Sounds like this iDevice WX app may have potential

[xairbusdriver]

Check this review at TidBITS.com: <Dark Sky 5 Offers Hyperlocal Weather Forecasts for iOS>

Here's the developer's site:<http://darkskyapp.com>

They encourage users to report errors in their data, you can provide some data automatically via you iPhone 6, since it has a pressure sensor. Others can provide some data manually. Didn't see anything about accepting PWS data.

[elagache]

Dear X-Air and WeatherCat iOS device fans, . . .

Check this review at TidBITS.com: <Dark Sky 5 Offers Hyperlocal Weather Forecasts for iOS

Okay, this is interesting, but I was puzzled by a key feature of this app:  the "hyperlocal precipitation forecasting system."

I did a little more digging.  According to the developer's website, it is "powered" by a system called "Forecast."

http://forecast.io

Digging a little further, there is a list of data sources:

http://forecast.io/raw/

The data sources listed for the "hyperlocal precipitation forecasting system" are all doppler radar sources.  This suggests that they use an algorithm based on radar echoes to decide when it is going to rain.  If so, this system will only work in areas were doppler radar is a reliable indicator of rainfall.  This summer we have seen a number of virga events:

http://earthsky.org/earth/virga-is-rain-that-doesnt-reach-the-ground

When you are in a drought there is nothing more frustrating than seeing what looks like a juicy radar echoes but not seeing any of it reaching the ground.

According to the developer who is in New England, the software works well there.  Places with a similar sort of weather pattern will probably find the app useful.  However, it may perform poorly in places likes like California and the desert southwest.

Cheers, Edouard 

[LesCimes]

I saw that report in TidBits as well. Hard to know which weather app to use - there are so many of them! I use the WeatherUndergound apps (iPad and iPhone) the most. As a member of WeatherUnderground through my PWS, I don't have to put up with advertisements! That's a big plus for me - no ads.

[Felix]

I'm a Starbucks gold card member (just means I've used the company's card to buy coffee or other items a certain number of times in the past 12 months) and they periodically give away free apps and music downloads. As luck would have it, Dark Sky was one of their freebies a year or so ago and I've kept it on my iPhone for just the reason Adam Engst articulates...the app is uncanny in it's accuracy with regard to predicting when rainfall is going to start. Within an hour out, you can almost set your watch by it!

[LesCimes]

Oops, I probably deleted that SB promo offer. Oh well. I don't delete my  free drink offers however.

[elagache]

Dear Felix and WeatherCat iOS users,

As luck would have it, Dark Sky was one of their freebies a year or so ago and I've kept it on my iPhone for just the reason Adam Engst articulates...the app is uncanny in it's accuracy with regard to predicting when rainfall is going to start. Within an hour out, you can almost set your watch by it!

Given your location, it isn't surprising that it works reasonably well. The new version of WunderMap also has a feature like this.  However, given how little it has rained recently in California, I haven't had a chance to see how well it works.

Cheers, Edouard