Friday, November 13, 2015

Friday Morning Long Range Outlook: Active Thanksgiving Week Ahead?

Good morning everyone. On Monday I discussed looking past the 19th for this pattern to START changing (its a slow evolution). Since then I am starting to see more evidence that things could get active for the eastern 1/3 of the country the week of Thanksgiving. I am not sure yet if this will be a permanent pattern change but I do think we at least get a spurt of cold and storminess. The overall all pattern still might be a few weeks away from its seasonal change. 

So lets take a look. To start off next week will be more of the same with a big ridge over our area and a trough over the west..

This has been the relentless pattern over the last few weeks which has brought cold and snow to the west, severe weather to the central US and warm conditions over our area. Notice that blue near AK I spoke about Monday. That is called the positive phase of the Eastern Pacific Oscillation (EPO) and it is a big contributor of this pattern. Lets now take a look at the even longer range..

Looking above look at the flip in the gulf of AK. We now have a big ridge of high pressure there projected for Thanksgiving week. This could have big implications on the pattern over the whole country.The high pressure in the gulf of Alaska (-EPO) changes the source region of the air which means it stops pacific air from entering the pattern. Instead we get the chance for arctic air to enter the country. Yes we still have that trough under it but in the long run the ridge is what is important. If we get a piece of that trough to break off and the ridge to intensify more we could be looking at mischief somewhere in the eastern 1/3. 

That does not necessarily mean a snowstorm for our area, it just means colder conditions could develop and a big storm could form somewhere between the Mississippi east Thanksgiving week. 

Moving on into Thanksgiving week, you can see the model is trying to hint at a potential trough further east. This is an ensemble which means it takes a main model and reruns it many times testing for potential error. So you have multiple members with an idea of what the pattern will look like. The fact we see the blue in different spots means the model is trying to figure out where the trough might be below. What will prob end up happening is we will see a very up and down pattern that week. There will be warm days and cold days as the jet streams wavelengths will shorten.

When its all said and done you might end up with this below by the end of thanksgiving week..

I do not think we see any snow that week but like I said colder and stormier especially by that weekend might be the issue here. Overall, I still do not see a pattern developing that supports a big east coast storm. I think we are a few weeks away from that. The main theme here is that we will start a grind from this warm mild pattern towards our winter pattern. In this process you will see a lot of variable weather conditions and storms slowly work their way more east each time. 

Be patient winter lovers we are not there yet but there is some light at the end of the tunnel. Just need to be patient. At this time we might be looking at the 2nd week of December for a permanent pattern change. One big factor to keep an eye on is the Arctic Oscillation. Lets see if that goes negative.

 Stay tuned!

No comments:

Post a Comment