December 15th, 2020

Another light to moderate snow producing storm in on its way for Late Wednesday and Thursday….

Taking a good look at the next weather system,  It is not all the impressive QPF wise as compared to the last storm. The last system dropped between 10 amd 12 inches on top of Mammoth Mtn.  Although it is still possible to recieve close to that amount, CRFC QPF only shows .50 for Yosemite, which is 1/2 of last weekends storms forecast. Now I will say that this systems vertical motion field is more dynamic this far south as compared to the last Sat/Sun system. However, it moves through so quickly that it is out of here during the day Thursday.   I will look at it again tomorrow morning, At the moment my Est. is for 3 to 6 in town and 6 to 10 on the Mtn by Thursday evening.  It will be a breezier storm and there will be a 3 to 6 hour period of mod to heavy snowfall Thursday AM.  Snowfall amounts on Highway 395…..1 to 3 inches.

The NWS has a Winter Storm Watch for Wednesday night, for the 12 hour period ahead.  That may be a bit much for Southern Mono County….

Medium Range;

The storm track shifts north again to the Pacific North West this weekend with two short waves into Washington and OR.  Friday night and Sunday is the timing for them.  Next week, there is a splitting system that may bring us light snowfall Tuesday afternoon/Night.  Light snowfall is 1 to 6 inches….   Then down the road we ridge up for Christmas. Great Travel weather expected then for those who “have to” travel. In the longer range, there is still no signifacant tropical forcing. However, I will be attending the CPC briefing this morning.  So if there are any changes in the tropics that would modulate the westerlies, I will report….

As we all know, it will be very risky traveling and visiting this holiday….Especially since the Virus is spreading so rapidly…..Please take all precautions to be safe……The Dweebs will most likey be hunkering down in Mammoth throughout the Holidays.

Dr Howard and the Dweebs………………………………………. 🙂


With the Jet Stream to our north, the current storm system is expected to bring warm air advection type snowfall to our area today, tonight through Monday. Although this is not a major storm, the weather will bring travel restrictions with snowfall amounts in the 1 to 3-inch range on Highway 395. Additional amounts of snowfall are possible in the Town of Mammoth with 4 to 7 inches possible and 8 to 12 inches over the higher elevations of the Sierra through the same time period. The high temperature today in Mammoth so far was 34 degrees at 9:30AM. It was 29 at 10:00AM after the snow started. The forecasted high today is 42. The low tonight is projected to be 14F.
The wave will be through by 4:00AM Monday, however a couple of vort centers on the back side of the trof will continue residual showers into the day Monday. A short-wave transitory ridge moves in Monday night into Tuesday AM.

Medium Range:
As chatted about in earlier discussions, Strong surface cyclogeneses off the coast of Japan yesterday Saturday into this morning has amped the pattern with propagation of energy expected to come through Wednesday night and Thursday. This should result in a decent storm later Wednesday night into Thursday. This storm has the capability of bringing moderate amounts of snowfall to Mammoth Mt this Thursday with amounts in the 12 to 18-inch range. Beyond that time frame, it looks pretty quiet until a hand full of days before New Year’s.
La Nina is peaking now……Gradual weakening is expected beginning this January.

Long Range Model European shows some big storms in January!


Dr Howard and the Dweebs………………………:-)