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

Captain Snow · 30-12-2020 1:26pm

Humberto Salazar wrote: »

Looking at GFS, the standout feature is the North Atlantic high. But it's a hindrance to opening the doors to potential colder weather from the north and east. It just sits there giving us a gentle east northeasterly, maybe a few flurries to the east up until the 6 or 7th Jan. Then there is a move with low pressure pushing southwards ,maybe opening Arctic doors again. But the milder push wins out, at least for Ireland. It's all a bit messy. I'm inclined, more than normal, to disregard anything past 144. With a SSW event imminent, I don't know how much of that is factored in. As the oldest forum cliche goes, get the cold entrenched and let the synoptics play out.

120 to 144. High pressure near by. Hopefully some flurries onto the east coast.

Wait till the SSW gets going...which it is. There will be some swings and roundabouts in the models over the next few days I think.

Kermit.de.frog · 30-12-2020 1:33pm

Wouldn't be surprised to see snow showers in the east over the next 10 days. For those of us on the coast looks mixed at times but if I was just a few miles inland I'd be happier with the charts!

lolie · 30-12-2020 1:45pm

Supercell wrote: »

See that line down the east coast of the UK..its means hope.
Isle of Man shadow, streamers...Kermit.de.Frog opening a new topic...

Maybe.

From Met Éireann's 5 dat forecast, long way out though.
attachment.php?attachmentid=537631&d=1609332301

[img][/img]

TTLF · 30-12-2020 1:47pm

Kermit.de.frog wrote: »

Wouldn't be surprised to see snow showers in the east over the next 10 days. For those of us on the coast looks mixed at times but if I was just a few miles inland I'd be happier with the charts!

How far inland is enough? I’m about 6km inland on the coast so I’m curious to see

Gonzo · 30-12-2020 1:47pm

the extended GFS run looks largely cold and wintry right into the first week of February with only a few short lived moments where it tries to get milder only for it to go cold again. Could the GFS be up for an almost unbroken run of cold weather throughout January, time will tell.

ens_image.php?geoid=64969&var=201&run=99&date=2020-12-29&model=gfs&member=ENS&bw=1

ens_image.php?geoid=64969&var=201&run=99&date=2020-12-29&model=gfs&member=ENS&bw=1

that is a very cold overall trend for the month.

Many of the runs turn mild at the end of the normal GFS run around the middle of the month with warmth up from the south or south-west, if this does verify there is a chance this return to mild could be very short lived before we get another reload of cold weather.

munsterlegend · 30-12-2020 1:54pm

Gonzo wrote: »

the extended GFS run looks largely cold and wintry right into the first week of February with only a few short lived moments where it tries to get milder only for it to go cold again. Could the GFS be up for an almost unbroken run of cold weather throughout January, time will tell.

that is a very cold overall trend for the month.

Many of the runs turn mild at the end of the normal GFS run around the middle of the month with warmth up from the south or south-west, if this does verify there is a chance this return to mild could be very short lived before we get another reload of cold weather.

The default as MT said is always a return to milder weather. I think until this SSW is resolved model watching will have many ups and downs. Intriguing to watch all the same.

Gonzo · 30-12-2020 2:01pm

this mornings ECM also ends on a very cold note with -9 uppers across Leinster and a bitter easterly wind off the continent, likely to be sleet and snow showers involved with that.

Supercell · 30-12-2020 2:08pm

Gonzo wrote: »

this mornings ECM also ends on a very cold note with -9 uppers across Leinster and a bitter easterly wind off the continent, likely to be sleet and snow showers involved with that.

Slack airflow too, would lead to prolonged heavy showers also where they do hit.

Kermit.de.frog · 30-12-2020 2:24pm

TTLF wrote: »

How far inland is enough? I’m about 6km inland on the coast so I’m curious to see

Depends on the depth of cold air.

Anything sub -8c at the 850 hpa altitude layer and it won't matter.

When we are kinda meandering between -5 and -7 then the marine layer from the on shore wind becomes more detrimental for snow on coasts.

Every km inland helps.

Can't really speculate yet as to how far inland is preferable. Hopefully we won't have to!

ZX7R · 30-12-2020 2:25pm

Humberto Salazar wrote: »

Moscow daytime max temperatures dropping gradually over the the next week to well below freezing. Trend is good.

Moscow's daytime temperatures have been well below freezing for a couple of weeks already averaging in or around -4
The upper temperatures are above normal .
Lower level temperatures are at average or below.
None of the charts long range or short have predicted the lower level temperatures under the Russian high correctly ,regional forecasts for that area could forecast temperatures up to 10 degrees lower than forecasted by the models.

Rougies · 30-12-2020 2:44pm

TTLF wrote: »

How far inland is enough? I’m about 6km inland on the coast so I’m curious to see

Depends on the wind speed. In stronger flows, the warmer sea surface air will be pushed further inland. It also depends on on the initial temperature of the source air, obviously the colder the better. 6km inland should be ok in a light to moderate flow.

bazlers · 30-12-2020 2:58pm

I can see the models having one of those eureka moments in 3 or 4 days time when they finally get a grip on the SSW.
They should all be on the same page then...hopefully bringing to our shores weather from a N NE or E direction.

Gonzo · 30-12-2020 4:01pm

a direct easterly would be my preferred option of wind direction as a NE wind really gets the IOM Shadow and indeed the Ulster Shadow into play for much of the northern half of Leinster.

SleetAndSnow · 30-12-2020 4:05pm

Gonzo wrote: »

a direct easterly would be my preferred option of wind direction as a NE wind really gets the IOM Shadow and indeed the Ulster Shadow into play for much of the northern half of Leinster.

I believe a NE system would be best then for us in the South, Cork, Waterford direction akin to 2018 IIRC?

Billcarson · 30-12-2020 4:26pm

Gonzo wrote: »

a direct easterly would be my preferred option of wind direction as a NE wind really gets the IOM Shadow and indeed the Ulster Shadow into play for much of the northern half of Leinster.

Perhaps in the middle an east- northeast wind would be best? My only worry about direct Easterlies is bringing higher dew points near/ not far from the coast ( I'm 12 km from the coast). Though if the easterly is cold enough
I suppose it wouldnt really matter regards dew points. One thing I dont like about easterlies is lack of sun,which means lack of frost. Always particularly love cold spells that have snow and plenty of frost.

JanuarySnowstor · 30-12-2020 4:43pm

Outlook does indeed look very good
But, that trough line coming down tomorrow could catch folk off guard!! For me it holds more potential than today's zilch. Worth watching for me it snows in the south Midlands area

nacho libre · 30-12-2020 4:46pm

From a imby perspective I would prefer a proper direct northerly, like the ones we used to know, that brings a polar low down over us. There is a chance of this happening at some point if things fall in our favour. The beauty of a proper polar low is most of the country can see snow from one. I would love to see a thread with Polar Low in its title at some point in the next two to three weeks.

Oneiric 3 · 30-12-2020 4:57pm

Billcarson wrote: »

Perhaps in the middle an east- northeast wind would be best? My only worry about direct Easterlies is bringing higher dew points near/ not far from the coast ( I'm 12 km from the coast). Though if the easterly is cold enough
I suppose it wouldnt really matter regards dew points. One thing I dont like about easterlies is lack of sun,which means lack of frost. Always particularly love cold spells that have snow and plenty of frost.

Proper east winds are best for the west when it comes to sun and temps, both in summer and winter. Despite all the cool weather around recently courtesy of this returning mP airmass, we are barely even able to scrape an air frost. A good, dry easterly would help sort that out.

Humberto Salazar · 30-12-2020 4:58pm

nacho libre wrote: »

From a imby perspective I would prefer a proper direct northerly, like the ones we used to know, that brings a polar low down over us. There is a chance of this happening at some point if things fall in our favour. The beauty of a proper polar low is most of the country can see snow from one. I would love to see a thread with Polar Low in its title at some point in the next two to three weeks.

OT but perhaps Sryanbruen can work his magic on that. I know about Dec 2000, that was a Polar low, but I think the Feb 1933 blizzard was one also? There must be more historic examples...

nacho libre · 30-12-2020 5:01pm

Oneiric 3 wrote: »

Proper east winds are best for the west when it comes to sun and temps, both in summer and winter. Despite all the cool weather around recently courtesy of this returning mP airmass, we are barely even able to scrape an air frost. A good, dry easterly would help sort that out.

Yes, also i love the breeze from a good easterly. There was a poster here several years ago who was fond of easterlies too;)

Billcarson · 30-12-2020 5:04pm

nacho libre wrote: »

From a imby perspective I would prefer a proper direct northerly, like the ones we used to know, that brings a polar low down over us. There is a chance of this happening at some point if things fall in our favour. The beauty of a proper polar low is most of the country can see snow from one. I would love to see a thread with Polar Low in its title at some point in the next two to three weeks.

Even though I live in the east ,I think I would prefer a good direct northerly over an easterly, especially ones that bring polar lows. Love the clear clean air they bring.

Gonzo · 30-12-2020 5:06pm

Gavsweather reckons that the charts we are looking at today may trend even colder for the second week of January over the next few days, that the cold will intensify and a freeze up is possible at some point. He also suggest that the blocking may carry on into February. The second half of January is currently showing milder air trying to get established from the south but this could end up in a battleground situation with potential for more wintry conditions. This battleground scenario may not happen and northerlies could still dominate into the second half of January.

No doubt about it, this is shaping up to be the coldest January we have seen in a very long time.

nacho libre · 30-12-2020 5:06pm

Humberto Salazar wrote: »

OT but perhaps Sryanbruen can work his magic on that. I know about Dec 2000, that was a Polar low, but I think the Feb 1933 blizzard was one also? There must be more historic examples...

There were a few in the Days of Aidan Nulty - he always seem to do the forecasts when there were polar lows. Aside from December 2000, I remember a particular one in the early nineties that gave heavy snow for several hours from Donegal all the way to Cork

Oneiric 3 · 30-12-2020 5:12pm

Gonzo wrote: »

Gavsweather reckons that the charts we are looking at today may trend even colder for the second week of January over the next few days, that the cold will intensify and a freeze up is possible at some point. He also suggest that the blocking may carry on into February. The second half of January is currently showing milder air trying to get established from the south but this could end up in a battleground situation with potential for more wintry conditions. This battleground scenario may not happen and northerlies could still dominate into the second half of January.

No doubt about it, this is shaping up to be the coldest January we have seen in a very long time.

Another good weather channel to subscribe to is this one:

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

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

German focused but informative about weather trends over the whole of 'ooropa'.

Artane2002 · 30-12-2020 5:25pm

SleetAndSnow wrote: »

I believe a NE system would be best then for us in the South, Cork, Waterford direction akin to 2018 IIRC?

that was mainly an ENE wind (switched to ESE at times though), I'd consider that an easterly slightly deflected to the north, that would be my preference too.

the UKMO is looking good this afternoon, marginal but probably on the right side for some areas:
UW144-21.GIF?30-17

JanuarySnowstor · 30-12-2020 5:39pm

Isn't the jet running over the high a worry though?
While the charts are great the risk of the high flattening out over us remains a concern for me?!
Also the uppers seem to be mainly coming from our own little cold pool.
So great charts but by no means perfect yet!

TTLF · 30-12-2020 5:41pm

JanuarySnowstor wrote: »

Isn't the jet running over the high a worry though?
While the charts are great the risk of the high flattening out over us remains a concern for me?!
Also the uppers seem to be mainly coming from our own little cold pool.
So great charts but by no means perfect yet!

im pretty sure this isn't any setup that could be flattened. My idea behind that is because of the extreme -AO and -NAO being forecasted, ontop of the SSW.

The only thing that's stopping us from getting that true cold is the Russian HP but if that moved more than likely flood gates would open?

Idk just my 2 cents.

Nqp15hhu · 30-12-2020 5:42pm

Villain wrote: »

The lack of cold to the East is frustrating when you see such charts but the end of ECM wants to bring the REAL cold down from the North. Interesting couple of weeks ahead and we might get a few bites of the cherry yet.

I am never impressed by cold from Eastern Europe. It never delivers here and always seems to moderate crossing the Irish Sea.

Nqp15hhu · 30-12-2020 5:46pm

eon1208 wrote: »

Kermit explain the 500 bar line meaning temp wise please..

It’s a measure of the thickness (height) from a surface pressure of 1000mb to 500mb. This changes with airmass... usually with a colder airmass the distance is less.

Nqp15hhu · 30-12-2020 5:48pm

Humberto Salazar wrote: »

Moscow daytime max temperatures dropping gradually over the the next week to well below freezing. Trend is good.

Good but temps in Oslo or Reykjavik would be more for guide for us.

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

Comments

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