Model Output Discussion - 1st February Onwards 12z--->

[knocker]

Michael Ventrice â€@MJVentrice 

When atmospheric angular momentum is low (below central horizontal line), global circulation is more La Nina'esk.

[Woollymummy]

There were a couple of years in which the OPI trend did not match the AO trend, maybe this is another odd year. Maybe.

Edited February 17, 2015 by Woollymummy

[Frosty.]

GFS 12z increases the risk of snow further south, more like the 0z than the 6z. Scotland has lots of snow showers piling in behind active frontal systems and through FI the snow risk extends further south. It's a very unsettled outlook with gales and heavy rain at times and thanks to the colder SST's compared to late autumn and early winter these polar maritime blasts look much more potent so I'm pleased to say judging by this run, most of the UK has a chance of snow during the next few weeks.

[Abyss]

Hi Knocker.Could you please explain what your most recent post means for those of us less knowledgeable

Edited February 17, 2015 by -Bomber-

[knocker]

Hi Knocker.Could you please explain what your most recent post means for those of us less knowledgeable

 

Hi Bomber I was rather hoping one of our resident experts on the GWO would explain it to me. The nina'esk comment I take to be a reference to varying intensity of the jet stream and possible increase of storminess although my understanding is that the links between El Nina and weather impacts in the UK are a bit tenuous. Bear in mind  Michael Ventrice is focusing on the US. Sorry I couldn't be of more help.

[Nouska]

Hi Bomber I was rather hoping one of our resident experts on the GWO would explain it to me. The nina'esk comment I take to be a reference to varying intensity of the jet stream and possible increase of storminess although my understanding is that the links between El Nina and weather impacts in the UK are a bit tenuous. Bear in mind  Michael Ventrice is focusing on the US. Sorry I couldn't be of more help.

 

I don't know much about the GWO but I think he is saying that there is/will be a major disconnect between ocean and atmosphere signals and therefore analogues/teleconnections will not be of much use in mid term modelling.

 

There's change afoot in ENSO regions with a Modoki taking shape. That has very different weather patterns to a regular El Nino.

Patterns for each month under different ENSO conditions from JMA climate pages.

 

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/newoceanindex/index.html

 

 

 

The MJO is in the 'Doldrums'.

 

 

All in, possibly a period of indecision in the NWP while it works out whether it should be modelling for air or sea.

[Woollymummy]

This link may help:

http://www.esrl.noaa.gov/psd/map/clim/gwo.htm

....I am still trying to learn what it means though so no more to add from me yet....

[Frosty.]

Apart from a few milder blips, tonight's Ecm 12z shows plenty of cold weather with sub -5 T850 hPa at times, looking at the thickness charts, frequently 528 dam and occasionally 522 dam flooding in behind very active frontal systems which is very much on the cold side with frequent squally wintry showers and a high risk of snow on northern hills but also a risk of snow in places elsewhere as well as spells of very wet and windy weather with back edge and leading edge sleet and wet snow being a possibility, especially on hills in the north.

Edited February 17, 2015 by Frosty.

[knocker]

I don't know much about the GWO but I think he is saying that there is/will be a major disconnect between ocean and atmosphere signals and therefore analogues/teleconnections will not be of much use in mid term modelling.

 

There's change afoot in ENSO regions with a Modoki taking shape. That has very different weather patterns to a regular El Nino.

Patterns for each month under different ENSO conditions from JMA climate pages.

 

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/newoceanindex/index.html

 

 

 

The MJO is in the 'Doldrums'.

 

 

All in, possibly a period of indecision in the NWP while it works out whether it should be modelling for air or sea.

 

Thanks Nouska. He did write this in his blog a couple of days ago which is relevant.

 

The eastern Pacific Ocean is now in cooling state that should last roughly a month or so; Shades of Winter 2013-2014.

Edited February 17, 2015 by knocker

[ANYWEATHER]

Evening folks. Well the gfs and ecm are stepping up a gear with some strong late winter storms across the nation, along with a fluctuation of mild and cold, generally the theme of this winter, at least its not "Boringmaggedon" with high pressure anchored over the uk as shown some days ago. Given the  increasing strength of the sun at this time of year, Convection is more likely over land during the cold unstable airmass, so something more interesting than the last ten days or so....    

[bluearmy]

i think these pm incursions are warming us up for a more marked one at the turn of the month. still uncertain how this all evolves thereafter but i note the russian high becoming rather a strong feature and it is feasible that we see the azores ridge trying to throw its influence rather more north than east as time passes.

[winterof79]

i think these pm incursions are warming us up for a more marked one at the turn of the month. still uncertain how this all evolves thereafter but i note the russian high becoming rather a strong feature and it is feasible that we see the azores ridge trying to throw its influence rather more north than east as time passes.

i was just going through the GEFS and ready to post the same

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=240

 

The russian high exerting its influence from 144z onward,strangely enough it coincides with our change to PM incursions

The Gefs toying only at present with the Azores ridging favourably for once

Edited February 17, 2015 by winterof79

[Nouska]

 

Thanks Nouska. He did write this in his blog a couple of days ago which is relevant.

 

The eastern Pacific Ocean is now in cooling state that should last roughly a month or so; Shades of Winter 2013-2014.

 

 

Thanks for the link - hadn't read that one.

 

Just to add to the above post - the NH Z500 anomalies for both La Nina and ENSO4 (Modoki) in March.

 

Nina    ENSO 4

 

You can maybe see where the GloSea5 and ECM32 are getting different messages from.

 

Although I've always been led to believe that ENSO has very weak influence on the UK region, this would indicate that it can make a very big difference in certain circumstances.

[damianslaw]

Models firming up on a vey unsettled end to the winter with frequent bouts of wind and rain for many and snow on higher ground in the north, temperatures overall average at best once we get to Friday, a bit below in the north.

 

Normally we see the atlantic quieten down by late Feb, but not this year, February the wrong way round..

 

Can understand its not everybody's cup of tea, but the outlook is far more interesting than the past 2 weeks and from my own perspective very seasonal with no long draw southwesterlies or southerlies.

 

The ski centres of Scotland will be happy with the outlook.

[winterof79]

Models firming up on a vey unsettled end to the winter with frequent bouts of wind and rain for many and snow on higher ground in the north, temperatures overall average at best once we get to Friday, a bit below in the north.

 

Normally we see the atlantic quieten down by late Feb, but not this year, February the wrong way round..

 

Can understand its not everybody's cup of tea, but the outlook is far more interesting than the past 2 weeks and from my own perspective very seasonal with no long draw southwesterlies or southerlies.

 

The ski centres of Scotland will be happy with the outlook.

The nursery slopes of Kirburton may get a  dusting

Edited February 17, 2015 by winterof79

[shaky]

Fax chart is very interesting! ! Small low south midlands and 528 dam line north if it!!gota be a bit if interest from that!! Ian fergie could hopefully give us more of an insight?

[winterof79]

Just to illustrate my point regarding the Russian High take a look at the CFS, and no its not at 500z either,and how it acts as a buffer to the energy moving towards the UK

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=180&mode=0&carte=1&run=10

[knocker]

Thanks for the link - hadn't read that one.

 

Just to add to the above post - the NH Z500 anomalies for both La Nina and ENSO4 (Modoki) in March.

 

Nina    ENSO 4

 

You can maybe see where the GloSea5 and ECM32 are getting different messages from.

 

Although I've always been led to believe that ENSO has very weak influence on the UK region, this would indicate that it can make a very big difference in certain circumstances.

 

And looking at tonight.s ext eps anomaly  at T360 it's showing increasing influence of ridging over the UK and eastern Europe and less from the trough to the NW.

Edited February 17, 2015 by knocker

[bluearmy]

And looking at tonight.s ext eps anomaly  at T360 it's showing increasing influence of ridging over the UK and eastern Europe and less from the trough to the NW.

They model is messing around with rising heights in the 10/15 day timeframe but from run to run, poor consistency. I imagine there will be a solution with blocking by mid march but where it establishes remains a mystery.

[Frosty.]

Who said winter is over?...well it isn't, not according to the 18z!

[Polar Maritime]

Yes Karl, Some fantastic Winter charts on offer from the GFS, Winter Marches on..

 

Edited February 17, 2015 by Polar Maritime

[Frosty.]

Yes Pm the 18z is turning into the most wintry run of the day / night with wintry reloads and snow reaching further south at times with some disruptive falls too..hopefully the upgrades will continue tomorrow onwards.

[Eugene]

Models firming up on a vey unsettled end to the winter with frequent bouts of wind and rain for many and snow on higher ground in the north, temperatures overall average at best once we get to Friday, a bit below in the north.

 

Normally we see the atlantic quieten down by late Feb, but not this year, February the wrong way round..

 

Can understand its not everybody's cup of tea, but the outlook is far more interesting than the past 2 weeks and from my own perspective very seasonal with no long draw southwesterlies or southerlies.

 

The ski centres of Scotland will be happy with the outlook.

 

 

Yep thats my mentality, avoid anything toasty, i enjoyed the past two weeks as it wasn't southerly dominated, now its turning cooler again, that high just had to go if all it was gonna do is bring warm air over us like on GFS runs late last week.

[bluearmy]

The latter stages of the ECM look plausible, given the recent ens guidance. Gfs op looks like it doesn't make enough of the Russian ridge and the jet splits too much energy over rather than se. The overall mainly pm flow allows for runners which could bring snowfall on their northern flank.

[shaky]

The latter stages of the ECM look plausible, given the recent ens guidance. Gfs op looks like it doesn't make enough of the Russian ridge and the jet splits too much energy over rather than se. The overall mainly pm flow allows for runners which could bring snowfall on their northern flank.

potential snow event for midlands southern northern england in the short term maybe! ! Low coming up from the south west at 60 hours hitting the cold air already over the mentioned areas! ! Worth keeping an eye on!! Ukmo looks similar to ecm so maybe gfs out of kilter again!!