Winter/Spring 2013 (Model Output Discussion)

BLIZZARD7

maquiladora wrote: »

It wasn't likely to shift to what the ECM was showing straight away on an 18Z run I think. If it does shift it will more likely happen on the 0Z.
This 18Z run looks worse than the 12Z out to 180 hours though, block shrinks faster and uppers are less cold here and even shorter lived. 24 hours or less of marginal upper temps just about covering the country at 150 hours out is not really something I'd be too bothered with personally. But at least there would be a chance of maybe a cold reload even further off in FI beyond that.

It's only the very start of winter though, but it would be nice if we got something nice around Christmas!

As I said last night- Stick with the UK met office FAX charts- and guess what model they go with tonight? The UKMO 12z Raw output- brilliant! Its very rare you get the GFS/UKMO vs the ECM, as its very rare that either the UKMO or ECM are ever wrong at +96hrs, but one of them has to be.

Also I still dont know where you are getting this 24hr snap stuff from, unless you are refering to the bad ECM run, which could prove to be correct.

The professionals in the UK and America both side with the UKMO/GFS tonight- That is the most important thing to me right now, also the teleconnections are completely at odds with the ECM and all indications point to a High latitude block in the greenland area...

The ECM maybe right but I doubt it, Il say 70-30 in favour of the UKMO being right...





Dan

ninebeanrows

Yep lads, so much lies on that Nova Scotian Low!

So the next 24hrs will be critical as the 96-144hr period moves into the reliable timeframe.

Fingers crossed for the 0z's

rickdangerouss

If I recall, MT advised on the forum, that winter could be milder and wetter than the models he presented for his winter forecast. Long lasting and deep cold is not an common thing in Ireland.

Pangea

Deep Easterly wrote: »

IMT mean max yesterday turned out to be 4.0c, which would make it the 2nd coolest maxima of the year so far, after the 3.4c on 2nd February last.

On an individual station basis though, the 2.6c daily max at Claremorris yesterday was lower than any daily max this station recorded last winter :eek:. We have to go all the way back to the 3rd Jan 2011 to find a lower daily value recorded here (2.1c).

Back to today, and still only 1.0c at Claremorris, Knock & Mt. Dillon on the 1pm reports.

http://www.met.ie/latest/reports.asp

Deep Easterly, Every time I checked Finner Camp today it read 1c, and its still reading it now. Might be worth checking if that has the coolest maxima of the year so far.

Su Campu

Cork's 23Z TAF calls for light sleet from 00-03Z.

TAF EICK 252300Z 2600/2624 33017KT 9999 SCT010 BKN015 TEMPO 2600/2603 5000 -RASN SCT007 BKN010 TEMPO 2600/2615 34018G30KT BECMG 2607/2610 SCT012 SCT020 BECMG 2620/2622 34012KT=

Waterford's just moderate rain

TAF EIWF 252300Z 2600/2609 35017KT 9999 SCT012 BKN020 TEMPO 2600/2607 5000 RA BKN010 TEMPO 2600/2609 35018G30KT=

Speak Now

rickdangerouss wrote: »

Long lasting and deep cold is not an common thing in Ireland.

Thats why it's so interesting

Speak Now

Su Campu wrote: »

Snow's 23Z TAF calls for light sleet from 00-03Z.

TAF EICK 252300Z 2600/2624 33017KT 9999 SCT010 BKN015 TEMPO 2600/2603 5000 -RASN SCT007 BKN010 TEMPO 2600/2615 34018G30KT BECMG 2607/2610 SCT012 SCT020 BECMG 2620/2622 34012KT=

Waterford's just moderate rain

TAF EIWF 252300Z 2600/2609 35017KT 9999 SCT012 BKN020 TEMPO 2600/2607 5000 RA BKN010 TEMPO 2600/2609 35018G30KT=

We're washed out though, 30mm today on soaking ground. Rain just running through the fields onto the roads at this stage. Back road driving not nice Currently 3.2c, might see first snow on the comeraghs in the morning.

Su Campu

Jerry Seinfeld wrote: »

We're washed out though, 30mm today on soaking ground. Rain just running through the fields onto the roads at this stage. Back road driving not nice Currently 3.2c, might see first snow on the comeraghs in the morning.

Waterford Airport and Johnstown Castle reporting light drizzle and visibility >10 km. Oak Park light rain and 7 km. Some localised intensification in your area

compsys

rickdangerouss wrote: »

If I recall, MT advised on the forum, that winter could be milder and wetter than the models he presented for his winter forecast. Long lasting and deep cold is not an common thing in Ireland.

And MT also forecast a fair amount of cold and snow last winter but that certainly didn't happen!

I'm not berating the guy but he doesn't always get it right (no one can).

Just because MT is forecasting a mild winter and plenty of rain doesn't mean it's set in stone. As with anything weather related, you have to study all the main computer outputs and long-range forecasts and then try find a common consensus.

Su Campu

compsys wrote: »

And MT also forecast a fair amount of cold and snow last winter but that certainly didn't happen!

I'm not berating the guy but he doesn't always get it right (no one can).

Just because MT is forecasting a mild winter and plenty of rain doesn't mean it's set in stone. As with anything weather related, you have to study all the main computer outputs and long-range forecasts and then try find a common consensus.

And therein lies your problem. Purely looking at models is not forecasting, it's just reading. Other factors need to be considered first, and only then should models be consulted.

This place is so cold-biased it's amazing.

Speak Now

Su Campu wrote: »

Waterford Airport and Johnstown Castle reporting light drizzle and visibility >10 km. Oak Park light rain and 7 km. Some localised intensification in your area

My locality is Waterford airport, lashing out

Su Campu

Jerry Seinfeld wrote: »

My locality is Waterford airport, lashing out

Yes, the 2330 and 0000 metars showed moderate rain.

METAR EIWF 260000Z AUTO 35011G26KT 290V070 9999 RA BKN009 03/02 Q0998=

Rougies

Su Campu wrote: »

And therein lies your problem. Purely looking at models is not forecasting, it's just reading. Other factors need to be considered first, and only then should models be consulted.

This place is so cold-biased it's amazing.

Su Campu, I'm flabbergasted at this statement coming from you. I know you take a lot of flak for your usually realistically conservative and sometimes pessimistic opinions/analysis, and most of it is undeserved. But this is ridiculous!? Maybe I've read it out of context, but surely models need to be consulted first then the skill of a forecaster considering other factors comes into play. Especially in short/medium term forecasting.

As for long term forecasting, unless you're the Donegal postman or Ken Ring I'm sure you agree with me that it's not scientifically sound or reliable at the moment. M.T. has my utmost respect but he will be the first to admit his research is experimental/theoretical.

And not bashing you, but yes I do think it's amazing how cold biased "this place" is too. That's why it exists in it's current form, and it's great for us snow bunnies in the winter.

Harps

Pangea wrote: »

Deep Easterly, Every time I checked Finner Camp today it read 1c, and its still reading it now. Might be worth checking if that has the coolest maxima of the year so far.

Max at Finner during the day was briefly 2.1C going by Ogimet although it was 1C and below for most of the day. Seems the temp has actually risen tonight though so the daily max will go down as 3.4C

http://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=03978&decoded=yes&ndays=2&ano=2012&mes=11&day=26&hora=00

snaps

Looks like its game over. 0z gfs confirms the high pressure to far south from Wednesday this week. It was looking so good for some cold dry weather this week. It could all change I suppose for next weekend onwards.

Kippure

snaps wrote: »

Looks like its game over. 0z gfs confirms the high pressure to far south from Wednesday this week. It was looking so good for some cold dry weather this week. It could all change I suppose for next weekend onwards.

It aint over till April 2013 man.:)

snaps

Kippure wrote: »

It aint over till April 2013 man.:)

for this week it is. This morning, no frost. 5c.

Eastcoastryan

snaps wrote: »

Looks like its game over. 0z gfs confirms the high pressure to far south from Wednesday this week. It was looking so good for some cold dry weather this week. It could all change I suppose for next weekend onwards.

ECM looks to be playing ball again!! This model watching isn't good for the nerves!

elvis99

snaps wrote: »

Looks like its game over. 0z gfs confirms the high pressure to far south from Wednesday this week. It was looking so good for some cold dry weather this week. It could all change I suppose for next weekend onwards.

ECM has followed the UKMO looks like the block may hold, so much chopping and changing the past few runs but it looks like the cold may hold firm

Su Campu

Rougies wrote: »

Su Campu, I'm flabbergasted at this statement coming from you. I know you take a lot of flak for your usually realistically conservative and sometimes pessimistic opinions/analysis, and most of it is undeserved. But this is ridiculous!? Maybe I've read it out of context, but surely models need to be consulted first then the skill of a forecaster considering other factors comes into play. Especially in short/medium term forecasting.

As for long term forecasting, unless you're the Donegal postman or Ken Ring I'm sure you agree with me that it's not scientifically sound or reliable at the moment. M.T. has my utmost respect but he will be the first to admit his research is experimental/theoretical.

And not bashing you, but yes I do think it's amazing how cold biased "this place" is too. That's why it exists in it's current form, and it's great for us snow bunnies in the winter.

That's the problem that Tim Vazsquez refers to as "the cancer of forecasting". People blindly looking at what the models are saying and trying to find common ground when instead they should be only used as a tool afterwards to refine the forecaster's opinions. Looking at what's happening now and how it's likely to play out, how similar setups evolved in other years, local peculiarities, etc. are all as important as the models, but who actually takes them into account?

So no, the model should NOT be consulted first, but unfortunately it usually is.

ninebeanrows

Well the Met have made a bullish call in their outlook.

Maybe they will be right but it is a risky call with such amounts of uncertainty.

Outlook

The cold weather will continue through mid-week with low daytime temperatures and severe frost at night. Mostly the weather will be dry and bright, except for some coastal showers driven onshore by northerly breezes. Patches of freezing fog will develop and linger during Wednesday night and Thursday. Some light rain or sleet will develop in the west during Friday, but precipitation will be small. There is a gradual return to milder weather next weekend as temperatures climb towards more normal values of 9 or 10 degrees

munsterlegend

Su Campu wrote: »

That's the problem that Tim Vazsquez refers to as "the cancer of forecasting". People blindly looking at what the models are saying and trying to find common ground when instead they should be only used as a tool afterwards to refine the forecaster's opinions. Looking at what's happening now and how it's likely to play out, how similar setups evolved in other years, local peculiarities, etc. are all as important as the models, but who actually takes them into account?

So no, the model should NOT be consulted first, but unfortunately it usually is.

Are the models not adjusted to take into account these factors? From my very limited knowledge Ireland's snow prospects are always very marginal and require a number of factors going in our favour which 99% of the time don't.

I think you said a few days ago you believed it was 60-40 in favour of a wintry outbreak - would you still be of the same view?

munsterlegend

Weathercheck wrote: »

Well the Met have made a bullish call in their outlook.

Maybe they will be right but it is a risky call with such amounts of uncertainty.

Evelyn on Friday night was saying the opposite in terms of cold to this weekend!
Not sure why they don't cover themselves like the uk met office and put in the phrase 'there is a deal of uncertainty'.

ninebeanrows

Su Campu wrote: »

That's the problem that Tim Vazsquez refers to as "the cancer of forecasting". People blindly looking at what the models are saying and trying to find common ground when instead they should be only used as a tool afterwards to refine the forecaster's opinions. Looking at what's happening now and how it's likely to play out, how similar setups evolved in other years, local peculiarities, etc. are all as important as the models, but who actually takes them into account?

So no, the model should NOT be consulted first, but unfortunately it usually is.

If this was the case Su, we would still be make forecasts to 2-3 days and no further.

It is quite a stupid analogy as well.

Of course perhaps there is an over reliance on the model output at times but that is because in recent years the models have become so reliable in the 3-5 day forecast period for the vast majority of synoptic.

The caveat in using the models is because they go so far into the long term that they can often be perceived as inaccurate, when used in the 2-5 day period they are critical and highly accurate.

Su Campu

Weathercheck wrote: »

If this was the case Su, we would still be make forecasts to 2-3 days and no further.

It is quite a stupid analogy as well.

Of course perhaps there is an over reliance on the model output at times but that is because in recent years the models have become so reliable in the 3-5 day forecast period for the vast majority of synoptic.

The caveat in using the models is because they go so far into the long term that they can often be perceived as inaccurate, when used in the 2-5 day period they are critical and highly accurate.

That's not what I said. I said they should not be consulted FIRST. I didn't say they should not be consulted. They are a vital part of forecasting, but there are others too.

I said around a month ago - not going on the models - that our best chance of a proper cold spell may be before Christmas, due to SST anomalies and other factors, but I highlighted that my confidence was still low. Last week the models started to hint at this too, therefore my confidence increased to around 60/40. The models now seem to be backing off on that, which is a perfect illustration of the point I was trying to make.

And what's the "stupid" analogy you're referring to?

Wolfe_IRE

GFS continues to trend milder but not significantly so. The most significant element of the transition from the current setup is that the jetstream (relatively weak) will be reestablished over Ireland and Britain.

munsterlegend

http://www.metoffice.gov.uk/weather/uk/uk_forecast_weather.html

UK Outlook for Saturday 1 Dec 2012 to Monday 10 Dec 2012:

Wintry showers are expected to affect some eastern areas on Saturday with snow on hills, possibly to low levels in the north. Elsewhere, largely dry and fine, but cold with the risk of frost, icy patches and overnight freezing fog. By Sunday, rain may spread into the far west, preceded by snow, mainly over higher ground. There is a lot of uncertainty for the remainder of the period but it is likely that northern and eastern areas remain cold with wintry showers for some. Elsewhere, it will probably become milder, at least for a time, but also more unsettled, with rain and hill snow accompanied by stronger winds. Later in the period, colder but drier conditions may become re-established across the UK, with frost and icy patches for many.

Updated: 1107 on Mon 26 Nov 2012

Looks like very mixed weather but certainly more milder outlook. The further extended outlook has not changes though:

UK Outlook for Tuesday 11 Dec 2012 to Tuesday 25 Dec 2012:

As is usual, there are uncertainties in the forecast for this period. However, there are signs that northerly winds may be quite frequent across the UK. So, on balance, colder than average conditions are likely to continue, with a risk of frost and fog, and an increased risk of some snow.

Updated: 1138 on Mon 26 Nov 2012

Deep Easterly

For what its worth, the ECMWF Ensemble mean at day 10 seems to want to flatten out the wider NH pattern but keeps Ireland in a mainly cool polar maritime westerly (Yippee) though with potential for some troughing to develop in mid-Atlantic around this time.




On another note, very unremarkable start to the cool spell here as temp is currently 5.0c higher than this time yesterday.

Tindie

Here's BBC Monthly Outlook
Very Mixed, Still a good chance of a Cold Xmas! Look more

Monday 26 November—Sunday 2 December
Generally mild although unsettled and rather windy
The showers moving eastwards across southern counties on Monday will be of rain but heavy at times with a risk of thunder. There is a threat of some more persistent rain across southwest England for a time too, not as much as during the weekend but falling onto saturated, if not already flooded, ground.
Of greater concern is the persistent and at times heavy rain across northern England and north Wales. This has the potential to bring localised flooding to these parts and the Met Office has weather warnings in force.

This rain gradually clears through Monday night and at first on Tuesday to leave a windy day with showers. From this point forward the temperatures will be on a downward trend through the rest of the week as the winds turn more northerly, with increasingly widespread frost, some icy patches, and showers wintry over hills. The showers though will become largely confined to the east, mainly along windward coasts.

This means the best of the weather will be in the west, with plenty of dry and at times sunny weather, although even here a few showers could skip by the coasts in the far west. However the more settled picture will be welcomed in areas drying out after the recent flooding.

As December arrives, further wintry showers are expected but perhaps falling to increasingly lower levels, with accumulations over high ground possible in the north and east of the country.

As a front tries to come in to the west of the UK, there is also a risk of some more persistent rain, especially towards the southwest. As the rain meets the cold air, this could turn sleety with the possibility of some hill snow. However this does rely on the front making progress inland from the west, and currently the signal is for the frontal rain to stay offshore to the west.

Monday 3 December—Sunday 9 December
December beckons, settled weather coming?
Picking up with the unsettled theme at the start of the week, it begins with showers or longer spells of rain possible for the UK, with temperatures returning close to or a touch above average.

As the week progresses, there is a trend towards some parts of the country turning a little more settled, with temperatures falling to allow an increased risk of frost and icy patches. Any further rain or showers could then turn wintry over higher ground at times.

Monday 10 December—Sunday 23 December
Winter's here, and on balance it does looks cold

Even at this long timescale there is greater than average uncertainty for the first full fortnight of December. However, the balance of probability does point to this period being colder than average, which would lead to an increased risk of frost and fog.

However there still could be some rain at times, although this presently looks most like to occur over northwestern parts of the UK. This could, coupled with the colder-than-normal theme, lead to a risk of snow, mainly but not exclusively over high ground.

Larbre34

I think the current UK Met outlook is the most balanced and credible summary available, there's too much pinning the tail on the models for a forecast going on all over the net. People are angling for a self fulfilling prophecy and the tetchyness evident over it not rolling out is just daft for the time of year.

By all measures Nov/Dec 2010 was exceptional, if we get a trend going to establish cool air origins by the middle of December we'll be doing well and after that we might get a few more typical 'Irish' snowdays, in the battle between zonal and siberian, i.e. short lived. I would not expect to see the kind of deep and penetrating cold spells that endured in 09/10 and 10/11