I'm now pretty confident of the cycle length of this years weather pattern which started setting up in early October. Results of sensible weather (what to expect for you and me) will be different during the fall and spring verse the driest part of the year - Winter. It is still unknown what part of the weather regime across the northern hemisphere is "forcing" the pattern itself, and what if any changes will occur going forward.
I'm sure most of you have heard that we are in a second, back-to-back La Nina pattern and it is actually bordering on a moderate event. Looking at composites of previous La Nina winters from history does not support what is going on across the west, especially the southwest part of the country. For the high plains of Texas, Kansas and Nebraska (and of course eastern Colorado), the composites of years past have been all over the board from wet to dry and from cold to warm. Obviously at this point our region has been in the "warm and dry". Will this continue? If only I knew but unfortunately question is very complicated.
Recently I believe the Madden Julian Oscillations (MJO) has been calling the shots. A fairly robust MJO across the western Pacific (phase space 7) has stalled. Looking at composites of previous MJO events across the that part of the globe for December has yielded dry but increasingly cold. Here is a look at the current chart of where the MJO is and where it is expected to go....
In that previous post (click here) I had mentioned the brutal winter conditions that had been stuck across the other side of the hemisphere (Siberia and Europe primarily). A severe energy crisis is ongoing in that part of the world. In that previous posting I saw hints that some of this cold could impact our area late December into early January. That seems plausible as the MJO location is favorable and the Arctic Oscillation Index has gone sharply negative (usually when this happens cold is dislodged towards the equator). This morning some really cold air was in place across Canada.
Based on the cycling nature of the weather pattern, any really cold air that moves into the high plains might not last too long (a week to 10 days). Again, the target date is the last few days of December and into the first week of January.
As far as significant precipitation - at this point for the high plains it does not look favorable. Yes, there could be some with the cold air but I'm afraid that anything meaningful may not materialize. I'll address that later. We could really use something. For the past 60 days, here is a look at how much has fallen - or not even occurred.
The jetstream as indicated on this map....
...is in a perfect position to bring wetness to the western U.S., including the arid southwest and into the Colorado Rockies, but is NOT favorable to bring meaningful precipitation to the high plains. The pattern is just too far west and too progressive (systems are moving across the central U.S. too quickly to draw up moisture).
So, for January and February, at this point, I don't see a really wet pattern developing. We might get lucky with a storm or two close enough and slow enough to bring at least something. But enough to make a dent into the drought just doesn't seem to be in the cards. This will be REALLY bad for fire concerns as there will be those periodic systems with a lot of wind and unfortunately there is a lot of fuel (grasses) present.
As another cycle of this weather pattern transpires, I hope to have a little more confidence going forward. More later...