October Record Rainfall to be followed by a Dubious November….some interesting developments through….
Tuesday November 1, 2016
Posted at 11:22 am by Howard
Its November 1st, and the Dweebs are beginning to look at the hemispheric weather pattern more seriously. I get that NOAA’s winter outlook shows no biases one way or another for Central CA and for good reasons. We are pretty much ENSO neutral with only a weak bias to La Nina. In looking at the last couple of days ONI, you would think that we would be heading back toward ENSO neutral with weaker trades. However, this morning, numbers have become positive again and hopefully will increase further. Some teleconnections are pretty interesting with an anomalous amount of snow piling up over Northern Asia. The feed back into northern hemisphere weather is very significant on a climate scale. Large heat sinks like that can feed back to cold deep Polar Vortexes in that region that can set up down stream patterns that will influence weather patterns going forward into the end of the year. Additionally, the QBO cycle which has been in it positive phase for some 15 month is getting old and will most likely flip during the up coming winter. The other important teleconnection is the Pacific Decadal Oscillation which dramatically weakened in August and September. The surge of cool water extending east across the mid latitude’s between Asia and the central pacific suggests that the PDO is getting ready to strengthen again in the positive mode. This forces warmer then normal water along the pacific west coast and spreads it north and south. The other feature worth commenting on is the Solar minimum which we are rapidly heading into. The Sun has been flatlining more often than not the past year.
The short and medium range forecasts are pretty much dry for Mammoth Lakes except for the slight chance of some light snow/showers Sunday. Temperatures will warm up and become more seasonal later this week before cooling again late in the weekend. High temps will be mostly in the 50s this week and with temperature inversions mid week, lows in the 20s and 30s can be expected.
Looking at this mornings GFS and ECMWF, the models show very quiet weather conditions for the Central Sierra the next two weeks. The Climate Forecast system as well as other longer range models show quiet weather the next several weeks and some for the next few months. I Look at those climate models un-enthusiastically.
Today I am very interested in what the MJO phase space charts are showing; A major “Highly amplified incursion into phase spaces 6-7-8 and 1.
- Precipitation relevance to phase space; http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Precipitation/NDJ/combined_image.png
- Temperature relevance to phase space; http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/OND/combined_image.png
So this is what I am looking at now for the month of November. (subject to change)
The three global models of choice today are showing a weak MJO single for this week. (Week 1) However, emerging in week 2, is a strong signal into phase space 6 propagating over time to phases 7, 8 and then 1.
If this signal is real, then the global models will adjust next week to become more highly amplified. Additionally, and again if the signal is real, we would expect the NAO to become strongly negative with a lot of high latitude blocking expected down the road. A big question will be, will the -NAO become west based or east based. What this amounts to is where the cold is going to go, West or East. Best guess, “if the MJO signal is real”, stronger ridging over the far west weeks two and into three with cold in the east then retrogression spreads the cold west weeks 3 into week 4. So the cold stormy weather would return during week 3 then into the end of the month.