Easterly Blast Prospect Thread :

MUSEIST

Well this is the last time I will follow the models this closely leading up to a cold snap. Yet again another let down. The mild breakdown looks disasterous and there is no sign of another cold spell. As for this cold spell , well it will last about a say. Yes, it willl be cold but its unlikely to snow where I am in tipperary. So disapointed again- Why do we even call this winter because their is nothing wintry about it. We must have the most depressing weather in the world, Sorry, rant over.:eek:

Supercell

Deleted User wrote: »

Your precipitation on thursday and friday will be snow up at 820ft,I have no doubt.

Hopefully to 700 also...
I honestly dont see anything but very wet snow from this and definitely no settling stuff below maybe 400 meters +

SpitfireIV

MUSEIST wrote: »

Well this is the last time I will follow the models this closely leading up to a cold snap. Yet again another let down. The mild breakdown looks disasterous and there is no sign of another cold spell. As for this cold spell , well it will last about a say. Yes, it willl be cold but its unlikely to snow where I am in tipperary. So disapointed again- Why do we even call this winter because their is nothing wintry about it. We must have the most depressing weather in the world, Sorry, rant over.:eek:

Keep the faith man! Still some time left . They call the 18z the 'pub run', right? See what tomorrow brings.

ch750536

Damn, so close....

http://www.boards.ie/vbulletin/showpost.php?p=54554648&postcount=9

Gonzo

as i expected, this will not work out..... this is not a matter of 'so close'.... it wud be very bad luck if it was 'ah so fekin close' since 1991 in my area but the fact of reality is ive given up on these snow events a few years ago. And why do I repeatly post negative thoughts and ramblings here winter in winter out without fail and thats because as much as we dont want to admit it...... GLOBAL WARMING HAS WON.... we are finished with snow in Ireland unless all the ingredients that make a snow event proper happen match up 100%. And the odd's of 100% snow perfect conditions are at the moment a once in a lifettime opportunity I take it as that... its 16 years since ive seen more than 3 inchs of snow lying on the ground in my area and thats not just bad luck... its reality unfortunately. I cant read charts like many of the much more experienced people here but im just going by my judgement of what has been witnessed before my eyes over the past 16 years and unfortunately I have to admit defeat as a snow lover.

We will see that magical event sometime over the next 20 years and hopefully we will still be here all on boards on witness it and talk about it and if it happens this year enjoy every second of it coz it will prolly a once in a lifetime opportunately.

/rant over:)

Ryanoneill2006

Hi guys,

Haven't been following the forecasts this week but I've read some of the earlier posts about the "Cold Snap" later in the week. Up until last night people were talling about Great Charts and then suddenly doom and gloom, did the forecast change last night and has the potential of a spell of snow diminished before it began, Sorry if I am asking a simple question but I am no good at reading charts and only follow weather on television.

Thanks.
R.

forkassed

Not too good at this stuff myself but looking at the charts from this morning i'd say we have a better chance at seeing snow compared with yesterday evening's charts.

arctictree

Charts don't look too bad this morning. UKMO now has the chart on their website for Thursday :

http://www.metoffice.gov.uk/weather/charts/FSXX00T_84.jpg

This is the one I usually follow until t+48 when the Irish met charts become available. The other charts are still showing a rapid breakdown late on Friday.

A

Villain

Looks like an upgrade but tbh I think the models are having real problems predicting this week, I'm sure things will change before Wednesday, I just don't know what way!

Villain

06z rolling out lets see whats changed

I think it's certain now that we will have possible snow thursday and friday(possible not probable as it depends on precip developing) with a risk (low) of sleet and snow preceding the rain a bit on saturday.

ECM (operative) at 00z keeps the scandy/siberian high in place further east and not sliding into Europe suggesting a possible build back westward of cold eventually but their ensembles don't agree so the probability they reckon (at this stage) is low.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

most of its members have the atlantic influence well into and the near continent for all of next week with mild temps.

They may change that probability though as it is reliant on things that they havent even firmed up on in the period prior to those ensembles (like where the jet is going ie whether it is going to take new atlantic lows south east into Biscay instead of into Ireland)

But that is a very "uncertain" may.

ninebeanrows

Interesting UKM this morning showing that the Atlantic ain't going to have it all its own way, lots of changes to come in the medium term.

Thursday morning interests me with regard to the potential for a band of heavy snow moving up from the south approaches, as cold air digs in from the east.

That could do more harm than good wc in that the cloud cover to the north of it would end any irish sea shower generation.

It's touch and go as to the type of precipitation from it.
The GFS suggests negative dewpoints for thursday but it doesn't prog that precip so far north.
Regardless I think the dp's could be negative if that precip moves north but only just as it contains a mix of maratime air.

Very borderline stuff.

One things for sure if that precip got up as far as longfield and artictree it would be pelting it down with snow at their inland and high locations.

My rule of thumb roughly with height and inlandness in borderline scenarios is as follows.
IF sleet on the coast
Then sleet/wet snow 3 miles inland or more above 450ft asl but not sticking.
Dryer snow and sticking above 600ft
Powder above 1000ft and all the time about 30-50% ahead in depth compared to those at 600ft

Lol by the way

ninebeanrows

Deleted User wrote: »

That could do more harm than good wc in that the cloud cover to the north of it would end any irish sea shower generation.

It's touch and go as to the type of precipitation from it.
The GFS suggests negative dewpoints for thursday but it doesn't prog that precip so far north.
Regardless I think the dp's could be negative if that precip moves north but only just as it contains a mix of maratime air.

Very borderline stuff.

One things for sure if that precip got up as far as longfield and artictree it would be pelting it down with snow at their inland and high locations.

My rule of thumb roughly with height and inlandness in borderline scenarios is as follows.
IF sleet on the coast
Then sleet/wet snow 3 miles inland or more above 450ft asl but not sticking.
Dryer snow and sticking above 600ft
Powder above 1000ft and all the time about 30-50% ahead in depth compared to those at 600ft

Lol by the way

Touch and go indeed but i have a feeling we are going to hard pressed getting showers out of the Irish sea so such a scenario could work out great.

Temps are progged 1-3c when that precip is there with colder air pushing in behind, unsure of the dewpoints.

Dew points are vital wc.
They absolutely have to be sub zero (I'd say they will be but just!)

You see if you have an air temp of 1 or 2c and a dewpoint of +0.5c you'll get sleet or worse icy rain.

But in those conditions,if you move inland and uphill,you'll have your snow as the ground level measurement of wetbulb and dp will be lower there and it doesnt have to be much lower than 0.5c or 1c to fall into negative dp territory.

Very seat edge stuff this.

Trogdor

Deleted User wrote: »

Dew points are vital wc.
They absolutely have to be sub zero (I'd say they will be but just!)

You see if you have an air temp of 1 or 2c and a dewpoint of +0.5c you'll get sleet or worse icy rain.

But in those conditions,if you move inland and uphill,you'll have your snow as the ground level measurement of wetbulb and dp will be lower there and it doesnt have to be much lower than 0.5c or 1c to fall into negative dp territory.

Very seat edge stuff this.

How much lower would temps/dewpoints need to be for lying snow? Or is it a case of if it falls as snow then it will probably stick?
Maybe you could put one or two WRF runs through on your site as it gets closer to the time WC?

ninebeanrows

trogdor wrote: »

How much lower would temps/dewpoints need to be for lying snow? Or is it a case of if it falls as snow then it will probably stick?
Maybe you could put one or two WRF runs through on your site as it gets closer to the time WC?

Unfortunately i can't at the moment as i don't have the application on my new pc!

Meteociel have a nice precip WRF, note the best for here but you can make out the southern portion of ireland!

http://www.meteociel.fr/modeles/wrfnmm.php?ech=42&mode=1

arctictree

Deleted User wrote: »

One things for sure if that precip got up as far as longfield and artictree it would be pelting it down with snow at their inland and high locations.

My rule of thumb roughly with height and inlandness in borderline scenarios is as follows.
IF sleet on the coast
Then sleet/wet snow 3 miles inland or more above 450ft asl but not sticking.
Dryer snow and sticking above 600ft
Powder above 1000ft and all the time about 30-50% ahead in depth compared to those at 600ft

Sounds good - bring it on! I'll make sure the camera is working!!

A

EDIT to say this reply is to trogdor



Falling snow doesn't guarantee sticking snow if it's wet snow.
It may stick temporally in heavier bursts but melt away quickly in lighter precip.

To answer your question,in my experience,if dewpoints are sub zero,then you can have snow sticking at anything below 3c (it can stick in really heavy bursts at higher temps than that but wont really last).The colder the better obviously.
That said the likelyhood is that if you are stuck under falling wettish snow,your temps are going to be falling(evap cooling) as the precip gets heavier if it gets heavier.

SpitfireIV

A raw day on Thursday with a biting easterly wind, which may be cold enough to produce some 'wintery' showers in the south of the country.

Thus says the weather lady on the RTE 1 o'clock news-weather

Kippure

They still dont know how things will go. Wait till 48hrs before the event, then they,ll have an incling. As cold spells evolve they change everything. Wouldnt look past 90hrs at this stage. Everything past that is FI.

darkman2

Found this neat explanation on NW

analysis from Will Hand on uk.sci.weather:

"OK, first thing, the Russian high circa 1055-1060 mb is not going to disappear
very quickly. It is becoming well established in the models with hints of an
omega block. Some runs like yesterdays GFS break it down very quickly
introducing raging zonality, although this was realistic it is unlikely because
the breakdown hinged on the orientation of the 200 knot jet coming across the
Atlantic on Friday having the precise orientation to do it, any small change
either way and one of two things happens.


1. Backing - The high stays where it is and a low trundles up to Iceland putting
us into a rather mild southwesterly with cold air persisting just across North
Sea, this is the recent UKMO scenarios.


2. Veering - The high stays where it is and deep lows crash into the UK bringing
extensive precipitation and a southeasterly flow on their northern sides,
eventually resulting in a low complex over UK giving a nightmare mix of
rain/sleet/snow but with most snow in the north. ECMWF has been bullish about
this option and is holding its ground. GFS now comes onboard on the 00Z run 31st
but to a lesser extent.


On balance I feel that we are in for an interesting time in January with very
cold air just to our east and lows over the UK - the usual borderline situation
and a real headache for our professional forecasters.


As I said in a previous post it is highly likely that northern Britain will bear
the brunt of any disruptive snowfalls, but that all important detail can change.
A bit more veer in the 200 knot jet and we will have a severe winter situation
with ridging across to Iceland/Greenland and a full blown easterly with
widespread frontal snow. To balance that, a precisely right jet orientation will
put us into raging zonality for most of January with the high rapidly sliding
away SE.


What an interesting couple of days ahead."

Kippure

One of which you predicted on Nw. Good call.

arctictree

I really like the UKMO chart for midnight on Thursday:

http://www.wetterzentrale.de/pics/Rukm961.gif

Is that FI? - Its t+96

There really looks like there could be a front embedded in that and the winds are now originating from Germany (not France). I'll be keeping an eye on this one...

A

man utd 07/08

DO YOU PEOPLE ACTUALLY HAVE A LIFE...TALKING ABOUT THE WEATHER ON THE NET...:eek:


MAYBE GO OUT 2 THE PB AND GET A WOMEN OR SOMETHING:D

ninebeanrows

man utd 07/08 wrote: »

DO YOU PEOPLE ACTUALLY HAVE A LIFE...TALKING ABOUT THE WEATHER ON THE NET...:eek:


MAYBE GO OUT 2 THE PB AND GET A WOMEN OR SOMETHING:D

Why are you here then! Maybe you should stop writing in caps and get a life:eek::D

Kippure

arctictree wrote: »

I really like the UKMO chart for midnight on Thursday:

http://www.wetterzentrale.de/pics/Rukm961.gif

Is that FI? - Its t+96

There really looks like there could be a front embedded in that and the winds are now originating from Germany (not France). I'll be keeping an eye on this one...

A

There are still to many changes to take place. Yes i would call that f1 cause it wont happen like that. We all know that. Its when the cold spell arrives we will start to see the full picture. Every 6 hours or more a head. Thats all ill be looking at. A good cold easterly and you never know what shower activity we will get off the irish sea.

On the 1 o clock weather they said wintery showers for the south, Yesterday it was the east coast. Tomorrow will be the north east.

I could nt even put a ball park figure on what the outcome will be. Still just speculation at the moment ....

man utd 07/08

YOU MUST HAVE SOME LIFE..YOU MUST BE REALLY BORED:D:D:D:eek:

GOOD LUCK WITH THE WEATHER NOW LOSER:cool:

maquiladora

arctictree wrote: »

I really like the UKMO chart for midnight on Thursday:

http://www.wetterzentrale.de/pics/Rukm961.gif

Is that FI? - Its t+96

There really looks like there could be a front embedded in that and the winds are now originating from Germany (not France). I'll be keeping an eye on this one...

A

That would be interesting if that came off....

All bets are off. Unpredictable times ahead but its exciting stuff.

Temperatures may be low enough to allow a few snow flurries also.

Conservative stuff from Glasnevin, due to the unpredictability.

Ryanoneill2006

Looks like the UK are bracing themselves.... This is taken from The Sky News Website.


An icy blast will bring snow, sleet and freezing temperatures to much of the UK in the first days of 2008.

Coming soon to a field near you...The New Year could see biting winds from the East bringing the harshest winter weather so far.

Forecasters say an inch or more of snow could fall "anywhere in the country" and in some areas there will be much more.

And that could mean roads and travel chaos as millions of people head home from New Year celebrations, and then return to work.

The freezing cold snap will arrive by Wednesday, as the chilly conditions that have already hit much of Europe move East.

Sky News weather forecaster Jo Wheeler said it would mean snow at first on higher ground - but then across the country.

Can I ask, How do todays charts compare to the charts before some of the big 80s snow events? Are there any similarities or is it a different Ball Game now??