Series of weak systems to move through mean ridge position this week…..Cold Temps great news for snow making on Mammoth Mountain….Mammoth Mountain opening up new trails……
Tuesday November 18, 2014
Posted at 7:43 am by Howard
Record cold continues to grip the nations central and east with the highest snow cover for so early in November according to news agencies… Dr Ryan Maue of Weather Bell says it’s the coldest across the country since 1976…some 38 years ago….
Looking at the analysis at 500MB, The Polar Vortex is located over the Great Lakes states with trajectories of Arctic chill moving south from Canada through the Northern Plains States early this morning. On the back side of the PV the latest Jet max was over the Dakota’s while the next max will be more west through Montana later today. As long at Arctic air is in trenched over the central states, our upper ridge will remain strong along the west coast.
This mornings 06Z GFS run showed a few short waves, (WX Systems) coming though the upper west coast ridge. Thursday a WNW short wave will bring the best chance a some light snowfall with 3 to 6 inches possible by Friday AM. Then Saturday, a NW slider will move through Northern CA with strong winds and showers. This NW slider is a particularly windy system with a 130 knot upper jet. However NW Sliders are usually dry bringing mostly snow showers if that. The best opportunity is from the Thursday/Thursday night system as the split is further north and the trajectory is more from the WNW. Again this is not a major storm but it could bring 1 to 3 inches in town and 3 to 6 over the crest.
Getting back with the Saturday/Night system, it will be interesting to see how the new BETA GFS T1534 does with the system. This is the new updated higher Res GFS out in its Beta run for the time being. Looking at the comparison between the old GFS which is widely distributed and the new High Res Model, it shows the upper NW Jet stronger over Northern California Saturday PM into Sunday AM. If by chance the NWS puts out a High Wind Warning for Saturday PM you’ll know that the new T1534 is a better model for our area…or at the least in this pattern at this distance in time. The official forecast is for breezy, not windy Saturday and Saturday night at the moment.
Pattern Goes into transition:
As touted two weeks ago by the Dweebs….The pattern will go into transition next week. That would mark the end of the 21 day cycle that started about the 5th of November. It is kind of like driving in your car with GPS and you take the wrong turn. Once you do, the GPA recalculates and gets you to your destination. Only this time it is a different destination…..So the question is….. where are we going and how to we get there?
1st, We have to get rid of the cold Arctic air in this country. It is part of the ridge-trough-ridge syndrome that keeps us drier then normal.
2nd, we need the eastern pacific ridge to retrograde or at the least, the high latitude block over AK/NWT to retrograde to Eastern Siberia….That change would shift the long wave trof eastward closer to the west coast.
3. We need an extension of the East Asian Upper Jet. The MJO would help if it would become more robust and transit into Phase 2 then 3. I think that this is where we have to look for the future of our longer range outlook 30 days. On a bright note, the ECMF, UKM and JMAN are all in favor of a robust signal, into at least Phase 2 and some into Phase three. If the Signal goes the gambit, expect a much milder CONUS with a wet west coast. With that said, we are a long way from that happening….
Optimistically, if the MJO goes into Phase space 3, it is likely that we will have a flip in the ridge Trof pattern that is currently occurring. So that timing of that is about 10 days or so away. IE We may have a couple of significant storms the end of the month into December. The CFS is in agreement as well.
On a bright note, the AU Gov just updated there NINO Basin SSTAs. I am happy to say that the SSTA’s are now at the threshold of Moderate as follows: Nino 4 (+1.05C), Nino 3.4 (+0.93C), Nino 3 (+0.96C), Nino 2 (+1.12C). Remember, +1C or greater is what we want so we are close and if the Nino Basin can hold on to the heat, through January and February, Odds are good that we could have a nice wet winter. We also need that for at least 3 months. I think that +.5C for 3 months seems like a good bet since we have had a good deal of time on that now.