[derekon]

With a milder regime about to kick in during next week and in the run up to Christmas Day 2011 along with the NAO and AO remaining positive, things do not look good at the moment for a potential Big Freeze.

With models forecasting no severe cold, the Atlantic currently raging and by the end of this month one third of the Irish winter would have passed, is it time to call it and say there will be no Big Freeze for winter 2011/2012 in Ireland?

Or is it just too early to say?

D

[blackius]

Originally Posted by Kippure

These are just notes and observations at the moment. But if you notice the warmer seas around our coast at the moment, WHEN we get the "BEAST from the EAST" in January, expect to see Explosive Snow streamers coming in off the Irish sea, due to very cold air rushing accross very warm water....








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Theres confidence for you.
But there are no signs of it happening.

NAO is positive.At the rate things are going to get that negative and the delay beyond that for any high pressure to set it self up mid atlantic and tilt in the right way to drag down said north easterlies,it will be march or april.
By which time it will be too late.
Iirc,the NAO was negative for most of the year in 2010..

Contrast that with 2011 and you can see theres a lot of bedding in to be done with the as of now non existent high pressure so getting hopes up is futile.

[blackius]

Nope.
You can have an effective severe cold in February,even march.
Anytime from mid January to the end of February is the window.
After that,It's bring on the heat please.

Iirc february 1991 did not involve an atlantic high,it was a super strong perfectly positioned scandi high and it delivered sub zero days and plenty snow

I'd agree,the lack of any real winter weather in sight is disheartening for the cold lovers.

I don't rate the current spell at all.

[cherryghost]

January is historically more common for a big freeze event to occur. We have 1 or even 2 months left until we can dash our hopes

[Kippure]

17 days in lads.......to early for this.

[DOCARCH]

The infamous winter of 1947 only got going mid to end of January, up to that it had been a pretty mild and wet winter.

The problem is that we were spoilt last year with possibly one of the earliest (in terms of winter) cold and snowy periods on record.

In the olden days I never expected snow before Christmas, it was always after Christmas that thoughts would turn to snow hunting!

[blackius]

Originally Posted by Kippure

17 days in lads.......to early for this.

[mcriot29]

Id like to draw peoples attention to the 2 nd part of last years big freeze at this time , frist the crew over on the strat forum on netweather said there was nout on cards before it came as in strat warming etc , so this shows us you cant just go by strat warming for a dip in the AO index . Another point is look how cold strat is yet we have had some very cold weather dublin has been colder then germany , warsaw , stockholm this past week .
Below is what a us forecaster thinks
However, I mentioned that the La Niña's influence would be weak. The true drivers of the long-term pattern will be the Arctic Oscillation, the North Atlantic Oscillation, and the East Pacific Oscillation. A negative summer AO and NAO is associated with a negative AO and NAO the following winter. This past summer the AO was the third lowest it has ever been, and the NAO was the second lowest it has ever been. In addition, both indexes were solidly negative for each of the months of June, July, and August. This would support a solidly negative AO and NAO this winter. Solar geomagnetic activity is still low, which would suggest enhanced chances of strong blocking (negative AO). The QBO is turning from positive to negative, which could bring an interesting situation, with the AO being forced farther down by the –QBO at 30mb without the enhanced southeast ridge that a –QBO at 50mb would bring. The summer SST configuration in the north Atlantic is pointing towards a negative NAO, though not as much as it did last year. However, a deeper look reveals that this pattern is very strongly pointing towards a negative west-based NAO, that is, a blocking high between Baffin Island and Greenland. This supports cold in the eastern US way more than a negative east-based (high between Greenland and Iceland) or neutral-based (high right over Greenland) NAO does. There is some speculation that the eruption of Eyjafjallajökull slightly reduced the NAO and AO during 2010-2011. If so, then it is likely that this year's eruption of Grímsvötn will have a similar effect this winter. There is currently record cold air over Alaska and Canada, and it is only a matter of time until the pattern changes and brings this cold air down to the United States. The final consideration of these three is the EPO. A first glance at the current pattern shows that the EPO is strongly positive and has been for quite a while, with a very powerful vortex over Alaska. However, that is not supported at all by the increasingly obvious east basis of the La Niña. I expect the vortex to become a bit weaker, and, more importantly, to retrograde toward the Aleutian Islands as the month of December progresses. This seemingly small change makes a world of difference for the pattern, as it would switch the EPO from strongly positive to strongly negative once an upper-level high takes the vortex's place.

[Redsunset]

http://www.instantweathermaps.com/wf_2011-2012.php
As above post
Deserves to be thrown in a big dustbin. Rubbish

[maw368]

Originally Posted by DOCARCH

The infamous winter of 1947 only got going mid to end of January, up to that it had been a pretty mild and wet winter.

The problem is that we were spoilt last year with possibly one of the earliest (in terms of winter) cold and snowy periods on record.

In the olden days I never expected snow before Christmas, it was always after Christmas that thoughts would turn to snow hunting!

Exactly, everyone I talk to keep comparing this winter to last year and saying ah well we've missed winter now and its crap in comparison. Last year was a freak of nature and I have always been the same, expecting and getting snow after christmas. I remember a few christmas days disappointed because I couldn't race my electric cars outside as it was still raining and then snow from late Jan until March; sadly though these have mostly been the wet kind of snow falls which are not as fun as the crispy stuff we had last year. Also these later snows tended to be short lived in my experience, often melted away withitn a couple of days. Last year was lovely, I got to enjoy a month of compacted snow and ice on my cycle to work.

[Redsunset]

The Strat Warming at the beginning of last November was near record breaking even though it was not classed as a Major Midwinter Warming it DID play an important role in weakening the Polar Vortex for our cold spells later on.

[mcriot29]

DEAR SANTA PLEASE CAN I HAVE THIS IN MY STOCKING THIS YEAR


AND THIS

[mcriot29]

Originally Posted by redsunset

The Strat Warming at the beginning of last November was near record breaking even though it was not classed as a Major Midwinter Warming it DID play an important role in weakening the Polar Vortex for our cold spells later on.

So whats your views on any chances of cold in jan feb 2012
can you see the AO dipping

[Redsunset]

Baby steps,
The Strat is so cold at the moment and not good cause this keeps a strong PV westerly flow,however get it to warm up somewhat and then this decreases Polar Vortex strength and gives us better chance of height rises,(negative AO).

There have been several years when Nov and Dec strat have been almost as cold as now and in Jan arrived a Major strat warming,(84/85 as an example).So all is not lost.
Monthly Mean Strat temps at 30mb

1984 QBO East
Nov -71
Dec -73

1985
Jan -53 (Major Midwinter Warming)

Result
Jan - Feb 1985

[Redsunset]

Maps drawn up focusing on La Nina central based years as we are currently in.


Without a Strat Warming conditions in Jan




With a Strat Warming conditions in Jan and i think is in line with M.T's view of Scandi high bringing easterly fllow