Cold Spell Prospects and Discussion (January + Early Feb 2012)

TheMilkyPirate

patneve2 wrote: »

Great 18Z ensembles, good chance that the final third of the month will be a nice bit below average temperature wise...expect more changes though :cool:

Yes but for the better

Rebelbrowser

How do they choose which of the ensembles to call the main one, ie the one they post on meteociel etc? Is it a human choice and if so does that not allow bias to enter into it?

Sponge Bob

An ensemble is an agreed average by some mechanism I know not, the squabbles, loony tunes and outliers are called perturbations.

TheMilkyPirate

Rebelbrowser wrote: »

How do they choose which of the ensembles to call the main one, ie the one they post on meteociel etc? Is it a human choice and if so does that not allow bias to enter into it?

The main run is run at a higher resolution than the ensembles. the ensembles are fed different data than the operational and run at a lower resolution.

So the operational is always the main, If ya get me.

Harps

A surprisingly nice look to the GFS ensembles tonight, op run has little support for a quick return to mild weather after the 20th. 0z runs should be interesting but have to be up at 8am so off to bed I think

Redsunset

Don't know bout the rest of ye but I feel as if I'm definitely on this yoke, and it don't look like stoping.

TheMilkyPirate

Well I'm up now so I might as well stay up.

Cup of coffee and the 00z, Let's hope it's a good'un.

blackius

I repeat,a repeat of early december does not excite me.
Thats all I see right now at best.

SO some transitory snow might happen from the northwest either well inland or on high ground.
Mainly ulster/north connaught.

West munster maybe but other than the odd rogue shower elsewhere,this will probably be boring again,I hope it doesn't pan out like that but on averages it should..
Model flux has been a problem since last year but only in determining an exact outcome sooner.But it hasn't brought us proper cold yet so why should we continue to in my view delude ourselves into thinking that model confusion beyond 120 is hiding a real/persistant cold blast?
the weather that has been hiding beyond 120 so far has been mostly mild and not any of the speculated cold.Nothings changed that I see in that regard.
Same old speculation,nothing concrete and I fail to see why some would base any optimism on the notion that the cold will come because the models are unable to resolve things quicker than t-120.
Thats been said for weeks now so don't be blind to the fact that hoping thats why we've no real cold is in fact nonsense and the proof of that pudding,we've already been eating so far this winter.

For sure anything could happen yet but models aren't providing any hope in my view and from a lifelong observation of irish weather and many decades of previous boring winters,I remain unoptimistic snow wise.

boatbuilder

blackius wrote: »

Same old speculation,nothing concrete and I fail to see why some would base any optimism on the notion that the cold will come because the models are unable to resolve things quicker than t-120.

What about the Negative AO/NAO? I've heard people base a lot of their forecasts on them being negative and that is something that has definitely changed recently.
For all of those years that we had mild winters with no snow, did the NAO and AO stay positive? Or are some people making too much of it?

Rebelbrowser

baraca wrote: »

The main run is run at a higher resolution than the ensembles. the ensembles are fed different data than the operational and run at a lower resolution.

So the operational is always the main, If ya get me.

Thanks. That explains it. I had thought the same as Sponge Bob but was then very confused that for certain runs yesterday people were saying that the GFS Op run was completely at odds with most of its ensembles....

Rebelbrowser

blackius wrote: »

I repeat,a repeat of early december does not excite me.
Thats all I see right now at best.

SO some transitory snow might happen from the northwest either well inland or on high ground.
Mainly ulster/north connaught.

West munster maybe but other than the odd rogue shower elsewhere,this will probably be boring again,I hope it doesn't pan out like that but on averages it should..
Model flux has been a problem since last year but only in determining an exact outcome sooner.But it hasn't brought us proper cold yet so why should we continue to in my view delude ourselves into thinking that model confusion beyond 120 is hiding a real/persistant cold blast?
the weather that has been hiding beyond 120 so far has been mostly mild and not any of the speculated cold.Nothings changed that I see in that regard.
Same old speculation,nothing concrete and I fail to see why some would base any optimism on the notion that the cold will come because the models are unable to resolve things quicker than t-120.
Thats been said for weeks now so don't be blind to the fact that hoping thats why we've no real cold is in fact nonsense and the proof of that pudding,we've already been eating so far this winter.

For sure anything could happen yet but models aren't providing any hope in my view and from a lifelong observation of irish weather and many decades of previous boring winters,I remain unoptimistic snow wise.

Blackius, I completely defer to your technical knowledge. I suppose though the only other reason for optimism is that people like MT here and GP on Netweather predicted winter to pan out like it has (provided there is a cold blast upcoming now). So those predictions, made in November and presumably based on macro information then available, are somewhat supportive now where its not clear what is happening in the short term (ie. an overview from afar sometimes shows things that aren't clear from close-up, kind of a wood from trees situation....).

blackius

I wouldn't say I've any more technical knowledge than the rest of ye tbh - my main point is to not rely on the models post 120 being useless as your salvation.

I certainly don't have the experimental research tools that MT or gp use.I know MT thinks we should all see snow by the end of February - maybe we will but there aren't many conventional signs I see at the moment.

Oh and unless you see sub -8 from the NW forget it away from high ground.
-8 850s are just about OK from the be or east as you don't have the mild Atlantic muck mixing to worry about.

WolfeIRE

Interesting to see AO and NAO being forecast to dip quite a bit later this week. Perhaps, something that will be picked up on in future runs.

GEFS has turned slightly cooler than 0z. It is progressively turning cooler in the last few runs but ultimately it is still predicting cool zonal. Pretty much a repeat of early Dec.

For any colder weather to develop by week's end we need to see the high pressure over the Azores (SEE BELOW) track further west or NW toward E Canada/Greenland. I think most other factors required for sustained cold are already in place. Even the slightest shift west or nw of that HP system would have a bearing on matters. Keep an eye on it here.

weatherfiend

can somebody pm me to tell me how to use the thanks system?

jirafa

Latest news and views from Brian Gaze, TWO's founder.

Details still very uncertain
Posted Mon, 16 Jan 2012 09:06:01

The big picture for the next 10 days weather looks reasonably clear I think, but the devil is in the detail and confidence levels reduce towards the end of the period. Here’s what I think will happen. The cold and frosty weather we have at the moment will give way to a couple of days of milder and unsettled weather on Wednesday and Thursday, with rain in places and temperatures getting to double figures in the south. Then on Friday and through the weekend colder weather will return, and there will be a risk of some sleet snow, but the extent isn’t at all clear at the moment. I’d not be surprised if most people don’t see any snow, but equally at this stage I’d not rule out the chance of wintry weather developing quite widely. The final piece of the puzzle is what happens next week, and my view is we’ll see milder weather pushing back in from the west, although it could take a while to reach the eastern part of the country. What’s clear is the coming spell of weather later this week will be very different to the freeze we saw during December 2011 as it won’t be anything like as cold or extensive, and the risk of snow is a lot more marginal. Nonetheless it should be an interesting week or so.

Remember I am only the messenger, so dont shoot me...:rolleyes::rolleyes::rolleyes::o:o

je55ie

weatherfiend wrote: »

can somebody pm me to tell me how to use the thanks system?

Its not active until you have something like 20 or 25 posts

john mayo 10

WolfeIRE wrote: »

Interesting to see AO and NAO being forecast to dip quite a bit later this week. Perhaps, something that will be picked up on in future runs.

GEFS has turned slightly cooler than 0z. It is progressively turning cooler in the last few runs but ultimately it is still predicting cool zonal. Pretty much a repeat of early Dec.

For any colder weather to develop by week's end we need to see the high pressure over the Azores (SEE BELOW) track further west or NW toward E Canada/Greenland. I think most other factors required for sustained cold are already in place. Even the slightest shift west or nw of that HP system would have a bearing on matters. Keep an eye on it here.

[/QUOTE/Is the high pressure in the middle of the chart the azores high ?

blackius

WolfeIRE wrote: »

Even the slightest shift west or nw of that HP system would have a bearing on matters.

Therein lies the problem.
Wishing that to happen given its so rare is almost like saying in July that the only reason there's no cold spell is because December hasn't came yet.

The nao or ao being predicted to be negative next weekend is only as reliable as the modelsfor that far out. so truly unreliable .
Remember our last proper sustained cold spell in November December 2010 followed months of a negative nao...that ultimately translated to the Atlantic blocking and our artic northeasterlies.

Imagine what we might get from a few days negative nao...should it even happen....sweet fanny Adams.
That's my counter point.

Rebelbrowser

jirafa wrote: »

Latest news and views from Brian Gaze, TWO's founder.

Details still very uncertain
Posted Mon, 16 Jan 2012 09:06:01

The big picture for the next 10 days weather looks reasonably clear I think, but the devil is in the detail and confidence levels reduce towards the end of the period. Here’s what I think will happen. The cold and frosty weather we have at the moment will give way to a couple of days of milder and unsettled weather on Wednesday and Thursday, with rain in places and temperatures getting to double figures in the south. Then on Friday and through the weekend colder weather will return, and there will be a risk of some sleet snow, but the extent isn’t at all clear at the moment. I’d not be surprised if most people don’t see any snow, but equally at this stage I’d not rule out the chance of wintry weather developing quite widely. The final piece of the puzzle is what happens next week, and my view is we’ll see milder weather pushing back in from the west, although it could take a while to reach the eastern part of the country. What’s clear is the coming spell of weather later this week will be very different to the freeze we saw during December 2011 as it won’t be anything like as cold or extensive, and the risk of snow is a lot more marginal. Nonetheless it should be an interesting week or so.

Remember I am only the messenger, so dont shoot me...:rolleyes::rolleyes::rolleyes::o:o

I presume he means Dec 2010? Dec 2011 is surely the least we can hope for!

Sponge Bob

WolfeIRE

john mayo 10 wrote: »

Is the high pressure in the middle of the chart the azores high ?

Yes, John.

weatherfiend

je55ie wrote: »

Its not active until you have something like 20 or 25 posts

aha, that's why thanks!!!

jirafa

Weather forecast: UK
Headline:

Mainly dry with sunshine. Cloudier at times in the northwest.
Today:

A cold and frosty start for most, some localised mist, fog or low cloud should lift through the morning. Generally sunny through the day, although cloudy at times in western areas, particularly western Scotland.
Tonight:

A clear and cold night for most with a risk of some mist or freezing fog patches. Cloud increasing from west, however, with some light rain possible in northwest Scotland.
Tuesday:

A largely bright, chilly start. Cloudy conditions with outbreaks of mainly light rain and strengthening winds spreading southeastwards. Rain heaviest across Northern Ireland. Many eastern and southeastern parts remaining dry.

Updated: 0322 on Mon 16 Jan 2012
Outlook for Wednesday to Friday:

Mainly cloudy with some rain Wednesday. Clearer, showery and windy conditions moving into the northwest and spreading to all parts through Thursday. Showers perhaps turning wintry, mainly in the north.

Updated: 0322 on Mon 16 Jan 2012
UK Outlook for Friday 20 Jan 2012 to Sunday 29 Jan 2012:

Unsettled, cold and rather windy at first with scattered showers, these wintry over high ground across the northern half of the UK. The heaviest and most frequent showers likely in the north and east. Turning cloudy and damp over the weekend but some quieter and drier conditions are expected as we start the new working week. It will turn more unsettled across the north of the country from Monday (23rd) though, with these conditions spreading erratically southeastwards with time. Temperatures should recover to near-normal but it will feel cooler in any wind and rain. Throughout the rest of the period, the unsettled conditions will likely be interspersed with cooler, more showery weather, with a risk of overnight frosts. It is also likely to be windy, especially in the northwest.

Updated: 1141 on Sun 15 Jan 2012
UK Outlook for Monday 30 Jan 2012 to Monday 13 Feb 2012:

Rather unsettled conditions are expected to continue through the end of January and into February. Temperatures around or slightly below average for the time of year at first with showers at times, which may turn wintry, particularly over high ground and in the north and overnight frosts in clearer periods. Some milder spells with rain are possible too. Temperatures are likely to become near to normal as we move through the beginning of February, with periods of rain and above average cloud amounts in places. Across the northwest temperatures may remain a little colder than average, with more in the way of dry spells.

Updated: 1141 on Sun 15 Jan 2012
http://www.metoffice.gov.uk/weather/uk/uk_forecast_weather.html

200motels

WolfeIRE wrote: »

john mayo 10 wrote: »

Is the high pressure in the middle of the chart the azores high ?

Yes, John.

So where do we want to see that high move if we want cold weather.

jirafa

Cold Weather Alert.





Current alert level: Level 3 - Cold Weather Action in one or more regions of England

Issued at: Monday 16 January 2012 at 10:08

There is a 90% probability of severe cold weather between 1000 on Sunday and 1100 on Tuesday in parts of England. This weather could increase the health risks to vulnerable patients and disrupt the delivery of services. This issue contines the level 3 issued yesterday. Please refer to the national Cold Weather Plan and your Trust's emergency plan for appropriate preventive action.

After one more cold, frosty night across much of England, especially central and northern parts, the cold weather looks like giving way to milder conditions during Tuesday, with Tuesday night generally much milder. Very mild weather is then expected in all regions on Wednesday.
Regional breakdown Region Risk Comments
North East England 90% Continuing dry and cold across the region, with widespread overnight frost and with daytime maximum temperatures again no higher than 3 or 4 Celsius.
North West England 90% As North East England.
Yorkshire & the Humber 90% As North East England.
East Midlands 90% As West Midlands.
West Midlands 90% Continuing dry and cold, with maximum daytime temperatures today of 5 or 6C and with minimum temperatures again tonight of typically minus 3 to minus 6.
East of England 90% As Midlands.
South East England 60% Somewhat higher daytime maximum temperatures and less cold nights here give a lower risk for this region.
London 40% Higher daytime maximum temperatures and less cold nights than elsewhere gives a lower risk for the London area.
South West England 30% Higher daytime maximum temperatures and less cold nights than elsewhere gives a much lower risk for this region.

An update will be issued by 1000 on Tuesday 17 January 2012.


http://www.metoffice.gov.uk/weather/uk/coldweatheralert/

cherryghost

200motels wrote: »

So where do we want to see that high move if we want cold weather.

Anywhere away from us :mad: Preferably southwards

blackius

200motels wrote: »

WolfeIRE wrote: »

john mayo 10 wrote: »

Is the high pressure in the middle of the chart the azores high ?

Yes, John.

So where do we want to see that high move if we want cold weather.

you want it to block all incoming from the Atlantic by it linking up to a high around Iceland somewhere

WolfeIRE

200motels wrote: »

So where do we want to see that high move if we want cold weather.

Away from the UK and Ireland for a start, preferably nw toward eastern Canada. This was modeled to happenby the ECM for roughly 5 days up to Saturday, but it has pulled back from that outcome. It still has the high moving slowly nw before collapsing south. One to watch as the models have a good distance to go before falling into line.

jirafa

UK - 14 Day Forecast



The fluctuating weather pattern across the UK looks likely to continue for the remainder of January and into the opening phase of February, with the driest of the weather being retained to the east of the country, and the wettest conditions holding firm across Scotland, Northern Ireland, and generally NW England and Wales. Sporadic colder incursions are likely at times bringing night frost activity for much of England, Wales, and Scotland, however, these are unlikely to be sustained. Any snow is still probably going to be confined to the mountains of Scotland, dropping to lower levels for a limited time. Temperatures will continue to significantly vary.

Positive Weather Solutions
Monday January 16th 2012

:mad::mad::mad::mad::(:(:(:(:(:confused::(:o:o

Min

jirafa wrote: »

UK - 14 Day Forecast



The fluctuating weather pattern across the UK looks likely to continue for the remainder of January and into the opening phase of February, with the driest of the weather being retained to the east of the country, and the wettest conditions holding firm across Scotland, Northern Ireland, and generally NW England and Wales. Sporadic colder incursions are likely at times bringing night frost activity for much of England, Wales, and Scotland, however, these are unlikely to be sustained. Any snow is still probably going to be confined to the mountains of Scotland, dropping to lower levels for a limited time. Temperatures will continue to significantly vary.

Positive Weather Solutions
Monday January 16th 2012

:mad::mad::mad::mad::(:(:(:(:(:confused::(:o:o

Sounds good, an early spring like last year would be great.