Scandinavian high to bring colder weather but how cold?

Snowbie

In situations like this,its simple yet complex to forecast what and where this HP will go or do.
Its simple, that a HP in and around the 1045mb mark aint going to budge too easy and has shown in our case its stubborness being anchored in the north sea,just 300miles south of a full blown easterly for the last few days.

Its complex, that our northern arm of the jet has yet to intensify and squeeze the HP south into europe,and also the southern jet(which is stronger atm) will probably shove the iberian LP nothwards displacing the high to a more semi northern latitude ie:scotland steering in a strong east wind.

It is why atm the models are struggling to find a definitive outcome even in the reliable time frame and is why a situation like this has to be taken at face value one day at a time.
Yes it is easy to forecast a HP weather and type but positioning determines weather.
So if ECM or whatever ensemble you prefere indicates snow,cold,mild or windy lets say for monday,it should be ignored as there is a model struggle with both jets and HP positioning.

If we had a raging atlantic(zonal) well its simple to forecast but again LP positioning in this instance is the key to severity for wind and rain.In this HP setup now,i wouldnt trust a forecast being accurate well into reliable for 48hrs out.

Again if southern arm gets its act together,watch the HP retrogress towards Scotland or a little further north,if northern jet intensifys,HP will slip south.
To make it more complex,the exporting of LP from the US is the key for intensification of the jets.Which will win???? is anyones guess.

Danno

Look at the Low near the Azores: http://www.metoffice.gov.uk/weather/charts/FSXX00T_84.jpg

Now look at what is driving her: http://85.214.49.20/wz/pics/Rtavn8414.png

If she can be shunted onto the very high jet over the med... ???

maquiladora

Weathercheck wrote: »

Nah all gone, ECM et al have swung to boring nothingness and then a Bartlett.

All gone until the next model swing.

Supercell

At this stage I'd prefer zonal - cool overcast with no wind and no frost just bores the pants of me tbh.

Villain

Whats kind of change has the 12z thrown up: http://85.214.49.20/wz/pics/Rtavn2881.png ??

maquiladora

Villain wrote: »

Whats kind of change has the 12z thrown up: http://85.214.49.20/wz/pics/Rtavn2881.png ??

Hehehe
That run is entertaining, if nothing else.

Trogdor

Gives us our own tiny patch of sub -5C upper air next Friday as well with a rain/sleet/snow? breakdown. I think surface temps would be too high for snow though. All speculation though given that the charts have become so unreliable past around T+96 at best.
http://www.wetterzentrale.de/pics/Rtavn1681.png
http://www.wetterzentrale.de/pics/Rtavn1682.png
http://www.wetterzentrale.de/pics/Rtavn1684.png
http://www.wetterzentrale.de/pics/Rtavn16817.png

SubjectSean

darkman2 wrote: »

but how cold?

Fairly cold

togster

Im in Sweden atm halfway between goteborg and malmo and its gotten very cold in the last few days. Was looking forward to coming home for xmas for some milder weather before the cold really hits here. Much more snow in Northern Sweden this year than last yeat too.

ninebeanrows

This high looks like clinging on and sucking any live out of the of Decembers winter chances, looks like an incredibly mild month is on the cards and another month of winter is set to fly by.

This winter aint looking good at the moment.

MUSEIST

Your negativity over this high is really spoiling the festive mood for me. I am suprised you are so negative about it considering that your blog seems to always go over the top every time we nearly have a snow event. D':ont you like this weather , its festive and it certainly will get cold over ireland next week.:p

ninebeanrows

MUSEIST wrote: »

Your negativity over this high is really spoiling the festive mood for me. I am suprised you are so negative about it considering that your blog seems to always go over the top every time we nearly have a snow event. D':ont you like this weather , its festive and it certainly will get cold over ireland next week.:p

Its just that its sucking days out of our winter.

And i do not find Anticyclonic Gloom in anyway festive:D

Gonzo

also as bad as our winters have become over the past 10 years I seem to remember that even during the good ole days back in the 80s and early 90s that December is nearly always poor for snow, often delivering nothing at all untill the last week of December and into January. January 1st to the end of February is usually our window of opportunity.

Supercell

I'm with WC on this MUSEIST( also known as..SubjectSean, wazzoraybelle, Duiske), anticyclonic gloom is really the pits of all weather conditions.

There is clear air over central UK at the moment giving nice sunny days and frosty nights.
If we can't have snow, thats just about my perfect winters day!, lets hope some of that makes its way eastwards.
I'm expecting a rather cool day tomorrow, temps have dropped to 2.7°C tonight and with the low cloud cover and weak sun, wouldn't be surprised if tomorrow doesnt top 4°C

Unless this high starts making motions northwards I'd wish it buggered off tbh , the jet is encouraging a little in that its moving south - if this high wasnt around we might have had a polar maritime low or two by now as a result with temporary snow cover (at low levels).

Snowbie

A good thing is for the continent to cool down.Thats good for the rest of winter.Any drawing of winds from there will reach our shores quicker than cold pooling over siberia and taking a week to arrive here swinging around a scandi block.

A bit of ice clear nights id agree be nice but i was worried last week that zonal would take hold for a few weeks and screw us up.Watch this space as there might be a breakdown closer to Xmas that might be interesting.Total FI speak.

arctictree

I've been watching this HP for a while and all charts are consistently showing a breakdown to milder weather next weekend. Hopefully, in the next day or two, this trend will break!

A

Mothman

We saw nothing of the very cold continent in Jan 06, but yes it certainly helps.
The Irish sea temperature is important as any cold weather to come our way has to cross sea. I keep a close eye on Bouy M2, for both sea temp, air temp and dew point


Sea temps continue to drop, reaching a min end of Feb, beginning of Mar. Its no coincidence that my coldest week on average is the first week of March.
Here are my 10 lowest mins
-5.5 7th Feb 2007
-5.1 1st Jan 2002
-4.9 1st Mar 2004
-4.7 3rd Mar 2006
-4.6 2nd Mar 2004
-4.3 2nd Mar 2001
-4.2 15th Feb 2003
-3.9 3rd Mar 2001
-3.9 2nd Jan 2002
-3.8 9th Mar 2004

See how often Mar is there, with 3 different years represented.
Irish sea temp are still at 11C, by end of Feb that figure should be down to 8C

As for this current muck, much rather have it now near beginning of winter and festive season rather than later on. It a long time till mid Mar, so still plenty of time left.

darkman2

Nothing really substantial on the horizon yet. Cold - yes but no snow. Should get milder by Christmas. Not expecting too much before January and still no real sign of pressure building toward GL which we need really.

Snowbie

It was a cool enough summer so i dont think sea temps are as high this time last year.Probably only a fraction in the difference as the gulf stream still sources are SST in the Irish sea.
Although lapse rates are reflected by SST's so if a sustained continental flow moves over warmer seas it increases lapse rates(formation of showers) but a warmer sea has the added addition of keeping us coastal resorts that bit cosier.Seems like we cant win on lower level.

I would only be convinced when 850mb temps are below -7c for snow at lower levels with -10 850mb temps are sufficient for snow on the beach or coast to settle and accumulate from an easterly direction.

Latchy

Hi , saw the door was open and just thought i would take a look in this room ,

Latch walks around the room......hmmm ,it's very cold in here .......

Latch leaves room .

Intresting topic , keep up the good work .

nacho libre

yeah, it looks like we'll have to wait till Feburary again for snow.

it'll be worth if we get a polar low coming down from the direction GL - well maybe not for the east and south east of the country!!

Gonzo

How can snow be written off already for January? were only half way thru December!

Danno

These *could* produce some snow inland, esp over the Midlands-East...

http://www.wetterzentrale.de/pics/Rtavn18017.png
http://www.wetterzentrale.de/pics/Rtavn1803.png
http://www.wetterzentrale.de/pics/Rtavn1804.png

...coming home after the Christmas Eve party!

Extremely unlikely.
3c is too high to outweigh an undercut of mild atlantic air and besides that chart is deep FI going on the recent definitions of what is FI.

Snowbie

Deleted User wrote: »

definitions of what is FI.

Fupping Impossible
Free to Ignore

The air is not cold enough over the country for it to snow,at best it be cold rain if and when the mild air breaks through.

Sierra Oscar

Snowbie wrote: »

Fupping Impossible
Free to Ignore

The air is not cold enough over the country for it to snow,at best it be cold rain if and when the mild air breaks through.

At best...?:(

Snowbie

Sierra Oscar wrote: »

At best...?:(

Could be worse,could be mild dank drizzle. Atm some of the models sink the HP into the continent,some split it and which stalls the atlantic moving totally across the country.See what the 18z brings later on.

Still a long way off and there is confusion in model agreement,it could upgrade but also downgrade further.Some would like the HP out of the way,id prefare it to take up residency over Oslo.

@Snowbie

@ sierra oscar
That chart Danno posted if it were say the chart for "now" it wouldn't deliver snow (except maybe transitory very wet stuff above 2500ft) because there would be too much mixing of various air types,most of which wouldn't support snow.
Cold rain yes.
@Snowbie
Yup fupping unbelievable etc
However what I meant by "recent definitions" is that lately FI is any model output predictions for weather more than 96 hours past the runs starting point.
FI usually stands for fantasy island in that people only bother looking at it and using it in threads when it shows charts that hint at snow or whatever it is that is their favourite weather.
Thats something I've always found pointless except for discussing theories or trends.
Mind you the best way lately to discuss trends is by comparing variations between runs inside the 96hr timeframe.

Snowbie

Deleted User wrote:

@Snowbie
Yup fupping unbelievable etc
However what I meant by "recent definitions" is that lately FI is any model output predictions for weather more than 96 hours past the runs starting point.
FI usually stands for fantasy island in that people only bother looking at it and using it in threads when it shows charts that hint at snow or whatever it is that is their favourite weather.
Thats something I've always found pointless except for discussing theories or trends.
Mind you the best way lately to discuss trends is by comparing variations between runs inside the 96hr timeframe.

True.As posted earlier in a thread,90% of the time a zonal forecast would be accurate within 4 days,apart for precip totals and temperature at 4 days away but based on wind direction,a general mild or cold zonal would be guessed.Obviously more accurate closer to time.

In the recent HP setup,it is near impossible to be accurate in a forecast for a given region even in close proximity on a daily basis for sun,cloud cover and temperature for that particular area but yes the majority of the time it will be dry.As it was an Azores high it will contain moisture and result was cloud cover or the stratus muck we all know it as.
It be a different story if it was an Arctic high with the crystal clear air and lower temps with precip dependant on other factors.

Now with the models and FI,this was not recognised in the zonal flow we had just gone at 5 days out,so who can call it in 7 days.FI will always make for good reading but be taken at face value with room for upgrades or downgrades or just the direct opposite.
Whats christmas going to be like? Well i could not tell you nor anyone else,but with a glimmer come the 18z on the 20th and more defined come the 23rd.

maquiladora

This would be quite an interesting Christmas Day if the GFS is right.....