Pattern change on horizon

Dry and rather mild conditions continue across the state today, with some strong winds in the Central Valley and mountain areas due to an inside slider-type system currently dropping into Arizona. Temperatures will rebound once again for the holiday weekend before taking a dive later next week as a more energetic jet stream and associated though begin to appraoch the coast. The models always break down persistent dry patterns down too quickly, but I still expect it to take hold by day 9. The obvious forcing mechanism for this shift is the evolving and eastward-propagating MJO signature currently developing in the West Pacific. As I have mentioned before, this is fairly unusual in a La Nina year, but the MJO has played a significant role in subseasonal variability this winter season, and looks like it will continue to do so until the end of the water year in CA. I don’t know how wet or prolonged this developing pattern may be, but it will certainly be welcome after January’s heavy rains have had ample time to soak in and run off…