Winter 2011/2012

Speak Now

M.T. Cranium wrote: »

Will be posting my winter forecast around 1030 or 1100 today, in a separate thread so this one doesn't get too unbalanced.

Returning to last year...............

Brilliant reading, thanks M.T.

I think I enjoy reading about actual weather events that occured more than forecasts of weather i'm wishing for
Mr.data on netweather posts some great stuff as well.

leahyl

M.T. Cranium wrote: »

Will be posting my winter forecast around 1030 or 1100 today, in a separate thread so this one doesn't get too unbalanced.

Looking forward to this!:) At least I think I am (presuming I hear what I want to hear lol!)

tylercollins

Winter forecast is now out on Irishweatheronline...

http://www.irishweatheronline.com/news/atmosphere/cold/iwo-winter-2011-12-forecast-for-ireland/41524.html

This seasonal forecast is based on Peter O’Donnell’s research into natural variations in atmospheric patterns using an extensive data base on both monthly and daily time scales.

Peter’s research began in North America around 1980 and was extended to Europe as part of global modelling efforts, with the major advance being a forecast and detailed research program that began in 2005. As a result, this is the seventh winter forecast that Peter has issued for the U.K. and Ireland. Global patterns and solar activity are factored into the forecasts, but the primary basis remains a numerical model of temperature variations that can be connected to index values for pattern types.

The model considers various factors that theoretically link the complex solar system magnetic field (which could be described as “space weather” or the state of the solar wind compared to average at various points in time. Then, using a theory that links the solar system magnetic field to earth’s upper atmosphere, the model derives a forecast of atmospheric variations from normal. A third and very significant step is to model in an independent set of variations based on lunar-atmospheric tidal effects.

The main point to keep in mind is that the forecast model is basically the sum of many small variations which, if they existed alone, would produce only slight variations in the weather day to day or year to year. But if there are twenty or more such variables all interacting, then the cumulative effects can become considerable. This particular seasonal forecast is fine tuned from “re-analysis” or a look back at recent seasonal forecast efforts and feedback into the research model from a study of timing or intensity errors.

Unlike some in the long-range forecasting business, we make no elaborate claims of high accuracy but we believe that over the past five years this method has produced some of the best results, for example, the severe cold spell of last December.
Overview for winter 2011-12

Overview of Winter 2011-12 forecast for Ireland
Overview of Winter 2011-12 forecast for Ireland

From a starting point in mid-October, we consider the five month period November to March, with “climatological winter” defined as being the months of December, January and February, whereas “meteorological winter” can, as we saw last year, fall in any of the five months in the Irish climate.

As is now becoming clearer on reliable time frame global forecast models, late October could be a lot colder than the past three weeks have been. That colder trend may fade out for part of early NOVEMBER with another mild spell, but colder weather with some snow may then return in the second half of November. In general this is not expected to be as dramatic as last year, and the severe cold is not expected to continue through most of DECEMBER; instead, there may be roughly equal spells of mild and cold weather with possibly a rather stormy theme and a wide variety of daily weather types that will include some strong winds, some heavy rainfalls and some snow or ice. The output for the Christmas to New Year period suggests a milder interval after some rather cold days about a week before Christmas.

JANUARY may be “the” month of the winter as our model forecast suggests some much colder than average weather through most of the month. The details may include a few brief milder turns which could involve snow to rain type breakdowns, but there are indications of cold spells with northeast or east winds that are often associated with snow in eastern counties, and in particular around Meath and Dublin. as well as Wicklow. The lunar components suggest that the week starting around 8th January could become stormy and cold enough for snow to be dominant by then, although the south could remain in more mixed precipitation. The greatest depth of cold, suggesting higher pressure building up from the east, should come a little after mid-January. More snow seems likely in the period that has delivered in some recent winters, around end of January and first few days of February.

The output then suggests a steady warming trend to produce a rather mild FEBRUARY once that early cold and snow comes and goes, and that scenario suggests some risk of flooding with the thaw and melt. Otherwise February may become a rather settled and almost early spring-like month with some of the model temperature output well above normal.

MARCH looks rather chilly especially towards the end, and could involve a minor return to winter or near winter conditions, so in terms of a seasonal “overview” the dominant theme might be variable but a colder winter than many in the “modern” period, perhaps a winter more typical of the colder climate periods of the past, but either not as extreme as last year, or if everything comes together just right (or wrong, depending on your point of view), a January that may remind us of the December of last winter, with some previews of that in mid-December. Wishing to remain a bit conservative, the monthly temperature forecasts relative to normal are set as:

NOVEMBER: -1 deg (variable but trending cold)
DECEMBER: 0 deg (normal but variable)
JANUARY: -2 deg (cold, potentially colder to -4 deg)
FEBRUARY: +2 deg (mild)
MARCH: -1 deg (cool)

Precipitation forecasting tends to be error-prone just because of greater regional complexity, but with so many changes in regime, it would be sensible to expect some intervals of heavy precipitation and also some two to three week dry spells. Over the research period, winter full and new moons tend to be more stormy than background in the eastern Atlantic, and we’ll explore some of the research model details in that regard as we move through the season. The full moon around 10-11 December should produce a significant storm (probably the second of a set) likely moving northwest to southeast given the expected setup, so that could be a time for one of the winter’s stronger wind events. The new moon around Christmas is embedded in a mild spell so we are expecting either a foggy inversion with the storm track well to the north, or possibly a mild storm running well north of Connacht around that time, and then there could be a northerly blast to follow around New Years, followed by a volatile period of strong west to northwest flow.

The January full moon energy peak 8th-10th coming around a time indicated to be turning much colder could be the trigger for the most significant weather event of the winter which could be a stormy period involving some heavy snowfalls. Later on, the new moon period seems more likely to drive the storm track well south towards Iberia. If there is a secondary track closer to Ireland this may become a time for snow or ice storms (20th-24th). There are secondary energy peaks that fall roughly five days before these main lunar energy peaks, which sets up an uneven modulation of five and nine or ten days in the likely pressure oscillation, that could show up in a tendency for one week to be settled, then the next week stormy, as a sort of background rhythm to the winter season. The settled weeks are likely to be also the coldest until February, but then the mildest as the flow becomes more southerly or southwesterly. And it appears from the numerical output that these settled periods will tend to fall around mid-months.
Conclusions and Updates

With this time scale, the details are bound to change to some extent and the main point of adding them to basic trends is to give the reader a sense of the range of weather types to be expected. To some extent, timing these exactly is not really the main point for those who want to plan their business ahead of time — the more conventional forms of forecasting will lead into the active periods, but this overview may give you some idea what to expect in general and we would stress the menu being more important than the order of service. That might not work for a restaurant but the current “state of the art” in seasonal forecasting is frankly well short of being what we could call a fully developed science, no matter what various gurus say in their press releases. For this forecaster, the stimulus of trying to provide some details has a positive effect on the research, and gives us a foundation that is better than just a vague outlook as was and is the custom with large agency forecasts.

Winter 2011-12 looks like being quite an active winter and not lacking in wintry weather types, although not entirely dominated by them either. Readers in more isolated and upland locations might be well advised to have extra supplies on hand at a fairly early stage of the winter in case the early opportunities for cold dig in, but we think your main challenges will come in January this year. In any case, updates to a long range forecast make even more sense than updates to a shorter time scale and so we don’t take a “live or die” approach to this early call, as patterns develop and interact, we may well have an adjusted outlook closer to the actual winter season. Not surprisingly, the outlook for the U.K. will tend to mirror this forecast for Ireland but a separate forecast for the U.K. will become available early next week.

touts

Thanks MT. Looks like a good well thought out forecast.
So back to our normal cold-mild-wet-dry-icy-perfect-cloudy-sunny-windy-calm winters.

There's going to be some tears on here for the rest of the day.

Pangea

touts wrote: »

Thanks MT. Looks like a good well thought out forecast.
So back to our normal cold-mild-wet-dry-icy-perfect-cloudy-sunny-windy-calm winters.

There's going to be some tears on here for the rest of the day.

I don't think its going to be an average winter going by the forecast.
Average winter is when the forecasts says we dont get heavy snowfalls and MT doesnt mention getting supplies in .
January looks promising for Cold.
Personally I am obviously not as excited as last years winter forecast but I can always hope he is wrong and get a Colder winter than last year! :pac:
Dissapointed for Christmas though.

Tom Cruises Left Nut

What would be very interesting would be to compare this forecast to that of last year. Does anyone have this ?

novarock

t|nt|n wrote: »

What would be very interesting would be to compare this forecast to that of last year. Does anyone have this ?

back a couple of pages, already discussed.

Speak Now

Looks like a good forecast to me, something for everyone. Last December was coldest in over 100 years so anyone expecting similar would be disappointed alright.

Rigador

That forecast will do nicely - mild enough to get into town to do me Christmas shopping, and possibility of some proper snow after Christmas - so long as we get a few days of it that will be enough for me - happy out!!

Big Daddy Cool

thanks MT, typical irish winter ahead so.

esposito

Big Daddy Cool wrote: »

thanks MT, typical irish winter ahead so.

Not necessarily. Could be similar to winter 2009/2010? at least that's what i'm getting out of it. Remember Jan 2010? Wouldn't mind some more of that!

Iancar29

*Hands around*....


.....:(:(:(

davidsr20

I'm very sad,it's looking like a tippical winter ahead :(:(

NIALL D

Iancar29 wrote: »

*Hands around*....


.....:(:(:(

:mad::(

novarock

Ah sure lock the thread til January! No winter for us! And keep an eye on met.ie for literal quotes from this forecast...

Speak Now

I dont get the pessimism from snow bunnies???

Novemeber colder than average.

Possible snow events in December despite the mixed bag :P

Plenty of winters have been snowless in ireland :mad: and M.T is not forecasting one of those, January sounds very interesting indeed!

February sounds like muck though but that's far out so the one likely to be least accurate

Did people expect to see M.T forecast a repeat of Dec 2010?
The extremes of that month weren't even forecast in last years outlook.

Tom Cruises Left Nut

Jerry Seinfeld wrote: »

I dont get the pessimism from snow bunnies???

Novemeber colder than average.

Possible snow events in December despite the mixed bag :P

Plenty of winters have been snowless in ireland :mad: and M.T is not forecasting one of those, January sounds very interesting indeed!

February sounds like muck though but that's far out so the one likely to be least accurate

Did people expect to see M.T forecast a repeat of Dec 2010?
The extremes of that month weren't even forecast in last years outlook.

Yeah exactly, surpsises can spring up at any time

to the FI thread !

delw

there certainly seems to be less snow forecast than last year ( lets be honest we were spoiled in parts of the country last winter) but there is more wind forecast this winter so a that could churn up interesting weather events,its not all doom & gloom

Rigador

Jerry Seinfeld wrote: »

I dont get the pessimism from snow bunnies???

Novemeber colder than average.

Possible snow events in December despite the mixed bag :P

Plenty of winters have been snowless in ireland :mad: and M.T is not forecasting one of those, January sounds very interesting indeed!

February sounds like muck though but that's far out so the one likely to be least accurate

Did people expect to see M.T forecast a repeat of Dec 2010?
The extremes of that month weren't even forecast in last years outlook.

+1

I think it's a reasonably promising forecast - it doesn't rule out snow completely. The way I'm reading it is that there will probably be some snow, but just not to the same extent as what we had last year. Forecast for last winter did not specifically say that we would be pelted out of it and sure look what occured - let's see what the next few weeks bring!

Pangea

Jerry Seinfeld wrote: »

Did people expect to see M.T forecast a repeat of Dec 2010?
The extremes of that month weren't even forecast in last years outlook.

If you look at his forecast of last year you will see that he got December pretty much spot on and also called for a near extreme outcome or extreme.
Also remember the words
"I'm predicting a cold winter with lots of snow, that could become an epic winter. "
Brillant

Speak Now

Pangea wrote: »

If you look at his forecast of last year you will see that he got December pretty much spot on and also called for a near extreme outcome or extreme.
Also remember the words
"I'm predicting a cold winter with lots of snow, that could become an epic winter. "
Brillant

Sorry i was just talking about temperature extremes.

M.T. Cranium

You may have noticed, I posted this in the forecast thread, but as some are saying, the general idea is not so much an absence of winter but more that it could be (a) spread out over more of the season especially January, and (b) it would be tough to repeat last December or even come close, but January could turn out almost as cold according to the output I have based this on.

And I mentioned that January has a wider range historically than December so you don't need to get the coldest imaginable month to equal last December during January. In fact, if it turns as cold as the forecast is saying in January, there should be good snowfall events in that spell.

I just have the feeling that the winter will produce a variety (as it did last year) but the distribution will be more jumbled together rather than one long cold spell and two long mild spells with a brief cool intermission sort of a mixture that was seen last winter.

Anyway, from the output I would say keep your fingers crossed that if you had a lot of snow last winter, you might get more than half of that amount this winter, and if you had only small amounts last winter, you might do better this winter. And it's by no means a set-up that would cause anyone to say "no chance of big snowfalls then" because you would be looking for something more like "mild most of the time" for that kind of absolute ban on snow potential, and even Feb 2007 as I recall managed to produce one significant snowstorm after weeks of record warmth. Maybe that was only in the UK, I wasn't following Irish weather very closely that winter.

leahyl

Good sign from met.ie:

"Monday to Wednesday of next week: Much colder with maxima 8 to 10 degrees and a risk of the first ground frosts of Autumn. The weather will be very mixed with showers or longer spells of rain. Also some hail and thunderstorm activity is likely."

I think it's on its' way!!:D (Perhaps a bit TOO optimistic!)

Iancar29

leahyl wrote: »

Good sign from met.ie:

"Monday to Wednesday of next week: Much colder with maxima 8 to 10 degrees and a risk of the first ground frosts of Autumn. The weather will be very mixed with showers or longer spells of rain. Also some hail and thunderstorm activity is likely.Everywhere bar the south of the country will be effected hugely by these showers

I think it's on its' way!!:D (Perhaps a bit TOO optimistic!)

.... For Cork yes.... yes u are ....hehehe

leahyl

Iancar29 wrote: »

leahyl wrote: »

Good sign from met.ie:

"Monday to Wednesday of next week: Much colder with maxima 8 to 10 degrees and a risk of the first ground frosts of Autumn. The weather will be very mixed with showers or longer spells of rain. Also some hail and thunderstorm activity is likely.Everywhere bar the south of the country will be effected hugely by these showers

I think it's on its' way!!:D (Perhaps a bit TOO optimistic!)

.... For Cork yes.... yes u are ....hehehe

Well I don't want hail, I want snow!!

Dotsie~tmp

Snowmegagiggatron III is inbound, it is inevitable.

opinion guy

M.T. Cranium wrote: »

You may have noticed, I posted this in the forecast thread, but as some are saying, the general idea is not so much an absence of winter but more that it could be (a) spread out over more of the season especially January, and (b) it would be tough to repeat last December or even come close, but January could turn out almost as cold according to the output I have based this on.

And I mentioned that January has a wider range historically than December so you don't need to get the coldest imaginable month to equal last December during January. In fact, if it turns as cold as the forecast is saying in January, there should be good snowfall events in that spell.

I just have the feeling that the winter will produce a variety (as it did last year) but the distribution will be more jumbled together rather than one long cold spell and two long mild spells with a brief cool intermission sort of a mixture that was seen last winter.

Anyway, from the output I would say keep your fingers crossed that if you had a lot of snow last winter, you might get more than half of that amount this winter, and if you had only small amounts last winter, you might do better this winter. And it's by no means a set-up that would cause anyone to say "no chance of big snowfalls then" because you would be looking for something more like "mild most of the time" for that kind of absolute ban on snow potential, and even Feb 2007 as I recall managed to produce one significant snowstorm after weeks of record warmth. Maybe that was only in the UK, I wasn't following Irish weather very closely that winter.

Ok MT I just bought snow tires on the strength of this. If it doesn't snow I'm sending you the bill :p:D

Pangea

Was that hail/sleet/snow behind Mary Davis today?
I take it this was Galway.



Heres a it up closer http://i.imgur.com/pbVps.jpg

bb1234567

Pangea wrote: »

Was that hail/sleet/snow behind Mary Davis today?
I take it this was Galway.



Heres a it up closer http://i.imgur.com/pbVps.jpg

cant see anything behind her

pauldry

no thats an aeroplane