FI Charts ( T120+ onwards) Winter 2020 **READ MOD NOTE IN FIRST POST**

Mr_A

TheMilkyPirate wrote: »

A little slower alright but looks to be better in the long run. Lows readily sliding under the block

Really enjoying this thread but sometimes get lost on some terminology. Would like to understand what folks mean when they talk about the lows "sliding under" like this and what the upshot is? I gather it's good.

lucernarian

Kermit.de.frog wrote: »

The only issue I have with some of these runs, while synoptically very nice, is that sea based convective potential looks limited. I'd like to see lower heights generally. Low cloud tops, snow showers look light to moderate at best in the absence of some embedded trough lines.

Something like this...

The heights and pressure are fine in that chart (as an example)?

teddybones

Rebelbrowser wrote: »

Streamers from Rathlin Island in the North to Mizen in the South by Monday morning on the Icon (with apologies for those in between affected by the IOM and Anglesea)!

I will cry if that happens and my in laws, all 7 siblings, partners and kids will actually lynch me because this is what happened in 2018 for wicklow town and looks to be happening again and I am their resident weather 'guru' (I just follow boards) . And I don't think I can cope with their anguished disappointment again. In 2018 it was 'when is the snow coming, when is the snow coming' with a great effing Anglesea shadow. But Wicklow was in a direct easterly and we got not so much as a flake until Emma roared in and gave us a dumping but was nerve-wracking to say the least.
Am hoping the winds veer more north easterly. Always a danger of IOM but didn't affect us in 2010. The fetch from a direct easterly is hopeless. Wicklow head is the closest point to the UK mainland from the Republic. I am doomed of that happens. They are already asking me is the snow coming. And when. I despair. Slight nudge ðŸ™

TheMilkyPirate

Mr_A wrote: »

Really enjoying this thread but sometimes get lost on some terminology. Would like to understand what folks mean when they talk about the lows "sliding under" like this and what the upshot is? I gather it's good.

Low pressure systems from the Atlantic are going underneath the cold block instead of blasting over us and ending the cold spell. The upshot is the cold lasting longer and also the chance of frontal snow with a low pressure system skirting the south coast.

Maybe one of the more knowledgeable posters can give a better explanation.

Kermit.de.frog

lucernarian wrote: »

The heights and pressure are fine in that chart (as an example)?

Aye, much more precipitation with a chart like that. Potentially isolated thunderstorms too. More moisture with the track over the north sea too and a longer sea track over the Irish sea.

There are trade offs though - a scenario like that might not last as long + temperatures a teeny bit milder.

TheMilkyPirate

A cracking set of 12Zs tbf. Bring on the ECM

KingdomRushed

GEM is rolling out and also an upgrade in the near term. I wouldn't be too worried about GFS precipitation it actually looks hefty enough from Tuesday and near constant along the east coast at least

snowstorm445

ICON and UKMO prolong the spell past midweek whereas the GFS blows up a low pressure system in the Atlantic which brings in milder air by Thursday. Either way some cold and wintry days to come next week for Ireland it would seem

TheMilkyPirate

GEM keeps the upgrade train rolling.

lucernarian

snowstorm445 wrote: »

ICON and UKMO prolong the spell past midweek whereas the GFS blows up a low pressure system in the Atlantic which brings in milder air by Thursday. Either way some cold and wintry days to come next week for Ireland it would seem

What is GFS para showing? I thought it was verifying better

Tom Cruises Left Nut

TheMilkyPirate wrote: »

GEM keeps the upgrade train rolling.

When does this move to the sub 120 thread !

nacho libre

Good old GFS blowing up lows as per usual, if the other models don't waver that will be flabbier in future runs.

Let's see does it have much support from its own members,

Gonzo

lucernarian wrote: »

What is GFS para showing? I thought it was verifying better

Not seeing an update to the GFS P yet, this mornings run was similar to the operational. Last night's control run was fantastic.

Artane2002

Gonzo wrote: »

Not seeing an update to the GFS P yet, this mornings run was similar to the operational. Last night's control run was fantastic.

I don't think it updated since yesterday's 6z.

Rebelbrowser

teddybones wrote: »

I will cry if that happens and my in laws, all 7 siblings, partners and kids will actually lynch me because this is what happened in 2018 for wicklow town and looks to be happening again and I am their resident weather 'guru' (I just follow boards) . And I don't think I can cope with their anguished disappointment again. In 2018 it was 'when is the snow coming, when is the snow coming' with a great effing Anglesea shadow. But Wicklow was in a direct easterly and we got not so much as a flake until Emma roared in and gave us a dumping but was nerve-wracking to say the least.
Am hoping the winds veer more north easterly. Always a danger of IOM but didn't affect us in 2010. The fetch from a direct easterly is hopeless. Wicklow head is the closest point to the UK mainland from the Republic. I am doomed of that happens. They are already asking me is the snow coming. And when. I despair. Slight nudge ðŸ™

I wouldn't worry, winds will veer this way and that. You should get your fill at some stage.

Mr_A

Update from Met Éireann

https://twitter.com/MetEireann/status/1357004955501146117

nacho libre

Actually given the jet stream profile, the GFS scenario isn't that unlikely. It will be hard to sustain the cold with an active jet courtesy of the cold over north America. The best we can hope for is that the GFS is underestimating the strength of the block and that lows will slide.. Mogrep must have seen this development too, but favoured the block being resolute enough to stop the mild winning out.

Let's see what the ECM shows.

Arduach

nacho libre wrote: »

Actually given the jet stream profile, the GFS scenario isn't that unlikely. It will be hard to sustain the cold with an active jet courtesy of the cold over north America. The best we can hope for is that the GFS is underestimating the strength of the block and that lows will slide.. Mogrep must have seen this development too, but favoured the block being resolute enough to stop the mild winning out.

Let's see what the ECM shows.

Hopefully as MT pointed out a few days ago, this will be a wintry spell like 1895 and others, where both sides of the Atlantic are cold.

lucernarian

Mr_A wrote: »

Update from Met Éireann

https://twitter.com/MetEireann/status/1357004955501146117

I'd like to think a certain guy in Met Éireann knew we can't see ECMWF ensembles normally and gave a nice tidbit for us

Gonzo

Would like to see a very similar ECM to earlier. It's actually much better than the GFS overall and brings possibly nationwide frontal snow potential second half of next week and into the weekend. GFS cuts off the cold from Wednesday with a mild Atlantic rolling back in with ease.

mcburns07

lucernarian wrote: »

I'd like to think a certain guy in Met Éireann knew we can't see ECMWF ensembles normally and gave a nice tidbit for us

:pac: it does look that way, a very personable tweet.

Oneiric 3

lucernarian wrote: »

I'd like to think a certain guy in Met Éireann knew we can't see ECMWF ensembles normally and gave a nice tidbit for us

You can! just enter in your location and choose between graphs.

https://www.ecmwf.int/en/forecasts/charts/web/classical_meteogram?facets=undefined&time=2021020300,0,2021020300&epsgram=classical_plume&lat=53.2719&lon=-9.04889&station_name=Galway,%20Ireland&altitude=-9999

sicknotexi

Some good runs but much of the very cold air has been pushed back to early Monday. No problem with that but I'd like a bit more than 48 hours cold as is shown on a lot of the gef ensembles. If we can get 3 or 4 days of it I'd be much happier. Hopefully the ECM can oblige.

Slashermcguirk

And there it is, even from Gerry Murphy

https://www.irishtimes.com/news/ireland/irish-news/weather-warning-as-siberian-winds-set-to-bring-significant-snow-1.4475268

Tom Cruises Left Nut

Tom Cruises Left Nut wrote: »

When does this move to the sub 120 thread !

Good point.

snowstorm445

Yeah the GEFS mean also blows up the low pressure and brings in the mild air quickly unfortunately. Although the heights over Scandi and Greenland don't go away, so it mightn't be game over if this spells ends.

Gonzo

Today is probably the last day of this cold spell remaining on this thread up to next Wednesday. Lets see what the ECM 12z brings and finally the pub run later. If all remains good then this discussion should move into the shorter range technical thread as we are almost locked into this cold spell from Sunday to Tuesday/Wednesday.

Arduach

snowstorm445 wrote: »

Yeah the GEFS mean also blows up the low pressure and brings in the mild air quickly unfortunately. Although the heights over Scandi and Greenland don't go away, so it mightn't be game over if this spells ends.

It only takes minor adjustment of a slightly more southerly track to turn that depression into a slider. Many of the longer cold spells like 1947 and 1963 looked like they were a few days from breaking down but rolled on.

We're in a great position this evening pre ECM as opposed to yesterday.

Rebelbrowser

Where do you get the upper temps for the UKMO? Would like to see temps at 144h

Reversal

Arduach wrote: »

It only takes minor adjustment of a slightly more southerly track to turn that depression into a slider. Many of the longer cold spells like 1947 and 1963 looked like they were a few days from breaking down but rolled on.

We're in a great position this evening pre ECM as opposed to yesterday.

The latest Met Eireann monthly predicts Atlantic making a temporary return late next week. They say the last two weeks of Feb will be dominated by easterlies with high pressure not the north.