Model output discussion - 21st Jan Onwards

[chris55]

The eastwards shift in the trop PV looks to be where our attention should be focused in the coming days. Could be a fascinating period of model watching coming up! And if we can get the PV out of the north west and into Scandi then Feb may hold much promise re cold?

[northwestsnow]

What worries me is yes we could see the 'core' vortex vacate its almost permanent winter home (Greenland) but leave a chunk across the NAtlantic which will continue to fire systems across the Atlantic and still leave the poor long suffering UK under an essentially flat zonal jet.

http://www.wetterzentrale.de/pics/Recm2401.html

Showing preety much that - still the strong euro heights and a strong jet, i have no doubt the blues and purples which have been sat like a horrid limpet will eventually relocate from Greenland but probably in time for easter ..

[Cheshire Freeze]

2 minutes ago, chris55 said:

The eastwards shift in the trop PV looks to be where our attention should be focused in the coming days. Could be a fascinating period of model watching coming up! And if we can get the PV out of the north west and into Scandi then Feb may hold much promise re cold?

Indeed and interestingly fits the stratospheric state very well. Displacement of the stratospheric vortex looks to be strongly allied to trop vortex displacement

Greenland-Icelandic heights could be a prominent feature of February's weather and not a million miles away from the GLOSEA seasonal rock steady projections of the last 5 months.

[Cheshire Freeze]

9 minutes ago, northwestsnow said:

What worries me is yes we could see the 'core' vortex vacate its almost permanent winter home (Greenland) but leave a chunk across the NAtlantic which will continue to fire systems across the Atlantic and still leave the poor long suffering UK under an essentially flat zonal jet.

http://www.wetterzentrale.de/pics/Recm2401.html

Showing preety much that - still the strong euro heights and a strong jet, i have no doubt the blues and purples which have been sat like a horrid limpet will eventually relocate from Greenland but probably in time for easter ..

Yes but remember some energy is required around the area (more specifically Canadian sector rather than Greenland) as this prevents a developing west based -NAO with HP 'over shooting' its target. It also supplies enough energy to support such a blocking feature in the form of energy heading SE as opposed to E or NE through the block.

This shows with the undoing of the 2010 cold spell

Too much of a good thing comes to mind!

Edited January 21, 2016 by CreweCold

[northwestsnow]

Just now, CreweCold said:

Yes but remember some energy is required around the area (more specifically Canadian sector rather than Greenland) as this prevents a developing west based -NAO with HP 'over shooting' its target. It also supplies enough energy to support such a blocking feature in the form of energy heading SE as opposed to E or NE through the block.

Oh i know where your coming from crewe- im with you brother.Im just not seeing anything 'sustained' aside from PM shots - the meto mrf reflects what im seeing-

The first weekend of February is likely to herald a change to slightly colder conditions as a north to south divide in the weather forms across the country. Northern areas are expected to remain unsettled, with further gales and hill snow possible in the northwest. Southern parts should stay drier, with lighter winds. Temperatures are likely to remain close to or slightly above average through much of the period, but may fall just below normal by the middle of February.
Which to me suggests high pressure never far from the South/South East, and those up north exposed to PM shots, not much use to most away from scottish mountains really, a change to slightly colder conditions is not going to cut it for the vast majority when the change mentioned is from a mild bast state ..

[Cheshire Freeze]

4 minutes ago, northwestsnow said:

Oh i know where your coming from crewe- im with you brother.Im just not seeing anything 'sustained' aside from PM shots - the meto mrf reflects what im seeing-

The first weekend of February is likely to herald a change to slightly colder conditions as a north to south divide in the weather forms across the country. Northern areas are expected to remain unsettled, with further gales and hill snow possible in the northwest. Southern parts should stay drier, with lighter winds. Temperatures are likely to remain close to or slightly above average through much of the period, but may fall just below normal by the middle of February.
Which to me suggests high pressure never far from the South/South East, and those up north exposed to PM shots, not much use to most away from scottish mountains really, a change to slightly colder conditions is not going to cut it for the vast majority when the change mentioned is from a mild bast state ..

The Metoffice will go on an ensemble consensus though. They will not talk about a frigidly cold spell until there is very good ensemble support for such. At this range that is unlikely. Give it a few more days....

[fergieweather]

3 minutes ago, CreweCold said:

The Metoffice will go on an ensemble consensus though. They will not talk about a frigidly cold spell until there is very good ensemble support for such. At this range that is unlikely. Give it a few more days....

....plus with eye on potential for SSW into Feb. Until that resolves, any longer medium-term pronouncements might prove rather worthless. 

[karlos1983]

Brilliant post @Tamara regardless of the outcome which never derails your clear passion of the weather, and I for one am humbled by that.

so consistently as ever, the theme is set, I for one look forward to the back end of the month for model watching, and as ever wil be reading the posts that really add value to this thread. Bring it on! 

Edited January 21, 2016 by karlos1983

[Ali1977]

Some positivity in here, and from the METO - it's a while away till that potential could reach us but great to have something to look forward too - let's hope it happens.

I reiterate Karlos in the Tamaras posts are fantastic, as are many others from the knowledgable folk in here - the better the charts, the more they come out with fascinating posts. 

As I said the other day, I think the ensembles by the weekend will be much much better into Feb.

[Allseasons-Si]

1 hour ago, fergieweather said:

....plus with eye on potential for SSW into Feb. Until that resolves, any longer medium-term pronouncements might prove rather worthless. 

 

Thanks fergie

and to add to that,if  we do get an SSW it is not garenteed to bring cold to the uk,it depends where it downwells am i right?

anyway,not to derail the thread,there has been some better synoptics today re:-pm incursions @144hrs

from left to right,ECM,GFS,GEM and UKMO all have a pm flow aproaching the uk

 

 

 

Edited January 21, 2016 by Allseasons-si

[nick sussex]

The last rites were being given and in true  Hollywood style there was a sudden improvement in the health of the patient!

That would sum up the ECM output which saved itself on day ten. However the patient isn't out of the danger zone and the ECM only improves at T240hrs.

The issues with where the pattern goes is where any PV lobe gets located to, if the trend to move the main PV towards Scandi is correct then where any smaller off spring depart to will be key for the UK.

You'll see the ECM moves the main PV on this side of the NH towards Scandi, one PV lobe goes towards ne Canada, we'd need any lobe to be further west and going forward this will be the thing to look out for.

So for the timebeing tentative signs of the flow turning more west/nw but to get deeper cold to the UK pressure will have to rise to the nw and this will be reliant on what the PV off spring do.

 

[damianslaw]

Back to a mobile atlantic regime and no surprise to see the models in consistency once more after a couple of weeks, of wildly different run to run variances..

All agree on a very mild immediate outlook with a long draw SW/S fetch, but it looks shortlived and into next week we see a more straightforward albeit still mild westerly especially in the south, with bouts of wind and rain.

Longer term - strong hints of a more NW polar maritime flow as we end the month, as we see the azores high back westwards and trough feature makes greater inroads into scandi - combined with a shift in the PV away from Greenland.

I think the next few days will see the models increasingly begin to latch onto a NW flow as we start Feb, marking the beginnings of a major shift in northern hemispheric base state we've been locked into since Oct (barring the temporary break of the past week) to one much more conducive to colder conditions sustaining, the key trigger a shift in the PV away from Greenland combined with heights ridging out of N Siberia and into the Poles, setting up height rises to our NW.

[Allseasons-Si]

Yes Nick

with most of the residual energy been sucked out of NE canada with that lobe of pv transfering to our NE.that should be the icing on the cake,all speculative at the moment but a small step in the right direction

it is certainly a better day model watching than the last few days when we was chasing that all elusive easterly again lol

 

 

[winterof79]

Hi Tamara,

(G)reat (P)ost that.With charts to boot?

You seem to be on the same train of thought as a certain other poster in this thread who can only post so much.

February shaping up nicely then.

Edited January 21, 2016 by winterof79

[BLAST FROM THE PAST]

Quote

Posted 22 hours ago · Report post

Personally I'm looking at LPs of a deep nature affecting us over next ten days. I have seen hints that this could be the case and we need to look NNW and N for incoming cold turn of the month.   It does seem that the mild battle is underway and models are showing a bad cold outlook at present. I think the length of time of the bad outlook should look less over coming days, but some mild initially we have to accept.  

BFTP

Interesting UKMO and ECM.  Will post charts when editing but look NNW/north, nowhere else.  Will be interesting to see what occurs after the stat I threw out re mild Dec/Jan,,,,if Jan doesn't become as mild as was showing last 2-3 days then we may have a shout here.  As above Euro HP shouldn't be as big a player as has been progged, ECM and UKMO say that on 'these' runs.  All to play for....end of Jan/Early Feb arr STILL target for coldest onset.....I'm 50% defunct....I hope not to be 100%

UKMO T120

http://max.nwstatic.co.uk/metoimages/20160121/12/metslp.96.png

ECM incoming

http://max.nwstatic.co.uk/ecmimages/20160121/12/ecmslp.120.png

Look NNW/N...

http://max.nwstatic.co.uk/ecmimages/20160121/12/ecmt850.240.png

 

So chill down hopefully well before UKMO thoughts...but stats favour that OUTLOOK...unfortunately as I like a warm up very late Feb/ early March?

BFTP 

Edited January 21, 2016 by BLAST FROM THE PAST

[Allseasons-Si]

Ok,the 18z coming out,will we see a more improvement on the 12z gfs?

i have a wireless mouse,and i am not behind the sofa but....

...it

 

[fergieweather]

Today's EC Monthly has now come into agreement with GloSea5 by building +ve MSLP as a mid-Atlantic ridge into mid-late Feb, with mean NW flow as a result. This will bolster current UKMO suggestion of chill-down 2nd half of Feb.

Edited January 21, 2016 by fergieweather

[Derbyshire Snow]

Well , whats happened today. More of the same generally with glimmers of hope.

The main feature by far is the strength of the jet stream producing more and more intense depressions heading across the atlantic. I would expect some quite stormy weather particularly Northern Britain. Because of this there is very little chance of looking east for our next cold blast. We really have to look north and over Greenland to obtain increasing heights and push the PV further east. The present model run does not present opportunities to produce a strong ridge in the atlantic to halt this strong jet stream. If we can move the PV east ,our next blast of cold air i feel will have to arrive from the north west and if we can then get a depression from the PV to swing south in to Europe eventually north easterlies.

However the Azores high needs to weaken and pull back to allow a trough to plunge in to Europe

We need a SSW  soon and i cannot see anything to show yet that the models expect one to interact with our weather at this time.

The jet stream looks unstoppable for now

 

 

Edited January 21, 2016 by Derbyshire Snow

[northwestsnow]

1 minute ago, fergieweather said:

Today's EC Monthly has now falls into agreement with GloSea5 by building +ve MSLP as a mid-Atlantic ridge into mid-late Feb, with mean NW flow as a result. This will bolster current UKMO suggestion of chill-down 2nd half of Feb.

I suppose thats positive news in that it will get colder but i wasn hoping for a bit more than a mid Atlantic high being honest, can i ask if there is any suggestion of this ridging into Greenland Ian?

[booferking]

Things are just getting put back further and further i would much rather have spring in March rather than cold wintry weather.

[northwestsnow]

Well 18z looks to be sniffing round some sort of mid Atlantic high for the start of Feb with potential for the 528DAM line to visit again

[nick sussex]

2 minutes ago, northwestsnow said:

I suppose thats positive news in that it will get colder but i wasn hoping for a bit more than a mid Atlantic high being honest, can i ask if there is any suggestion of this ridging into Greenland Ian?

As Ians Press Secretary! lol That's a good first step to get the ridge in the Atlantic. The UKMO are probably monitoring any possible SSW but they won't comment on how that might impact things until they're sure of it verifying.

 

[Cheshire Freeze]

4 minutes ago, booferking said:

Things are just getting put back further and further i would much rather have spring in March rather than cold wintry weather.

That might be a case of 'tough titties' this year. It has been well advertised for months that this would be a back loaded winter and I had my suspicions that winter would linger into spring. Probably pertinent to note that diurnally driven convection may feature more prominently the further into Feb we go so, in essence, we may experience some very nice cloudscapes should any polar airmass interact with greater surface heating. 

Loverrrly jubberly!

Edited January 21, 2016 by CreweCold

[northwestsnow]

The depth of those systems coming off the eastern seaboard are ridiculous for the beginning of Feb,surely we should be seeing some sort of slowing down of the jet?

[Catacol]

11 minutes ago, northwestsnow said:

I suppose thats positive news in that it will get colder but i wasn hoping for a bit more than a mid Atlantic high being honest, can i ask if there is any suggestion of this ridging into Greenland Ian?

Medium term models provide a very broad brush. So within a signal for a mid atlantic ridge there are all kinds of mesoscale possibilities. Straight northerlies, damp NWesterlies, drier but very cold NEasterlies and even undercut scenarios bringing E or SEasterlies are all possible from a mid atlantic ridge even if the dominant vector over the period is mainly from N or NW. The news today is therefore good.... but second half of February needs the skies to stay cloudy....

Edited January 21, 2016 by Catacol