Good Monday, everyone. Our new week is off and running on a milder note, but things look to turn very busy again before the week is over. That’s when the first in a series of systems will impact our weather with the potential for heavy rain and a few strong storms.

All this is the battle between different patterns. The one we’ve been in for much of December verses the much colder one we are about to go into. The slower that colder pattern is to arrive, the worse things can get around here in terms of too much rain and even more big thunderstorms.

Temps over the next few days take off and reach the 60s again for Tuesday and Wednesday, and this may hang into Thursday. That’s when our first front arrives with showers and thunderstorms, and some of those storms may be strong.

That front slows down just to our south as low pressure develops along it and lifts it back to the north. This looks like another round of heavy rain and storms.

Finally, a third system develops along this same front late Sunday into Monday. The track of the low is the deciding factor on whether we get in on more heavy rain and if we can see some winter weather out of it.

Here’s how the GFS looks with all three systems…

The rainfall forecast from this run of the model is rather alarming…

The Canadian is very similar, but has a little more of a snow look with the third system…

Here’s the rainfall forecast during this time…

The EURO only sees the first two because it leaves all the energy back in the southwest for the third system (a well known bias of the model)…

Even without the third system, the model still spits out a lot of rain…

Looking deeper into Christmas week, the GFS has some winter action…

That’s part of the colder pattern finally beginning to flex some…

The signs of a pattern change continue to show up with our MJO signal. We continue to go from Phase 6 into Phase 7 and most models are also showing a gradual push into Phase 8…

GFS ENSEMBLES

EURO

Phase 7 and 8 are much colder phases for this time of year. You can see that on the NDJ temp anomalies composites…

We are getting toward the end of December so we should also include those the DJF composites which start to soon take over…

Notice how 7 is a little warmer during this time, but phases 8, 1 and 2 are very cold.

In addition to a more favorable MJO, other indices are also becoming more favorable. The models are forecasting a -NAO, -AO and -EPO to take shape in the next week or two.

I will have updates later today, so check back. Make it a good one and take care.