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

TheMilkyPirate · 15-01-2021 10:15am

Colder air from late Tuesday/early Wednesday on the 0z GFS

Colder again on Thursday and Friday with snow showers pushing in over the north of the country

Tentative upgrades this morning and still all to play for over the coming week or two in my eyes. It's going to turn colder anyway that's for sure.

nacho libre · 15-01-2021 10:44am

It's interesting to see the ECM picking up on the GFS para idea of a link up between those two highs. The Para has been showing that on and off for a while. The TP vortex could be lifted out, yet we still miss out on frigid cold. Incredible.

Anyway it's looking good for at least a short term cold snap with snow for some later next week. Lets hope it does not get downgraded!

munsterlegend · 15-01-2021 12:23pm

froog wrote: »

Jeez this thread is like a rocky movie!

And if the ECM can change, and the gfs can change we...

Gonzo · 15-01-2021 12:31pm

nacho libre wrote: »

It's interesting to see the ECM picking up on the GFS para idea of a link up between those two highs. The Para has been showing that on and off for a while. The TP vortex could be lifted out, yet we still miss out on frigid cold. Incredible.

Anyway it's looking good for at least a short term cold snap with snow for some later next week. Lets hope it does not get downgraded!

I don't see us getting much in the way of snow if we're only going to be getting a brief northerly. Those are usually relatively dry as the showers usually die out over Northern Ireland and fail to reach most of the republic, and what does fall is usually a dusting of dandruff. Northerlies are good at getting the cold in if they are not highly modified by the Atlantic and last at least several days.

Next week's potential northerly only has -4 to -7 uppers with it and is modified by the Atlantic/long sea fetch so it will be a fairly similar situation to the first week of the Christmas/New Year cold spell. We need serious upgrades for it to ignite any real excitment such as deeper cold, a big unstable upgrade with polar low opportunities and winds switching into the east/north-east at some point dragging down air far less modified by the Atlantic and shorter sea stretch.

15-01-2021 1:00pm

nacho libre wrote: »

It's interesting to see the ECM picking up on the GFS para idea of a link up between those two highs. The Para has been showing that on and off for a while. The TP vortex could be lifted out, yet we still miss out on frigid cold. Incredible.

Anyway it's looking good for at least a short term cold snap with snow for some later next week. Lets hope it does not get downgraded!

Yeah except for one thing
Get up the historical charts of 2018 and look up the weather south of that easterly...
Here's Rome last week of February, 1st week of march 2018 under a westerly
Thats potentially us in this new regime except maybe 8 to 12c and wetter

typhoony · 15-01-2021 1:03pm

Gonzo wrote: »

I don't see us getting much in the way of snow if we're only going to be getting a brief northerly. Those are usually relatively dry as the showers usually die out over Northern Ireland and fail to reach most of the republic, and what does fall is usually a dusting of dandruff. Northerlies are good at getting the cold in if they are not highly modified by the Atlantic and last at least several days.

Next week's potential northerly only has -4 to -7 uppers with it and is modified by the Atlantic/long sea fetch so it will be a fairly similar situation to the first week of the Christmas/New Year cold spell. We need serious upgrades for it to ignite any real excitment such as deeper cold, a big unstable upgrade with polar low opportunities and winds switching into the east/north-east at some point dragging down air far less modified by the Atlantic and shorter sea stretch.

latest GFS showing a potentially very snowy scenario for next weekend, we saw this week over in the UK a similar brief scenario where the milder air encroached from the west and met with the Colder air and produced snow for the northern half of the UK, we've got similar setup showing this time for Ireland next weekend but instead of the milder air encroaching from the West we have what's known as a slider low where the fronts push up from the South West, stall over the midlands and then retreat south again. Ideally we need the orientation of the front to be SE to NW. this development is definitely one to watch on the charts over the next few days, i have the likely of it happening as high as 60%

nacho libre · 15-01-2021 1:05pm

Gonzo wrote: »

We need serious upgrades for it to ignite any real excitment such as deeper cold, a big unstable upgrade with polar low opportunities and winds switching into the east/north-east at some point dragging down air far less modified by the Atlantic and shorter sea stretch.

We are not going to get deep cold that sustains, if that's what you are still holding out for you are going to be disappointed. The GFS northerly could bring snow showers to some, especially those further north.
We are further along in the winter and ssts might be on our side now. We'll see what happens.

Gonzo · 15-01-2021 1:10pm

nacho libre wrote: »

We are not going to get deep cold that sustains, if that's what you are still holding out for you are going to be disappointed. The GFS northerly could bring snow showers to some, especially those further north.
We are further along in the winter and ssts might be on our side now. We'll see what happens.

I think most people here are holding out for something much better but as you say right now a decent cold and snowy spell is not looking likely unless there are serious changes in the models. Next week's northerly looks very tame and most likely too marginal, I think it will be cold rain with bits of sleet mixed in for those who are lucky enough to get any precipitation. However these brief northerlies make good walking weather with plenty of sunshine and frosty mornings so at least there is that. Could be alot of rain between now and the beginning of that northerly too so we could do with a few dry days by then.

nacho libre · 15-01-2021 1:16pm

AuntySnow wrote: »

Yeah except for one thing
Get up the historical charts of 2018 and look up the weather south of that easterly...

Yes, as you say it could induce a reverse flow but unfortunately too far north for us to profit from. The story of our winter so far; from a synoptic point of view it all looks great, but we end up with very poor surface conditions.

Kermit.de.frog · 15-01-2021 1:32pm

bazlers wrote: »

Hopfully the frog will make an appearance soon. He is a good omen.

Am here, just waiting to see how it evolves. Hints of some upgrades here and there but nothing special yet. Plenty of time for things to advance further for us.

We need to see colder air continue to make progress further south over us. Best prospects I can see for snow is for fronts to come in from the southwest interacting with whatever extent of colder air we can get...

But like I say we need to see what happens over the next couple of days.

TheMilkyPirate · 15-01-2021 1:37pm

GFS control run giving some nice eye candy out in FI.

15-01-2021 2:45pm

lucernarian wrote: »

Rome had lying snow in February 2018 too...

Untill it got south of an easterly ,our easterly which is my point
You don't want to be south of an easterly if its cold you're looking for because by definition you are south of the polar front which is the reverse zonality further north if you follow?

Meteorite58 · 15-01-2021 3:09pm

ECM still showing wintry precipitation in the latter half of next week more so towards the end of the week, this mornings run showing frontal snow opportunities but a long way off of course to be anywhere near reliable but will be watching to see if this becomes a feature, GFS also showing snow opportunities next weekend. Might be short lived though as it looks like the Jet is firing up introducing more Zonal weather ??? Wondering if weather might get a bit more lively after next weekend ?? A bit more interesting.

sicknotexi · 15-01-2021 8:16pm

ECM 12z looking like a decent run and then those Iberian heights come and smash the dream. What causes them to be so volatile?

nacho libre · 15-01-2021 9:38pm

sicknotexi wrote: »

ECM 12z looking like a decent run and then those Iberian heights come and smash the dream. What causes them to be so volatile?

Someone might have a better explanation, but I think you can trace it back to the ridge to the west of Greenland. If we had a true Greenland High instead, it would likely mean heights would eventually lower in Iberia.

Kermit.de.frog · 15-01-2021 11:14pm

...

sicknotexi · 15-01-2021 11:44pm

I'd bank the gfs para. Decent snowfall Saturday week morning covering a decent portion of the island. Yes,indeedy, who cares if we don't get a month long freeze.

Edit:More snow follows on the Sunday and even Monday.

nacho libre · 16-01-2021 12:03am

A good run.
It's just a shame its 8 days away. Also that the GFS Para is not verifying very well compared to the old GFS. The less said about the old GFS run the better.

Dickie10 · 16-01-2021 12:07am

is there looking like cold dry weather next weekend? i need to put out slurry and want a few dry days in a row , pref even hard frost.

sicknotexi · 16-01-2021 12:18am

nacho libre wrote: »

A good run.
It's just a shame its 8 days away. Also that the GFS Para is not verifying very well compared to the old GFS. The less said about the old GFS run the better.

Let me enjoy my digital snow.

Reversal · 16-01-2021 6:03pm

UKMO at t144 rebuilding mid Atlantic ridge with stronger heights around Greenland too.

6034073

This overall NH pattern is certainly nothing to be complained about, showing at the edge of the reliable timeframe. Who knows where we'd go from there. But I wouldn't rule out a decent blocking set up. If I was to get off the fence and give my hunch/hopecast. I think over the next few days we might see a trend in the models to drain the tropospheric vortex away from North America and GL, leaving an elongated trop vortex reaching from Eastern Siberia across Eurasia into Europe. Like this;

6034073

Gonzo · 16-01-2021 6:10pm

We haven't had a response yet to that SSW so anything can happen over the next 4 to 5 weeks. Signals for February are starting to look interesting. In the short term it looks like we will lose any influence from blocking as the Greenland High is just too far over on the Canadian side and the Iberian high is set to strengthen so we may have a more Atlantic driven second half of January but this is yet to be determined.

There are hints in the models that as we move into February we may start to see a response to the SSW which could bring back blocking to a more favourable position for us and the Iberian/Azores high could collapse back south-westwards allowing colder air to dig in easier. The past week has been very dissapointing but I've a feeling we will be back on the ramp at some stage over the next few weeks.

bazlers · 16-01-2021 6:30pm

Runs are not too shabby this eve. Someone will benefit the second half of next week.

Artane2002 · 16-01-2021 7:39pm

we are actually seeing a response to the SSW, just not a favourable one. look at the easterlies stretching from Russia to Canada, that is remarkable. we're just way too far south to really benefit from the pattern.

ECH1-168.GIF?16-0

ninebeanrows · 16-01-2021 7:49pm

Flooding Tuesday-Wednesday to heavy snow for many parts of Ireland on Wednesday PM/Thursday on latest ECMWF run!

Very wet snow but some places would get plastered.

snowstorm445 · 16-01-2021 7:56pm

Artane2002 wrote: »

we are actually seeing a response to the SSW, just not a favourable one. look at the easterlies stretching from Russia to Canada, that is remarkable. we're just way too far south to really benefit from the pattern.

Iceland could do well out of that by the looks of it :pac:

16-01-2021 8:31pm

Artane2002 wrote: »

we are actually seeing a response to the SSW, just not a favourable one. look at the easterlies stretching from Russia to Canada, that is remarkable. we're just way too far south to really benefit from the pattern.

Yes but that's like an elastic band really
Something flukey and it snaps
Thats when the fun actually starts believe it or not

Sleety_Rain wrote: »

Flooding Tuesday-Wednesday to heavy snow for many parts of Ireland on Wednesday PM/Thursday on latest ECMWF run!

Very wet snow but some places would get plastered.

Some of us will be glued to Radio Éireann at 5 to 8 in the morning for the latest

Looking at the isobars, I'd imagine Dublin,certainly higher parts of it has a better chance of being plastered than Donegal due to the long fetch marine modification

nacho libre · 16-01-2021 10:21pm

Artane2002 wrote: »

we are actually seeing a response to the SSW, just not a favourable one. look at the easterlies stretching from Russia to Canada, that is remarkable. we're just way too far south to really benefit from the pattern.

Excatly. That reverse flow is a direct consequence of the SSW. It simply would not happen without the SSW.
If the brief split in the strat worked out favourably we could be looking east eventually. There are hints that this might happen, but given the story so far i'm not pinning my hopes on it. Lets just see if this event for Tuesday into Wednesday comes off.

Gonzo · 16-01-2021 10:32pm

I'm not convinced that what we are seeing now are effects from the major SSW itself as that only happened first week of January. However there were a series of small to moderate warmings through December and those could be having some affect. The warming is still going on so there are opportunities for bigger effects and hopefully more favourable alignments developing over the next few weeks.

Danno · 16-01-2021 10:33pm

Johanna Donnelly mentioned hill snow and sleet for Wednesday as the polar front stalls and moves south.

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

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