5:00pm Monday Update:
An impressive set of storms appears poised to strike California the next 7-10 days, but the computer models keep flip-flopping on whether or not Southern California will get in on the action. As of Monday afternoon, here are some of the highlights:
- The arctic blast that appeared headed for Southern California later this week is no longer likely.
- The arctic blast will be replaced by a juicy set of storms barrelling across the Pacific into California, potentially bringing EPIC amounts of rain and snow to Central and Northern California the next 10 days
- Southern California is on the extreme southern boundary of many of these storm systems so confidence is LOW in whether we will see periods of rain and mountain snow, or just periods of cloudiness and wind the next 10 days.
Here's how thing are set up this afternoon:
- A modified arctic airmass has drifted south into Northern California, as a huge high pressure system is sitting just south of Alaska, funneling northeast winds off the cold Northwest Territories of Canada far south into an area of low pressure near Oregon.
- The high pressure over Alaska has pushed the jet stream and storm track far to the south, with several low pressure systems lined up off the coast of California.
- A large area of warm, humid air is being pulled up from the tropics between Hawaii and the southern tip of Baja, adding extra moisture to incoming storm systems.
POTENTIALLY HISTORIC PRECIPITATION AMOUNTS FOR CENTRAL AND NORTHERN CALIFORNIA
There is still a lot of uncertainty in this storm cycle, but Central California is going to be hit hard. Some models are showing 10-15+ inches of rainfall in the Sierras the next 7 days, with much of that falling as snow in the higher elevations. Rainfall of this nature may fill up many of the reservoirs that have been so low the past 5 years. Snowfall of 4-6 feet may be common for the higher altitude communities such as Tahoe and Mammoth, with 10+ foot snowfall totals in the higher peaks a possibility. Take a look at these incredible estimates at this time:
WHAT ABOUT SOUTHERN CALIFORNIA?
For us in the south, it is unclear if we will get in on this gravy train the next 7 days. We are on the very southern end of this atmospheric river. The forecast keeps alternating wet and dry for the south. At this time, it is probably best for us to prepare for the possibility of precipitation Wednesday night and Thursday, and then again around Saturday night - Tuesday. However, I cannot stress enough that there is a high amount of uncertainty surrounding our forecast here in the desert! The details will likely continue to change. Just keep that in mind! This is a highly unusual pattern that is filled with weather patterns from the north (arctic), weather patterns from the West Pacific, and weather patterns from the southwest Subtropical Pacific. How each of these variables will eventually play out could mean the difference between a wet week, and a historic week that will soak and flood the state to our north.
We may be spared the worst of this weather this week here in the deserts, but anyone traveling north should be prepared for the possibility of MAJOR travel problems during the stormy periods. Heavy rains, strong wind and heavy snows will all play into travel plans from about Bakersfield and Santa Maria all the way north into Oregon at times the next week and possibly beyond.
I don't give much credence to the details of 14 day outlooks, but many of those are showing the equivalent of a massive 30 inches of rain (or snowfall equivalent) throughout the Sierras the next 2 weeks. Again, I always exercise MAJOR RESTRAINT when examining long term computer forecasting, but it's worth mentioning that the trend for an extended period of stormy weather, regardless of the specific details, is a complete turnaround from the dry weather we have experienced for 5 years. Rainfall and snowfall of this proportion is something the state has not experienced for a very long time. We may very well see headlines of mudslides, floods and avalanches hitting the media the next few weeks if this storm cycle comes to fruition.
For us here in the deserts - I look forward to sharing further updates this week!
Happy New Year's!!