Small AR expected to impact the Central Sierra Wednesday night pushing south of Mammoth By late afternoon Thursday….Precipitation will begin as early as Wednesday afternoon……Expect a drying trend by Friday Morning then dry through Saturday….

Tuesday AM:

AR has become a moderate to strong AR now with the entrainment of extra moisture from a tropical system…..I will update after 8:30AM this morning the 14th….




Monday Pm…Love posting when stuff is happening!

OK…Interesting twist this afternoon!  The new 12z EURO is splitting the trof coming in this Sunday. This is the one that the GFS has going north into Northern CA and the pacific NW with another AR.  But actually there is a fresh twist!  If the EURO is correct, it is going to cause a pretty significant change to our pattern, both upstream and down stream as it kicks the trof over the Eastern US out off the coast.  That would not make snow lovers on the east coast happy!

More importantly, that change if correct and that a big if, will tend to keep our pattern some what progressive and that means more storms hitting the west coast while the GFS wants to cut it all off. The current solution will help LA get some rain as well as the next upstream system actually splits with a lot of energy going south this Sunday into Monday.

I have to say that the ensembles are against the Euro solution, but why the change?   Stay tuned….this is what it’s all about!


PS> The snow level this Thursday is going to be critical to the Town of Mammoth, as there is going to be a lot of precipitation falling.  The big question is going to be about how soon the cold air is going to get here.  If it comes in earlier than expected, the town could get over a foot.  It is too early to know at this time. I will update on the potential change that the Euro is showing in the morning, or sooner if the GFS starts to follow later tonight….


Dr Howard and the Dweebs……………………………….:-)


Monday AM Update:

CRFC is showing about 3.75 inches of water over the west side of the sierra west of Mammoth Mt, Wednesday through Thursday night. With the snow level rising Wednesday from 8000 feet to 9000 feet, little impact from snowfall is expected in the Town of Mammoth Lakes during the day Wednesday. As the AR shifts south Wednesday night, heavy snowfall is expected above 9000 feet over Mammoth Mt with generally heavy wet snow expected to begin accumulating later Wednesday night/Thursday AM above 8000 feet. The Freezing levels is expected to fall Thursday morning and all day Thursday. Rain-snow mix will become mostly snow during the afternoon Thursday for the Town of Mammoth. I expect over a foot of wet snow at the Village at Mammoth, by Thursday Noon and 4 to 8 inches in town later Thursday afternoon.

At the moment, 18 to 36 inches of snow seems reasonable for Mammoth Mt Between Wednesday and Thursday night.  Precipitation rates will be especially high Wednesday night through Thursday AM.


I will fine tune all this in the morning Tuesday and again Wednesday….


The Dweeber…………………….:-)


Forecast models continue to vary on the strength of the 1st wet system of season. The main issues are with the two jet streams, both Polar and Subtropical jets and associated dynamics. The Moisture is a given, but moisture without dynamic lift in an area can play havoc with precip amounts.  I think that we are close enough in time to have a fairly good idea that this will be a wet storm for Thursday from early morning to evening as the meat of the AR according to the 00z Monday European model is between 4:00am Thursday and 4:00PM Thursday.  There will be good orographics,  so precipitation is a given.

The freezing level will be high at about 10,000 feet, however, with subtropical systems, micro-physical processes can mess with snow levels to a big degree, especially during the wettest part of the storm Thursday. However, without much antecedent cold, it is difficult to believe that there will be significant snowfall accumulation below at least 8000 feet Thursday morning.

As cooler air begins to arrive during the afternoon Thursday, the snow level will come down and light accumulations will develop in the lower elevations down to about 7000 by evening. Snow showers are possible Thursday night.   Light accumulations are expected in town, as at the moment, the timing says that most of the precip will be over by late afternoon Thursday. Will update again tomorrow.


Potentially, this will be a good base building storm with wet snow from bottom to top on Mammoth Mt.. Amounts could range from “between” 1 to 3 feet. According to the ECMWF, the AR is forecasted to push south of Mammoth by 4:00PM Thursday. The extended looks dry…..

Dr Howard and the Dweebs…………………….:-)

Drier than normal weather pattern for the Southern 2/3 of California likley to continue as upper jet is focused over Northern CA….Expect periods of wind and a chance of snow showers Thursday and again Monday and Monday night as the next upstream’s upper Jet is again focused upon Northern CA……

The Weather over the far west is highlighted by the polar jet located over Northern California. Although there has been plenty of blocking near the Bering Sea the past week, the flow coming off Asia has been split to weakly diffluent at times. West coast weather system’s have been quite progressive with the upper jet bottoming out over Northern CA. This makes for a dry, windy pattern for the Central Sierra with below normal precipitation. This is especially true for the Southern Sierra and southern portions of the Central Sierra including Mammoth Lakes



There is some hope in the longer range models this morning as the new 11/8/17 12Z GFS control is showing more consolidated flow coming off Asia after mid month. At the same time, there is plenty of blocking in the -WPO region near the dateline.  The are an increasing number of ensembles in the GFS showing some under cutting of the westerlies with the formation of a Kona Low developing around the 18th of November. It is possible that moisture may get picked up from this area by a deep positive tilt, long wave trof extending SW from British Columbia around the 20th/21st. If this does come together, it would be more of a southern latitude system with a tropical connection or “AR” with fairly high snow levels for Central CA.  This may be followed by a colder system about the 23rd with the upper jet over Central CA as well.

For what ever its worth, the climate model,  the CFSv2  is showing the period  during week 2, which covers the 20th wet for Central CA.

Stay Tuned…the Dweebs got you covered!…….:-)

Main Branch of Upper Jet to favor the Northern Sierra this week with several systems headed for Northern and Central CA….Expect colder than normal temps….Breezy periods, light to moderate amounts the next 7 to 10 days….

Fair  weather will redevelop tonight and continue for the next few days…  Mammoth Mt reported 1 to 3 inches total with the Town of Mammoth getting a dusting. It is cold and breezy! Highs in the upper 30s today. Next upstream system will most benefit the Northern Sierra again with again light amounts expected for the Mammoth region, Thursday. (Between 1 and 6 inches over all.  I Will update Monday PM or Tuesday on amounts….

Upper jet is split into two branches this morning with one Branch over the northern part of the pacific NW and the southern branch across the desert SW and southern Rockies. As we proceed into the new week, the two jets consolidate into one strong healthy upper jet but well to the east of us. We remain in the Rear Left Quad which favors upper convergence. AKA high pressure at the surface.  The Pattern still favors migratory cyclones with the next upstream system bringing windy conditions to Mammoth Wednesday night and FLQ of the upper jet favoring The Northern Sierra again Thursday. However, with that said, the Rt  rear entry area of the upper jet (may) favor the Central Sierra Thursday. (stay tuned)

We will have a break in the weather beginning tonight through late Wednesday. Thereafter, the next  system will increase winds and bring mainly light amounts of snowfall to the Town of Mammoth Lakes early Thursday AM, through Thursday. Again, the upper jet will favor the Northern Sierra,

In retrospect, so far, the beginning of this wet season has been much more of a challenge to the medium range forecast models and thus forecasters as well.  The Dweebs will be more vigilant in noting where the upper jet track tracks. And as always, noting the front left exit region as favored, in addition to at a lesser extent the rear right entrance region…..Both areas are key to UVM.

At the moment, The MJO is close to the circle of death and thus no help from a tropical forcing factor in the short-term as it re-develops over the Indian Ocean.

Longer Range:

The big message is that the European Model is gradually pushing the upper polar jet further south week 2, as a series of cyclones progress through the west coast.  If this verifies, storms systems with higher snowfall potential will push further south the following week into the Central Sierra .  The timing is of course subject to change. However, from this point in time; looking at my calendar,  target about Monday the 13th for a storm with good Central Sierra Upper Jet Support!

This system at this point in time would have the potential to bring footage.



Once again, I thank the many readers of last years weather letter and offers of compensation for my service to do another weather letter this winter.  I will not be doing a letter this year as I found it too confining time wise. I do this as a passion, not as a job. I need the flexibility to update as necessary.

If one wants to compensate, the best way is that if you or if know of anyone that is looking to buy or sell resort property real estate in Mammoth Lakes; Contact me for real estate assistance. I have been a licensed real estate agent in Mammoth Lakes since 1982 with more than half my life providing assistance to buyers and sellers alike.    I currently have my license with Coldwell Banker Mammoth Real Estate. My contact cell number is 760-9141800 🙂


Dr Howard and the Dweebs……………………..:-)