In a flash…the Warmth of Fall is Gone….New weather Types Await the Eastern Sierra……..

It was just two days ago, our highs were in the upper 60 and today upper 20s..   That’s pretty remarkable and difference in 40 degrees of cooling over two days….   Our closed low that brought us rain and snow showers to town yesterday afternoon has moved inland and located over Kern County. it will meander in the same areas today before moving over southern NV later Thursday AM. The Rapid Refresh model brings some .25 to .5 inches of QPF to our area, Mainly this evening. So expect a better chance of snowfall accumulations this evening. (2 to 5 inches)

After a chilly day Friday, expect a fair and cool weekend with high climbing to the upper 40s by Sunday.  Thereafter it will grow cooler Monday and Tuesday as a NW slider pushes drier cooler air into our area from the Pacific NW.  Night time temps will be in the 20s, then teens early next week in the drier air.  Snow making is full on now on Mammoth Mtn.

The comments from the CPC were well taken yesterday. Again they are looking at the possibility of a cold western trough late this month and into December. Exactly where it sets up will be key. This is an even colder weather pattern than what we have now.   The storm track will retrograde a bit around the Thanksgiving holiday. That means that there may be more over water trajectory and a better chance of accumulating snowfall.  However the main emphasis is going to be the cold that will be headed our way toward the end of the month.  Both the Euro and the GFS still have their differences and a difference of only 100 miles will be a big deal on how much snow we get from the changing weather system. Further retrogression of the western trough is expected in December…..

This month….These systems will still spin up off the west coast and drop south over California. That is usually not a great pattern for snowfall, but again, a little more of an off shore track would make a big difference. December looks much better!

 

I will have the EURO’s long range outlook update this Friday for snowfall in December…..

 

Dr Howard and the Dweebs………….:-)

 

 

Impressive heat wave to end today with 30 to 35 degrees of cooling expected by Wednesday…light snow in forecast for Tuesday night and Wednesday with fair dry weekend…,

 

3:45PM Tuesday the 19th

 

There was a very encouraging update for the CPC this Morning.   They chat about the extreme IOD out over the Indian Ocean. That is bringing flooding to parts of Africa and drought to parts of Australia. They now expect a response to the mid latitudes which is surprising!

This post is pretty esoteric, however, I know that there are several Dweebs out there that they will be happy to read this discussion…..

 

From the CPC today:

The MJO remained active during the past two weeks, propagating rapidly across the Pacific before returning to the Western Hemisphere. During the past several days, the RMM index stalled over the Western Hemisphere. This slowdown is likely due to constructive interference between the MJO and the strong positive phase of the Indian Ocean Dipole (IOD). Dynamical model forecasts of the RMM index are mixed, although most depict weakening with no additional propagation to the eastern Indian Ocean or Maritime Continent during the next two weeks. In addition to the IOD which favors convection over Africa and the western Indian Ocean, robust Rossby wave activity and above-normal SSTs across the central Pacific may help generate additional convection that is “out of phase” with the current MJO event. This may be why some GFS and ECMWF ensemble members favor a quick return of the index to the Pacific. Based on these forecasts, the MJO is favored to play a diminishing role in the evolution of the tropical convective pattern over the outlook period. The IOD will likely become the “dominant mode” of tropical variability, and widespread convection over the Western Indian Ocean may teleconnect to the midlatitudes and help change the downstream pattern over North America with more “troughing across the West”. 

Dweeb Comment….For one thing, it this comes about….This is likely to bring some very cold weather to the Eastern Sierra in December…..  The fact that this IOD is going to become the dominant mode of tropical variability is pretty astonishing! Get ready for the possibility of some Real Arctic Air in December…..

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68 degrees for the 18th of November?….Pretty amazing for Mammoth Lakes. Not a real heat wave but pretty mild for November. In looking at the Bishop Airport obs…so far 77. Official records were broken over the south-land today with highs in the low to mid 90s in some areas. Our storm system will drop quickly south tomorrow and actually track somewhat inland. Moisture will be provided by remnants of Raymond as well as off shore. The best area of deformation, (Surface Convergence) seems to be over Northern Mono and Eastern Alpine counties. Areas just east of the CA border may get up to a foot of snow in some of the mountains. Here in Southern Mono, somewhere between 2 to 5 inches seems reasonable. (Light Amounts) Areas east of Mammoth may do pretty well. Crowley Lake, Toms Place and Sherwin Summit may have some surprises….

This is not your usual Fall/Winter Weather system with a cold front. It is an area of Low Pressure that develops and spins up as it drops down or just east of the west coast, combining some moisture from a cut off low off Baja along with some of its own from off shore. It is small, but packs some real cold with it.  Highs in Mammoth on Wednesday will be in the low to mid 30s…..Some 30 degrees of cooling expected.  The storm clouds will retreat Thursday night leaving a fair dry weekend. The next system looks drier next week and the following one toward the end of the month may be colder yet and showery….

The Dweebs do not see any wet systems until we get into the month of December, where according to the longer range Euro, may bring some real snow!!

PS, the colder temperatures will really enhance the snow making efforts on Mammoth Mountain. I expect the snow making crews to be able to make a lot of snow and open many more ski and boarding runs over the next week.

 

Dr Howard and the Dweebs……………….:-)

Fair mild weather to last through Monday with the last of the 60 degree highs in Mammoth for this season and next…..Enjoy those last hikes in the Back Country Sunday and Monday…Major change in the pattern coming mid-week with cold and snowshowers……Tropical moisture may get involved with the system from Tropical storm Raymond Mid week…..Will update later…….

Enjoy the last few days of early fall like weather as more “winter like” weather is on the way by Mid Week.  A wave from the westerlies pinches off from the Gulf of AK and spins up off the Central Ca Coast and stalls out over Southern CA. This brings the good possibility of upslope snowfall for the Central Sierra. How much? its too soon to tell.  Some models are wet, some are fairly dry.  But the trend seems to be wetter…..That’s good.  The other complication is moisture moving northward from TS Raymond. That will be another interesting part to watch. It may or may not come into play but we’ll know by the end of the weekend.  If it does, than some parts of the eastern slopes of the sierra may get a lot of snow above 7000 feet. Think Snow and lots of it!!  Highs Sunday and Monday in the low 60s…with highs by Wednesday in the 30s….

 

Dr Howard and the Dweebs……………………:-)