The current mild pattern will slowly revert back to more average December temperatures over the next several days.
A storm that had been expected to form over the weekend will probably pass off to our south,
The models are advertising a big change around Christmas Eve, with deep amplification of the jet stream, colder temperatures and possibly the development of a major storm. Stay tuned.
Last time I looked (Saturday morning), the models had sunshine for today. Looking at the satellite imagery, we still have a NW cyclonic flow around that departing low. Plenty of clouds. These models are good, but sometimes weather just can’t be accurately modeled.
Latest models still have a fair amount of cloudiness on Saturday. Some sunshine early, but mid level altocumulus will cause considerable cloudiness for much of Saturday. Fairly windy with highs only around 40.
Last year, the meteorological term that was in vogue was “polar vortex”, something that always exists but like a spinning top, can sometimes spin eccentrically off the main polar axis giving us bitterly cold weather. As I noted in a previous climate forecast, this year looks very different. The vogue climate phrase I expect to see this year will be the Madden-Julian Oscillation (MJO)
For the coming week, the large scale weather phenomenon that is causing all that rain on the west coast will give us warmer than normal temperatures. This large scale climate phenomenon is associated with a certain phase of the Madden Julian Oscillation– warm moist tropical convection (thunderstorms) in the Indian Ocean and Pacific that slowly migrates eastward and affects the US. Most noticeable during lulls in the El Nino cycle.
This usually brings heavy rains to the west coast and can result in deep storms in the Eastern US as a result of a natural “wavelength” to the jet stream. This is what is speculated to be what’s happening with the heavy rains in California and the deep low that just affected us. These phases last 30-60 days, so a wet and milder pattern will likely be with us for much of the remainder of this month. The next “phase” of the MJO isn’t expected until late December or early January, so cold weather may return. This phase of the MJO is simply a bias towards wet and warm and the East coast effects are less deterministic.