frd

If true, anyone whomever posts the stupid weeklies should be banned Have you noticed the continuous, almost laughable, repetitive predictable failure of the modeling when it forecast cold or a colder pattern, been happening more and more the last three years, maybe related to the whatever, all I know is modeling can not be trusted and the evolving base state is ruining everything it seems.

Ah, but the weakening Nina, a game changer.

Isotherm stated earlier for a major SSWE I think it was a full 5 days or more of a wind reversal. Looking at some data tonight it appears a secondary push below 0 will occur in about 5 days and from there it could be 5 to 7 days until the winds revert back to Westerly Also noticed here both the GEFS and the bias corrected CFSv2 have trended with a weaker vortex moving forward. Euro

It is an improvement from now, but beyond that period you will see the concerns that psu mentioned.

Wonder if when the block makes a subtle shift is when it marks a time period when we can score. 21 st or 22 nd. You can see though the general retraction also seeing a junior Beast of the East over Eastern Europe. Wonder in time what occurs to the extreme cold that looks to gather over the pole. .

Yes Ocean Spray Jellied

@Isotherm Tom does this mean anything , enough to sway you that the event, although not a 5 day reversal, still might be considered major. Any thoughts would be appreciated.

I wanted a large portion of stuffing, and cranberry sauce, but the one without the berries.

Again, no one can really be sure with these events, but as this animation shows, note how long the wait is for the cold after the official SSWE, and please be aware we are only looking at 1959-60 and 2005-06 in the animation loop. Others years however are relatively close.

Worth keeping track for any longer term implications, even though as Isotherm stated, this may not achieve Major SSWE criteria.

Or simply if the great pattern ends up being a week versus several weeks. As Isotherm stated, it sounds like the best opportunity is later this month, and then maybe March.

Require universal agreement for a snow threat these days and unless it's a 1996 type event would like that in the medium range. Simply can't put much faith in modeling these last few winters. An abundance of failures. However, still like the threat period ahead.

Appreciate your posts PSU , I imagine it is a double edged sword to a degree, we'll get our opportunity hopefully between the 16 th and 25 th.

psu talked about this. I would not weigh too much into the MJO forecasts at this time. The blue color indicates a - NAM state, ie. HL blocking, and as mentioned here before, there is a tendency that even if the AO goes positive later in the month it will once again go negative , normally there are several cycles to this event on a time a scale going out to almost 60 days. Also worth mentioning, the real impacts of the SSWE is not due to hit sensible weather for 20 to 30 days after the official wind reversal. So, the models may adjust to colder longer term if our area is favored for the Southern displacement of colder anomalies. If this occurs hopefully a baroclinic zone sets up near by and we can reap the benefits of increased probabilities of snow over rain. I guess the bottom line is don't over react to model data in the long range, and set expectations within rational levels.

This looks good

Going where ?

Yep. Ah the old days of 2002 - 2003 I remember - 4 and -5 up there. An update from @Isotherm seems in order in regards to the SSWE. Here is his outlook for this month: January: z500 structure = neutral or +EPO/Near neutral AO/Near neutral or negative NAO/+PNA: this month, while still warmer than normal for most of the United States, will provide the highest opportunity for winter conditions in the coastal Northeast and Mid-Atlantic. Temperatures will be colder than normal across the Lakes and New England, near normal into the northern Mid-Atlantic, and warmer than normal elsewhere in the country. Snowfall will be above normal in the Lakes, New England, and near normal in the Mid-Atlantic.

Yes that is true, we have record North America snow cover the last two winters, not sure about the other side of the pole. However, keep in mind we went from record North America snow cover to dropping like crazy during Jan both of those years, I believe one was due to the SSWE and the other the Pac induced flow into Canada. I do know that Siberia set record high temps back in the summer and possible the Fall. Not sure of the consequence of that. Both of the past horrible winters, as you know, featured so so Pac patterns with little blocking in the NAO domain and I believe the AO averaged positive. The Pac effects the EPO region, PNA region and Canadian snow cover. It has HUGE implications for us. So far the - AO and the - NAO has done little this winter. Also, keep in mind the numerous model failures the last three years in bringing cold to our region. There is way more to it than that though.

True , and hopefully the PNA/EPO ridge develops as modeled.

Certainly seems post 2015 that a Greenland block and a - AO will not produce for us like they did years ago. There are exceptions though. In my opinion it has to do with the warming arctic summers and a slow to develop NH snow cover, that we need to induce the build-up of very cold air that we can tap into to. Also, a delivery method is need to get that very cold air into the East. The last several winter the Northern Plains have been very cold. I feel to get colder weather to the East we really need a very cooperative Pac. I profess that is more important now than ever. The elusive - EPO which has been a model forecast bust for the past 3 years never gets to real time. A Best pattern since xxxx has failed now several times this year and the end of December as well. Bluewave made a post that I brought over but you can see that the Pac really needs to be the prime driver for cold and snow in my opinion. I am no expert but just sharing some thoughts, It simply feels that drivers that would typically produce a SECS , fail to deliver for us on a greater frequency. Of course, the caveat is, we have a Nina and right there you know there will be challenges. Here is bluewave's post below: I am just calling it a window of opportunity for snow starting around the 16-18th. But it’s uncertain how much of the potential gets realized. The EPS is weakening the PNA faster now than just a few days ago. New run Old run

This still looks poor. The Pac puke has left its mark in Canada. I know some are expecting a change here by mid month, we shall see.

Are you feeling our window has narrowed down a bit? Its looks like it can produce near the 20 to 23 rd , but the longevity of it seems to be lessening. We kind of knew the Pac would improve, but then go the other way again. Certainly possible we warm up in early Feb only to turn colder again later. If indeed this SSWe has any role in our sensible weather it would produce another period of - NAM later in Feb.

It's possible we get little to zero snowfall , it has been mentioned above if a negative 4 standard deviation Arctic oscillation cannot deliver snow to the DC area then just forget about it , come back next year. Or, after the comet hits.

The GFS has issues we know, but many times it is very good at identifying large-scale features many days ahead , even 15 days ahead. I would feel confident about the prospects down the road and later January

Well why not. Shoulder month , fits the bill.