Storm System Winds Down as Cold Front Dissipates over Mono County this Morning…..Mammoth Mtn picks up between 1 and 2 feet between 9000 and 11,000 ft as expected…..Improving weather now expected for much of this week but lots of clouds remaining in the forecast…..Will California be hit with an Atmospheric River Event this Winter?
Sunday November 18, 2012
Posted at 10:38 am by Howard
Current Forecasts For December from the climate forecast system.
Precipitation Anomaly for California is wetter then normal: http://www.cpc.ncep.noaa.gov/products/people/mchen/CFSv2FCST/monthly/images/CFSv2.NaPrec.20121119.201212.gif
T2 temperature is warmer than normal:
700 Hpa Anomaly:
Looks like a wet December with wet, mid latitude storms for the state. Atmospheric River??
Yes…as expected it was wet wild and woolly. But what would you expect for a big Mammoth? From what the Dweebs have been able to gather…..about a foot of heavy wet snow had fallen over the past few days and about 2 feet at elevations above McCoy Station. The snow that fell was just what the Dr. ordered. “Sierra Cement” That is what we needed prior to the holiday of Thanksgiving. A nice base to begin the season.
Mammoth Pass via telemetry picked up 2.56 inches of water eq. That was right on the QPF of which many of the models touted. Mammothweather.com picked up .99 storm total of liquid and so somewhere in between was what the Main lodge picked up. The Dweebs can only imagine that the snow to H20 ratios were about 7:1 at the Main Lodge as temps remained in the low 30s while upper elevations were in the upper 20s giving them ratios EST of about 10:1 or so.
So where to we go from here?
Its pretty messy in the world of WX models. There are lots of changes, including changes in the -PDO which came in -.79 for the month of October, much weaker then the previous month of September. So thus the Tripole of the *-PDO is now broken. and is now similar to the Fall year 2009. Effectively, this means in our case, that SSTs have warmed off the west coast and most likely will have some effects upon the upcoming winter. This puts winters 2009/10, 2003/04, 1968/69 at the top of the analog list. The winter of 2010 was a heavy winter, 2003-04 an average winter and the winter of 1968-69 was…..well I’d rather not go into that one……
Earlier in the month I indicated that research showed that La Nada winters had a higher percentage of Pineapple Express or atmospheric river events in California. It was also indicated that the highest percentages were associated with a positive PDO according to a published study that I supplied a link to. I also indicated that we had a fairly strong -PDO occurring…..So that the odds indicated, that current conditions were not “as” supportive of such an event. As you can see from the latest information, that condition may be changing…… Again have a look at the published information at the following link:
*The PDO reflects a tri-pole of ocean temperatures that have warm north and tropics and cool relative to normal in between in the positive phase, and cold north and tropics and warm in between in the negative phase. By normalizing the two data sets and then adding the two, you get a measure of net warmth or cooling potential for both global and arctic temperatures.
Outlook: Rising heights are in our forecast for the week and so the upper jet will be mainly effecting Northern Ca, Oregon and Washington State while higher pressure aloft keeps our weather mostly dry with the exception of late Tuesday and Wednesday with some showers possible from a storm to our north. At the moment we may pick up an inch or two of snow over the crest and some rain/snow showers for the Town.
Thanksgiving is expected to be fair.
The next chance of a storm will be the very end of the month. The EC has it as an inside slider while the GFS has it as a west coast system. Will be keeping an eye on all that for you over the coming week……..