gives average wind speed but you may well experience significantly higher gust speeds.

Please use this forecast information advisedly and utilise your knowledge of the area when making decisions.

For more information on interpreting numerical weather prediction information take a look at Frank Singleton's web pages. For the meteorologists out there GFS is not a mesoscale forecast.

 

Observation Information

Current weather information is taken from instruments sited at each location and barring technical difficulties should reflect the conditions at the time of the observation. Most wind speed measurements are made at a height of 10 meters above ground level.

The maps are updated every 30 minutes. Please note that the time stamp on the map is when the image was created which will not necessarily be the same time as the observations were taken. The actual time of each observation is clearly noted below the station name. If the observation is over 3 hours old the map arrow will be grey and the time stamp will be in red. Observations over 5 hours old are removed from the map.

 

How do I print the forecast?

To print the forecast for a given location, place your mouse pointer over the required station and then whilst the forecast is displayed press the ctrl and p keys.

You will also need to set your browsers print preferences to "Print Background Images" as otherwise the forecast icons won't print. I'm hoping to resolve this issue at the next release.

 

Station X has disappeared from the maps is there a problem?

All of the data plotted by WindMapper is obtained from free sources on the internet and sometimes this data is temporarily unavailable. This maybe because of problems on the internet itself (web servers crashing, internet connections going down) or because of equipment problems at the station.

In addition to transient problems, some stations are only manned during office hours so they disappear overnight and at weekends. Others are just notoriously fickle and only seem to submit reports when they feel like it.

In any event WindMapper will keep looking for the data every half an hour and automatically start plotting it as soon as it's available. Unfortunately it's rare that I can do anything to speed up this process.

 

Can you add a new arrow for location X?

I currently plot all of the freely available data that I've managed to find on the Internet so if your location is not already on the maps then I don't have a source of weather observations for the location and unfortunately I can't plot it.

 

What was the wind strength at location X last Thursday night?

Unfortunately I don't keep any historical records so I can't help with this kind of enquiry. However you could try Weather Underground who do keep some historical data.

 

Look at the size of that arrow! That's never right!

I try to filter out as much erroneous data as possible but because WindMapper is totally automated it can be quite hard to catch all eventualities. Sometimes the problem is a miss-calibrated sensor at one of the stations or else it might be a genuine mistake on the part of the observer who's submitting the reports. In any event the problems are almost always transient and correct themselves in an hour or two. If a station consistently miss-reports let me know and I'll remove it from the map until it's fixed.

 

Do you mind if I put a link from my site to WindMapper?

Please be my guest, the more the merrier.

 

Can I use your images and data on my website?

Please don't take the images or data from WindMapper.