Nouska

Excuse me quoting myself but in view of earlier comments - a reminder about the climatology we are setting the anomalies against. I like to use the NOAA upper air charts for purposes such as this. Take a look at the progged day eleven upper air anomaly - when was the last time you saw something as spectacular as that in early November. Even as dramatic as it is, it is not enough of a height differential to reverse the contours right across N America. http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php?dayin=11

Remarkable 10 mb stratosphere chart here. If that was rotated ninety degrees anti-clockwise it would be a good example of a Canadian warming - bearing in mind the terminology is geopotential height displacement rather than temperature based. Does anybody know if there are any analogues for this unusual configuration for early November?

Altering geomagnetic fields on earth and in the sun have been a bit of a crackpot theory in climate but I wonder... https://www.researchgate.net/publication/222817231_Are_there_connections_between_the_Earth's_magnetic_field_and_climate http://www.esa.int/Our_Activities/Observing_the_Earth/Swarm/Earth_s_magnetic_heartbeat Below diagram of shift in magnetic north is very similar to the dots in the PV shift plot in the linked paper.

Looking at October to date, that did not work out so well. I'm going to have a closer scrutiny of this new model when it updates next month. This model accounts for Arctic ice variability besides many other climatological factors.

Interesting tweet from Dr Ventrice. New kid on the block model (NCAR CESM; recently added into the NMME suite) absolutely nailed the US Summer (JAS) forecast. Kudos to NCAR. https://twitter.com/MJVentrice/status/790640972212346880 I posted about this model way back in early autumn as it was showing 'unusual' things for winter season. Has since walked back on the early winter cold but very out of date since so much has been happening in the last month. Due a new run early next month so perhaps one to cast an eye over. http://www.cpc.ncep.noaa.gov/products/NMME/model_monanom_body.shtml Edit to add a bit of background on this model http://www.cesm.ucar.edu/about/

They are not as big as they might appear - at this time of year it is normally a big mass of very low heights over the polar regions. The NOAA anomalies there are also double blends ie. blending five day period and also mix of models. There could well be individual days with more northerly or north easterly influence but it will be mixed out on those charts. Flow might be easier seen on the contour map for day 11 without the anomalies shown.

Positive anomalies indicated by red hatched lines - not necessarily indicative of flow pattern.

JMA seasonal update - quite strong signal for high latitude blocking to be in evidence December and January. Dec Jan http://ds.data.jma.go.jp/gmd/tcc/tcc/products/model/map/4mE/index.html

From the perspective of traditional climatology, you have a valid point but consider this SSTA map for 1st November 2010, QBO in a westerly phase ... Summer transition from El Nino to weak La Nina by late autumn .... What would you have been forecasting for the first month of winter 2010-2011?

Oh, I did!! - and the one from the year before - my favourite go to for unwinding. http://www.mikeolbinski.com/theblog/2015/10/monsoon-ii/

Indeed! A reanalysis of the last thirty years of October AO reveals this very distinctive shift. '85-'00 '01-'15

In answer to some of the questions about what the current stratosphere modelling can bring, it might be useful to look at some of the images from a low sea ice discussion. The focus of this is on the theory of warm Arctic/cold continents but it does show the circulation patterns associated with meridionality and Arctic dipole anomalies - where high and low pressure reside one side or the other rather than low pressure focused in the core of the Arctic circle. The push from N. Canada to W Siberia side results in this type of flow .... The ideal type for cold in the Atlantic bordering countries. With the positioning of the vortex dipole, the feed is cross polar with polar or arctic maritime air mass favoured. Push the high in that image over the Greenland sector and polar continental air comes in to play. Whether the influence is low ice or low solar - I think they are interconnected - there has been a tendency to meridional weather patterns with some very negative AO/NAO winters. Whether this will be one, I don't know but what we are seeing at this early stage can only be a help rather than a hinderance. Images courtesy of the Met office and a great write up by John Mason for Skeptical Science. http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/air-masses/types https://www.skepticalscience.com/print.php?n=1967

Just going to divert a wee bit with an interesting factoid for @claret047 From the Wunderground blog. Nicole is venturing awfully far north for a hurricane Don’t look now, but Hurricane Nicole is making a run for Greenland. Nicole regained hurricane strength on Saturday, the first Atlantic storm to cross the hurricane threshold at least three times in its life since Hurricane Tomas in 2010 (thanks to Phil Klotzbach at Colorado State University for researching this statistic and to wunderground member Oxfordvalley for updating it]. Nicole has stubbornly retained its warm-core characteristics well north of the tropics, making it to 41°N as of 5 am EDT Monday. Nicole was heading north-northeast at about 9 mph and should accelerate in that direction. Eventually, Nicole will become a cold-core system, although that transition may happen extremely far to the north. The National Hurricane Center predicts that Nicole will become a post-tropical cyclone by Tuesday. However, a phase-space diagram produced by Robert Hart (Florida State University) for Nicole on Sunday, October 16, suggested that Nicole would remain a warm-core system (though increasingly asymmetric) until Thursday. On Thursday morning, the NHC forecast has Nicole as a post-tropical cyclone located between Greenland and Iceland, less than 70 miles from the Arctic Circle. Even then, Nicole should still be a powerful storm, with a surface pressure below 970 millibars and peak winds on the order of 60 mph. After Nicole finally dissipates somewhere near Greenland, its core of warm, moist air will continue into the Arctic, where the extent of sea ice is at its lowest mid-October level for any year on record except 2007 and 2012. https://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=3482 The latest phase space diagram showing still borderline warm core very far north. http://moe.met.fsu.edu/cyclonephase/gfs/fcst/index.html

Gavin's videos are a great watch and very informative but you need to remember the charts he is showing are a snapshot in time. The CFS runs four times a day, seven days a week and is constantly varying in output through these runs. I've made a quick gif of the most recent runs and definitely a trend to less positive temp anomalies. Thanks to the user friendly Tropical tidbits which does all the gif work for you. http://www.tropicaltidbits.com/analysis/models/?model=cfs-mon&region=eu&pkg=T2ma&runtime=2016101500&fh=2&xpos=0&ypos=68

I've brought this over from the ENSO thread as I think it might be relevant in terms of what we are seeing modelled in the stratosphere for late October. Strong signals in recent runs for an offset 10mb vortex by the end of October - it would need to be pushed further into the Siberian side for a Canadian warming/ reversal but it is certainly something worth keeping tabs on.

Now that the model runs go out to the end of the month - this October should be a good test for the Taymyr theory - this is the concept of high heights in the region, through all layers of the troposphere, promoting a continuing winter negative AO. October so far ... 500mb 100mb Looking at forecasts, this pattern should remain dominant throughout the rest of the month. http://onlinelibrary.wiley.com/doi/10.1002/joc.3968/abstract

I would not get too hung up on what the seasonal models are showing at this stage of Autumn. Mr Fergusson mentions three models - the three that were used in the winter '15/'16 forecast - how did they perform for last winter from the early November run? GloSea5, ECMWF and Met France monthly mean sea level pressure for December, January and February. Below, the reanalysis for each of the months. As you can see, there were months/models well off the mark with their November runs. Because the models run regularly throughout winter, we get updates and these tend to skew perceptions that the early forecast was better than it actually was.

A tropical cyclone is a warm core storm - relying on ocean heat content to maintain convective activity. As soon as it travels over cooler waters, that convection dies and the storm/hurricane weakens. Mid latitude storms are cold core, relying on air/sea temperature contrasts for baroclinicity. http://www.met.rdg.ac.uk/~storms/concep/baro_inst/

For anybody worrying about what monthly or seasonal forecasts show now - what about this turnabout in one week! Below are the SE European tmax projections from the EC32 last thursday and the new update today. Focus on week commencing 10th October.

A southern hemisphere connection has been a theory mooted previously in scientific studies - some new research to add to the idea. Gulf Stream slowdown tied to changes in Southern Hemisphere http://onlinelibrary.wiley.com/doi/10.1002/2016GL069789/abstract;jsessionid=A3BC7DD017659FBCA9FBF7A3015D3590.f02t04 Abstract. Recent measurements of the strength of the Atlantic overturning circulation at 26°N show a 1 year drop and partial recovery amid a gradual weakening. To examine the extent and impact of the slowdown on basin wide heat and freshwater transports for 2004–2012, a box model that assimilates hydrographic and satellite observations is used to estimate heat transport and freshwater convergence as residuals of the heat and freshwater budgets. Using an independent transport estimate, convergences are converted to transports, which show a high level of spatial coherence. The similarity between Atlantic heat transport and the Agulhas Leakage suggests that it is the source of the surface heat transport anomalies. The freshwater budget in the North Atlantic is dominated by a decrease in freshwater flux. The increasing salinity during the slowdown supports modeling studies that show that heat, not freshwater, drives trends in the overturning circulation in a warming climate. Paper paywalled but a bit more info here. https://www.sciencedaily.com/releases/2016/10/161005084916.htm Looking at other observations to determine the cause, the researchers ruled out what had been the prime suspect until now: that massive melting and freshening in the North Atlantic could stop water from sinking and put the brakes on the overturning circulation, which moves warmer water north along the ocean's surface and sends cold water southward at depths. "It appears that this 10-year slowdown is not related to salinity," Kelly said. In fact, despite more ice melt, surface water in the Arctic is getting saltier and therefore denser, she said, because of less precipitation. "That means the slowdown could not possibly be due to salinity -- it's just backwards. The North Atlantic has actually been getting saltier." Instead, the authors saw a surprising connection with a current around the southern tip of South Africa. In what's known as the Agulhas Current, warm Indian Ocean water flows south along the African coast and around the continent's tip toward the Atlantic, but then makes a sharp turn back to join the stormy southern circumpolar current. Warm water that escapes into the Atlantic around the cape of South Africa is known as the Agulhas Leakage. The new research shows the amount of leakage changes with the quantity of heat transported northward by the overturning circulation. "We've found that the two are connected, but I don't think we've found that one causes the other," Kelly said. "It's more likely that whatever changed the Agulhas changed the whole system."

This hurricane has a double whammy as far as extreme precipitation is concerned - another peculiar 'blob' to add the growing number in meteorology. Dr. J. Marshall Shepherd discusses possible land/atmospheric interactions as the cause. http://www.forbes.com/sites/marshallshepherd/2016/10/03/why-have-we-seen-a-blob-east-of-hurricane-matthews-eye-and-why-it-should-concern-us/#19cbf4f63926 For more insight I reached out to tropical cyclone expert Dr. Stephanie Zick, a professor at Virginia Tech. She agrees with my assertion and adds, “I think there are multiple factors: 1) the stationary band complex, so there would be confluence downshear (east of the TC center), but combined with, 2) a surge in the trade winds and 3) confluence downstream of the South American landmass/terrain. Professor Zick also added, “another factor (albeit more speculative) that I think might be enhancing the convection is a working hypothesis that asymmetries can develop during landfall as drier air from over land moves over the moist boundary layer (modifying moist static stability)."

Another discussion that would point to this being the case. Do strong warm ENSO events control the phase of the stratospheric QBO? Abstract Although there in general are no significant long-term correlations between the QBO and the ENSO in observations we find that the QBO and the ENSO were aligned in the 3 to 4 years after the three warm ENSO events in 1982, 1997, and 2015. We investigate this indicated relationship with a version of the EC-Earth climate model which includes non-orographic gravity waves. We analyze the modelled QBO in ensembles forced with climatological SSTs and observed SSTs. In the ensemble with observed SSTs we find a strong and significant alignment of the ensemble members in the equatorial stratospheric winds in the 2 to 4 years after the strong ENSO event in 1997. This alignment also includes the observed QBO. No such alignment is found in the ensemble with climatological SSTs. These results indicate that strong warm ENSO events can lock the phase of the QBO. http://onlinelibrary.wiley.com/doi/10.1002/2016GL070751/abstract

Ant Massiello has some interesting tweets on solar activity. https://twitter.com/antmasiello This long summer NAO index I can see a low solar signature there - even more startling is the change in our Z500 summer pattern since 2007.

I note the Met office contingency planners forecast is mentioning all the seasonal modelling is showing the signal for November/December as shown in the analogues I posted up the page. http://www.metoffice.gov.uk/media/pdf/1/p/Forecast-temp-OND-v1.pdf

Thanks to @fergieweather for sourcing an answer to my question. Tropical tidbits do an analogue forecast based on SST, cyclone activity and atmosphere - in light of previous comments about different picture this winter, here is their take on the years closely resembling the NH pattern in August. Up until August, it was quite an as you were forecast but the August pattern seems to have changed the ballgame as far as the N.Atlantic picture. Note extensive Arctic blocking for next month and the anomaly for December. Caveat: 2010 in the analogue composite may be totally skewing the December picture. http://www.tropicaltidbits.com/analysis/analogs/