Nouska

The new DWD Icosahedral model is having a stab at forecasting placement of convective activity. I've been monitoring it over winter for the few occasions in France - so far so good but the real test is about to begin. Zoom for England/France and below the wider European view. http://www.meteociel.fr/modeles/icone_cartes.php?ech=6&code=0&mode=10&map=1&archive=0 http://www.meteociel.fr/modeles/icone_cartes.php?ech=6&code=0&mode=10&map=0&archive=0

These low cycles can bump about a bit - no guarantees - but the forecast for the next month shows similar to what has been recorded recently. Images courtesy of the BOM and NWRA. Past month forecast

A question for Vorticity..... Why have you used the JFM rather than the FMA composites? As said on model thread, I don't know a lot about this subject so would be interested to know if there is a lag that indicates we should be back two months for the composite rather than use middle month (March) which is the one that the current mid term forecast goes into. Both those composites have a tendency to Greenland blocking - as per IF, isn't that what the GloSea5 was showing for March?

Thanks for the link - hadn't read that one. Just to add to the above post - the NH Z500 anomalies for both La Nina and ENSO4 (Modoki) in March. Nina ENSO 4 You can maybe see where the GloSea5 and ECM32 are getting different messages from. Although I've always been led to believe that ENSO has very weak influence on the UK region, this would indicate that it can make a very big difference in certain circumstances.

I don't know much about the GWO but I think he is saying that there is/will be a major disconnect between ocean and atmosphere signals and therefore analogues/teleconnections will not be of much use in mid term modelling. There's change afoot in ENSO regions with a Modoki taking shape. That has very different weather patterns to a regular El Nino. Patterns for each month under different ENSO conditions from JMA climate pages. http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/newoceanindex/index.html The MJO is in the 'Doldrums'. All in, possibly a period of indecision in the NWP while it works out whether it should be modelling for air or sea.

The Finnish Met Institute have been doing some research on this factor and have a graph of winters 1958 to 2012. http://journal.frontiersin.org/Journal/10.3389/fphy.2014.00025/full?utm_source=newsletter&utm_medium=web&utm_campaign=Physics-w18-2014

No one thing can work alone. As S4Lancia and Enteritus point out, a multiplicity of factors and how they all interact with or nullify each other makes any long range forecast an impossible goal. What we can say is that certain factors predispose towards certain outcomes. Professor Lockwood (and others) talk about a low solar predisposition to blocked weather patterns in the N Atlantic regions. This comes about by a weak and displaced jet stream - for a location such as the UK, it is just as likely to be in the warm sector as the cold sector and even the cold sector can be modified substantially by oceanic influence.

I'm afraid I will have to take issue with the highlighted sentence - '62/'63 was about as close to minimum as it is possible to get, especially considering the intensity of the cycle. Sorry, taking this off topic but it is part of the stratosphere dynamic.

IMO, both the Cohen and OPI theories have fallen foul of looking at too limited a time span and (probably) too limited driving mechanisms. The recent changes in mid latitude weather patterns and extreme blocking events have been well researched and variously attributed to changing solar conditions and/or rapid decline in Arctic ice/snow cover. These factors are not constant - continuously reconfiguring - depending on a multitude of factors. Europe's recent cold winters coincided with very low ice in Kara/Barents seas but they also coincided with low and extended solar minimum - one or the other? - bit of both would be my guess. Kevin, I know you are not a fan of solar theory for cold winters but, again IMO, it is of no help if the two geomagnetic spikes in this cycle have occurred just before or during NH winter.

For those who don't have access to the ECM data on Weatherbell - the WSI blog has posted up some charts from the most recent ECM32. Headline - cooler into March. Images courtesy of WSI ... http://www.wsi.com/blog/wp-content/uploads/ECM_125.png

These guys think winter is over too Big skeins going overhead today - about a month too early! Looking at the late run modelling for their destinations - let's hope a similar fate, to the one detailed below, does not await some of them. http://www.spiegel.de/international/germany/thick-fog-causes-cranes-to-fly-to-deaths-during-spring-migration-a-888609.html

The more recent climatology of the Environment Canada SST anomaly map shows this I think. Just a thought - could the lack of coast hugging hurricanes, over the last two seasons, have the effect of not mixing out the warmth of the gulf stream? A good site for analysis of the oceans and ice. http://bulletin.mercator-ocean.fr/fr/PSY4#2/69.7/-51.3

The three steps that we don't see on the regular ECM output; 150, 156 and162 shown in comparison to the GFS. Differences couldn't be more stark. Who will be nearer the mark or will it be a halfway house?

The EPS show it to be such an outlier that it will not show up on the mean charts. last night and this morning. 12Z 00Z

The signal was in the ensembles - I mentioned it yesterday - in reply to mushy. https://forum.netweather.tv/topic/82438-model-output-discussion-1st-february-onwards-12z/?p=3166155 Growing support on the GEFS as well. 850 winds on the bottom graph.

The NWP output is not surprising given that two of the key drivers of weather signal high pressure cells in the vicinity of the UK. The MJO wants to perform handbrake turns in phases seven and eight.... ...and the ENSO composites for the warmer three/four sector are also high pressure dominant.

I think your Manchester index would be a good example - it is weather we see and feel on the ground.

I was comparing like for like ie Holland as it was the ECM ensemble output that was being looked at. There is a scatter in the ensembles for mid month with lowering of 850 temps while increasing winds at that height. It is not reflected in the ops or the bulk of the ensemble so will be very muted out on mean charts.

Does the northerly have ensemble support in the longer time frame? - yes it does , but is it normal scatter at that range or is it a valid signal. Quiet anticyclonic conditions up till the 12th and then a scatter to stronger winds on a westerly to northerly vector. Wind direction won't tell much as it is around the high into Holland - wind speed a better indicator of change. The GFS ensembles have been signalling some kind of change is possible around mid month. Perhaps the ECM32 being run with the most recent data will give a more coherent signal.

That's a doozy of a low! Now where have I seen one similar? - ah yes, I was looking through the charts for the upstream analogue years.

NOAA are doing something similar with analogue calibrations. http://www.esrl.noaa.gov/psd/forecasts/reforecast2/probabilities/index.html A bit more meat on the bones of the GS5 and detail about the hindcasting to bias correct. http://onlinelibrary.wiley.com/doi/10.1002/qj.2396/full

Further to my post on the MJO last night - first output reflecting possible phase eight coming into very low resolution. It is not there yet on the Pacific side but it is a step in the right direction.

Absolutely....and may continue to do so if the cycles stay low or erratic. A look at individual cycles does show a tendency for these cold winters to occur when there is a sharp drop in the activity - in some, maximum is ill defined due to being very weak overall - a figure of around 50 seems associated with some of the very severe winters of early last century. This Berlin table gives a good analysis of stratospheric activity for last sixty years - the SSN is in the first column. The state of the early vortex and the synoptic pattern in place does seem to have a bearing on how the winter pans out. http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html The archive of the sunspot cycles. http://www.ips.gov.au/Educational/2/3/1 For example, 1906 is technically at maximum but look at the dip just before a cold winter. Again, the dip in 1916 and also a very pronounced drop in late 1939. 46/47 was definitely at peak - by my definition it should have been the next one along - we don't know what else was going on above as archive doesn't go back that far.

Solar cycle 21 was an active one which had some very sharp dips during the maximum and down slope period. Quite a few of the memorable cold months occurred during or just after these sharp downswings. Maybe coincidence but if the newer theories on geomagnetic activity have any mileage, there might be a link. It has been shown from papers linked on the Strat threads that solar activity has an influence on stratospheric conditions - both the winters you mention had very disturbed vortex patterns due to Canadian warmings in the late autumn/early winter.

I know it has been mentioned that the MJO is not expected to be a player in the near future but I wonder if that will actually be the case. Perhaps the idea of heights retrogressing to Greenland and a Euro trough might soon appear on future modelling. The multi-model chart for the MJO has more agreement than of late and there is a bit of amplification. Note the UKMO is not at the party but only shows a week rather than the fortnight. The composites for six, seven and eight are all plausible with six/going on seven already showing in current suite. I've chosen the composites that are not specific for El Nino as I don't believe the atmosphere and ocean are properly coupled.