Friday, January 7, 2011

Resurrection of the MJO......

The weather is so boring this week I decided to get out of town for the weekend to relax before the real winter starts here in January. Over the past several years we really didn't even start to see any significant storms until January. We have had so many already that it feels like we are halfway through the season or more. We are not though and we still have a lot of snow ahead of us.

One thing we should remember is that this season of big storms actually started back in October. We had around 300-400 percent of average precip that month, although it all fell as rain. What preceded that big event was the Eastward propogation of the MJO into the Western Pacific. I suggest that you google Madden Julian Oscillation if you want to learn more because I am not going to explain the whole cycle, just the affects on us.

In short it is an oscillating area of convection and deep moisture that starts in the Indian Ocean a lot of times and then moves East into the tropical Pacific. The stronger the activity & the further East it comes in the Pacific, the bigger the impacts are on our Weather. Basically about a week after it enters the Western Pacific it has caused the ridge in the Eastern Pacific to retrograde Westward and a trough to form in its place. This trough will have the jetstream that has scooped up all that moisture and will aim it at the West Coast. We end up getting series of storms that can last several days to over a week.

The MJO is forecasted to strengthen into the Western Pacific over the next week. If this forecast holds then we could be in for a major storm event again the third week of the month. Just something to watch but we also have some other things going on that will assist in the return of snow over the next week. We also have a ridge that will begin to build in over Alaska that will push the jetstream South down the coast.

Wednesday will be 10 days since the last storm and right on cue we should see the first storm arrive on Thursday. Not a big storm but it is just the beginning of an evolving pattern that could easily push us over our seasonal snowfall average by the end of January. The storms should continue into next weekend and into the following week. This pattern of the blocking in the North Pacific is perfect for suppressing the jetstream South for the 3rd week of the month, and if the MJO stays on forecast we could have one heck of a week the final week of the month. Stay tuned as we begin to re-open the storm door over the next 7 days. BA

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