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Hey psu what do you think abut the 06z GEFS? Some models put a trough in the SW and cut back on the West Coast ridging. You feel anything there is transient or simply the models are not getting it correct? Maybe a simple case of a relax, and then a reload. Some features at the HL are persistent and encouraging. Nothing really bad to say. And the things I am referring to are in la la land anyway. But, still interesting to attempt to figure out what is going on and thier implications for the base state as we enter December.

I see a lot of blue positives on that map. Funny thing is maybe we don't lose a ton of NA snow cover this coming December like last year. That in itself ups the ante for future arctic outbreaks here.

BAMMWX energy clients following their advice must be very happy. Potential for some traders to make big bucks if the real deal does go down. Not sure what the short positions currently are in the NG market. There goes the tropical analogs

Do you have any research or memory to support how well the GEFS , the Euro and the regular GFS does with strat forecasts ? ( or how well against each other ) I recall at times the GEFS does very well. I also read that the GloSea model ( from Euro I think ) has had a coup from time to time. I ask because I came across this morning two interesting posts. Goes along with my post above. You may even be aware of this already.

Yes, the signs so far are positive. I was looking this morning at the other side of the pole and there are forecasts going out in time for some crazy low latitude snowfall in that region. Speculation increasing that if we do re-establish the previous cross-polar flow in late December or Jan., it could be very brutal. Some mets who engage in seasonal forecasting have mentioned this potential for the first half of winter. My request is some moisture to go with that cold please.

Peak climo can't get here soon enough. I hope we get snow on snow on snow. Like A Hallmark card please .

Have to see how this plays out in December. This is the latest update. So you have the Euro versus the UKMO

According to the the Euro, as you know, most of the true arctic air shifts over to Siberia by day 10. Wonder again about the progression of things at the very end of November and early December. Really have two schools of thought on the matter. I believe it was two or three winters ago when a similar occurrence happened and eventually that arctic air mass sloshed back to our side of the pole and eventually made it to the lower latitudes. Over time the air mass over Siberia is really going to get even colder. Some 1065 mb Highs over there. Maybe the seeds planted for the next time we tap into cross polar flow. No extreme cold in sight after day 10 though. .

Split flow

Close to real time, and just bringing this up, because of the lack of sea ice in this region, and the cause and effect relationship in this new era of reduced sea ice and forcing patterns. This is one region where sea ice recovery has been almost nonexistent so far this Fall. Cool post by Tom.

This is one time where the rapid delivery of snow cover to our far North and Northwest contributed to the very anomalous cold air mass here, setting all sorts of records. Nicely put by Maue in a weather related post of all things :-) We also had the air mass originate at the pole as well. Pretty awesome ! There was even cross-polar flow as well. Regardless of snow cover and the SAI theory having a robust NA snow cover really helped in the arctic discharge this go around Imagine if we do this again in some form, or fashion in the next 4 to 8 weeks, it will be truly brutal.

Lets see if we can get some agreement from the EPS. But, for many burnt by last year, mets I mean, most are taking a wait and see approach, can't blame them. But, this is nice to see.

I like Sam's post here almost as much as the one he originally did on this topic, a couple months ago, from a tool he created himself. Looks like cold might be on the way. ( not counting the the cold that is here already )

Well, another great post by Tony. Will be most fascinating watching the developments in the coming weeks.

Well, that is interesting, get an early- season SSW , ( absorbing type vortex split ) and then without coupling the vortex recovers and gets very strong. Simon mentions it was a non-downward propagating event. Didn't HM mention something the other day about a bottoms-up event.

Need to keep an eye on this, just for trends. Regardless, in the short-term, seems elongated towards our region.

Fascinating the evolution you have here Ray regarding December and Jan. and the potential warming in Feb. Seems the opposite, to a degree, versus some other mets and pros. However, the December you portray is along the lines a few others who are calling for colder risks in December. The most surprising and interesting part of your outlook is the timeline. I have always thought getting the progression correct is just as challenging as getting the temps correctly forecasted for each month. Seems the best winter weather according to your outlook is in December into Jan., and then again as you state. " February 17-March 2nd may be conducive". Thanks for your hard work on this presentation. I will need coffee and time put aside later today to read it all, and reflect back on last winter as well.

@bluewave as some have alluded to, including DT in a indirect manner, when we have these Fall coastal storms it may be a good sign for the upcoming winter. My question is when there is such an event as portrayed here can it cause atmospheric eddies, or atmospheric memory that may cause other low pressure areas to drop into this area further down the road in December or even Jan. Or, on the flip side, maybe this system feeds off the one area of still warm SSTs, and that ocean fuel is used up after this event. I imagine there are multiple ways to look at this. Always appreciate your insights.

Another dive into the crystal ball of the NAO domain, venture carefully here.

I like a weakened and perturbed vortex, but one concern I have, is the eventually outcome should we get a SSWE or a split. I prefer a deep long lasting -AO regime. I have been following SSWE for many years and sometimes we do not benefit here. The eventual target zone is hard to pin down and the science is still evolving. Sure weaken the vortex , makes it easier to move around but then as you mention it could reform and get stronger in an area that may not be as conducive for our backyard. You know all this, I am just explaining my concerns. Here are a couple interesting things I came across this morning. Personally I love the depiction in Anthony's post.

HM sounds like he is looking for the progression suggested by few that we are ahead in certain time scales. ie. Jan cold that goes into early Feb. Versus Jan turning gradually colder. Hard to say with his short post. So disclaimer alert there. If we proceed in that fashion then maybe a later thaw, a Feb thaw if you will, and then late Feb and through March very cold with active storm threats. Of course right around Pres weekend :-) going right into March . Many have made associations that a cold November = a cold March. That outcome might be even more so certain this year with the QBO and the solar min, later season or renewed late season blocking. Bring it !

They are riding a hot hand lately. I enjoyed the webinar they did a couple weeks ago, the conclusions are not mere analogs, or even modeling, but a combination of different methodologies. They are going with the colder December, 60 % / 40 % but low confidence, very interesting. I think later December we roll into real winter. I have never have experienced a winter that starts at the winter solstice, with the shortest days. That would be cool to have the flip start at the end of December, or right near the holidays. Uncle ( from NY forum) has analogs that point to a white Christmas. I could go for a marshmallow world by Dean Martin.

Great question. I am not really sure about the need to couple. First, there are different ways to get a vortex disruption/warming, etc. If you go simply by the QBO, and the descent, according to Isotherm we really need to wait for it to decline further, so his forecast of the best blocking is later in season. Personally, I like to see the forecasts of wave 1 activity and the vortex weakening. Are these forecasts correct, I am not sure. I would pay close attention to the next updated QBO value, and the progression of the NAM. I refer to this section of Isotherm's ( I bolded the interesting parts to your reply ) forecast and lets see how the balance of November goes and early December. Maybe it can provide us with hints for the sensible weather in our region for the holidays and late December. As Bob said, if we continue with a -AO later in November and early December it will mean red flags as to the seasonal modeling. @Isotherm snippet from his winter forecast : << The QBO easterly shear stress will eventually down-well to z30; however, the pace of descent as evinced by the slope, and the temperature profile, suggests that there could be a multi-month period of weak positives or near 0 values, prior to the full transition into negative. Concordantly, the true negative phase should not effectuate tropospheric vicissitudes until the second half of winter, particularly February and March. At which time, it is more likely that the NAM/AO tends on the negative side, countermanding the more positive NAM/AO of the first half of winter. It is – additionally – critical to cognize that the likelihood of the stratospheric polar vortex reaching zonal winds of 40 m/s at the 10hpa/60N level in November is very high. Since that event is relatively anomalous, analogs may provide a further hint insofar as auguring the ensuing mean stratospheric (and tropospheric) vortex state. The vast majority of the cases wherein zonal winds reached 40 m/s continued to feature stronger than normal vortices during the winter. Often, reversals occurred in late winter (late January onward). In this particular winter, I anticipate that the stratospheric vortex will weaken significantly in late January, potentially leading to more tropospheric blocking in February. Whether this results in a technical stratospheric warming event is indeterminate. >>

Your dropping the ball, you should be down there chasing that beach snow and get a few brews too !

Really like what is going on the next few weeks in the HL. In a couple weeks we have this : We can see here what is going to transpire the second half of November as we move away from record strong vortex to date. Continued weakness moving forward....tropospheric NAM continues in a negative state Trends and associations with 02 - 03 winter, a decent QBO analog. And wow look at the 1960's Hey timelines are different, but wondering whether we are going to drop big time but just later. Here is a mention to 2009 regarding the weakest zonal wind for today's date ( Weakest zonal wind 10hPa 60N for todays date: 10.6m/s 2009 ) A speculative mention of the GloSea which has done well at certain times, this for Jan and Feb.