Cold Spell Media Forecasts and Model Output (General Chat)

thetonynator

Elmo5 wrote: »

Righty, model runs. MT's winter storm could be on the way after the new moon over the next few days. Although it doesn't seem like it will be cold enough for this to bring snow, it could be what he was predicting?
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New moon isn't for more than two weeks, the full moon is in a few days time, which is the energy peak MT spoke of.

th3 s1aught3r wrote: »

That says wave after wave of snow for England, Wales... Ireland bone dry apart from maybe south coast getting a bit

Maybe not, but BBC and the UKMO don't really care about the accuracy of their irish forecasts (at least not for the republic) so Met eireann and MT's would be much better to follow.

mickger844posts

Musicman2000 wrote: »

Cant see it myself lads, it will either stall, break up or swing in a south west direction, at the moment it dose look like its heading in a North East direction

Was thinking it was too good to be true.

200motels

According to Gerry tonight we might see snow and more widespread on Monday night into Tuesday but just saw Sky's forecast and we are clear all week. Which one is right well I'd go for Sky's as they have been a lot more accurate than ME of late.

thetonynator

200motels wrote: »

According to Gerry tonight we might see snow and more widespread on Monday night into Tuesday but just saw Sky's forecast and we are clear all week. Which one is right well I'd go for Sky's as they have been a lot more accurate than ME of late.

Met eireann would generally be better than sky, as sky dont really care about the republic. M.T. is very accurate 95% of the time.

Musicman2000

The Sky charts you are looking at are not updated yet, just looking at the 18z run the south east are in for a nice fall of snow, if its still on the 12z run tommorow, it would look very good, but as over the weekend, it could change within 24 hours and be left with nothing

Edit : Just looking at the Hirlam model all snow gone for Tuesday. Disaster

mickger844posts

Musicman2000 wrote: »

The Sky charts you are looking at are not updated yet, just looking at the 18z run the south east are in for a nice fall of snow, if its still on the 12z run tommorow, it would look very good, but as over the weekend, it could change within 24 hours and be left with nothing

Edit : Just looking at the Hirlam model all snow gone for Tuesday. Disaster

In line with what the BBC forecast said earlier, they must be using the same models.

M.T. Cranium

The problem continues to be this -- too many small, weak lows all competing for the same energy, not enough frontal contrast because the PV pushed all the really mild air way south of 45 deg. I have some hope for the Monday system because it will be capturing the energy peak which comes at 08h Tuesday. And you can see this one trying to get started out to the southwest of Ireland, not the system that's been hanging around near Kerry, which is the reflection of the upper low, but a small swirl of clouds out around 50 N 13 W.

I think it's hopeless to give much of a forecast of its actual track and snow potential until the morning update although perhaps by 0300h there would be better indications available.

I posted a semi-update on the forecast thread, it basically reviews the ifs ands & buts of this situation and gives my standard don't believe the warm-up until it turns warm disclaimer. I wasn't actively forecasting in this part of the world in the 1970s or 1980s (but I was over here) but I do recall the times when the old style forecasting went "t*ts up" on numerous occasions relating to frontal boundaries and warmups that never arrived, turned to snow and left everyone mystified. I can see how that's quite possible given these patterns emerging on the models for 24-26 December.

On the other hand, that front could go through, so we'll just have to keep checking the signs -- I just can't see a cold spell this intense giving up without a fight, the only interruption we had was that easily gained NW'ly flow that never really broke normal or moved in any moisture. That takes little energy or pattern shift. All the cold water around the region now is a factor too.

Trotter

MT would you, at this point, be disregarding the latest HIRLAM that takes the snow off the agenda for Monday-Tuesday?

lucernarian

Has anyone seen any posts by Su Campu lately? I haven't heard much from him.

thetonynator

To_be_confirmed wrote: »

Has anyone seen any posts by Su Campu lately? I haven't heard much from him.

i haven't seen any sign of su since this cold spell started, sorely missed at the moment.

nacho libre

M.T. Cranium wrote: »

The problem continues to be this -- too many small, weak lows all competing for the same energy, not enough frontal contrast because the PV pushed all the really mild air way south of 45 deg. I have some hope for the Monday system because it will be capturing the energy peak which comes at 08h Tuesday. And you can see this one trying to get started out to the southwest of Ireland, not the system that's been hanging around near Kerry, which is the reflection of the upper low, but a small swirl of clouds out around 50 N 13 W.

I think it's hopeless to give much of a forecast of its actual track and snow potential until the morning update although perhaps by 0300h there would be better indications available.

I posted a semi-update on the forecast thread, it basically reviews the ifs ands & buts of this situation and gives my standard don't believe the warm-up until it turns warm disclaimer. I wasn't actively forecasting in this part of the world in the 1970s or 1980s (but I was over here) but I do recall the times when the old style forecasting went "t*ts up" on numerous occasions relating to frontal boundaries and warmups that never arrived, turned to snow and left everyone mystified. I can see how that's quite possible given these patterns emerging on the models for 24-26 December.

On the other hand, that front could go through, so we'll just have to keep checking the signs -- I just can't see a cold spell this intense giving up without a fight, the only interruption we had was that easily gained NW'ly flow that never really broke normal or moved in any moisture. That takes little energy or pattern shift. All the cold water around the region now is a factor too.

perhaps we should show the cold airmass some rocky movies in preparation for the battle to come?

force eleven

The debate continues on this and other forums about whether this cold spell breaks down on Saturday. Met Eireann have nailed their colours firmly to the mast for milder weather and you have to take that opinion seriously despite recent events. However, not all models agree at this time about this mild scenario. Gerry Murphy was positively Chesire catlike earlier on. Never a good thing for cold weather lovers given his mild bias at this stage I'm starting to see charts appearing when I close my eyes so I'm taking a break for one day to go cold turkey...I tried before and lasted one run before I had to check the data.....;)

pistolpetes11

To_be_confirmed wrote: »

Has anyone seen any posts by Su Campu lately? I haven't heard much from him.

He does be here , but when boards was acting up a lot during the last cold spell he spent a good bit of time irishweatheronline.com and he actually writes for them too

Trotter

When do you guys think we should have a relatively high degree of confidence about the south east being hit or otherwise on Tuesday? Tuesday? :P

fizzycyst

Met Eireann predicted the mild weather to return once already and then went back on what they said, obviously, with the current situation I am not saying they are wrong, but in all honesty I don't see how anyone can predict anything. I think it's a waiting game until at least Thursday, this is just from a pure amateur admittedly but, at the moment it seems nobody can see what's coming.

delw

thetonynator wrote: »

i haven't seen any sign of su since this cold spell started, sorely missed at the moment.

yeah agree,would love to hear his views on the latest charts&what he expects to happen,defo missed

Birdnuts

Nice cold run on the 18Z right through the Crimbo period:D

fizzycyst

how is the mass of cloud off the SE coast not going to give us snow, can anyone answer this?

http://sat24.com/Region.aspx?country=gb&sat=ir&type=loop

mickger844posts

Trotter wrote: »

When do you guys think we should have a relatively high degree of confidence about the south east being hit or otherwise on Tuesday? Tuesday? :P

I echo what fizzycyst said. Its so hard to predict anything. Its purely radar and Sat watching at this stage. A few models are saying that the south east will get hit Tuesday but models haven't been reliable of late so keep checking in here for updates

mickger844posts

fizzycyst wrote: »

how is the mass of cloud off the SE coast not going to give us snow, can anyone answer this?

http://sat24.com/Region.aspx?country=gb&sat=ir&type=loop

The upper atmosphere winds at 850hpa are easterly or south easterly thats why its not going to hit us.

fizzycyst

mickger844posts wrote: »

I echo what fizzycyst said. Its so hard to predict anything. Its purely radar and Sat watching at this stage. A few models are saying that the south east will get hit Tuesday but models haven't been reliable of late so keep checking in here for updates

Mick, I've been watching the winds come from a northerly direction, but this mass of cloud seems to be heading straight for us and I honestly would love to know why we will not see ant precipitation. I do realise that not all cloud gives precip but, from sat24 it just looks very promising.

Irish Steve

Been watching the EUmetsat animation at http://www.yr.no/satellitt/europa_animasjon.html of the cold plunge coming west out of Scandinavia and then south of Iceland, and the question that's going through my mind, as I'm not that experienced with these charts, it looks to me as if the Cold air has then gone South and from about 14:00 Sunday, it looks to have punched a huge bulge into I think is the frontal line of cloud that's been moving over the Atlantic all day.

Am I right in thinking that the dissapearance of the line of cloud has been caused by the cold plunge undercutting the warm air and forcing it up, which has dispersed the cloud, and if that is correct, are there any implications in this for the next few days, and particularly for the doubtful looking thaw that's supposedly on the way.

In passing, I should probably mention that I have (childhood) memories of 62/63 in the UK, where it snowed on St Stephen's Day, and then with no real let up, was cold enough for the snow to stick even in Devon right through till March. I don't recall any further falls in Devon, but my memory may be faulty, as Wikipedia certainly talks about more significant subsequent falls. The main thing was the length of the cold period.

Thanks

Steve

lucernarian

fizzycyst wrote: »

Mick, I've been watching the winds come from a northerly direction, but this mass of cloud seems to be heading straight for us and I honestly would love to know why we will not see ant precipitation. I do realise that not all cloud gives precip but, from sat24 it just looks very promising.

Northerly wind is from the air moving off very cold land to warmer air over sea, which is less dense. The opposite of a sea breeze during the summer I suppose

snow ghost

ME's latest warning:

"Issued at 20 December 2010 - 00:40
Severe Weather Update
Widespread very severe frost and icy conditions this morning and temperatures generally not rising above zero during daytime Monday. Some snow showers/pockets of freezing fog but most areas dry.
Arctic conditions continuing up to Christmas Day then Atlantic airflow becoming established.

Valid from 20-Dec-2010
until 25-Dec-2010"

Birdnuts

snow ghost wrote: »

ME's latest warning:

"Issued at 20 December 2010 - 00:40
Severe Weather Update

Arctic conditions continuing up to Christmas Day then Atlantic airflow becoming established.

Valid from 20-Dec-2010
until 25-Dec-2010"

A brave call given that most models are having problems only 24hrs out and even less in some cases - tonights 18z extended the cold towards the new years but we'll see whats the story in the morn:)

Harps

Met Eireann will confirm warming at the slightest hint on the models, it does seem that warming is briefly on the way but I wouldnt take it too seriously yet as this time yesterday they were adamant it would happen on Christmas Eve

snow ghost

They're basing their Christmas day Atlantic warming from the 12z ecmwf, I believe:

delw

Harps wrote: »

Met Eireann will confirm warming at the slightest hint on the models, it does seem that warming is briefly on the way but I wouldnt take it too seriously yet as this time yesterday they were adamant it would happen on Christmas Eve

yeah it seems like its to get pushed back 24hours

delw

snow ghost wrote: »

They're basing their Christmas day Atlantic warming from the 12z ecmwf, I believe:

is that not temps of 10+ on christmas day,what a waste of cold if we got double figures on CHRISTMAS DAY


(not that we didnt before)

Redsunset

I know this will change but tis good to get a wee bit excited ,BANK

It's tomorrows output,ya would think it was set in stone at this stage but unfortunately Hirlam gets rid