Full on winter storm in progress at this time as the southward push of the strong closed low off the Oregon coast  continues into Northern California throughout today. The onshore flow has been strengthening this morning and Mammoth Mountain has picked up well over a foot as of 8:00am. The latest satellite motion shows a nice tap (.8-pwa)of moisture from the mid pacific that seems to be favoring the southern and south-central sierra.  This will support heavy amounts to accumulate throughout the day today and tonight. The latest update from CRFC is showing another 1.8 inches of QPF  for our area by morning. By Saturday…the strong height falls that are currently occurring offshore will shift east into Southern California and bring heavy amounts of snowfall to your local mountains. All in all considering how cold this storm is…..UVM and  moisture,  amounts over Mammoth Mountain will easily be in the 3.5 foot to 4.5 foot range over the powder fields of the upper mountain by Saturday.

Further Discussion…….

A strong cold front is pushing south across the Sacramento Valley. At the same time, a developing lee side surface low is slowing the progress of the front. Without this development the front would have been already south of Tahoe by now limiting the amount of snowfall the Mammoth area would  receive. So, in retrospect, the wetter models were better, especially once the moisture moved eastward reaching the coast and the right rear entry region of the upper jet set up over the northern part of the state. All considered, this system is making the most of the current moisture influx.

Looking ahead today. The cold front will slowly drop south today toward Central Ca. However, over Northern Nevada where the Lee side development is expected,  the front may hang up a bit longer delaying the front through Mono County until very late afternoon or evening. Surface convergence is likely to persist over Eastern California into the night for another foot of snowfall beyond this afternoon. 

Pacific Sat view:

1. Nice lingering Kona low continues to draw up moisture from the tropics into the subtropics. This moisture will become a player later next week……

2. Current upper anti-cyclone at 50 north/150west is positive tilt and will aid with the short wave coming south to push the current cold off shore system southward.

3.  ((((“More importantly”))))…a strengthening low latitude subtropical upper jet will work into the western pacific in the days to come strengthening.  This will have the effect in developing a tremendous amount of amplification in the central pacific upper ridge, building it into the Bering Sea. There is the suggestion of the confluence of a strong low latitude subtropical jet with the Polar in early March.  One break through of the westerlies may occur about the 28th of February as a cold upper trof from the Gulf digs southwest to meet up with it, the second half of next week. At the moment the emphasises is for Northern Ca for the heaviest Precip, however this is a developing situation and subject to change. What is happening here is the “potential” for a very wet pattern for the west coast over time. 

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

Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.