Cold Spell Late Feb/ Early March Technical Discussion only MOD NOTE POST #1

sean555

Hirlam still has heavy snow for the parts Connacht Friday morning.

WolfeEire

Period Wed PM to Fri PM

Precip chart (pink = snow, blue = rain)



Precip accumulation. This latest run would be in line with Met Eireann's Red Alert areas for Storm Emma. Would expect Galway to be added.

chemwiz

Guys, not sure if this is the correct thread. Any discussion around when we expect the polar vortex to stabilise on it normal atric rotation. Charts I have been looking at >4 days still show disturbance to the rotation.

nacho libre

chemwiz wrote: »

Guys, not sure if this is the correct thread. Any discussion around when we expect the polar vortex to stabilise on it normal atric rotation. Charts I have been looking at >4 days still show disturbance to the rotation.

The UKMO have been saying up to the Middle of March for things to return to normal.

Gaoth Laidir

Latest snow depths up to 23:00, now including my Celbridge measurements too. Casement didn't include snow depth in the 22:00 report.

WolfeEire

Met Eireann's STATUS RED warning area for Emma is accurate as of now. There is an argument for Galway to be included however

HIRLAM


ARPEGE


ICON


GFS

chemwiz

nacho libre wrote: »

The UKMO have been saying up to the Middle of March for things to return to normal.

Has this happened before for such a sustained period of time. What's the implications for arctic temperatures etc..

Liffey4A

WolfeEire wrote: »

Met Eireann's STATUS RED warning area for Emma is accurate as of now. There is an argument for Galway to be included however

HIRLAM


ARPEGE


ICON


GFS

I dunno I can see it running out of steam around North Dublin.
Even though Rain radar is currently showing snow showers over Louth and it isn't falling.

I can see the South East getting a lot of snow however.

nacho libre

chemwiz wrote: »

Has this happened before for such a sustained period of time. What's the implications for arctic temperatures etc..

Yes it has. It means arctic temperatures will be well above normal for a sustained period of time. A couple of days ago they were close to rising above zero.

Nettle Soup

I know its not a weather model but the latest cold/dry spell has resulted in water levels going down rapidy. The ground is really getting a chance to drain.

This is the station at Dangan, Galway. Down 0.4m since early February.

https://waterlevel.ie/0000030098/0001/

Gaoth Laidir

Satellite image showing the highest (greenish) cloutops off to our west now, with much lower (orange/yellow) clouds over the UK where stability is now greater as upper levels warm. As this stability moves westwards it will dampen showers over the Irish Sea.

pistolpetes11

All Ireland RED warning level now , anything in the latest charts that would see that warranted ?

nacho libre

Gaoth Laidir wrote: »

with much lower (orange/yellow) clouds over the UK where stability is now greater as upper levels warm. As this stability moves westwards it will dampen showers over the Irish Sea.

You say that but we've had three hours of moderate to heavy snow with these warming upper levels.

WolfeEire

pistolpetes11 wrote: »

All Ireland RED warning level now , anything in the latest charts that would see that warranted ?

No, Pete. Would hate to think it was political pressure. Worst case scenario is that the economy will lose out and everybody stays safe I guess.

snowstorm445

Have to say I'm worried that some of the charts have Dublin mostly missing out or barely being clipped by the snow tomorrow, seems to be Wicklow south on some models (Wexford in particular looks like getting hammered).

stephenjmcd

snowstorm445 wrote: »

Have to say I'm worried that some of the charts have Dublin mostly missing out or barely being clipped by the snow tomorrow, seems to be Wicklow south on some models (Wexford in particular looks like getting hammered).

To me looks like right up to South Dublin and into the city. North would be close but there must be something in the charts for national red now

pistolpetes11

pistolpetes11 wrote: »

All Ireland RED warning level now , anything in the latest charts that would see that warranted ?

....and an extension in time too. From now until 3pm Friday. Something ME are seeing that the general public don't have access to? As a matter of interest when do the likes of ME get access to the latest runs of the ECM etc?

SleetAndSnow

Harmonie must be showing something which we can not see yet possibly?

Zzippy

Nettle Soup wrote: »

I know its not a weather model but the latest cold/dry spell has resulted in water levels going down rapidy. The ground is really getting a chance to drain.

This is the station at Dangan, Galway. Down 0.4m since early February.

https://waterlevel.ie/0000030098/0001/

Probably not the best example since the water level is artifically regulated by the weir downstream in Galway and responds to sluice gates being opened and closed. Water level there is also affected by wind speed and direction - a northerly wind pushes water south down a long fetch of the lower lake, raising water levels downstream, while an upstream southerly lowers water levels. Your point holds, the dry spell is lowering water levels everywhere, just that gauge is not a reliable yardstick.

Sorry if this is off topic mods.

Oneiric 3

Deleted User wrote: »

As a matter of interest when do the likes of ME get access to the latest runs of the ECM etc?

About the same time as we do I think.

Scubadevils

Scubadevils wrote: »

Yeah same concern from a North Dublin perspective with regards to Emma tomorrow, really doesn't look like she reaches here... we shall see I guess.

18Z HIRLAM puts the area in the firing line at some stage tomorrow evening.

Rougies

Oneiric 3 wrote: »

About the same time as we do I think.

Pretty much exactly the same time. The time it takes for the various websites to process the data into readable charts as it rolls out is negligible. Some sites may delay updating the images, but I don't see why they would.

WolfeEire

Deleted User wrote: »

18Z HIRLAM puts the area in the firing line at some stage tomorrow evening.

The precipitation rates at that point in the run (featured in your image) are negligible away from Leinster and Munster. This is a Red Alert for Munster and Leinster, and perhaps Galway. Fundamentally, I think our system of weather warnings needs redressing. Met Eireann are superb but I don't think for one minute that there was unanimous agreement or anything close to it in Glasnevin over this. Maybe, Gerry really is on holiday.... However, they are the experts and they get it right the vast majority of the time.

Edit: The precip doesn't really reach beyond the north midlands here so it's all the more puzzling - http://www.met.ie/forecasts/5day-ireland.asp

Kermit.de.frog

Looks quite possible precipitation may not reach Dublin

Oneiric 3

The last Met Éireann hourly weather report of Winter 2017-2018:

ThaitaniumM

WolfeEire wrote: »

The precipitation rates at that point in the run (featured in your image) are negligible away from Leinster and Munster. This is a Red Alert for Munster and Leinster, and perhaps Galway. Fundamentally, I think our system of weather warnings needs redressing. Met Eireann are superb but I don't think for one minute that there was unanimous agreement or anything close to it in Glasnevin over this. Maybe, Gerry really is on holiday.... However, they are the experts and they get it right the vast majority of the time.

Edit: The precip doesn't really reach beyond the north midlands here so it's all the more puzzling - http://www.met.ie/forecasts/5day-ireland.asp

That's the ECM model. I wouldn't go off of that for events within 48hr. It's too low res. I would go with the HIRLAM or ARPEGE for closer events.

snowstorm445

Oneiric 3 wrote: »

The last Met Éireann hourly weather report of Winter 2017-2018:

-5 is very impressive for Cork! Can't remember anything that cold in Cork since 2010.

Brae100

Hmm, latest runs look like we have just dodged some serious floods this weekend, but have maybe just kicked the can a bit down the road. There's a flood thread coming.

NMB

So going by the models there is no precipitation reaching Dublin cc before tomorrow morning and from Emma - ok using that as a starting point there’s a rise in temp Saturday and then back into the freezer Monday - have I got that right ? MT where are you ?

Oneiric 3

ECM ensemble spread for snow depth possibility from 'Emma' for my region (NE Co. Galway) which is in the lower risk area, but look at the amount of 'spread'. Really shows the high uncertainty regarding how far north the potential impacts of 'Emma' would be felt.