I have similar issues where my available PWS's in the BeWeather2 app don't display wind speeds. For me, the default station is always at 0. I think I may have seen it at either 1 or 2mph before, but when checked against other sources their wind speeds reported much higher. The #2 PWS for my home location always displays -9999mph. The #3 PWS displays wind speeds more inline with other sources, but then has other info that seems off, like higher temps and humidity levels almost always near 100% while the others report very differently. It's also kind of a hassle to always have to manually pick #3 for wind speeds and then go back to others for temp, humidity etc.
I have checked on the wunderground site, and it shows what type of weather station is in use for each PWS. Unfortunately all the ones available to me through the BeWeather2 app for my area are the really cheap ones, or just aren't being maintained. You can send reports for wrong/bad reports for the PWS, which I have done before but I don't think anything will really be done.
I think what could really help this app out, especially for people in areas like myself that aren't being covered by the better PWS stations, is the ability to select which nearby PWS you want to be default for your particular home area instead of just picking the closest one.
Also, comparing it side by side with the Dark Sky app (which has problems of its own), the BeWeather2 app seems to need clearing out of memory before getting the dark sky info updated. If dark sky is opened and shows a particular "next hour" forecast, then say 10 minutes later there's a change, in my experience BeWeather won't report that update until cleared out of memory.
This app is awesome and has so much potential but I currently can't rely on it to be my main weather app, because of needing to rely on PWS's in my area that unfortunately don't seem to be very good.