End of November/start of December Forecast

Snowbie

Some interesting charts been outputted from GFS over the last few days but in FI and should be taken with a pinch of salt.
Consistent but mouthwatering for the cold and snow lovers. ie:me and a few others:)
Almost a repeat of Nov 2005 at the same time peroid also.

A Greenland HP cell builds as early as next Saturday 12th and really exerts itself into the following week. With high pressure never too far away from our west coast also, the two HP want to link up, thus allowing another cold blast if not even colder down from the north before the Atlantic HP retreats south allowing less cold WNW winds in.

Usually GFS tends fall apart but it was consistent into FI for the October northerly even this far out in time. Will it be two times in a row?

Greenland HP


Outcome


Another interesting end to the month??

Danno

Sweet looking charts, especially for the North and East of Ireland. The last chart shows the potential of a Med Low forming.

Snowbie

Danno wrote: »

The last chart shows the potential of a Med Low forming.

Yea, with a foot or more of snow for the Alps

mike65

Oh whoopi!

Mike

nacho libre

any chance of a polar low?:)

Snowbie

nacho libre wrote: »

any chance of a polar low?:)

Always the chance in a setup just like that above, but polar lows are really a nowcast event with maybe a hint of development from +24hrs out.

Polar lows are only polar lows with a cold sector. There can be confusion when LP flow down in a N or NW'ly stream but with warm sectors and make things more marginal or just hilly and Mtns events, these are not PL.
Polar lows can deliver snow to low levels with almost 100% certainty.

These can look like a comma shape on satellite or can even mimic mini hurricanes with a definite spiral form to it but tend to be shallow and without a significant wind event, usually more squally around the core when the cold is dragged down when it passes overhead from what i witnessed in 2001.

PL's affect Ireland usually from the NW more so than the north and very rare the NE. From the NW, Iceland and it's topography aid in the development of PL with slightly higher SST's between Iceland and Ireland.

From the North, usually trough's form in the airstream pepping up showers for mainly the north and west of the country. I find that PL formation decreases from N'ly airstreams as we move through the winter months.

The NE direction, in an omega block setup (rare) when HP is located to the north of Scotland from a retrogression(moving back west) of a Scandi HP and a NE feed across Ireland. The mtns of Scotland can create LP to the lee side which then flow's over the Irish sea. With LP, cold air travelling over warmish SST's, moisture is picked up and can quickly develop into a PL or even a small low level circulation which can dump alot of snow to Leinster. eg: 9th Feb 1991 (which was the 3rd snow event for Dublin that year). However the omega block has to hold for great length of time but never does and the retro of the HP continues back towards the Atlantic. When it holds, oh happy days.:)

Deep Easterly

I am getting exicted.

arctictree

Am really hoping for some exciting weather soon.....!!

kerry1960

It looks like some frosty nights on the cards later this week , snow/sleet is rare enough down here even in Jan/Feb never mind in min Nov , so i will happily settle for some cold/clear nights ...........for now........:D.

holly1

Sorry but Im a laywoman or person whatever,in normal words are you saying we in the East (Kildare, North)are going to have a spell of wonderful snow?

darc

I know this forum uses the first link, but the german site also has Temperature, cloud & presipitation forecasts for 9 days ahead.

http://www.wetterzentrale.de/pics/avnpanel1.html
http://www.wetterzentrale.de/pics/avnpanel2.html
http://www.wetterzentrale.de/pics/avnpanel3.html
http://www.wetterzentrale.de/pics/avnpanel4.html

With cloud cover for most of the next 9 days, hard frost is unlikely.
Wednesday 26th is very interesting for snow lovers, but as with all weather patterns, it could change.

Snowbie

At this range out we look at the middle and upper air temps first to get a hint of cold or warm air approaching. Surface temps, precip and cloud cover are really just a guestimate due to the upper air temps. There are still quite a few affects that can alter the weather condition.

But as we get closer to an event, there would be a better idea of what surface temps, cloud and precip can be expected.

ninebeanrows

Looking coooooooooold later this week, with a few frosts and perhaps a flake or 2 of snow.

England and Scotland could get some nice snowfall too (surprise surprise).

nacho libre

well i'm going to commit blasphemy(snow-lovers cover your eyes) i do not want snow on the 26th - at least not during the afternoon:(

Danno

May you burn in the place that your profile says your from!

Snowbie

I'd say this thread is warranted as this might get interesting?
Just in reliable timeframe now but another blast of arctic air with strong winds bringing a noticeable wind chill with crisp clear air southwards. Atm, it looks to be clear and dry with an intense high pressure(1040mb) centred only a few hundred miles just off the west coast and keeping pressure high across Ireland dampening out any showers.

Too early to call this but if the HP cell moves back west, pressure will decrease from the north and east and the chance of some wintry stuff mainly to north and NE of Ireland and if it moves closer, winds be light with less wind chill but still cold.

As is shown the 528 DAM thickness stays out to the east but 850mb temps down to -6C to -9C generally low single figures by day and subzero at night with severe frost likely. Scotland and east UK look favoured for some snow.

Still time for things to change with the HP to the west but it seems to be anchored there for the minute, maybe a little arctic air will kill all the stomach bugs going round in this mild moist laden airmass.:(

danni2

shocking 06z, that high pressure pushes the coldest air east over the uk, if that high can move further west it will alow the colder air over us and we'll be in business, still time for things to change though

patneve

If the high pressure moves further west then...BINGO:D However I doubt that will occur:( I wouldn't mind being on Italy's East coast on Saturday night however:pac:

what altitude are those air temps?

patneve

Deleted User wrote: »

what altitude are those air temps?

1400 metres

Mullaghteelin

Several days ago the GFS was expecting this northerly to miss us to the East, with the coldest air blasting across down the North Sea. I was suprised when the models moved it closer to us, and then even over us. Its interesting to see the most recent runs backtracking again and pushing it all futher east again.
Even if we do get a taste of cold air, I wouldnt expect anything too exciting. The high pressure was always going to be too close to us and thickness too high. It probably would have given favoured places a night or two of frost, and a few mostly light wintry showers in the usual coastal parts of the north and west, at most.:)

nilhg

Mullaghteelin wrote: »

Several days ago the GFS was expecting this northerly to miss us to the East, with the coldest air blasting across down the North Sea. I was suprised when the models moved it closer to us, and then even over us. Its interesting to see the most recent runs backtracking again and pushing it all futher east again.

ECMWF has been very consistent in having the HP just off our west coast all week, at this stage with both models in pretty good agreement its probably going to work out that way, it will be interesting to see if there are any last minute hiccups.

Its going to be a quite a change across parts of Central Europe though.


Edit: I've just checked the 12z ECMWF, we mightn't escape totally.

Fantasy Friday?

Mullaghteelin

nilhg wrote: »

Edit: I've just checked the 12z ECMWF, we mightn't escape totally.

Fantasy Friday?

Often when theres a big Midatlantic high drifting around like that for a week or two just off our west or southwest coast, but never moving very far, it will EVENTUALLY drift off to Greenland and the floodgates open!
Off course it could always just collapse southward and let the the mild muck in along with double figure temps night & day.

Snowbie

nilhg, that chart is for Thursday 27th you have just posted there.

The 12Z has the HP roughly still in the same spot but i will post up the 18Z later and keep the runs for 24hr timeframes. Although i reckon the charts will be little different over the next runs, the HP is forecasted to remain around the 1040mb but is too far away to be certain if it will still block or even shallow and then which it can be nudged more west by a potent NNW flow and northern arm of the jet and more out of the way?? Still too far out to be exact on this.

Were not certain to get the cold air yet countrywide but the NE and east look best chance of much colder air than the west which still looks under the influence of the pond.

High pressure looks intense but only atm but agree there has been a downgrade.

mike65

I don't think this is going to amount to even a hill of beans unless 6c for 24-36 hrs is now a cold snap.

Mike

Supercell

Meh, already had blizzards this year..this looks pretty tame by comparison :P

danni2

Ok the 18z has stop the eastwards progresion of the northerly flow which we seen on earlier runs, the flow moves slightly back west, but still nothing too exciting really

Snowbie

Again the uncertainty is evident in each run. The 18Z is upgrading the cold but has delayed the arrival till Saturday. The cold is pushed back more to the east, heights remain above 530 thickness though but the jet seems stronger on this run allowing the flow to penetrate more to the west and pushing the HP back SW.

Although i think this be a +24hr until we can call the exact position of the HP cell as it seems to meander a bit on each run. Models can't handle the position on this block and unfortunate for the cold lovers is the Atlantic block is further south and east than we would like.

The position of the HP will determine whether a more wintry flavour(precip) will push in or plain auld dry and cold.

Friday 2100


Saturday 0600


Saturday noon

nacho libre

the east of england and scotland look like the places to be this weekend if you like snow

Snowbie

nacho libre wrote: »

the east of england and scotland look like the places to be this weekend if you like snow

Agree there is one more spot on the plane if your interested, when Deep easterly and Supercell moves the cans and the snowshoes you can join us skiing down Ben Nevis arsebout face if you like:D

hellboy99

Never any snow here