FI Charts ( T120+ onwards) Winter 2024/2025 **READ MOD NOTE IN FIRST

I think you said it before re: cold prospects, @Gonzo . You need to be seeing some sub -10c members showing up on the ensembles to generate interest in proper cold/wintry weather potential when you are looking at days 10-16. I swear by this too. I also swear by the NAO index (moreso than AO index) for real cold prospects. Very rarely do we see very cold weather with a strongly positive NAO, with the exception of brief cold northwesterly delivering high ground snow in the W and NW.

Let's see if the dip south continues into the first week of February. p.s. for those who don't know, a negative NAO means a less mobile Altantic setup and a higher likelihood of blocking. The dip shown below in mid Nov corresponded with the snow brought about by Storm Darragh, there was a brief cold spell in mid December, and the January dip correlates with the most recent cold spell.

Our weather will cool down from next week and we will most likely see a slow transition to a SW to W/NW setup that we are accustomed to at this time of year i.e. Atlantic systems drawing in colder air for 1-2 days before another system lands. Nothing by way of deeper cold is currently signalled. Eyes peeled for any change to that.

Far out in FI but latest GFS shows blocking to our North east. Unfortunately we have low pressure close to our west which doesn’t allow an easterly to get to us or UK (Scandinavia gets the beast instead) A few adjustments and we would be in business.

Looks like a battle coming up between a big lobe of the polar vortex to our NW and a big strong block forming to our E/NE.

The type of setup that can leave us in southerlies/south westerlies and the rest of mainland Europe sent to the freezer, if the block is too far to the East.

If the lobe of the vortex to our NW starts chucking out big lows towards us ala GFS 6z I just can't see the block winning and it will all fade away eastwards.

GFS 6z as good as splits the vortex but everything is just in the wrong positions for it to mean much, shows how many cards have to fall into place for us! Too much energy in the lobe to our NW. I was posting the previous week about getting the bulk of the vortex to displace towards Asia, would give the more favourable gap for retrogression. But having a strong lobe over Canada/Greenland...not ideal as it can really fire up the Atlantic. But it's something to work with and track.

We had some lovely weather in March around 2010 or 11, I think it got above 20C if memory serves. These days more often than not it seems to be an extension of winter and often the coldest most miserable month of the winter as everyone's fed up of the cold.

On the current charts, the Siberian high building westward in late Jan/Feb happens most years but rarely amounts to much for us, but at least it's something to look at again after what looks like a very boring couple of weeks coming up

And the blocking to our Northeast is on the latest GFS 12z as well (Same timeframe) Again the pesky purple vortex to our west is causing us to remain in cold zonality rather than a continental freezing easterly. Certainly worth keeping an eye on though and to see if other models show similar.

850 temps below:

Yes, March 2012. I remember wearing a t-shirt and getting a tan, but that was our summer. The summer was one of the dullest and prolonged wet to damp periods ever.

The charts are in battle mode towards the 2nd half of January. Very cold airmasses meeting warm air masses over the atlantic and firing up the Jet means some serious storms brewing. These storms might affect our shores, depending how far east that high drifts .With storms like these churning up the airmasses, I don't think any charts can handle the aftermath. I don't think any charts or forecast predicted the recent snow down south until 2 days out, so there's plenty of time for twists for snow lovers. As Syran pointed out though, we've had no prolonged wet spell for a while.

And who can forget that Storm Darwin landed on us in February 2014. Lets hope that we don't get a repeat of that, Darragh was quite enough destruction for one season.

For now the GFS is showing a 100mm difference between east and west in precipitation totals for the rest of January. Cork tends to get around 130mm in January on average so the rest of this month is trending fairly wet for the SW, hopefully not a sign of things to come.

18z is a lot more interesting with low pressure undercutting into Europe and a proper Scandi trying to get an easterly airflow going. This would be quite cold.

This particular solution shows Tipperary getting another snow event on the 24th January - giveitholly look away and hopefully for you this does not come off.

It is the pub run as they say..

Edit: Just seen Ros4Sam24's post above after I posted it!

I think late January could be a re run of winters when the continent was locked in the freezer while we had to endure low pressures on a north west to south east trajectory- which could bring brief colder outbreaks between Atlantic systems, but nothing too severe

That could very well happen, I think what is very interesting with the models is over the last couple of days they have been showing the block pushing back against the progression of the Atlantic and the energy coming out of Canada. If this trend continues it could become very favourable for cold but there are a lot of options on the table and most aren't cold so at this stage it is just a watching brief.

To give an example below is the GFS 6z today and below that is the 6z from yesterday both for 24th Jan. Over the next few days we are going to see some great runs and very poor runs depending on whether the block holds and where it is positioned. Beats looking out at the grey mist and drizzle and temps of 11.5C anyway!!

Interesting how the UKMO mention that (very small) chance of easterly winds.

The Met Éireann long range is just an interpretation of the EC46, nothing we don't already know from reading the charts ourselves.

EDIT: I accidentally pressed post before I was finished typing. I meant to also say but yeah it would be surprising if a Scandi were to be able to hold back the influence of the Atlantic trough via the Greenland vortex lobe.

Shades of Jan/Feb 2012 about those charts, I remember all the hype and anticipation for a whole week beforehand only for the Atlantic to push far enough east at the last minute while the whole of Europe, including Britain were plunged into an extreme cold spell. The Six Nations match in Paris had to be postponed right before kickoff as the pitch was frozen solid