Winter 2018/2019 - General Discussion

Im predicting a harsh early winter

nacho libre wrote: »

Why exactly are you leaning to a backloaded winter, with the declining QBO easterly phase surely that favours a milder end to winter? What factors do you see overriding this?

After heavily researching the QBO in the past year since I did my 2017-18 forecast, I think too much weight is put on the QBO. I posted a chart previously in this thread (quoted below) showing the correlation between QBO and Winter CET, there was not much correlation though the severest Winters tended to be on the easterly QBO side (like 1962-63) but this could be more of a coincidence than anything. Winter 1978-79 was a westerly QBO Winter (albeit weak) coming out of a peak of the westerly QBO in Summer 1978 whilst Winter 1979-80 (the easterly QBO Winter then) was mild and wet.

GavsWeatherVids did a good analogue analysis on the QBO in his latest Winter update going back to the 1950s. As you can see from this video, Winter 1977-78 was a transitional easterly to westerly QBO Winter and it was probably the most similar Winter you can find to 2017-18 in terms of our conditions (funny how it was exactly 40 years before). February 1978 had a severe blizzard for the south of Ireland and a notable cold spell. February produced the coldest conditions of the Winter despite being westerly QBO. That's just one example. Other examples include 1985-86 (which was one of the coldest Februaries ever recorded with an enormous amount of northern blocking and persistent easterly winds) and 2008-09 (which had the very snowy spell in early February and was preceded by a major SSW in January).



Looking at the reconstructed QBO cross-section, other Winters that transitioned from easterly to westerly QBO (before 1950) include 1945-46, 1939-40 (mmmm), 1933-34 (nice and frosty), 1931-32, 1925-26, 1913-14, 1911-12, 1909-10, 1907-08. Very interesting to see 1939-40 here, one of the most severe Winters of the 20th century and the first Winter of World War 2. Ironic how the first three Winters of World War 2 were all severe Winters, as well as 1916-17 (the Winter of Ireland's worst snowfalls) of World War 1.

Overriding signals of the westerly QBO can include stratospheric warming events (and we are the most favourable phase of the QBO cycle for a SSW event to occur according to Eric Webb - see stratosphere watch 2018/19 thread that I've been regularly updating as much as I can) and the Atlantic SST profile. Mind you, the Atlantic SST profile is still not particularly favourable for a negative NAO - not impossible for one to occur though.

Just because this Winter is going to be westerly QBO doesn't mean it can't be an epic one. It all depends on how everything lines up. 2008-09 was westerly QBO as was 2010-11 as was 1978-79 as was 1977-78 as was 1946-47.... you could go on and on.

I don't think it will be a straightforward backloaded Winter as one might assume from my post that you quoted nacho libre. As M.T. describes, expect a lot of volatility this Winter. Analogues so far have been very strong on an intriguing January and March with mixed results for December and February. I will not say anything further as I'll give too much away on my Winter 2018-19 forecast in 9 days now.

sryanbruen wrote: »

My graph I generated below shows the QBO for every Winter back to 1949-50 up to 2017-18 (y-axis) along with the Central England Temperature for each of the Winters (x-axis). We can see colder Winters (the Winter average is 4.5c) tend to occur relatively more during easterly QBO years than westerly QBO years especially if it's very/extremely cold levels such as 1962-63 or 2009-10. Not impossible to get a severe Winter in westerly QBO, one in particular there stands out like a sore thumb; 1978-79 which contained the last subzero January for the CET and the last New Year blizzard we have had. 1978-79 was very weak westerly QBO though so explains that.

I thought I already said this in September but looks like I didn't...

I will guess that December will hold some interest but won't be particularly amazing. My guess is that January will be the best month of the three for cold and snow with the pattern easing as we enter February.

circadian wrote: »

I've been trying to figure it out for years. I bet it's something really obvious too.

Your head must be empty if you haven't figured it out

Took me a while also to get it though

Ohhh I just got it

The final frames of the ECMWF shows Scandanavia cooling down considerably (-12c uppers) which is some good news. A low pressure system is expected to developed in the atlantic this day week and the exact westward path of that system will probably create a lot of variation in the model output until it is resolved.

I only got it just before the Beast from the East this year and I've been on boards longer than some of you have been alive (lookin' at you Sryanbruen ;-)

Was telling a family member about MT Craniums' prognosis on the Beast from the East and they stopped me and said, "Empty Cranium???". I laughed and said, "Nooo!! LOL. Its M.T. Craniu........Oh dear God!!"

Gfs gone back to doing its thing into fi

sdanseo wrote: »

A few more frames at the end would be nice. :pac:

It's definitely drunk again.

Seems as tho the FV3 model is popular amongst the net weather guys , any thing to say about that model?

sdanseo wrote: »

Never heard of it!

I think it’s called the gfs parallel in other terms , apparently trialed as it might replace the gfs model in 2019

sdanseo wrote: »

Have messed about with the Parallel but not sure of it's significance. I do remember it being fairly bang on for temperature during the early summer though, albeit with the -3 or so degree bias GFS seems to have.

It's the best performing model in FI at the moment. Believe it or not, the ECM is the worst model at day 6 and guess what... the NAVGEM is the best at day 6 for now!

There’s no doubt that the promise of an early clean Greenland high has consistently downgraded every day since last Thursday, to the point where super cold solutions in the output have all but disappeared right across the board.

First bite of cherry has evaporated, let’s see if a new pattern of interest can emerge from the carnage in the coming days. Looks a lot wetter for month end now with a stalled low likely to impact us from about a weeks time.

icesnowfrost wrote: »

The parallel will replace the operational model in 2019 as the main model.

Thanks for that, was pretty sure it was something like that

It’s crazy how quite it is in here compared to net weather .. mind blowing

ZX7R wrote: »

Not really it's a much bigger forum, have been a member there for years .plenty of straw clutching going on and meltdowns at the moment

Quite a lot , it’s hard to picture what’s going on