Fair Warm Weather to Continue in the High Country for Another Week then Colder unsettled Weather a good bet by Early Next Week…..Although No Major Storms on the Horizon…..It will be cold enough to begin Making Snow by Next Monday
Tuesday October 22, 2013
Posted at 10:29 am by Howard
Wednesday AM Update:
Concerning the cold short wave digging into the intermountain west next Monday/Tuesday….
The 12z GFS has it again and so odds are increasing that at least some snow showers are possible the first part of next week.
The ECMWF and GFS have reversed roles with the GFS digging the upper trof furthest west now. It appears to be responding to energy from phasing western pacific typhoons. Although the ensemble spread is too great for a confidence forecast to bring measurable precipitation to Mammoth Lakes Monday or Tuesday at this time, one can not rule out snow showers.
By Friday which is 72 Hours out from the event there should be enough runs to make that call. In the meantime, both the GFS and GEM have the further west solution with the GEM showing a closed low over the Central California coast Tuesday night next week. Should the models sync tomorrow….the Dweebs will be all over it….
The 00z Wednesday ECMWF which is usually the best global model is further east over the Rockies
Either way it will cool off to make snow…the big question this morning is how cold will it get??
Enjoy the rest of this week…..its a beauty!
CFS has done a 180 and is now indicating normal to above normal for precipitation in November. THIS IS BRAND NEW!!
The trend is always my friend and so I will be watching this carefully….
Incidentally….the new 12z Wednesday has a full latitude trof off the west coast for the 6th/7th of November….
This is fantasyland but will be fun to watch in the coming days….
Dr Howard and the Dweebs……………….:-)
Currently, a strong Omega Blocking pattern is in effect and will persist this week. Apparently there is not enough energy in an incipient southern branch to push a cut off low to the Sierra later this week. Instead, the short wave cuts off to a upper low which leaves a REX block to contain it off shore, until about All Hallows Eve when it may get the boot! In the meantime some high clouds get generated over California but nothing else. High temperature anomalies will remain on the plus side this week with highs in the low to mid 60s in Mammoth Lakes and lows in the 20s and low 30s. 700mb temps will be about +5C so snow making opportunities remain remote this week until next Monday. By next Monday a strong cold short wave will dive either to the Rockies or to the western Great Basin depending which model you believe at this time. The latter brings more cold with the chance of snow showers here to Mammoth between Monday and Tuesday next week. That is the ECMWF’S solution which is more amplified at this time.
The MJO is in a weakened state using the EMON, IE the seasonal prediction ensemble model of the EC. This is in contrast to the NCEP – Global Ensemble Forecast System which shows a strong intrusion into Phase space I. Interseasonal forecasters are poo- pooing that solution and following the ECMM which shows very weak MJO action for the next two weeks.
So expect a continuation of the recurring typhoon pattern over the West Pacific which will contribute to the current persistent, amplified pattern across the North Pacific and North America, through at least the end of October. Mammoth will experience either cooling from inside sliders or ridging with high clouds from the west. IE No Snow of significance the next two weeks.
The Climate forecast system has a weakening of the above normal bias it has had to temperatures for the Mammoth Lakes area next week. An inside slider should put the chill on Mammoth early next week. However beyond that time frame, weeks 3 and 4 show a return to the above normal bias of some +.06 for Mammoth which is not all that significant. The bias continues to be less significant through the 17th of November, however the trend suggests that an increase of storminess may occur the 2nd half of November.
Significant changes in the ENSO forecast from the CFS shows that it has been trending more toward neutral for the Winter, contrary to earlier predictions of a Weak to Moderate period of WARM CONDITIONS IN THE 3.4 REGION. This makes the Winter Outlook more uncertain now. So far most of the blocking has been up over Alaska this Fall. Should that continue into the Winter that would certainly be more favorable for Sierra Snowfall.
The Westerly phase in the QBO usually does not support much blocking or any sustained blocking over Greenland and so this is less likely now for the eastern half of the country this Winter. So odds are it will not be nearly as cold in the east and not nearly as dry in the west as last year.
It may be that high latitude blocking may be able to develop more over Western Canada or even Alaska during this winter which would be better for southern stream energy to be stronger for latitudes further south along the west coast.
The solar cycle continues to be anemic supporting a continuation of the -PDO. Over all, the bias so far supports a colder winter out west and because of ENSO will most likely remain between 0 and +.05 this winter, it may end up that our biggest weeks of precipitation occurs with short period MJO induced extensions of the Asian Jet later this winter. Thus once again, as I have reported during several Fall years, the incidence of MJO initiated pineapple connection’s are at there highest when ENSO SSTA’s in the 3.4 region are between 0C and +.05, which is where it will most likely be this winter after the 1st of the year.
So this winter may be highlighted by long periods of dryness followed by periods of very wet weather of high intensity precipitation later in the Winter. Although I will have once more look at everything the end of this month, I am of the opinion today that that the MJO will be the biggest and most significant driver of precipitation this winter for Central and Northern Ca now that ENSO will not be factor.