Noon

The models have been inconsistent on the week ahead. There is a reason, let’s go back to the MJO. If you are new or don’t remember my past references to it, the Madden-Julian Oscillation is a tropical disturbance that moves clouds, winds and precipitation and pressure changes eastward around the global tropics about every 30-60 days.

It has a huge effect on our weather, especially in the winter. There are phases in the MJO cycle and models predict where the cycle is headed generally 14 days in advance.  Below are the MJO forecasts form the US and European Models. The numbers 1 through 8 correspond to the 8 phases of the MJO cycle. The red and purple lines are the past, the green line with black dots is the forecast for the future.  The black dots on the green line are days  You literally have to count the dots on the green line because only the past dates are listed (on the purple and red).

GFS

This is a fairly confident forecast. If you follow the bright green line, you see we are leaving phase 2 and heading into phase 3. I circled3 dots on the line, that is December 12th-14th. That is a moderate phase 3, you then see it diving into phase 4 and towards that circle which is a null phase by the 19th. The null phase means the MJO is not affecting our weather pattern. In fuschia, I circled a bunch of squiggly yellow lines. Those are “model members” whereas the green line we follow is the average position of all of the members(technically the mean). The fact that most of them are in that null phase, indicates the consensus is that it will dig into the null phase, hopefully, we will then see it venture back to phase 1.

Stay with me, I will show what each phase means this time of year after we look at the Euro.

Euro

The Euro looks, on the surface pretty similar, until you look at its model members (yellow squiggly lines) they are all over the place, starting tomorrow. This is a disaster and tells me I really cannot rely on the Euro past a couple of days out if that.

Here are a couple of charts that you can follow to see what each phase means for us. Remember the further the forecast (green) line tracks away from the center of the square, the more of an effect the MJO will have on us.

Temps (4,5,6 are bad for us)

This week, I have low confidence in the incoming storm, we need it to dig in more to the south. For now, my eyes are on the MJO. Next update Monday.