If you have to make a choice right now to book your vacation dates, the safe bet would be to come out here the first and second week of June. I have spent the last 12 years paddling in the Arkansas Valley and the majority of the time the river will peak the first or second week of June. Usually its a safe bet that the other rivers in CO are running good during this time too. The 3rd week (the weekend that FIBArk happens) is usually on the down side of the peak, but still running good.
The snowpack for the Arkansas drainage is looking very good right now. The overall average shows it to be lower because the snowpack in the lower (southern) parts of the drainage area are having a bad snow year. But, the main sources of the upper parts of the drainage are having an awesome snow year.
And to add to what tj@cu stated... the next couple of months (March and April) are the crux of our river season. If we get a snowy and cold spring the rivers in the central and northern parts of CO should go BIG!!! If we get average precipitation during the spring we will still have a pretty good year. And if we get a warm and dry spring the snowpack will dwindle and we'll probably have a below average season.
Just keep an eye on the snowpack and weather conditions in CO during the March, April and early May months. Your July 2nd 2800CFS trip down the numbers is not the norm and was due to an incredible snowpack year (all of June it ran at or near 3000). It was colder and snowy ALL of March, April and May during that year.
I hope this info helps.