Gulf Stream

nacho libre

https://www.breakingnews.ie/ireland/report-finds-ireland-to-face-cooling-temperatures-as-gulf-stream-weakens-1471461.html

Sorry if this has been already covered in one of the threads. I thought a cooler Atlantic would lead to less Stormy winters. A weakening would be welcome by me if it lead to more blocking episodes during our winters.

Robwindstorm

Hi all, just thought I'd ask your opinions on few things.

Just today we have a new report, 2 years in the making, now claiming our North Atlantic seas are cooling affecting the gulf stream. This is expected to have a cooling effect on Ireland's climate with less intense summer rain but be more stormy similar to Iceland's weather. This appears to be the opposite of what we're told as soon as we have a couple of hot days here in Ireland. Then we're told of droughts and heatwaves with less storms?

The second thing is that maybe We are using too much complicated computer modeling to give a fairly accurate forecast for at least a five day period. I remember the UK met office updated it's forecasting after the 1987 storm failure and they give very accurate weekly forecasts on a Sunday afternoon. If they predicted a storm on Wednesday and snow on a Thursday they got it right. Now we're model watching nearly nowcasts of cold easterlies to be replaced suddenly with mild and wet south westerlies. We are warned of a fast jet stream on computer models spawning dart board lows to being replaced by flabby elongated lows as the time arrives. As Oscar bravo eluded too, there is now new detailed imagery of earth available recently now expected to give more scientific weather forecasts to our phones in the near future. Are we trying to predict the exact shape a cloud ☁️ might be passing over one townland to the next?

Finally, the first autumn and winter with no named storms and probably rightly so. There was a few wetter and windier spells this year than previous years storms in my opinion. I think Met eireann should now update there take on this similar to other countries. A storm to me should concern a large portion of the Island i.e Storm Emma and Storm Darwin affecting inland areas as well as coastal. Because we live on an island facing the large Atlantic Ocean, the West coast might experience very strong coastal winds with a large sea swell and thus might merrit an orange or even red warning along this coastal stretch rather than extending inland around county borders which might only experience a very windy day but no need for storm names?

That's all folks, thanks for reading and looking forward to your opinions

.Donegal.

My understanding is that there has been more traction in recent years to the weakening of the Gulf Stream caused by freshwater melt from Greenland disrupting the conveyor belt of the Gulf Stream. (Think it’s at its weakest in 1000 years?) I’ve read before that the warming will probably mitigate/exceed any cooling caused by the weakening Gulf Stream. This is the first time that Met Eireann have been involved in anything that concluded cooling is likely.

The report also states that the globe will continue to warm but our part of the world may cool because of the weakening of the Gulf Stream. It also states a lot depends on future emissions and just how much the Gulf Stream weakens with a very remote chance that it could collapse completely.

Regarding the impacts to our weather. I read quotes earlier from that Dr in Maynooth(forget his name) He said without the Gulf Stream we’d have a similar climate to Iceland. He went on to say a relative cooling of temperatures, with increased storminess and a decrease in precipitation, especially in the summer.

Less rain in the summer, more storms in the winter and cooler temperatures, I’ll be in the minority here but that sounds good to me. In that scenario if the summers are drier perhaps they could be warmer than now but the winters,spring are cooler and takes down the yearly average overall. Just thinking out loud^

I hope Met Eireann write a piece on this to explain it a little better. I might even email them to see if they would, maybe they might if a few of us did.

sryanbruen

I don't normally give my opinion or stance on topics like this, in spite of how much I talk about stats and past weather, because there's much unknown and I veer away from easily flammable debates (no pun intended there). Significant effects of a Gulf Stream weakening in my opinion are unlikely to be felt in our lifetimes any time soon to reverse the effects of warming. It is a true fact that a certain portion of the North Atlantic Ocean has indeed seen a cooling in stark contrast to anywhere else on earth. This became most evident especially in the years 2014-2016 when we seen the developments of a "cold blob" and wide speculation took place as to where this came from, is it a sign of the cold AMO phase coming soon or was this nature trying to tell us something else. The cold blob resulted in the miserable cool summer of 2015 bringing unusually cool westerly winds at times and combined with an intensified stratospheric polar vortex enhanced the jet stream for winter 2015-16 including the wettest December and month on record in the country. 2015 was the windiest year of the century to date too although still doesn't quite compare to some of the years seen during the 80s/90s when the North Atlantic was in a very cold state until 1995. 2017 was a temporary warmer year in the North Atlantic aiding the hyperactive Atlantic hurricane season that year whilst it cooled back down again in 2018 with a cold horseshoe shape. This was theorised to result in a dry, high pressure dominated summer with similarities to the sea surface temperatures in the famous summer of 1976. Of course that indeed happened. However, the North Atlantic has been in a warm state ever since 2019 and reached record heights in 2022 so who knows..

If we are to see the Atlantic return to a cold state, I could see winters becoming stormier again and summers becoming drier because the cold SSTs can lead to steeper gradients to fuel deep depressions in wintertime or aid high pressure in summertime. Important to note that there has been a decline in winter mean speeds over time, this difference is especially noticeable in the north in exposed places like Malin Head. The years 2010 and 2021 were among the calmest years in Ireland on record. Up until the 1990s, there was somewhat of a trend for drier summers too though of course very wet summers still happened such as 1985 and 1986 but this changed during the 2000s and especially during the infamous 2007-12 period which numerous of those set national or localised rainfall records. This exceptionally wet period of summers, being the result of often strong Greenland blocking and a southerly tracking jet stream, was enough to push summer averages up. More recently, we've seen a higher variety of summer extremes in terms of rainfall - the very wet 2020 contrasting with the dry 2021 and 2022 for example.

I get a sense of this recent history I've described is what inspired a lot of ICARUS Maynooth's thoughts and theories. I could be wrong but I don't think for a long long time that we will see any noteworthy effects of this on the climate and warming will generally continue. That's not discounting the chance of short-term fluctuations as happened in 2015 or 2018 for example. I can believe that this Atlantic cold blob will slow down Ireland's rate of warming relative to other countries but cooling? I don't see that happening.

Robwindstorm

Thanks for opinions guys, you are more technically educated with the scientific end than I certainly am. I remember the buzz words nearly 40 years ago at school to describe Ireland's climate were 'temperate climate' , Gulfstream and one I haven't heard in a long while 'the North Atlantic Drift'. You can see a dramatic change in windspeed and storm tracks in the last couple of decades, your brilliant storm chart readings and comparisons that you frequently post Sryan are testemen to this. I would say you in particular Donegal can see this with Malin Head falling way back on strongest gusts. I enjoy the rainfall radar watching along with the model watching but it appears the last couple of years the weather models fails, sometimes quite dramatically, in a short forecast timeframe. Is there too much information being fed into these super computers every hour where science has overtaken technology and maybe a bit more simplistic approach to forecasting might serve us better for now?

Akrasia

There's a great lecture from last week that discusses this topic

https://youtu.be/KTgj5v0R6os

Ramsdorf doesn't consider a complete shutdown of the AMOC to be a remote chance, and he also spoke about evidence that it could happen quickly and within our lifetimes (if you're under 50)

DOCARCH

Mod Note: Threads merged (and thread name changed).

kindredspirit

In opposition to the forecast cooling of the North Atlantic Drift, I see there is an "Extreme Marine Heatwave" at the moment with sea temperature 4°C to 5°C above normal. Would this be a factor also in our present thundery weather or nothing to do with it at all?

igCorcaigh

https://www.boards.ie/discussion/comment/120738018#Comment_120738018

I'd like to know too! Any expert opinions here?

WolfeEire

https://www.boards.ie/discussion/comment/120738018#Comment_120738018

Would say it's more got to do with a few weeks of very warm temps and generally light winds, thus minimising mixing of the water. The SST refers just to the absolute top of the water only. I would imagine the high SSTs have had some bearing (increased convection) on the recent thunderstorm activity.