Tuesday, November 8, 2011

The Storm Door Stay Open, But How Far?

With cold nights and some fresh snow on the slopes the snow guns continue to fire here at Northstar. We have a few changes here for the weekend forecast but the storm door stays open so cold and snow in some fashion looks to be in the foreseen future.

The weather models have been all over the place the past 2 days trying to get a handle on a cut-off low spiraling down off the West Coast. The consensus seems to be that the cut-off low will come in to our South on Friday and Saturday with most of the precip missing us just to the South. We should see clouds as the storm goes by on Friday and Saturday and maybe a few flakes on the mountain.

The next storm dives down the coast on Sunday and models have been struggling with the track of this storm as well. In the weather pattern we are currently in the track of the storms down the coast will make a huge difference. With the high pressure ridge out in the Pacific around 150w 40n the storms go up and over the ridge into the Gulf of Alaska and then down the East Side of the rigde along the West coast. If they come down just over land then we get cold and maybe light amounts of snow. If they come down over water just offshore then they pick up moisture and bring heavier snowfall.

With the ridge out as far as it is in the Pacific and looking at the global teleconnection forecasts I have felt like the track should be further West over water. The models however have been trending towards a more over land track with the storm staying to our North and East. That would mean just some colder air and light snow showers for Sunday and Monday.

The European weather model then keeps the cold and unsettled weather digging slowly down the West Coast with some more light snow events for next Wednesday and again Friday. The Japanese model agrees but the GFS model shows the ridge in the Pacific shifting slightly East, just enough to keep any precip to our North and East. The Euro tends to have a better track record in the long-range this time of year.

Looking into the super long-range it makes more sense to look at the global teleconnection forecasts rather than the inconsistent weather models. What is interesting to watch is the movement of the MJO or Madden Julian Oscillation teleconnection as it continues to strengthen as it moves through the Maritime Continent on its way towards the Western Pacific. It is forecasted to be in the Western Pacific next week. In November, history shows that about a week after the MJO enters the Wester Pacific it means cold and snow for the West Coast.

That combined with the PNA or Pacific North American teleconnection staying in its negative phase it should mean that the storm door stays open through Thanksgiving. The MJO in the Western Pacific should help the jetstream juice up and so with the storm door open the odds increase of having a bigger storm roll in the week of the 20th. What is interesting is that the weather models have been in good agreement and consistent the past several days for the week of the 20th. They show a storm digging down the West coast again for a Sunday the 20th and then a bigger storm around Thanksgiving.

Stay tuned for updates.....BA