Winter 20/21 - General Discussion

nacho libre wrote: »

A bit different to this time last year! Could we be on the cusp of something decent?

What is this a chart of?

A frosty one tomorrow night. I always like to see the frost coming. It gives hope.

hatrickpatrick wrote: »

The pub run is now showing the development of a Scandi high beginning within the reliable timeframe. Certainly some more interesting charts than we've had over the last few winters since The Beast...

It’s definitely improving alright as the runs go, but the gate to the garden path is still wide open at this point.

Very little chance of Nov/Dec 2010 ever being repeated in our lifetimes never mind the coming weeks

The world is 10 years warmer. Also our weather appears to have got more mobile in the past few years so even a spell of -5c will quickly be shoved away by slightly milder Northwesterlies or the boring Southwesterlies of the past 5 Winters

It looks like it is going to get cold and dry, but to get all the pieces in place for something really wintry you need a low in the med and that high out west to take proper hold in Greenland. Unfortunately, it look as if on current guidance that there is still too much residual energy around Greenland for that to happen
It's easy to say there is very little chance of a repeat of 2010 since it was likely a once in a lifetime event, but the hemisphere profile is a lot more favourable than this time last year, it would just take a few tweaks for snowy cold to come here.

The fact December 2010 is getting mentioned as a comparison is completely unwarranted. As others have touted, that was a once in a lifetime event and it is likely we will not see a period as severely cold as that in Ireland any time soon. Met É have said themselves that it was probably the most extreme sustained cold spell in Ireland on record (which takes into account cold spells such as 1878, 1881, 1895, 1917, 1947 and 1963) whilst 1947 and 1963 were longer but not quite to the depths of cold as late 2010.

This looks more like late November/early December 2016 (if one wants to make a recent comparison) before the mild weather returned for the rest of the winter. We had a settled and frosty spell at that time caused by high pressure either centred over us or in the Sceuro region between Scandinavia and central Europe and ridging towards us. Similar occurring this time around.

We also had a couple of frosts to end November and to start December last year... then the impending 'Polar Vortex of Doom' dominated right until mid-March.

I'll be giving an update in the stratosphere watch thread later or soon but looks like the stratospheric polar vortex continues to develop around 2 standard deviations above average meaning stronger than normal zonal mean zonal winds in the stratosphere which should increase the risk of stormy and mild weather. However, at the moment and for the foreseeable future, it looks like we have a disconnection between the strat and trop so that is partly how we're getting this cool and settled weather.

SST anomalies continue to not look great for the 8th year in a row with no evidence of a North Atlantic tripole pattern to favour a sustained -NAO.

La Niña has stalled recently and the ENSO region has actually warmed up somewhat to solidly moderate levels. But of course, we've seen this November that there has been a lack of Niña footprint - i.e. mid-Atlantic ridge which is typically seen in Nov/Dec during La Niña events. This can be blamed on the tropics where convection activity has made patterns more indicative of El Niño than La Niña. This is set to change very soon according to model forecasts and gives an increased risk of blocking retrogressing to higher latitudes but as ever, that is not a given.. as I said, other things like SST anomalies are not great.

There's always "something" isn't there.

I think we might need Icelandic volcano to give us another 2010

Frosty in North Kildare since not long after 17:00.

I already set up the stratosphere watch thread hatrickpatrick

Looks like a standard minor warming to me that we see a few of every winter pretty much.

Stat warming is false hope for cold lovers. Every year around this time it is the same story. It is pretty much like the concept that the 'jet stream' dictates large scale weather patterns, when in reality it is the large scale weather patterns that dictate the position of the jet stream. Winter is coming, and that will be the most important determiner of all as to whether we got a good cold, snowy spell or not.

I think it is amusing though that I observed more frosty mornings in September than I have done in Oct/Nov combined.

Slashermcguirk wrote: »

WTF? We had an incredible winter as recently as 2018! Like over a metre of snow in places. The negativity on here never seizes to amaze me. Winter starts next week

That incredible Winter was 2 days of heavy snow. The rest of all the Winter was benign