XML Data Errors -- -999.00 in (0mm) recip_1hr_string

Has anyone else had data return as negative?

I'm getting a few of these during a huge storm:
<precip_1hr_string>-999.00 in ( 0 mm)</precip_1hr_string><precip_1hr_in>-999.00</precip_1hr_in>

The url I'm using is:
http://api.wunderground.com/api/KEY/conditions/q/CA/95624.xml

Edit:
I guess this has to do with one specific weather station, others seem normal.

Nevermind, I actually read more docs and -999 = a null value I guess