Good Saturday, everyone. While things have been rather calm over the past 6 weeks or so, our pattern is about to become very active. As a matter of fact, it’s really getting my attention for a potential early start to winter as we roll into November and December.
Let’s begin with today. A couple of showers will be located across the region, but a lot of dry times will be noted. Temps will be deep into the 70s on a strong southwesterly wind. 80 is likely in the west and far south.
The weather from Sunday-Tuesday looks windy and very warm. Daytime highs will run from the upper 70s to low 80s as winds continue to gust up from time to time.
The setup for the end middle and end of the week continues to look rather potent. We will have a big dip in the jet stream dropping toward our region. At the same time, something tropical may try to develop near Florida. There’s the chance these two interact. How, and if, that transpires. means some wild fluctuations in model runs.
The Canadian currently has the wildest solution. Here it is at 500mb…
Here it is at the surface…
That shows a blast of very cold air into our region and has snow in the WV mountains. Several other models have shown similar solutions over the past few days. Among them is the European Model. However, the recent run of the model isn’t as robust with the initial storm…
That’s still a very deep trough that catches whatever system comes from near Florida, and develops it along the east coast…
Think of this… Next will start with 80 degree temps and could end with a frost or freeze threat, depending on how this system comes together. That transition should also give us our best rain chances since August.
Last week, I started talking about how blocking was showing up in pretty big fashion across the Arctic. The Arctic Oscillation (AO) has turned severely negative recently and is forecast to remain there for a while…
You can see how it spent much of the summer and early fall deep into Positive territory. That is no longer the case, and that severely negative AO may keep going for a while. Hence, one of the reasons I’ve been looking at the potential earlier than normal start to winter.
While on the subject, let me share some work from Dr. Judah Cohen. Dr. Cohen has become very popular over the years for his forecasting of the Arctic Oscillation (AO) and the Polar Vortex. He has some interesting theories about the buildup of October snow cover in Eurasia and how it may impact the winter ahead. Here are some of his latest thoughts:
Arctic Oscillation and Polar Vortex Analysis and Forecasts
- The Arctic Oscillation (AO) is currently strongly negative and is predicted to remain negative over the next two weeks. The AO is predicted to trend positive towards neutral through the end of next week and then reverse and trend further negative.
- The current negative AO is reflective of positive pressure/geopotential height anomalies in the Arctic especially north of Alaska and on the European side of the Arctic and negative pressure/geopotential height anomalies across the mid-latitudes of the Northern Hemisphere (NH) especially in the North Pacific sector. The North Atlantic Oscillation (NAO) is currently also negative but because the positive height anomalies in the North Atlantic side of the Arctic are closer to Scandinavia than Iceland/Greenland, the NAO is predicted to fluctuate around zero over the next two weeks.
- With pressure/geopotential height anomalies predicted to remain positive across much of the Arctic and pressure/geopotential height anomalies predicted to remain negative across the NH mid-latitudes, the AO is likely to remain in negative territory into the foreseeable future.
- With the AO firmly negative for the remainder of the next two weeks, this favors below normal temperatures across large portions of northern Eurasia including Europe and Siberia. However because North America will be dominated by mostly positive pressure/geopotential height anomalies, temperatures will average above normal much of next week in eastern North America. The following week with heights predicted to build once more near Greenland lower heights and temperatures are predicted for eastern North America for week two.
- Eurasian snow cover is above normal but has currently stalled. However both low sea ice and a persistent negative AO are favorable for the resumption of a more accelerated advance of Siberian snow cover. High Eurasian snow cover and low Arctic sea ice in the Barents-Kara seas favor first, a strengthening Siberian high and then a weakened polar vortex in winter.
- The polar vortex both in the stratosphere and the troposphere look to remain relatively weak for the remainder of October, if this trend continues severe winter weather is likely for widespread portions of northern Eurasia, including Europe and East Asia, and the eastern United States (US).
Check out the highlighted part above. Very interesting!
Have a great a great Sunday and take care.