FI CHARTS AUTUMN/WINTER 2014/15 **Mod Note Post #1**

icesnowfrost

BLIZZARD7 wrote: »

This is going to be a close run thing early next week... Somewhere in Ireland is likely to get a big dumping... Where is very uncertain.

yeah that low could bring an epic dump of snow

gerrybhoy

BLIZZARD7 wrote: »

This is going to be a close run thing early next week... Somewhere in Ireland is likely to get a big dumping... Where is very uncertain.

give us it here please god ya big bassa,i wont watch porn drink alcohol or be abusive to Rangers fans on twitter and Facebook for a day or 2

munsterlegend

This is going to be a close run thing early next week... Somewhere in Ireland is likely to get a big dumping... Where is very uncertain.[/QUOTE]

Well it won't be down south anyway going on recent past experience! the east,north and midlands have a decent shout.

BLIZZARD7

munsterlegend wrote: »

This is going to be a close run thing early next week... Somewhere in Ireland is likely to get a big dumping... Where is very uncertain.

Well it won't be down south anyway going on recent past experience! the east,north and midlands have a decent shout.[/QUOTE]

Wouldn't rule out north cork just yet... Wait and see where the models agree this low will go first. Won't know specifics til +24hrs to be honest.

Calibos

It ain't 'On' till Su Campu says its on

maquiladora

BLIZZARD7 wrote: »

This is going to be a close run thing early next week... Somewhere in Ireland is likely to get a big dumping... Where is very uncertain.

Looks like a washout apart from high ground in the north.



With a chance of back-edge snow for a while as it passes south. The showers following it might be more productive.

typhoony

trying to predict a shallow low 5 days out is unpredictable, low probability at this stage, the cold hangs on unitl wednesday after that it looks like some quite pleasant early february sun with cold frosty nights

Rebelbrowser

Apologies if this is discussed already in the snow thread (its too large to look) but whilst the Hi Res models were largely correct yesterday on where would get snow, they were right partially for the wrong reason IMHO. By that I mean they were fairly clear that precipitation would struggle to reach the east and south coasts. As it happens I spent most of yesterday in Dublin and drove to Cork last night. I personally witnessed precipitation (of every type) throughout the day in Dublin, last night in Cork and everywhere en route in between. Worth bearing in mind for future events. In my view when there's a north westerly flow on decent winds precipitation is not going to be a problem and our local knowledge would trump whatever weather balloons are telling the High Res models in that regard.

TheMilkyPirate

06Z GFS control isn't great but it's very marginal dealing with a low like this 4 days out. A few of the ensembles go the way we want, #1 would be up there.

John.Icy

The problem with Monday is that it's pretty much a lose-lose for a lot of people as far as I see it. If we want plenty of precip. around, it means warmer air will be much closer and it'd be rain for many (to get the bulk of the front over us). If we want to have a colder airmass, we'd need the low and front to stay further south, so less precip. is around and we retain some colder uppers, but now there's less precip. in play as most of it passes to our south.

The perfect balance (to get a big event for many) is such a fine line. Early days yet though.

snowstreams

John.Icy wrote: »

The problem with Monday is that it's pretty much a lose-lose for a lot of people as far as I see it. If we want plenty of precip. around, it means warmer air will be much closer and it'd be rain for many (to get the bulk of the front over us). If we want to have a colder airmass, we'd need the low and front to stay further south, so less precip. is around and we retain some colder uppers, but now there's less precip. in play as most of it passes to our south.

The perfect balance (to get a big event for many) is such a fine line. Early days yet though.

The high precip scenario would be great for the wicklow mountains though. The mountains above 500-600m would surely get plenty of snow in that scenario.

BLIZZARD7

snowstreams wrote: »

The high precip scenario would be great for the wicklow mountains though. The mountains above 500-600m would surely get plenty of snow in that scenario.

Id say above 200-250m in general to be honest but as John says you need everything to go right for low level widespread snow.

lucernarian

Rebelbrowser wrote: »

Apologies if this is discussed already in the snow thread (its too large to look) but whilst the Hi Res models were largely correct yesterday on where would get snow, they were right partially for the wrong reason IMHO. By that I mean they were fairly clear that precipitation would struggle to reach the east and south coasts. As it happens I spent most of yesterday in Dublin and drove to Cork last night. I personally witnessed precipitation (of every type) throughout the day in Dublin, last night in Cork and everywhere en route in between. Worth bearing in mind for future events. In my view when there's a north westerly flow on decent winds precipitation is not going to be a problem and our local knowledge would trump whatever weather balloons are telling the High Res models in that regard.

Plenty of northerlies bring showers falling as sleet and snow. But unless they will be widespread and last longer than 20 minutes, they won't survive in a typical northerly outbreak with daytime temperatures around 3 degrees.

It depends how you define East coast anyway, the models did show precip reaching Down and Louth and into the Irish Sea, perhaps not for Dublin.

If I look at charts for Monday and Tuesday optimistically, I still don't see widespread snow on the agenda.



The above chart looks great, but anywhere outside of >300 masl saw a very long day of sleet and wet snow. I drove to Belfast that day and when in Ravensdale in Louth, there was a mix of sleet and wet snow falling and snow was only lying at the 300 metre mark. After Newry, the wet snow just died out and it was dry and very cold in Belfast. As John.Icy succinctly said, it can be a bit of a lose-lose situation. Events like 1982 are incredibly rare and the key ingredient missing above was a total lack of potent cold air nearby.

This is the cold air pool straddling the UK and Ireland in 1982:


The ECM's 00z run t+120 chart. Cold but not cold enough for widespread snow.

Rebelbrowser

Doesn't Saturday look interesting? Just looking there at the 6z Euro 04 at 6am on Sat morning (the latest it goes) and it shows uppers of -7/-8, sub 522 thickness, temps of +1/-2 , DPs of -2 and lower and there seems to be some precipitation around. See below. Any thoughts?

Snow/rain map



Uppers



Temps

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/01/29/basis06/ukuk/tmp2/15013106_2906.gif

DPs



Thickness

Rebelbrowser

GFS 12Z looks colder to this untrained eye inc. some snow potential on Saturday and especially on Tuesday (for all parts). Monday is an all rain event on it. Cant post charts right now.....

yorlum11

Rebelbrowser wrote: »

GFS 12Z looks colder to this untrained eye inc. some snow potential on Saturday and especially on Tuesday (for all parts). Monday is an all rain event on it. Cant post charts right now.....

Here ya go

Rebelbrowser

I see Tuesday is being discussed in the main thread too. Apparently that's a Polar Low we are looking at......

Villain

Ya Tuesday looks interesting on the 12z but its only relative to FI thread really i.e. still a dream

maquiladora

Tuesday on closer inspection looks like a marginal, messy rain/snow mix. So we won't know until much closer to the time with that. Though the showers following it would be more snow and less rain.

RED L4 0TH

Rebelbrowser wrote: »

I see Tuesday is being discussed in the main thread too. Apparently that's a Polar Low we are looking at......

I predict a forum meltdown if that happens.......

Kermit.de.frog

Rebelbrowser wrote: »

Doesn't Saturday look interesting?

Certainly does especially across Ulster. :cool:

Another thing is the nights will be much colder with ice and frost much more prevalent than the last few days.

TheMilkyPirate

UKMO for Tuesday

yorlum11

Kermit.de.frog wrote:

Certainly does especially across Ulster. 

Kermit.de.frog wrote:

Another thing is the nights will be much colder with ice and frost much more prevalent than the last few days.

Looking at DP and temps Sat should be mostly snow/ hail in Ulster and down the west coast. DPs much better than today.

maquiladora

Looks like the 12Z ECM has 2 little lows to look out for on Tuesday.

Iancar29

RED L4 0TH wrote: »

I predict a forum meltdown if that happens.......

Heres a polar low , they aint always a good thing. This one bringing some severe gusts to places over the next few hours but also some warmer temps ...

RED L4 0TH

Iancar29 wrote: »

Heres a polar low , they aint always a good thing. This one bringing some severe gusts to places over the next few hours but also some warmer temps ...

True. I was imagining one of the snowmageddon variety might come along.

Villain

The 18z makes for some interesting viewing for Monday night and Tuesday

John.Icy

How about Monday has another little shift of the front ala 18z NE to give a chance of snow to a wide area AND have Tuesday to occur as per 18z?

Is that too much to ask??

pistolpetes11

Il have P19 please

BLIZZARD7

lucernarian wrote: »

Plenty of northerlies bring showers falling as sleet and snow. But unless they will be widespread and last longer than 20 minutes, they won't survive in a typical northerly outbreak with daytime temperatures around 3 degrees.

It depends how you define East coast anyway, the models did show precip reaching Down and Louth and into the Irish Sea, perhaps not for Dublin.

If I look at charts for Monday and Tuesday optimistically, I still don't see widespread snow on the agenda.



The above chart looks great, but anywhere outside of >300 masl saw a very long day of sleet and wet snow. I drove to Belfast that day and when in Ravensdale in Louth, there was a mix of sleet and wet snow falling and snow was only lying at the 300 metre mark. After Newry, the wet snow just died out and it was dry and very cold in Belfast. As John.Icy succinctly said, it can be a bit of a lose-lose situation. Events like 1982 are incredibly rare and the key ingredient missing above was a total lack of potent cold air nearby.

This is the cold air pool straddling the UK and Ireland in 1982:


The ECM's 00z run t+120 chart. Cold but not cold enough for widespread snow.

That 2009 new years eve chart actually delivered 2-3 inches of dry powdery snow via an Irish Sea streamer to the south Dublin area- that snow lay on the ground with little or no melt until it was topped up 4 or 5 days later.

I wish I was alive to experience that 1982 event... Hopefully a repeat is to come early next week