Good morning Weather2020 bloggers,
The warm weather pattern continues for the next few days and there are big changes showing up by the weekend. In today’s blog entry we will discuss El Niño and some uncharacteristic things already happening in this weather pattern. We will take a look into this weekend’s storm, and the next two storm systems to follow as a series of storm systems is setting up.
We are currently moving into the winter season with one of the strongest El Niño’s in history. The Climate Prediction Center has stated and shown that typical El Niño results are likely. And, one of the big characteristics is for it to be drier farther north along the Pacific northwest coast, and possibly wetter across Southern California where they really could use some rain. Thus far, it has been the exact opposite. Let’s take a look at this developing pattern.
The flow aloft is zonal today. Zonal flow means west to east. The flow is about to buckle big time in the next three to four days. Between now and then this will lead to the big warm-up that has been in progress this week.
There are a few things to notice on this map, and in the developing weather pattern between now and Christmas.
- The first thing is that zonal flow
- The second thing to notice is the lack of any blocking. You can see this in the stream of flow tracking over the far northern territories of Canada near the North Pole. This is another symptom of the Arctic Oscillation and the North Atlantic Oscillation staying mostly in the positive.
The buckling begins within the next two days. Take a look at the 72 hour forecast valid Friday night:
Again, by Friday night there is a northern stream, no blocking, and a huge dip in the flow developing over the southwestern United States. In our winter forecast we described this type of pattern as the dominant pattern #1 in this year’s winter forecast, which will also have huge impacts next spring. This trough developing by late Friday night will produce the conditions for a wet storm system. Yesterday, one of the models had enough cold air to produce a strong winter side of this storm, but the trend on the models has been for it to not be cold enough for any snow with this first storm. It is still something to monitor closely, but some very warm and humid air will be drawn in from the Gulf of Mexico.
The other thing to notice is the rainfall forecast for the next 15 days. Where is the rain in Southern California? Are you ready for this? Look at the rainfall amounts since the rainy season began in October in Los Angeles:
- October rainfall: 0.45″
- November rainfall: 0.01″
- December rainfall: 0.00″
This was not supposed to be happening and I have concerns. Central California has been getting some rain and snow, and Lake Tahoe has been getting some decent early season snow, but there seems to be a rain shadow just south of Monterey Bay. Take a look at this rainfall forecast for the next 15 days leading into Christmas Day. In a typical El Niño it supposed to be drier than average over the Pacific Northwest, and this is not happening at all. The pattern has set up to blast the Pacific Northwest Will it continue through this winter, or will the jet stream shift south in January and February? It may depend on the blocking that is lacking.
In Kansas City we are still waiting for our first inch of snow. I will update our forecast for chances of the snowflake contest ending between now and Christmas on tonight’s weathercasts on 41 Action News, which you can watch streaming live on www.kshb.com during our newscast times. Last night I showed that there was just a 20% chance of it ending by Monday, but an 80% chance of it ending before Christmas Day. There is a series of storm systems that are cycling through the flow during these next two weeks.
The models have been just horrible at predicting this pattern in the past few days. Why? The models will always have a difficult time forecasting when the flow will buckle, and then how the energy, the strong and powerful jet stream energy that continues to increase, will dive in and out of the less zonal and more meridional (North/south) developing flow. The GFS model now predicts that a piece of this first storm will close off and take a track that would usually produce a major snowstorm near KC. It appears that it will be too warm. And, then as you can see on the left, the flow continues to buckle near the west coast.
This next map on the right shows the flow at day 10. This is the GFS model showing the two stream joining forces. The European model has been hinting at something similar. That is a big ridge forming off the west coast. I doubt it will last that long, but it should create the conditions for at least some build-up of Arctic air and some of it could push south. Analyzing this closely, however, I still see very little blocking, and the AO and NAO indexes may dip just to below neutral into negative territory before rising back up again.
Overall, we are about to have significant changes. El Niño is very strong. How is all of this going to impact winter? Winter officially begins in less than two weeks.
Have a great day. Thank you for participating in the LRC Forecast Experience Blog. We will discuss the trends in the comments section of this blog.