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FI Charts ( T120+ onwards) Spring 2023 **READ MOD NOTE IN FIRST POST**

  • 25-02-2023 1:11pm
    #1
    Moderators, Science, Health & Environment Moderators Posts: 16,693 Mod ✭✭✭✭


    Mod Note


    This thread is for posting/discussing/analyzing FI CHARTS ONLY i.e. Charts in the unreliable time frame, generally +T120 onward for Spring 2023.


    If your post does not specifically relate to an FI chart then it doesn't belong here - Off topic posts will be moved


    Thanks


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    After another mild Irish winter we now turn our attention to Spring. We are currently in a relatively dry pattern since the second week of January and this looks like continuing for at least another 7 to 10 days. The first half of March is likely to be fairly dry overall with high pressure near or over us much of the time.

    After a very warm February, temperatures have cooled down back to about average for the time of year. Temperatures look like they will stay close to average for the first week of March with maybe a slight cooling trend for the second week of March. Frost is possible at times over the coming 7 to 14 days but as of now there is nothing particularly cold in the outlook with night time temperatures generally above 0C for the most part, however we may get a few nights of -1 or -2C. Day time temperatures generally between 6 and 11C.


    At the moment it is looking unlikely we will see any significant cold outbreaks for the first half of March with Ireland possibly stuck in no mans land between cold northerly plunges to our east and milder more unsettled conditions from the Atlantic which will struggle to make much progress over us.


    There is a chance we may have some cold spells around the middle of March which will either produce some cold rain or wet snow depending on if we get a direct hit or a glancing blow.

    Up to the 7th of March looks mostly dry but there is a trend to turn things more unsettled as we begin the second week of March. This is dependent on either the Atlantic making a come back with mild and unsettled conditions or an unstable and cold plunge from the east/north-east. If these 2 scenarios don't happen we are likely to stay high and dry into the middle of March but that is a long way off.

    Most of the GFS ensemble members keep things relatively mild or average in terms of upper air temperatures up to the middle of March with not much support for genuine cold.

    Just for reference the ECM ensembles are very similar keeping things relatively dry till the 7th of March and temperatures around average for the time of year.

    GFS precipitation charts show little to no rainfall over the next 10 days or so. A chance of some light rain showers on the eastern and southern coasts as well as coastal areas of Donegal.

    At the very end of week 2 of March not much change, still looking largely dry across the country so it's very possible we are looking at a very dry first half to March.


    Post edited by Meteorite58 on


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Comments

  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    Just another GFS run to add to its growing list of ridiculous runs... likelihood: 0.1%


    Post edited by sryanbruen on


  • Registered Users Posts: 1,009 ✭✭✭Neddyusa


    What's taupunkt. Dew point?



  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    Yes, second dew point chart was meant to be air min temp for Friday morning. Fixed now.



  • Registered Users Posts: 995 ✭✭✭Ragwort and Stones




  • Moderators, Science, Health & Environment Moderators Posts: 16,693 Mod ✭✭✭✭Gonzo


    -20C dew points near the south-east coast of England, very believable also. The 12z is obviously an outlier but not on it's own, there are 3 other members that go significantly colder around the -15 to -16 upper air temperature range. The pub run should sober up later.


    Post edited by Gonzo on


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  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    I will give this till about Tuesday or Wednesday by that stage the models should have factored in the fallout from the final warming. If by that stage we find the deep cold still remains elusive to the east of us, I might call it a day.

    If this does fail, I can see another attempt at a cold outbreak later on in the month. At that stage It would have to be something truly exceptional then to grab my interest - like a snow storm that will be remembered decades from now.



  • Moderators, Science, Health & Environment Moderators Posts: 16,693 Mod ✭✭✭✭Gonzo


    Pub run tonight, a definite warm outlier but temperatures lifting up and taking off into the middle of March with temperatures possibly reaching 18C or 19C if it verified.

    Overall the ensemble backs away further from anything remotely cold with a fairly significant swing to mild. Temperatures reaching 20 or 21C in parts of England on this run if it verified.



  • Moderators, Science, Health & Environment Moderators Posts: 16,693 Mod ✭✭✭✭Gonzo


    The GFS 00z and 06z continue with an average to mild, sometimes very mild outlook. It is becoming much clearer now that the chance of getting a proper cold snap or spell in the first half of March is looking increasingly unlikely. Unless we see a sudden change in the models by tomorrow or Tuesday at the latest, I am done looking for cold and snow at this point and see what next winter brings, but i'm quickly losing my enthusiasm for winter in general.

    Summer is quickly becoming my favourite season as we usually do get some nice summery days or spells. Our summers are not the best but at least they make some sort of a half decent effort most years which sadly cannot be said about our non event winters.

    As for this Spring I'm hoping for a generally anti cyclonic Spring with plenty of dry weather, some sunshine and warmer than average temperatures (although I think March will be fairly average overall).

    Back to the GFS and the models look like the Atlantic is going to make a come back around the 7th to 11th of March and we go flat as a pancake with mild and cooler sectors alternating.




  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    Those hoping for a warm spring could be disappointed. While the SSW may not deliver snowy cold, it's possible we will see period of below average weather well into April due to it.

    As for the Summer I am not a big lover of very warm weather. 20 - 25 is my preference.


    I will always hope for colder weather, but given the expansion of the Hadley cell it seems to be getting harder for us to get snowy weather in winter. We seem to be getting longer periods of dry weather too

    If only we could see a climatological norm of a persistent Greenland high developing for the winter months in the years ahead, then we would be in business!



  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    The current major SSW will peak Monday night around ~-19 m/s and will take 2 weeks to recover back to westerly. If we are to see any effect it will be from the second week of March. However, it must be said that there are overall less perturbations taking the 850hPa temperature below average in the day 8-16 timeframe around the expected window of effects from the major SSW. This despite the PV getting displaced towards Asia which you can see nicely on the northern hemispheric view of model charts. Goes to show the fluidity of the weather patterns and another example of why there are never any guarantees with our weather even when there is a high degree of risk.

    The initial northerly/retrogression for the 3rd-6th March that was possible due to MJO looks to have flopped a few days ago. Not enough oomph to send the high northwestward. The negatively tilted Atlantic low not in a position for warm air advection to aid the high.

    I am definitely less "positive" than I was previously for us to advect in some cold air that would be conducive to a significant cold spell but at the same time I will be glad to be wrong because I don't want that. A significant cold spell at that time of year will still get afternoon highs to 4 or 5C usually unless there's persistent heavy snow or fog. Both of which are difficult to achieve, especially fog with the sun getting stronger day by day. I am way past enjoying winter. If I didn't experience the snow in the mountains or on the southside of Dublin in December, this would probably be up with the worst winters I've seen for my location and be glad to see the back of it. Had more snow on 7th January 2022 than this winter which is pathetic especially given this winter had at least two reasonable colder than average periods. Glad some have had a better winter than some years of late with their January snow but I can't relate.

    The main point in the outlook is how anticyclonic it will be with a dry end to February and start to March under plentiful high pressure but it will be chilly with an easterly wind drawing in fair amounts of cloud. Good that Gonzo brought this up yesterday as with all the talks of major SSW and cold potential, this has been put to the side it seems and there should be more discussion surrounding it than there has been. It does make me wonder though, we've been at large in this settled regime under relatively mild high pressure since mid-January once the frosts disappeared from the cold northwesterly episode. How long before we find ourselves in an Atlantic dominated regime again? Doesn't look like for at least a week at the earliest, possibly longer if this ridge stays around for a while.

    There's still time for a change it must be stressed. But less likely than it was looking on previous days.

    On a thread related note, just amusing to note... a rare GFS win from 10 days ago versus the corresponding ECM at the time. High pressure much more centrally located on GFS which has been the case compared to the ECM which had high pressure further south.





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  • Registered Users Posts: 1,342 ✭✭✭esposito


    Just a hunch but given the two sudden stratospheric warmings recently, I wouldn’t be surprised if we see a major flip to cold charts over the coming days. Think we will have a colder than average Spring but hey, more often than not, a cold Spring leads to good Irish summers so I will happily accept this.

    Post edited by esposito on


  • Registered Users Posts: 5,902 ✭✭✭OldRio


    Signs of that cold snap rescinding. Thank goodness for that. Lets get Spring sprung.



  • Registered Users Posts: 23,432 ✭✭✭✭Kermit.de.frog


    Finally starting to see things turn a bit more firmly on the models towards a potentially much colder period of weather from the northeast and all that might go with that from later in the week and next weekend. Interesting times ahead.



  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    12zs so far say yes. Of course that happens as soon as I open my mouth 🤨



  • Registered Users Posts: 202 ✭✭CirrusBusiness


    Spring could be put on hold yet.. mid-week charts could get interesting.



  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    I would not trust the GFS OP given its track record this winter. It may have got a rare win over the ECM but overall it has been very poor. The last couple of days underline that, showing extreme cold then flipping to unusual warmth. I bet this is another outlier with little ensemble support. Of course if it has broad support and the ECM supports it, it will have become the best model again:)



  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    All the 12zs so far (GFS, UKMO, GEM, ICON etc) show retrogression next weekend, not specifically the GFS. Each model produces differing results of the extent of the retrogression however, for example the GEM shows part of the block splitting and sinking southward to give a milder southwesterly flow.

    There's so much conflicting discussions on this and it's difficult to keep track of. Should have listened to what I originally said and just wait for more time to pass.



  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    Yes, to be fair the UKMO is close to the GFS. The GEM has been performing very well this winter. I suspect the ECM will probably be closer to the GEM. In these scenarios the final result is usually something in the middle, which won't be good enough at this time of year. I would love for the GFS to be right as we get an epic Snowstorm in deep FI, but it will likely have sobered up by the pub run



  • Moderators, Science, Health & Environment Moderators Posts: 16,693 Mod ✭✭✭✭Gonzo


    The GFS 12z just like yesterdays 12z is very much a cold outlier, almost on it's own.



  • Registered Users Posts: 995 ✭✭✭Ragwort and Stones


    There'll be a cold blast in March and probably hill snow. But it's being pushed back and back, hard to get too interested in anything post mid March. You'd want April 1917 event.



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  • Registered Users Posts: 911 ✭✭✭WolfeEire
    Clare (410ft asl)


    GFS following up on its afternoon run. Slightest changes in that retrograded high over Greenland holds the key to whether a cold spell of weather will materialise. Milder air attempts to push in the days that follow.

    Whether/weather as always for Ireland


    www.x.com/wolfeeire



  • Registered Users Posts: 911 ✭✭✭WolfeEire
    Clare (410ft asl)


    As expected, the GFS ensembles mean is not indicating any deep or prolonged cold spell. At least seven days of largely dry, relatively cool (cold at night) weather to come. The NAO returns to negative if not slight positive territory in 7-8 days. A brief push of much colder air about 8 days from now (may not reach the southwest and far west) followed by a slow transition to milder and less settled conditions is the form horse right now.

    The next 48 hours could bring about a flip with changes in the orientation of the area of high pressure to our NW. Should it do so, then there is a very cold airmass ready to tap into. It's looking unlikely right now.

    www.x.com/wolfeeire



  • Registered Users Posts: 278 ✭✭almostthere12


    UKMO looks the best of this mornings runs for anything longer than a day of cold, although it only goes out to the 6th so can't see exactly how it evolves.

    ECM gets the cold into Ireland for a day and maybe some battleground snow for north Munster upwards, no good IMBY further south!!

    GFS keeps us mild.



  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    Whatever the reason it seems height decline over Greenland. We have seen this theme at times throughout the winter, models wanting to build heights there but then the signal fades with weak heights. As was said the UKMO is the pick of the bunch as the Atlantic undercuts and would seem to prolong the cold, but it seems out on its own in that regard, so we know what will happen there. ECM if it was even a month ago would lead to a snow fest rather than cold rain.

    Maybe if we we were dealing with a split vortex rather than a displaced one, height over Greenland would be reinforced by a lobe of vortex close to Canada. I am nearly ready to pack it in, unless we see upgrades across the board within the next 48 hours

    Post edited by nacho libre on


  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    I wonder is the ECM an outlier?

    If not.... It looks like the perfect response/ imprint on the Trop' to the most recent warming in the Stratosphere.



  • Registered Users Posts: 151 ✭✭Niall145


    Mild outlier hopefully



  • Registered Users Posts: 13,492 ✭✭✭✭sryanbruen


    Doesn't look it judging by the mean on the hemispheric charts, a significant change from what they've been showing.




  • Registered Users Posts: 4,676 ✭✭✭SleetAndSnow


    I think it's time to hop back on the rollercoaster after jumping off in January....

    The anomaly is pretty impressive on the ECM!




  • Registered Users Posts: 1,496 ✭✭✭Billcarson


    Can't help but think if those charts come to fruition what might have been if the ssw had happened a few weeks earlier. Imagine similar charts in January or even start of Feb.



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  • Registered Users Posts: 16,618 ✭✭✭✭nacho libre


    Record challenging cold would have been on the table. It's looks like this could be a repeat of 2018 if it comes off- no, not another storm Emma, but the block becomes west based just like in 2018. I just hope if that proves to be the case we get a decent snow event before the Atlantic creeps back in.



This discussion has been closed.
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