I love the NRCS map of percent of average snowpack. They also publish a percent of average precipitation map.
Unfortunately, unless you query these maps daily and
have a very good memory, these maps do not permit an understanding of the trend of these two parameters, i.e. is snowpack and precipitation improving or degrading as a percent of average. In fact, no where to my knowledge is average trend data available, well, uh, except in the flow report I publish daily(please forgive me if I'm wrong, and please forgive me for seeming so proud(boastful?)).
For select western river basins I tabulate and graph the two most recent weeks of daily NRCS percent's of average for snowpack and precipitation. They are the same values posted on the map provided at the beginning of this thread. I also calculate and report a daily value for percent of average flow in each river basins.
The interplay and trend of these three values is very interesting and informative. For example, if snowpack percent of average is less than the precipitation percent of average one valid conclusion is that temperatures are too warm to preserve the precipitation as snowpack. If snowpack percent of average is greater than precipitation percent of average then local factors are resulting in preserving the precipitation as snowpack. The percent of average river flow adds another parameter to ponder.
Bottomline, when all three parameter and their trends are considered as a whole it will permit someone with a strong imagination to stand on a soapbox and pronounce best informed decisions about the status and near term future of runoff conditions in a river basin. In general, that is about as good as you can do as a armchair predictor especially when factoring in NOAA short and long term weather outlooks.
For example, based on what I've said about making bold conclusions using the best available information I will venture to guess that the Salt River will flow this year. At this time the Salt is trending toward 100% of average river flow, precipitation and snowpack. If you haven't done the Salt especially when the cactus/wildflowers are blooming, I highly recommend putting it on your bucket list. This prediction may change next week but then at that time by consulting the flow report the current status and the only available source of trends will be at just beyond the tip of your nose, hopefully, on a high-resolution, big-landscape monitor.
I generate the flow report almost everyday and my friends at Down River Equipment are kind enough to post it on their website when their time permits. The flow report is available at the following link.