We are still expecting nice weather for the weekend. Highs into the 50s for areas near the base and 40s for the upper mountain through Monday. Ridgetop winds could start to become a little gusty on Monday.
Rain or No Rain?:
Tuesday we could see some sun and clouds with temperatures a few degrees cooler in the 40s for highs, along with some gusty winds for the mountain tops. A deep trough is forecast to dig south off but near the West Coast by Wednesday, and it begins to pinch off from the trough to the north.
A large low-pressure system is forecast to spin up into the base of the trough off the coast and start to send moisture into the CA coast by Wednesday. It is forecast to tap into some deeper subtropical moisture with an AR (atmospheric river) of moisture aimed at the CA coast.
A few days ago the models had the low off the coast tracking down farther east, closer to the Sierra, and pushing the AR into the Sierra. That is why the forecasts were showing some big rain and snow chances. Some forecast models still show this chance, with heavy rain and high-elevation snow possible for Wednesday – Friday.
But two of the major models that most forecasters heavily rely on have been showing the low staying far enough off the coast that the moisture barely or doesn’t reach the northern Sierra at all through Thursday. They show the heavy rain stopping near the coast and then the low being steered into southern CA to our south on Friday as the storm finally moves inland.
There is so much moisture available so close to us that it is still a nail-biter as we try to figure out the forecast for next week. We could see anything from heavy rain and high-elevation snow to nothing at all Wednesday-Friday. The snow levels look to be near to above 8000 ft. through Thursday, and then possibly coming down Friday as the center of the low with the coldest air flowing into it moves inland.
We’ll continue to watch the trends closely…
The long-range models are all over the place with the ridge/trough pattern beyond Friday. Some runs show additional storms possible next weekend, and others are dry for several days.
Overall they look to keep the pattern moving with at least a chance for a storm every few days or so. We have enough forecasting headaches this week and we’ll worry about the following week after that.