Cold Snap, T0-180Hours Only

darkman2

UKMO - Wednesday

Tom Cruises Left Nut

And the fun keeps on going !

hotwhiskey

UKMO rolling out also! GFS and Ukmo so far at 96h pretty much the same.

You beat me to it Darkman!!

DOCARCH

Dónal wrote: »

...does the thread title mean low-ground snow risk or a low risk of snow anywhere?

Really too early to say. The main thing is the cold would appear to be on the way or certainly very near by to tap into (which obviously you need for it to snow).

Slowly slowly catchey monkey!

Tom Cruises Left Nut

I want to see what the GFS does in FI with this, those -20s are barreling our way !

Tom Cruises Left Nut

Germany well and truly in the freezer ! I hope this run is a mild outlier :pac:



Right... im cracking open a beer to watch FI !!!

Lucreto

I meant to be going to Birmingham on the 7th Feb. So is there a high possibility of it being white when I land?

200motels

I just saw the 12Z run from GFS and it's totally different than the previous run, it's amazing for cold lovers, lets hope it will come off as we need a winter blast.

darkman2

UKMO loses it's way slightly and tries to sink the block at 120hrs. Main thing is it's pretty solid with the GFS at 96hrs with a very cold easterly breeze and very low surface temperatures. I have a feeling the ECM will be similar to the UKMO as it often is. So doubt we will be any wiser post 96hrs today. Good 12z runs for coldies so far.

Musicman2000

200motels wrote: »

I just saw the 12Z run from GFS and it's totally different than the previous run, it's amazing for cold lovers, lets hope it will come off as we need a winter blast.

Another great run is right, Even the snow shield down in Waterford would be blown apart:D But GFS is probably being a bit to progressive as usual.
UKMO not good

Eastcoastryan

darkman2 wrote: »

UKMO loses it's way slightly and tries to sink the block at 120hrs. Main thing is it's pretty solid with the GFS at 96hrs with a very cold easterly breeze and very low surface temperatures. I have a feeling the ECM will be similar to the UKMO as it often is. So doubt we will be any wiser post 96hrs today. Good 12z runs for coldies so far.

I think I am going to get off this rollercoaster at the next stop! These upgrades and downgrades aren't good for my heart. Maybe this is a silly question but how are models so different from run to run? What changes?

mickger844posts

12Z GFS more in line with the amazing 0Z run. A real upgrade on the 06Z. The signals are good but a lot can go wrong or right before this becomes reality.

Sponge Bob

Eastcoastryan wrote: »

Maybe this is a silly question but how are models so different from run to run? What changes?

In what is invariably a very large and complex model sometimes something very small changes and the computation takes the outputs in a dramatically different direction. It is impossible for two model runs, even only 6 hours apart, to be the same.

darkman2

Eastcoastryan wrote: »

I think I am going to get off this rollercoaster at the next stop! These upgrades and downgrades aren't good for my heart. Maybe this is a silly question but how are models so different from run to run? What changes?

My understanding is that the starting point changes - 00hrs the models start with the data collected from all over the world (bouys, met stations, aircraft measurements etc) at the time the run started (in this case 12pm) and the data is always different to varying degrees to that originally forecast so the outcome changes. The changes get more and more wide as the run progresses and the variables get bigger and bigger. Essentially they are operating off a sort of chaos theory which science can never overcome. The data is processed through supercomputers and complex algorithms to produce a forecast. The forecast is always different to the last one.

darkman2

t|nt|n wrote: »

Germany well and truly in the freezer !

So are we, it's part of the bailout.

TheMilkyPirate

Comparing run to run as in 12z to 12z and 00z to 00z i think is a lot better for our health than each run in succesion (sp?)!

nacho libre

baraca wrote: »

Comparing run to run as in 12z to 12z and 00z to 00z i think is a lot better for our health than each run in succesion (sp?)!

Also investing too much emotion into epic runs from one model is a bad idea, when others are showing less cold solutions.
Although hopefully before the inevitable transition back to milder weather for all occurs, the east of Ireland will tap into proper cold. Unfortunately it looks quiet possible the west of Ireland will stay on the mild side throughout.
Sponge bob must be feeling utterly deflated at the thought of this.

doccy

darkman2 wrote: »

My understanding is that the starting point changes - 00hrs the models start with the data collected from all over the world (bouys, met stations, aircraft measurements etc) at the time the run started (in this case 12pm) and the data is always different to varying degrees to that originally forecast so the outcome changes. The changes get more and more wide as the run progresses and the variables get bigger and bigger. Essentially they are operating off a sort of chaos theory which science can never overcome. The data is processed through supercomputers and complex algorithms to produce a forecast. The forecast is always different to the last one.

I read that two of the GFS runs have more accurate data fed daily?

munsterlegend

nacho libre wrote: »

Also investing too much emotion into epic runs from one model is a bad idea, when others are showing less cold solutions.
Although hopefully before the inevitable transition back to milder weather for all occurs, the east of Ireland will tap into proper cold. Unfortunately it looks quiet possible the west of Ireland will stay on the mild side throughout.
Sponge bob must be feeling utterly deflated at the thought of this.

Why do met eireann rely primarily on the ECM? The gfs show the easterly reaching Ireland but its not reflected in their forecast.

darkman2

GFS control run is completely in sync with the operational at 96hrs so that improves confidence somewhat.

pistolpetes11

doccy wrote: »

I read that two of the GFS runs have more accurate data fed daily?

Yeah something to do with sounding Data used on the 0Z and 12Z and its not used on the other two.

Il have a route about later to see if I can get a more info on it.

pistolpetes11

A little video of how the GFS 6z and 12z evolved

https://www.youtube.com/watch?v=te8o8Sx4dGA

darkman2

doccy wrote: »

I read that two of the GFS runs have more accurate data fed daily?

No that's a myth I think. Some also say there is missing data around the holidays as well. The 4 GFS runs per day must have a full data set or there would be no consistency. All the models are working off the same data. It's just some are better then others. Just my opinion - I could be wrong on the availability of data. I doubt it very much though.

Tom Cruises Left Nut

Well its all eyes on the ECM now starting at 18:00

TheMilkyPirate

darkman2 wrote: »

No that's a myth I think. Some also say there is missing data around the holidays as well. The 4 GFS runs per day must have a full data set or there would be no consistency. All the models are working off the same data. It's just some are better then others. Just my opinion - I could be wrong on the availability of data. I doubt it very much though.

I think they use balloon sounding data on the 00z and the 12z that isn't used on the 06z and 18z as their only launched twice daily

darkman2

munsterlegend wrote: »

Why do met eireann rely primarily on the ECM?

Because they pay for it with all the other member states of the organisation;)

munsterlegend

darkman2 wrote: »

Because they pay for it with all the other member states of the organisation;)

And the have to follow it? Is it more accurate?

doccy

baraca wrote: »

I think they use balloon sounding data on the 00z and the 12z that isn't used on the 06z and 18z as their only launched twice daily

I think that's it actually!

force eleven

http://www.wzkarten3.de/pics/Rtavn14417.png

A bit chilly on Friday. All the way to the west coast. IF this verifies. T144 still deep FI in this set up.

BEASTERLY

munsterlegend wrote: »

And the have to follow it? Is it more accurate?

Yes it is the most accurate of the medium term models, which is why i wont get excited until the ECM backs the GFS.