We're off to southern Spain next week and the Met Office app is showing temps of high 30s and even a couple of days above 40c. The BBC and others are showing 28-30, which is a hell of a difference. I know most apps are cr*p but the UKMO are usually the best of the bunch, so who do we believe?

Originally Posted by: DickyBill 

Early snow cover patterns point to polar vortex disruption, signaling harsh winter ahead across North America and Europe.

Originally Posted by: DEW 

Ahh, reminds me of the good old days of the OPI.

https://community.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/ 

Whatever happened to that? Oh yes, it was a load of rubbish. Sounded good though!

(We get these sorts of articles every year, of course, and one day through pure luck rather than skill they may end up being right. It's comforting in a way, though, that despite several orders of magnitude of improvements in computational power over the past few decades, we still can't really do seasonal forecasting with any great accuracy. I doubt we ever will in my lifetime, TBH!)

Retron wrote:

I know - We had an easterly QBO last winter and despite that along with early snowfall in Scandinavia we still didn't pull off anything colder. I wonder if the incredibly wet autumn we are having now will have any impact on our winters weather, as it has been a while since we have seen a wetter than average autumn.

Originally Posted by: tallyho_83 

Ahh, reminds me of the good old days of the OPI.

https://community.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/ 

Whatever happened to that? Oh yes, it was a load of rubbish. Sounded good though!

(We get these sorts of articles every year, of course, and one day through pure luck rather than skill they may end up being right. It's comforting in a way, though, that despite several orders of magnitude of improvements in computational power over the past few decades, we still can't really do seasonal forecasting with any great accuracy. I doubt we ever will in my lifetime, TBH!)

Originally Posted by: Retron 

I remember that set of posts in here and on NW about the October Pattern Index.  Some Italian researchers were attempting to correlate the degree of "non circularity" (or some arcane math function !) of the 500mb pressure pattern in the NH in October with the weakness of the Arctic Oscillation in the following winter on the premise that a weak AO generally leads to a colder winter in the NH as polar air tends to leak out more

They boasted a r value of about 0.9 IIRC between their OPI and the following AOI using a few years of historical data but they managed to prove that correlation is not causation when the following winter failed the test and the whole project seemed to disappear without a trace

As Retron says, even  with the huge increases in computing power and data availability, no-one has ever come up with a seasonal predictor that actually works 100%. Given the number of feedback loops and feedback of the feedback ad infinitum, perhaps it is an impossible objective as it is in effect down to chance. OTOH, the weather often does follow long periods of "sameness"  such as winters like 1963, 1979, or summers like 1976 or 2018 so it is not just switching wildly from type to type every day. Some higher level controlling events must be at play somewhere so I am still interested in initiatives like the OPI even when they always seem to end up doomed to failure

Originally Posted by: lanky