Originally Posted by goatboater
Does anybody have a good idea of how close to the run the storms that cause such a drastic rise are dumping their rain? In other words, is it the headwaters of the Animas that are getting soaked, or local storms that are flash flooding the side canyons directly in the vicinity of the run? I'm putting on at Mexican Hat Sept. 17 and would am looking for a good weather forecast that might give us some idea if a big spike like this is expected during the float. Have a good forecasting tool you like to use for this area?
The most recent storm dropped most of its rain over Cortez (about 2 inches of rain), some over Durango (an inch in most places), etc. McElmo was running very high, and the Animas tripled for a day or two, but much was directly over the San Juan.
Unfortunately, it's hard to predict with monsoon season exactly where the cells will sit and drop most of their moisture- especially which basin or specific drainage- that's close to impossible. We use a combination of CBRFC (better for snow than for rain) and weather models to see if it's going to rain in the general San Juan River Basin, but it's hard to pinpoint which drainage will be hit. You can give us a call before your trip though- best bet is to watch for NWS's flash flood alerts.
Susan Novak Behery, P.E.
Western Colorado Area Office