Big Change Monday Onward, much colder, ice and snow later

Su Campu · 15-12-2009 11:27AM

I think we're too early in the season for any significant event with the way the synoptics are looking to be shaping up. If it were a month or two later then I'd be much more optimistic - seas would be colder, and the artic airmass would be much more widespread.

As it is we're currently looking for the upper low over northeast USA to cutoff, hoping the pool of cold air currently over the islands of far northern Canada will make its way over the top of the Greenland High and shoot down to the east of Iceland towards us, joining up with the Russian airmass as it does. There are just too many variables at play for everything to fall into place this time around.

Let's hope for a similar setup in 6 weeks time, then we'd be all be laughing!

maquiladora · 15-12-2009 11:30AM

Not too worried about the 06Z GFS now, seen the ensembles for the rest of the run and the mean 850 is still below 0 until the end of the run. Wouldn't be surprised to see the 18Z and 0Z showing a better cold spell. :pac:

12Z ECM should be interesting...

Duiske · 15-12-2009 11:35AM

Pangea wrote: »

looks like met eireann are right afterall

Met Eireann were looking at the very same charts as us,and what they got right was to release forecasts only for what they expected to happen in the "reliable" timeframe.

Deleted User wrote:

Well isn't that what the long timers of
us always tell you on this board.
Never pin hopes on specifics in fi just
the trends.
Also never take one model or one run
in isolation-forecasters don't!

Exactly right. I,ve had an interest in forecasting for quiet a while, and despite seeing charts over the past week or so showing everything from -3 daytime max's, to blizzards, the only thing I was even remotely sure of was that it was going to get colder.

Anyway, as Black Briar says, no need to get down about this yet. A few could still get a pleasant surprise from this colder blast.

Min · 15-12-2009 11:44AM

Met Eireann mentioned showers of hail, sleet and snow for Eastern and Northern areas later this week at 7:55am.
They also said a band would push down from the north and with the cold air it would fall as sleet and snow before turning to rain...

It was the forecast that they were not afraid of the word known as snow.

munsterlegend · 15-12-2009 12:05PM

maquiladora wrote: »

Not too worried about the 06Z GFS now, seen the ensembles for the rest of the run and the mean 850 is still below 0 until the end of the run. Wouldn't be surprised to see the 18Z and 0Z showing a better cold spell. :pac:

12Z ECM should be interesting...

on the other forums they reckon the 06Z GFS is a rogue run and inconsistent with the other models...heres hoping. still think the fact that met eireann have even mentioned snow for the weekend is a positive sign.

i see where the met office uk have issued weather warnings for the end of the week in the south east of the uk.

Su Campu · 15-12-2009 12:17PM

Met Éireann have got a lot of unjustified slagging from people on this forum this week, some even saying they should be keeping an eye on here, but I think they've played it spot on. They are justified in playing it cagey early on. A meteorologist's job is not to look at the models and purely translate what they're saying, but to use them as a tool only, after first getting an overall picture of the atmosphere and calculating in his/her head what's likely to happen in the future. This should be all done BEFORE even looking at model output. A good meteorologist will have a wealth of local knowledge and experience which will allow him/her to weed out the crazy scenarios and home in on those that look most likely. As the odds of us getting the scenarios painted by the models earlier this week are statistically pretty low, then they did well in not throwing around the S word recklessly.

I think Met Éireann do this very well. I have seen countless occasions where they have got it spot on despite what even the short term models were saying. They do a very good job IMO and should be the first place people look for their forecast, instead of the automated sites like weatheronline, accuweather, Metcheck, etc, which are not worth a sh*te most of the time.

maquiladora · 15-12-2009 12:21PM

Su Campu wrote: »

I think Met Éireann do this very well. I have seen countless occasions where they have got it spot on despite what even the short term models were saying. They do a very good job IMO and should be the first place people look for their forecast, instead of the automated sites like weatheronline, accuweather, Metcheck, etc, which are not worth a sh*te most of the time.

Absolutely agree, the computer generated local forecasts on Metcheck and Accuweather are a joke, I don't even look at them anymore.

Villain · 15-12-2009 12:21PM

Very true SuCampu I suppose the issue for some may have been that even when it has snowed the past few years they haven't forecast it so while they may be right this time its not always the case when it comes to snow.

zeppe · 15-12-2009 12:44PM

Yeah I find Met.ie the most accurate and honest forecast site. I'd use it over any of the other sites, Accuweather etc
I did however find Accuweather great last year when I was in the US (Florida and Georgia) it was spot on for the US forecast.
Its bloody depressing tbh for those of us who love snow because if met.ie say there's going to be sleet and rain this weekend I'd put a good bet on that there probably will be...

On the plus side, myself and my US girlfriend are probably going to emigrate to the US next year, thinking of Vermont/New Hampshire. I'll post up some nice snow pics if and when we get there:D

Su Campu · 15-12-2009 12:45PM

Villain wrote: »

Very true SuCampu I suppose the issue for some may have been that even when it has snowed the past few years they haven't forecast it so while they may be right this time its not always the case when it comes to snow.

Of course, it is an inexact science afterall, and they're bound to be wrong the odd time, but overall from my experience I find them one of the better Met Services in Europe

howlinwolf · 15-12-2009 12:47PM

couldnt agree more the automated sites on the net are a joke .....9 times out 10 met eirann are spot on

Su Campu · 15-12-2009 12:51PM

Most of the automated sites are taking their point forecasts from the GFS model, which has its shortfalls. They take a numerical figure for each of the variables from that point on the grid and translate it into nice fancy graphics but do not benefit from the human input I described above.

howlinwolf · 15-12-2009 01:00PM

well if we are to go by met eireann (and i really think we should cause all the other stuff is just fi) then its really startin to look like a snow no show:( there really startin to change there tune ...even mentioning wind turnin westerly ?

Su Campu · 15-12-2009 01:05PM

howlinwolf wrote: »

well if we are to go by met eireann (and i really think we should cause all the other stuff is just fi) then its really startin to look like a snow no show:( there really startin to change there tune ...even mentioning wind turnin westerly ?

A No Snow Show Fo Sho!

howlinwolf · 15-12-2009 01:09PM

Su Campu wrote: »

A No Snow Show Fo Sho!

Deep Easterly · 15-12-2009 01:10PM

howlinwolf wrote: »

couldnt agree more the automated sites on the net are a joke .....9 times out 10 met eirann are spot on

Well said! Met Eireann forecasts are issued by human beings, who are tuned into the idiosyncrasies of the climate of Ireland. Not every forecast is 100% perfect, but I would be worried if they were!

As for the models themselves, I only rarely look at the GFS, as it is not great for considering the eccentricities of the west of Ireland climate. Some of the most intense rainfalls I have recieved occured when GFS forecast it to be totally dry!

Another recent example was when both the UKMO and ECM model picked up on the potential for extreme rainfall in the west in mid November almost 8 days in advance. The GFS only picked up on this just 2 days in advance, despite showing more or less the same synoptics before that.

One day I will always remember is the 21st of June 2008. The forecast was for light rain for the west of Ireland clearing in the evening. It was the evening when I recieved a fall of 47mm in less than 40mins. Severe flash flooding as a result over a wide area of East Galway.

The only site which did forecast this extreme event in advance was the DMI.DK Hirlam model:

http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

Probably the best freely available HI Res model on the web.

gothwalk · 15-12-2009 01:47PM

Way I see it, Met Eireann are going to be the best, being local, but in our particular climate, snow is usually really hard to predict.

It relies on a particular combination of circumstances - easterly or north-easterly wind, certain temperatures over a few days previous and at the time, and so on.

There are plenty of times where those circumstances might come together. There are very few where they will. And to make it worse, there are sometimes times when it doesn't look like it'll happen, and then the wind swings by that crucial two minutes of arc, the temperature drops by that crucial point-oh-five degrees, and there you have it, snow.

The next fortnight is solidly in the "might happen" category, and that in and of itself is something we don't usually see in December anymore.

maquiladora · 15-12-2009 01:55PM

gothwalk wrote: »

The next fortnight is solidly in the "might happen" category, and that in and of itself is something we don't usually see in December anymore.

Yeah its important not to forget that this is only the start of winter really. Still a long way to go and I predict this wont be the last thread of its type over the next couple of months. :pac:

maquiladora · 15-12-2009 02:15PM

For anyone interesting, the 12Z GFS which will be rolling out in just over an hour will be the new and improved version, according to this (http://www.nws.noaa.gov/os/notification/tin09-34gefs.txt).

Should be interesting...

Redsunset · 15-12-2009 02:22PM

All i can say is ummmmmmmmmmm.

It's not really doing what i had in mind,and i have been bullish about it.

looking more like a few wintry flurries.

i see england is getting the snow and more forecast.

However we simply can't just say its not gonna snow because there's every chance that a good covering could come in any precip down the road where conditions are spot on.

We should have all answers by the weekend.

maybe this major volcano eruption thats imminent in philippines will help cool us down.

Min · 15-12-2009 03:07PM

Met Eireann at 12:55 on radio 1 said wintry showers and the areas that would get them being mostly the coastal areas of Leinster and Ulster but all of Leinster is at risk along with east Munster.

munsterlegend · 15-12-2009 03:13PM

Min wrote: »

Met Eireann at 12:55 on radio 1 said wintry showers and the areas that would get them being mostly the coastal areas of Leinster and Ulster but all of Leinster is at risk along with east Munster.

for what day?

howlinwolf · 15-12-2009 03:18PM

Min wrote: »

Met Eireann at 12:55 on radio 1 said wintry showers and the areas that would get them being mostly the coastal areas of Leinster and Ulster but all of Leinster is at risk along with east Munster.

sounds promising esp since its comin from a relieable source:)

Villain · 15-12-2009 03:18PM

From Met.ie:

A few wintry showers will persist during Thursday in coastal counties of the east and southeast while the rest of the country will have a mainly dry day with some bright or sunny periods. A rather cold day everywhere with temperatures only reaching between 4 and 7 degrees in a moderate east to northeast breeze. Sharp or severe frost Thursday night. Friday should be a dry day in all but some coastal regions of the southeast, where the odd wintry shower is still likely. There should be some bright or sunny periods also, but it will be a cold day - temperatures only struggling up to between 2 and 5 degrees and the overnight frost may be slow to clear in places. Winds light or moderate northeast will gradually back northwest. Very cold and frosty Friday night. Temperatures will be a little higher on Saturday, though it will still feel very cold in a freshening west to northwest wind. Cloud too, will be on the increase from the north and will bring scattered outbreaks of rain or sleet, possibly preceded in places by a little snow, especially over high ground

howlinwolf · 15-12-2009 03:22PM

any updates from the ukmo or any of the others ........the doom and gloom at the mo is depressing .....hopin for the models to cheer us up a bit

Villain · 15-12-2009 03:25PM

Postman predicting white xmas on RTE Radio 1

munsterlegend · 15-12-2009 03:29PM

Villain wrote: »

Postman predicting white xmas on RTE Radio 1

for where though?!

howlinwolf · 15-12-2009 03:29PM

London Snow Warning Amid Flurry Of Xmas Bets

2:21pm UK, Tuesday December 15, 2009
Mark Langford, Sky News Online
Heavy snow showers are expected over London and large swathes of eastern England by the weekend, weather forecasters have warned.

Large parts of England can expect snow by the weekend, forecasters say

seems england is in for some hope it keeps headin west:)

pistolpetes11 · 15-12-2009 03:29PM

Villain wrote: »

Postman predicting white xmas on RTE Radio 1

Thats it then, batten down the hatches and get in the supplies

It would actually be funny if this guy pulled it off, I know he has a good record , but it seems so very hard to predict a long range forecast using scientific measures.
Although it would be cool if his traditional ways came up with the goods !

Villain · 15-12-2009 03:31PM

Sorry the story has been widely reported in the media I thought everyone had heard about him, he is based in Donegal he will be on after Nuacht now. Bit of banter although never underestimate expierence and what Animals can sense

Big Change Monday Onward, much colder, ice and snow later

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