FI Charts ( T120+ onwards) Winter 2019 / 2020 **READ MOD NOTE IN FIRST POST**

Gonzo

Rebelbrowser wrote: »

Very unscientifically, I reckon on average we get decent snow every four years. What better day therefore than 29 Feb for a snowstorm to arrive!

depends as well what part of the country we are all in. I'd say the north-west has the best chances with decent snow every 2 or 3 years.

The midlands doesn't do too bad either as they can benefit from westerlys, easterlys and some frontal snow due to distance away from coasts.

Waterford and Dublin probably the least chance, usually once per decade as those locations including surrounding areas pretty much depend on that direct hit easterly anytime from mid November to mid March at the latest. Sea breezes often put curtains on snow, particularly from frontal wintry spells.

Cork probably every 4 or 5 years, they can get lucky from both a westerly and an easterly if there is a SE wind. Cork can also get unlucky at times and miss out completely on everything.

As for next week's potential, the north and north-west should do pretty well, remains to be seen about the east and south of the country.

Gonzo

this afternoons GFS is currently rolling out and with this run it wants to double down on the early March cold snap. I feel like we'e been here so many times recently only for things to downgrade completely or vanish without a trace on the next run.

For a while now the charts have been suggest a cold last week of February to 1st week of March - a cold zonal flow with us on the cold side of the jet.

The latest run looks rather interesting, hence why I don't think this will play out.

The cold zonality is in place by 28th of March with a very chilly north-west wind, bands of showers of a wintry nature or longer outbreaks of cold rain/sleet or possibly snow crossing the country.



29th of March see's the zonality evolving into more of a proper north-westerly:


1st of March, we have a go at getting the winds into the north at least for a day or 2. Any showers would be more of snow at this point.



milder air moves back in from the west by March 2nd but is short lived.


cold zonality back again by March 4th:


Major truckload of salt: March 6th. The Azores high heads straight towards Greenland. Staying cold with winds swinging back into the north.



High builds towards Iceland/Greenland and winds swing into the north-east with the -10C uppers getting into the north and east.



A ridge of high tries to get going but bitterly cold by this stage.


I think the cold zonality part of this will work out, but not so sure on that northerly or northeasterly in March, looks a bit flipsy. Still interesting to see as we've had so little of this all year.

Wine Goddess

Verify! Verify! Please let there be an end to incessant rain and wind, and let there be SNOW!!!!

Gonzo

Wine Goddess wrote: »

Verify! Verify! Please let there be an end to incessant rain and wind, and let there be SNOW!!!!

The ECM backtracked on yesterday's cold runs with a milder outcome. None of the short range charts are suggesting much in the way of dry and settled conditions. The charts I posted above look flipsy enough, the high doesn't get to Greenland, it doesn't move far enough north and it begins to collapse over us just as we get the cold air in. Lots of low pressures over Greenland and Canada are waiting and creating increasing pressure on that ridge. If we could run further on the high would most likely track into the continent and we would be back with the westerlies. My confidence of any easterly based cold spell is very low given the relentless power of the jet/pv. Any suggestion of an easterly this winter hasn't lasted more than 1 single run.

Rebelbrowser

Need help understanding this please. GFS shows as follows for next Saturday



But the corresponding upper temps are -2 or -3. Given the wind is coming from due north, with a very direct feed, and given the artic is so cold right now, how is that so?

Gaoth Laidir

Rebelbrowser wrote: »

Need help understanding this please. GFS shows as follows for next Saturday



But the corresponding upper temps are -2 or -3. Given the wind is coming from due north, with a very direct feed, and given the artic is so cold right now, how is that so?

It's from a warm seclusion that sits south of Iceland after Wednesday's low pressure northwest of the Azores. It's not actually a direct northerly flow as such, just the backend of a low transitioning eastwards. If that pattern had stopped and stayed set up for a few days then we'd have air sourced from the north, but in reality our air at that stage will be coming in from the west.

nacho libre

Gonzo wrote: »

My confidence of any easterly based cold spell is very low given the relentless power of the jet/pv. Any suggestion of an easterly this winter hasn't lasted more than 1 single run.

I think we will continue in this pattern of brief pm airflows, followed by tm airflows.

it's just a question of what happens with the pv when the final warming inevitably begins- will it be a gradual decline, or will it be sudden, which could lead to strong northern blocking at precisely the wrong time- we could end up with a cold and wet late spring, which then follows on into summer.

Gonzo

nacho libre wrote: »

I think we will continue in this pattern of brief pm airflows, followed by tm airflows.

it's just a question of what happens with the pv when the final warming inevitably begins- will it be a gradual decline, or will it be sudden, which could lead to strong northern blocking at precisely the wrong time- we could end up with a cold and wet late spring, which then follows on into summer.

I really hope we don't end up again with last year's Spring and June. June in particular felt like autumn or winter for the first 20 days of the month. Northern blocking has been completely absent since it's domination last summer, I suspect it will be back over the next few months and that would be a recipe for cold and unsettled conditions for us.

Once we reach May I expect temperatures in the mid to upper teens, rather than low teens. June last year struggled to get past 12C for much of the month and we had the fire lit for most of the month too. Really don't want a repeat of that this year!

Logan Roy

Gonzo your endless optimism never ceases to amaze me

Meteorite58

ECM is continuing the cold theme out to +240, currently showing wintry precipitation/ snow potential next weekend .

Meteorite58

ECM pushing the cold wintry stuff out further.

Gonzo

plenty of cold on tonights GFS runs. A continuation of what we have now for the most part with cold zonal which veers more northerly as we head into March. The run ends with a Scandinavian high and we get winds into the east.

Several other of the lower resolution runs either get us into high pressure by week 2 of March or they build high pressure over us, sending cold into central and eastern Europe while others bring the winds into the east for us, some of them cold, others not so cold. The east itself hasn't had any cold all winter, so getting winds into the east would take a while to get any sort of cold here.

The models have hinted at this for the past while, they really want a pattern change but with the Atlantic refusing to let go of the peddle, this is proving a very difficult pattern to change.

All in all, a potential mild spell of weather/taste of early spring seems a long way off too. Staying generally cold over the next 10 days.

Donegal Storm

Here's hoping..

Gonzo

GFS still playing with the idea of a pattern change and some dryer weather, but as ever it is along way off and liable to fall through with the PV and jet still very strong for the time of year.

I think it's the time of year were looking for cold and snow has shipped away for another year. Bring on the mild and something substantially dryer.

GFS tries to end the current run of cold zonality and brings in much milder south-westerlies with a ridge building towards us.



ridge attempts to settle over us, but it is still looking a bit flipsy, look at the PV still bottling in the cold over the pole.



we end with a lovely mild SE flow but this doens't look like it will last long. More low pressures are waiting out in the Atlantic and there is some very cold air just to our north which may shave past us interrupting the mild flow.



Many of the lower resolution models are supporting high pressure for the second week of March while a few others are trying to bring in bitter winds from the east, however I think there is almost zero chance this will happen.

Comhrá

Gonzo wrote: »

GFS still playing with the idea of a pattern change and some dryer weather, but as ever it is along way off and liable to fall through with the PV and jet still very strong for the time of year.

I think it's the time of year were looking for cold and snow has shipped away for another year. Bring on the mild and something substantially dryer.

GFS tries to end the current run of cold zonality and brings in much milder south-westerlies with a ridge building towards us.



ridge attempts to settle over us, but it is still looking a bit flipsy, look at the PV still bottling in the cold over the pole.


we end with a lovely mild SE flow but this doens't look like it will last long. More low pressures are waiting out in the Atlantic and there is some very cold air just to our north which may shave past us interrupting the mild flow.

Many of the lower resolution models are supporting high pressure for the second week of March while a few others are trying to bring in bitter winds from the east, however I think there is almost zero chance this will happen.

Gives us cause for hope at least. I think everyone is weary of 'zonal' at this stage!

Gonzo

and just for fun here is that very bitter run, it is out on it's own and not well supported. There are a few other runs that go for easterlies but none of them are this cold or prolonged. If this verifies i'll eat my hat. This is just for fun.

9th of March, the cold zonal flow comes to an end as a ridge attempts to move towards Iceland and Greenland. Ireland still has very similar conditions to what we have right now.



10th of March the ridge builds more, and we bring a long fetch of winds in from the east right over Ireland. However this is not an unstable flow for us as we are very close to that ridge. Getting progressively colder, the UK looks quite wintry.



The high makes more progress towards Greenland, and the air over us get's colder. Snow showers maybe getting into eastern and south-eastern UK, looks on the dry side of us and potentially very frosty indeed.



We end the run with a bitter easterly well established, the high is trying to push away northwards bringing some of those snow showers close to the SE of Ireland and potentially into Wicklow and Wexford and possibly parts of coastal Waterford and eastern coastal Cork. -10C uppers starting to make it's way into the country on a bitter long fetch flow from siberia.



As I said above this is just for fun and i'm almost 100% certain this will be nowhere to be seen on the next run, but if it did happen, it would be substantially colder than the muck we have right now, even if it is the second week of March, that source is so much colder than anything the Atlantic can throw at us. However this is not a particularly snowy run with pressure too high over Ireland for the most part.

Gonzo

GFS continues to play around with a serious pattern change coming soon (week 2 of March). It has toyed around with alot of outcomes such as mild high pressures building from the south, mild and cold easterlies as well as some extremely bitter long fetch northerly shots.

It is becoming more obvious now that things are trending more towards a major reduction in the wet conditions and a spell of high pressure and an increase in temperatures.

This afternoons runs really send the temperature profile soaring from the 9th or 10th of March.

Latest ensemble runs shows a considerable reduction in rainfall spikes (although never completely settled), but a serious ramp in temperatures from -5C@850hpa to between +8 and +11C @850hpa



This would be enough to get our temperatures to mid teens at least by the middle of the month and possibily 16 or 17C under ideal and sunny conditions.

There have also been attempts to get +20c uppers into parts of southern Europe, which would bring a very early African plume of heat to some Mediterranean regions.

The pub run is rolling out now, let's see does this continue to evolve or throw everything I just said out the window.

Gonzo

pub run continues with the high pressure, this time drawing up a nice plume from Morocco and Algeria by the 9th of March.

This draws up +8 to +10 uppers over us for a time bringing in Spring! However we end the run with the high starting to move from the UK/Ireland towards Greenland.





Not all the lower resolution runs are finished, quite a few of them bring up the warmth and height rises while others attempt to bring the freezer closer to us. Very few are showing any sort of continuation of the Atlantic.

Looking forward to updates over the weekend. A warm plume or a cold freezer, i'll happily take both, anything other than the continuation of the Atlantic is a good thing.

Neddyusa

Any updates on the status of this FI high pressure???

tanko

Neddyusa wrote: »

Any updates on the status of this FI high pressure???

The BBC weather was downplaying it last night, they gave low pressure and more rain for next weekend.

nacho libre

GFS in the last run i looked at was going for it, the ECM had other ideas, but i think the conveyor belt of deep low pressure systems are going to run out of steam; so maybe it will be a case of it being unsettled at times, but not near as bad as we have seen this month.

Gonzo

I've been away for the past day and just had a look at the GFS and the lovely warm trend that has been building over the past week looks to be more or less gone. The Atlantic domination looks like continuing right into the middle of March and the possibility of cold and wintry conditions as well, a possible mixture of cold zonal and some brief northerly action as we get closer to saint Patrick's Day.

Oscar Bravo

Gonzo wrote: »

I've been away for the past day and just had a look at the GFS and the lovely warm trend that has been building over the past week looks to be more or less gone. The Atlantic domination looks like continuing right into the middle of March and the possibility of cold and wintry conditions as well, a possible mixture of cold zonal and some brief northerly action as we get closer to saint Patrick's Day.

Was just looking at that. Cold NW'ly all the way

Gonzo

Oscar Bravo wrote: »

Was just looking at that. Cold NW'ly all the way

I'm very dissapointed to see this big change. High pressure with some warmth really was becoming a possibility and it's something we all need.

The GFS also shows more possible storm potential as well as rather cool to cold conditions, not something I want to see in March.

A cool or a cold March could be on the table with the PV weakening and cold leaking into Europe at times.

Donegal Storm

Yep, the calm, dry, mild forecast for the second week of March has now been replaced with this :rolleyes:

pad199207

Gonzo wrote: »

I'm very dissapointed to see this big change. High pressure with some warmth really was becoming a possibility and it's something we all need.

The GFS also shows more possible storm potential as well as rather cool to cold conditions, not something I want to see in March.

A cool or a cold March could be on the table with the PV weakening and cold leaking into Europe at times.

It’s so depressing

mahoney_j

Cool tge jets folks lots of chopping and changing ,those charts are a week away

pauldry

Looks like March will be a cool first half but not as wet as February which is impossible

Probably a lot of cold showery days but whereas February averaged nearly 10mm of rain per day Id say March will be 5mm per day

Logan Roy

Gonzo wrote: »

I'm very dissapointed to see this big change. High pressure with some warmth really was becoming a possibility and it's something we all need.

The GFS also shows more possible storm potential as well as rather cool to cold conditions, not something I want to see in March.

A cool or a cold March could be on the table with the PV weakening and cold leaking into Europe at times.

At least the days are getting much longer and theres a bit of warmth in the sun again, its not all doom and gloom.....

pad199207

pauldry wrote: »

Looks like March will be a cool first half but not as wet as February which is impossible

Probably a lot of cold showery days but whereas February averaged nearly 10mm of rain per day Id say March will be 5mm per day

So the way it is, it will be raining every day anyways for March