Friday, March 15, 2013

Clouds and Wind

A few minor changes today but still expecting a decent snowstorm next week.

We have lots of clouds streaming over us today and that should continue through the weekend as the jet stream stays aimed at the Pacific NW to our North. The good news is that the clouds cover is and will keep the sun off the snowpack and keep the high temps down a little. By Sunday we are expecting high temps to only reach the low 50's at the base and the 40's on the mountain with breezy conditions. That is in response to a colder system moving through the Pacific NW.

Next week low pressure approaches from the West and from the North. The cold trough dropping down from the North will merge with the low pressure from the West to bring us a cold storm on Wednesday. We may see light snow begin on the mountain as early as Tuesday morning, but only expecting light precip on Tuesday. The main cold front and period of heavy snow occurs Wednesday morning with snow showers lingering into Wednesday night.

The biggest change today is the model agreement that the low pressure in the Northeast Pacific will push inland more quickly Wednesday into Thursday cutting off the moisture Pacific flow. With the snow not lingering into Thursday anymore that also cuts back on the higher end of the snowfall forecast from the past couple of days. Yesterday afternoon the GFS was really wet with the storm but has pulled back today. Snowfall totals with the latest runs look like 6-12 inches at the base and 12-18 inches on the mountain. There is still time over the next few days for the forecast models to trend wetter so we'll have to keep fine tuning.

After this storm the forecast models have done a flip this morning. Yesterday they were showing coast to coast troughs with storms continuing into the West Coast every few days. That makes sense given the PNA pattern tanking into a negative phase and the NAO pattern in the East forecast to do the same. Today they are trying to pump a large ridge over the Rockies for week 2. There will be several large areas of low pressure moving into the Northeast Pacific but the question is will they be able to push the jetstream far enough Southeast into CA with the large ridge to our East. I'm not buying the large ridge quite yet with the PNA tanking and the MJO moving out of the Pacific and fading over the next week.

Several of the forecast models try to push the jetstream back into CA week 2 around the 26th with more storms beyond. It will be interesting to watch how the forecast models handle the evolution of the teleconnection patterns over the next week with the week 2 forecast. I'm still leaning towards stormy.

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