Wintry potential December 09

darkman2

Hi, well t'is that time of year. The time when speculation begins to mount and the ludicrous incursions into fantasy land begin......so let's get to it.


The ECM seems to be providing the first chink of light of the season with signs that the train of Atlantic depression may be coming to an end.

At 72 hours - everything is pretty much as is except for a milder southerly flow but the windy damp spell continues




At 120 hrs (Saturday next) it's still dark and wet but a change is occuring as the Jet Stream weakens and starts to split slowing everything down. Pressure starts to rise to the North.

MJO entering a new phase?




At 168 hrs the scene is set as a ridge of high pressure extends from Greenland pushing the cyclogenisis south creating a kind of squeeze with which we would hope incoming Low pressure would undercut. The Jet Stream is taking a holiday to the Med.




Nothing spectacular just yet but they are the building blocks.

On to 216 hrs and we are in - we are in!




LP starts to grate against a push of very cold air out of Scandinavia and beyond. But the LP is not going anywhere. So it undercuts the high pressure to the North. Things about to get wet in Iberia and cold over Ireland and the UK.

At 240hrs the Polar Vortex (the darkblue and purple area) is completely moved from Greenland to were we want it to be - Scandinavia. Snow and raw winds await




UKMO also has a similar evolution out to 144hrs. GFS not having it atm but whilst the above may not occur it is by no means out of the question either. This is the first real sign of a pattern change this winter. Long range Christmas charts looking quite yummy for snow aswell atm but we won't go that far;)

Incidentally if the above did happen there is a real snow risk but id prefer it in December as opposed to November. Maybe a little early yet for Easterlies.

Anyway just a little something to keep the spirits up

cinnamon

darkman2 wrote: »

Long range Christmas charts looking quite yummy for snow aswell atm but we won't go that far;)

Anyway just a little something to keep the spirits up

Thank you kind sir, you've just made my night

danni2

Great post darkman2, its been rather depressing looking at the charts in the past few weeks, so nice to see things are looking brighter and hopefully we won't have to wait to long now to see some snow:D

Deep Easterly

darkman2 wrote: »

Maybe a little early yet for Easterlies.

Nonsense! Never too early or too soon for an easterly! :pac:

roryc1

So what your saying is that in around two weeks it will start snowing and not stop till april, thanks darkman now im happy

Gonzo

wouldnt mind a 2 to 3 week period of dry, crisp and sunny weather before winter sets in, so sick of the wind and rain! then snow from mid december onwards wud be nice.

ronbyrne2005

any updates? Im sick of this wet windy warm weather we're having.

patneve

YES WE CAN:D

GFS 12Z showing a nice cool down before a bit of a wintery snap (however those charts are in FI). Am 80% certain that a nice change is on the way:D

arctictree

GFS showing a very cold and wintry Saturday morning:



Temps are low:



There is precip around:



This could possibly be our first sleet/snow event of the winter. Could be a very nowcast event though.

Deep Easterly

:pac:

Gonzo

4/5C max for the weekend, could be some snow on high ground, im generally hoping for things to just stay calm and dry up.

JanuarySnowstor

I've been watching developments from afar all week and I firmly believe that Ireland is a hare's breath away from a snow event this wkd. Heavy ppn, Northeasterly winds, and 528dam air very closeby. Most importantly,a point being ignored on here, is some ferociously cold air just to our North!!
Someone will see a lot of snow

cian1500ww

God I hope we get some snow *fingers crossed*

Deep Easterly

cian1500ww wrote: »

God I hope we get some snow *fingers crossed*

Evelyn on the TV forecast tonight mentioned the possibility of some "wintry showers" in the east and south east this coming weekend. Looks like being dry here in the west which I am sure for many will be a much welcomed relief.

Drummer Mummer

Why is it we NEVER get snow on the East Meath coast? It could be snowing like mad a few miles away and still we wait.....! I could count on one hand the times it snowed here in the last 30 years. What are the chances (if any) for snow in the next few months?

loup

Does the colder weather mean it will rain less in the next while? I really hope so especially for all those in flood risk areas.

maquiladora

loup wrote: »

Does the colder weather mean it will rain less in the next while? I really hope so especially for all those in flood risk areas.

Looks like mostly showery in the near term apart from Friday night / Saturday morning when the southern half of the country could see fairly heavy rain. Next week looks fairly showery again but could see heavy rain towards the end of next week...

forkassed

:pac:

MUSEIST

forkassed wrote: »

:pac:

Lol, indeed, I saw this earlier and was going to post this.
Damm FI, i swear somebody just puts charts like that in FI to piss us off.
If only something like that happend, but we all know it w'ont:D

patneve

i will not be fcuked up the ... by GFS once again!! 100 hours is my limit!

It would be highly unusual for extremely cold air from the East to come in early december.
In my lifetime,I've only seen it happen once,thats how rare it is.
Ergo no breath holding.

Anyhow,FI is ridiculous-always was.
It's short for fantasy island because post 96 hrs , theres no many errors multiplying in gfs/nwp data sets that they become rapidly meaningless.

darkman2

Im not going to bother posting charts or even commenting on something that far out for the same reason as above. However there is an interesting situation about to occur in the Polar regions where a large area of high pressure is going to build from the Pacific right into the interior of the artic. This looks like splitting the Polar Vortex and probrably heading our direction so expect a pressure rise from the North which most models agree with. What's not known is how it will effect us. It should create an unusual change in pattern I would think in the next couple of weeks. The options would favour a colder outlook (perhaps very, very cold) but a milder one could also occur. Alot of variables to consider.

This page on the NH synoptical evolution and height disparities clearly show what I mean about the ridge going into the Artic and coming down on our side.


http://www.meteociel.fr/modeles/gfse_cartes.php?mode=0&ech=6&carte=1


Press "suite" to continue to 192+ just to illustrate.

patrick ryan

its - 2 i hope we get snow tonite?/???:)

danni2

patrick ryan wrote: »

its - 2 i hope we get snow tonite?/???:)

Don't think it will snow tonight, tempertures will rise as that band of rain will spread across the country tonight and tomorrow morning.

Hopefully we won't have to wait too long for our next cold spell with a proper northerly/easterly then we will see some snow, remember we have the whole winter ahead of us;)

patrick ryan

anybody get snow

Trogdor

Moved your posts in here as i think the old thread had run its course:)

patrick ryan wrote: »

anybody get snow

Snow's fairly unlikely tonight, the temperatures are set to rise quite a bit before any precip starts unfortunately

Supercell

Light stuff here, but not settling and probably will turn to drizzle soon as the temp is rising as is the DP

patneve

GFS 12Z - what an amazing run!!:D I tend not to comment on cards past 180 hours, but on this run there are important changes already at 150 hours (high pressure building on Ireland...all we need is that high pressure to shift and build to our north and it's bingo;) too early to say now though...

roryc1

The 12z have gone mad :eek:
but they do show a steady build up from the east,
i think i might go and find my snow boots, just in case

Kippure

roryc1 wrote: »

The 12z have gone mad :eek:
but they do show a steady build up from the east,
i think i might go and find my snow boots, just in case

Thats the best 12z run i,ve ever seen. Prue winter magic.

forkassed

As patneve said..Some nice trends developing on the GFS the last few days. It has showed an easterly on and off now for about 4 days. It all hinges on whether the high pressure over europe builds Northwards at around 144 hours, will be looking for evidence of this on the ECM this evening.

Doubtful this far out but a trend to watch all the same..