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Does the nature of the EPO block wreck havoc on the previous NAO block? . I read the Pac block will aide in the destruction of the NAO. You can not have both that extreme for such a long duration. Any thoughts on that. I know Isotherm had mentioned the NAO block would be transient . I mention these things understanding I am referencing a Day 11 to 16 forecast. However, pretty sure last winter might have touched on this topic. If am interpreting HM's postings correctly than I am guessing he is anticipating possibly more -NAO this winter. And, he did say recently the weeklies are "useless " !

Weeklies are trash, but I find this look very ironic for the period, especially in view of the regular post 12/20 warm ups recently, right in time to mess up my eternal hopes of a White Christmas!

I hope some of this is white.

@psuhoffman very interesting thread here if you read all the replies from HM. Over at 33 Isotherm and others talk about the atmosphere's , AAM, momentum budget , GLAMM, etc. and why they foresee a warm up in December while reading between the lines here it appears Anthony has other ideas. This stuff is awesome to read about.

Fascinating data by HM. Need to read the replies and further answers by Anthony to appreciate it it fully. There is more than meets the eye just looking at the chart.

Not sure about early December. Depending on the location of the block and the set up in the Pac we may revert back to what we had last winter with cutters as one of the primary storm tracks. After the block breaks down, if the Pac does not improve the SE ridge will grow more prominent ( High North of Hawaii ) and we will warm. I mean the NAO is transient and then we enter the warm MJO phases Here it can last a while before moving on. So, in the end we waste the NAO block and enter the typical December Nino warm up, only to transition to colder by the end of December or early January. Could be totally wrong, time will tell.

Well, it is not all about the block, you still have to look at the flow across the Pac as it enters the country and how it interacts with the block.

Not sure if strat folks would concur, but yeah, it is very quiet. Also, I read there is other data used to determine the bottom of the cycle. But this low point can last months and maybe even drop further.

There was a post 3 months ago that indicated a very cold and stormy December based on the record positive PMM at that time. However. maybe the record + IOD is interfering some how to achieve that outcome next month, or simply the correlation may work, but occur later in December. Some some research indicated increased odds of cold an enhanced sub tropical jet during December based on the +PMM association along with increased odds of phasing along the East Coast. Some of those things are already happening if you look close enough. There are indications the STJ is picking up steam and there have been ample coastal storms this Fall season as well.

Imagine if the -NAO has legs. I admit, I am happy to see this because at least it provides an indication that maybe we will be seeing more -NAO episodes this winter. That is all we can hope for at this point as we near the end of November.

The look back and trends do support the idea here that the EPS, as it gets closer to real time, is indeed sensing the -NAO more so.

More possible support for a -NAO down the line from Matt.

If Webb is honking and HM backs him up, well, that sounds like music to my ears. Webb did mention to keep an eye out for this as a clue to the next big time - EPO 20m Replying to When this MJO wave finally begins to dislodge from the low frequency Indian Ocean/+IOD forcing, that's probably when the next big -EPO is coming

Sounds good, I am bored. And it appears the Southern stream will be a player as well. So hopefully we snow.

EPS may be correct, but too far out to know. The default pattern bluewave speaks about has been a real issue the last couple winters and you can see it here yet again on the 240 hour EPS. The Pac I believe has a hand in this set-up and a weak -NAO will not help us unless it is really very negative, otherwise the Pac rules. So many reasons could be at play in the Pac from certain ENSO regions to the Hadley cell, I simply don't know the real reason. But, this pattern for us here in the East has been a snow and cold killer that is for sure. Might work out well for North Dakota , but not the Northern Mid Atlantic. Here is bluewave's post: I am just weary of the Pacific defaulting back to its multi-year Niña-like base state. Notice how the EPS has the ridge north of Hawaii and SE ridge holding on with the weak -NAO near the end of the month. My guess is that the warm western Pacific and cold Niño 1+2 has a hand in this pattern of the last few years.

Not every winter in the 1960's were super awesome, but many winters were above average snowfall. A good time to be a snow weenie !

This is why to a degree.

Interesting @Isotherm spoke about Canadian warming today at 33, and here Anthony is bringing this up in his post . Some have used a couple 1960's based analogs for this coming winter despite the climate being warmer now, versus then. Of note is one analog, believe 65 or 66 possibly that featured a warming and then all hell broke out in mid Jan.

This is a great thread to read further. Ventrice and BammWX added comments here. Always so much to consider, the IOD, the standing wave, VP forecasts and the MJO progression.

I enjoyed this post vey much and put more faith into it than the "weaklies"

So much for their hot hand....................( well like they said - need a few more runs )

Who knows whether the EPS will be correct, however, just two days ago it had the East in a cold pattern at hour 240, but now after losing the -EPO we are above normal, as are most areas East of the Mississippi River. Not horrible temp-wise, but not a winter-like period. Someone here, forget who, mentioned he did not like seeing the ridge North of Hawaii. I agree, that messed things up last year, responsible partly for the fast Pac Jet, lack of West coast ridging and assisted the SE ridge to show up. Hopefully if it does come along, it is simply a transient feature. Decembers can be, and are typically are transitional months, asking modeling to pick up correct outcomes a month ahead is difficult. A progression to above normal in early December should be taken in stride after the recent cold spell. Whether it is a month long affair as some are saying is really a reach. I prefer to concentrate up to 7 days. It is fun to talk about the possible weather drivers and the pattern but getting stressed over model runs after day 7 is simply not healthy and takes away the fun of this hobby.

Hot Off The Press , maybe the precursor pattern is working .

That makes sense. So, maybe he ends correct on the apparent turn to milder, but the duration of any warm up is shortened. I know HM talked about cold at the end of December which matches your thoughts here. Along with the general talk lately about warm or mild Decembers bluewave was mentioning the turn of events in the Pac since 2013, and how the recent warmer early Fall seasons turn colder in November and then mild in December. Here the focus is on massive warming in Pac this decade, and sea ice melts during the recent summers etc. This makes a lot of sense. Seems we have new players as a consequence of a warming global state and they seem to really impact the period form October to December. know it effects the entire year, but to us here at this time of year you can see it and feel it. The effects of a warmer base state promote increased ice melt but also effect seasonal blocking with warmth in the Pac ( mostly the deep tropics ) effecting the MJO, EPO regions, Hadley cell , tropical forcing , snow cover, etc., even SSW and other weather phenomena. Then there is feedback on certain ocean locations in the form of anomalies, and these are players to a degree as well. Looking beyond day 7 is a real gamble these days. models struggle as do forecasters. But, I guess, in this new day and age you have to incorporate these new players on how you decide to forecast the weather in the long range.

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