You can send latitude and longitude of Your location or just description how to locate it and Vaclav will add it in the menu list.
He made even special adjustments for Latvian surfing locations based on my three year observations depending on wind direction (Modified wind). As you know wind forecasts offer wind speed on certain altitude where no obstructions like forest, mountains or just buildings are not taken in account but here you can set up own preferences. For example: offshore wind always is weaker than forecasted and.
For me as a Latvian local wind observer for many years this site seems as a one of very best since creator himself is windsurfer and source is reliable. Looks like source is the same as for http://www.wetteronline.com
(NOAA) but forecast is more precise, detailed and have flexible design to make your own adjustments.
Just be patient and go through all of features. Besides Vaclav is really easy accessible through e-mail just keep in mind that next week he will change the job so probably will be busy for beginning.