11:30AM Sat:

Both 12z EC and 12z GFS have about 2 feet painted over the Mammoth Crest by next Sunday AM the 25th. As mentioned below, the Friday system may have an AR connected with it.



Good Day Eastern Sierra! It’s a beauty!…Highs to day will be in the upper 50s with lows tonight in the 20s. Daytime high will cool to the 40s by Monday. With lows in the teens and 20s later in the week. The winds will be picking up next week and will become strong by Wednesday.


A closed upper high at 500MB was west of Washington State this morning with a weak belt of westerlies underneath to its south over Baja CA. We are in-between and that means little change in the weather this weekend. This weather pattern offers strong valley inversions and warm temps for this time of the year at resort levels. Daytime highs at 8000 feet will range in the low to mid 50s  Saturday and Sunday.

Next week the upper ridge builds NW to AK and the westerlies under cut with a long wave Trof setting up off the west coast. this will initiate a cooling trend and snowfall by Wednesday afternoon.  The Dweebs here have been forecasting this for over 2 weeks now. The first storm will arrive by  Wednesday afternoon and it looks like a moderate precipitation producer with over 6 inches in town and over a foot on Mammoth Mt….I will fine tune on Monday.   There are several other systems coming in through the holiday weekend. The GFS is painting some 2 feet over the crest by weeks end. The ECMWF is now dryer than that as one of the storms is omitted. So that is why the hesitation in the forecast at this time as we are too far out to pin down “amounts”, Either way, odds are very good that well see between 1 and 2 feet on the upper mountain by week’s end as the first system alone looks to bring 1 foot+ over the crest. the good news is that is it now coming in much more consolidated (less splitting)  in this mornings 12z run.

Additionally, The GFS has the Friday system with an Atmospheric River connected with it.  It looks warmer than the Wednesday night system but more moisture leaden….


The Dweeber…..:-)


Friday AM Update:  GFS has come into line with the EURO as far as timing, however it is still not as moist as the EC through the end of next week.  Just to put an estimate on snowfall amounts, that I am sure will change by the time we get to Thanksgiving, it looks like 12 to 18 inches over the crest by the end of next week and about half of that in town above 8000 feet. This is looking like a moderate snowfall producer  (6-18 inches)


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


Forecast remains on track.

Differences still remain in the global models whereby the European model is still a lot faster in getting the precip going than the GFS. In fact it is a day quicker today, whereby it develops precip early Thursday morning vs the GFS which is dry for our area until Friday morning. The 10 day precipitation QPF reflects this as well as the Euro deterministic, as it paints over 2 inches of H2O over the upper San Joaquin drainage while the GFS is half of that. However, there is another storm on the way that may get it there by the following day or so.  So by today standards time wise, this looks to be a good couple of storms for Mammoth Lakes bringing a healthy amount of snow by the end of the Thanksgiving weekend or just a day or so later.  At least for down here in Southern Mono County. I would not want to down play this storm at this time…

What is interesting is that the European, spins up the subtropical jet over Southern CA Thanksgiving day as it lifts it north from Baja. The upper jet becomes confluent with the polar jet over that 24 to 36 hour period. That is most likely where it is getting all the QPF it paints…

It always a bit scary to go out on a limb and call for a series of systems that will bring beneficial snowfall to the high country some two weeks out. Especially when we have been dry since last Spring.  The climate CFS, (climate forecast system) has been touting this change for 2 to 3 weeks now and I have to say that as of this time, they have done a marvelous or even miraculous job! To get to this point time wise with a forecast some 2 weeks ago to week’s 1-2 is nothing short of amazing.  Now it is true that we are not there yet and we still have about a week to go. Certainly, stranger thing’s have happened, but it sure does look good for a couple of storms that would bring “at least” moderate snowfall by the end of that holiday weekend and just beyond from this point in time to Mammoth Mt.

The forecast two weeks ago was a combination of the CFS and “pattern recognition” without any global numerical guidance. With this method, you can not predict how much snow you will get, or when it will storm. However, you get the opportunity for a pattern change that offers a better chance of storminess during the colder time of the year.  Looking at pattern recognition,  that fact that there was so much cold air over the mid west and the east that was not progressive, actually held the ridge over CA and off shore. Now that the cold air and upper toughing is moving out away from the CONUS, the ridge is starting to weaken. Sensibly, that is why were getting high cloudiness on and off for the remainder of this week.


As a note, during drought years when the east is buried in snow and cold, it’s often is times like this when this big cold trof moves out for just a week that we get a storm or two. However, during the dry years, this is often the only opportunity to get precipitation into the sierra.  It is worth mentioning that this year’s El Nino will be at work. It is still not known if this Modoki with be wet or dry. One thing in our favor is that anytime you have a decent El Nino, it activates the southern stream.  And….It is the southern stream that can flush out the cold air and even displace the PV or Hudson Bay low eastward enough to create the excessive wavelength that we on the west coast just love. Excessive wave length usually = weak west coast ridge.



Dr Howard and the Dweebs………….:-)