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Nice time lapse. Thinking in the process here extensive snow cover in NA the next 15 days, and then with the PV back closer to Siberia building cold air and the snow cover/advance resumes shortly.

@bluewave do you see anything to be concerned about here with the latest PAC SSTs ? ( that is if you enjoy cold and snow in the East later in December ) Seems we are having some changes as we knew there would be. The warm pool has diminished somewhat , warmer anomalies near the Aleutian islands , cooling off the West Coast. Does this current set-up support a Se ridge and reinforces the High North of Hawaii? Or, is the weather pattern out there in flux as you mentioned going towards a -EPO.

When I think back to last winter and things to watch of real substance as clues to the upcoming winter one would be getting the trough in East and the ridge to set up out West for more than a day or two. Last year and this year as well, there has been a very fast Pac jet that broke down quickly any attempt out West for a ridge to form. I thought the seasonal guidance had a forecast of robust West coast ridging at times extending into a + PNA . To make matters worse we set records for the speed of the Pac jet last fall and winter , some really crazy numbers. We need to buckle the flow and get some real changes out West extending into NW Canada, These are some things I would look for in the next 4 to 6 weeks as possible clues for the period DJF.

The association that we once thought was so important has certainly faded in the last 4 to 5 years. I really started to doubt the importance of this when one fall we had an incredible October Siberian snow cover advance and a then a flat AO and NAO in the months ahead. The following Feb. Judah stated the October advance was actually too fast and because of that the anticipated blocking never developed. Huh.... Maybe we need a shake up and I see no concerns about the Siberian snow cover presently. I am more interested in the Pac including Pac forcing, PDO and the IOD, etc.including the QBO for the upcoming winter. Also, very interested in seeing how November plays out. Would like to see some West Coast ridging and the Davis Straights block to really develop and a continuation of a stormy and active pattern in the East.

This is great news regarding the QBO. Ditto for the solar connection

Here comes the next batch of rain for early next week, courtesy of the tropics and the GOM.

@showmethesnow Wow, it is big ! If this actually happens maybe we can place more confidence in the models later in the winter should ( " IF " ) they forecast another huge Greenland block.

This is really nice to see, another unusual mid-October powerful cyclone. Wonder what happens as we shift to late Nov. and early December as the baroclinic zone shifts South. Also, previous monthly Euro runs showed an active East Coast .

You have to think now that maybe the NAO is starting to show its hand. I know some long range models take it back up to positive in later November but still it is at the least nice to see it going negative again.

@poolz1 HM beating the drums

Maybe the old saying should be , the weather in November the winter will remember, versus, December. Mostly because lately Decembers have sucked ! And then the following winter also sucked. So let's go Cold and active November !!!! Yeah baby

Almost seems with tomorrow's event we might turn the corner, dare I say. Day 4 to 5 Wow, to day 6 and 7 , system and moisture look to move NE towards us day at 8

The models are certainly keying in on something and that something may very well be the extreme + IOD. Are they resolving the future outcome correctly, hard to say , but the general consensus among the models is pretty remarkable, in that a likely a +NAO will occur. Now are the model correct? Not sure as indications seem to reveal the extreme + IOD may decline soon and continue to weaken through the winter. @showmethesnow wanted to add there is some research out there does point to a averaged -NAO for the period DJF.

To balance the goods and the bad this most likely goes in the bad column. Sea ice for this date is the lowest it has ever been. I would think less ice formation would equate to less build up of cold air. That would likely be a poor factor in the creation of a robust cryosphere where cold air builds up and becomes colder and colder over time and then moving South given the impedance. Just my own thoughts here. However , there is great post on 33andrain from member Bring Back who composed an excellent summary on the topic. Here is a brief updated post by Bring Back and the link further down to an in-depth article he composed on sea ice. From Don S Arctic sea ice extent has now fallen below the 2012 figure... On account of abnormally slow sea ice growth, Arctic sea ice extent on October 13, 2019 had slipped below the 2012 amount. In 2019, Arctic sea ice extent was 4.881 million square kilometers on JAXA. In 2012, it was 4.912 million square kilometers. <<< From Bring Back Don, yes 2019 is currently at the lowest extent on record (for mid-October) at this early stage of the re-freeze season. I did an "Arctic Update" on the 2019-20 Winter Discussion/Forecast Thread yesterday and went into the reasons for this. I am not as pessimistic as some commentators and expect the re-freeze rate to increase substantially during this week and into next week, particularly on the Atlantic side of the Arctic which has seen very little growth at all so far. Here's the link to that post: ( I believe you will have to copy and paste into your browser ) https://www.33andrain.com/topic/1710-2019-20-winter-discussionforecast-thread/?do=findComment&comment=153515

Pretty impressive bump up from the WPC , I LOVE IT...... new grass will be partying . hey @C.A.P.E.can you believe it, been waiting ages for an event like this.

This is cool about the NAO 2 takeaways for me : 1 Low solar backdrop does indeed play a role in the weather , as you can see below from HM's post 2 Low solar min seems to have an effect on the NAO but more so on a lagged time scale ,

Yep, relative climo is indeed changing.

Here is an interesting piece of information ...... Now keep in mind this is for the NYC metro area but I would think the same general results would hold for our geographic area as well. This is from Don S., the master of weather stats The take away here is if you are hoping for cold winter we better get a cold November. As Don mentions the association with snow is a little more mixed. Location:New York Posted yesterday at 08:57 AM From Don S. It is typically a signal of a warmer winter. Since 1980, the following has occurred in New York City when both October and November were warmer than normal: Succeeding winter: Colder than normal: 3/13 (23%) cases Near normal: 1/13 (8%) cases Warmer than normal: 9/13 (69%) cases Breakdown of months: December: Colder than normal: 4/13 (31%) months Warmer than normal: 9/13 (69%) months January: Colder than normal: 2/13 (15%) months Warmer than normal: 11/13 (85%) months February: Colder than normal: 2/13 (15%) months Warmer than normal: 11/13 (85%) months December-February: Colder than normal months: 8/39 (21%) months Warmer than normal months: 31/39 (79%) months The snowfall signal was mixed. Mean: 24.2" Median: 24.9" Lowest: 3.5", 2001-02 Highest: 61.9", 2010-11

Looks Pac driven, which is great, if it continues all winter, because the continued theme for the NAO from the seasonal models is positive. That's not going to help us down here.

Ah, well, you might hear some real thunder on this Wednesday. Mount Holly's AFD mentioned the possibility, but believe they were not totally sold on it . Good rains seem likely though on Wednesday.

From simply a sensible weather point of view this October, and even this past September to a degree, not the same as last year weather-wise around these parts. Also, I couldn't agree more, love seeing the coastal action. A good sign for early winter, I hope they keep up.

Speaking of AAM

Ha ha your funny! Yes the low AAM state is more Nina like. So the talk was about the AAM state. I know Ventrice talks about in the winter as does HM, and others. Seems to add a spark to the atmosphere as well. The link in the article above talks about it and is interesting. To thicken the plot though I read that there have been winters in the East that were cold and snowy with a low AAM. However these winters were many years ago, not sure whether they can add value now in this day and age. For example, this came across my mind regarding the the great winter of 95-96 which was a Nina wondering what the AAM would have been then ? I imagine you also have to think about the Pac in years before 95 -96 as well. What was that Nina following up on. I know that enters the outcome as well. The Nina state would suggest a low AAM state but was it? I am sure too the lower solar cycle at this time and the QBO were at play as well.

An interesting older article on AAM . Some things included in the article are the Nina connection, wind fields and workings if it . Some cool images too. https://climateimpactcompany.com/wham-bam-aam-explains-hostile-global-weather-january-2018/

A little more on snow cover advance last week via member bring back 62-63 from 33andrain <<< Now this "temp trend" is a key chart, particularly early on in the re-freeze season. This allows for the rapidly falling "mean" temps during October. If all else was equal (which it never is!) the whole chart would be blue! Again, most of the Atlantic side of the Arctic will see steady short term cooling. Interesting that much of central/northern Siberia will see a warmer period following the cold and early snow accumulation there (more below on that). Contrast that with the top chart. The deeper cold is shifting to north and west Russia and good to see northern Greenland getting very cold. The pressure charts for the next week to 10 days (not shown) show a mix of HP ridges and relatively weak LPs with no serious WAA and no major storms in the Arctic. Overall, although the re-freeze will slow down on the far side, much of the rest of the Arctic should see the rate increase substantially and that curve on the graph (top chart) "should" see a steady rise during the next few days. Let's hope that the recovery rate continues to rise during the second half of October. Last Sunday I posted the Siberian snow cover extent (see chart copied below) and the chart above shows that this has continued to increase - in fact it paused for a few days and then resumed its steady spread south westwards. Given the higher temps expected in Siberia this coming week, I would expect little further growth in Siberia but with much of northern and western Russia becoming very cold and an LP system pushing eastward through Russia around mid week we should see substantial snowfall there and the main snow area should expand steadily westwards. This will lead to the Eurasian snow cover being well ahead of normal for mid to later October. Overall it is a very mixed picture but with no cause for extreme pessimism at this stage. Displaced Arctic cold may provide lower temps in North America and Eurasia but it is bad news for the Arctic. The consequences for the impacts on ocean-atmosphere interaction and disconnects and changes to the jet stream are the subject of a great deal of research and no firm conclusions are yet available. I will place more of the recent papers on this into the Research Portal in the coming weeks and then I'll review the most relevant ones in several post >>>