El Niño is still kicking, and there's an 80% chance it will last through the calendar year. Does the series of unusually strong late season storms in the Southwest have to do with El Niño? In my opinion...absolutely. In the figure below, sea surface temperatures continue to be anomalously warm in the equatorial Pacific. Thunderstorm complexes tend to form in these regions where there is a lot of available evaporating ocean water(see global satellite).
The National Weather Service in Flagstaff has compiled 2014 weather statistics for much of northern Arizona and the numbers aren't very good. Flagstaff recorded it 3rd warmest year since 1898 while Prescott recorded it's 1st warmest since 1948. It was also the 1st warmest year recorded for Winslow and 2nd warmest in Page. Flagstaff ended up with 20.67" of precipitation which is 95% of the yearly average. This is largely due to a wet monsoon.