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

[blizzard81]

But Alaska is supposed to be a frozen wasteland in winter. I'm talking countryside that resembles where we live .......just crazy conditions and it looks like it will keep coming through the month for them.

Would love to feel the extent of that brutal cold but just to make ourselves feel a little better, I don't think they will see much snow - too cold! Lol.

[Cheshire Freeze]

Going to be a interesting FI one way or another...That low exiting the eastern seaboard is actually spinning back NNW whilst sending energy SE. GFS starting to play about in the midterm (especially upstream) which is a sign that changes may be imminent...

 

 

Edit: Nope barrels across on the jet in the end. More of the same into FI, perhaps with some increasing amplitude. Let's see where ECM goes.

Edited February 7, 2015 by CreweCold

[Ali1977]

Some really good Ens in FI...

[Sky Full]

High pressure almost perfectly stationed over the UK on this image

... and then losing identity after 24 hours leading to very quiet conditions indeed...

...but precipitation showing showery activity...

Can anyone help me to understand what is causing the showery activity in this extremely settled situation? Sorry if this is not the correct thread but I am trying to interpret the models....😕

[nick sussex]

Looking at this mornings outputs its hard to see where the UKMO are getting their negative NAO.

 

The ECM once again proved wanting past T144hrs although its idea of low pressure tracking close to the UK next weekend now looks supported by the UKMO.

 

Its however dropped the idea of low pressure cutting into northern France and then goes onto produce charts that for cold lovers are dire to say the least.

 

The ECM T240hrs would get vertigo in a sewer! The GFS plays with a bit more amplitude but waves the white flag pretty quickly. As for the MJO signal phase 8 the outputs are miles from showing any response to that.

 

A few GEFS look more interesting but most if any interest is well past T240hrs, there is one  one member 14 that survived the bloodbath with some interest at T168hrs but even that then sinks without trace.

 

Overall even some highly paid spin doctor couldn't save todays outputs, unless something happens in response to the MJO phase 8 then effectively theres little chance of anything wintry in the next ten days unless something more amplified appears towards next weekend.

 

Earlier though still some chances of some frost and fog as the high edges further east and helps to pull some drier and colder air in from the se.

 

Personally if its not going to be cold then I'd rather it was dry and pleasant, still time of course for things to develop towards the last ten days of February, often a time when you do get something a bit colder but as with last winter the Canadian PV is reluctant to leave home.

Edited February 7, 2015 by nick sussex

[knocker]

Would love to feel the extent of that brutal cold but just to make ourselves feel a little better, I don't think they will see much snow - too cold! Lol.

 

They are not exactly short of snow.

Chart weatherbell

[Paul]

High pressure almost perfectly stationed over the UK on this image

image.jpg

... and then losing identity after 24 hours leading to very quiet conditions indeed...

image.jpg

...but precipitation showing showery activity...

image.jpg

Can anyone help me to understand what is causing the showery activity in this extremely settled situation? Sorry if this is not the correct thread but I am trying to interpret the models....

 

Some models can have a tendency to put unrealistic spotty showers under high pressure, looks like GEM is doing just that on this occasion.

[bluearmy]

Nick, I assume the - NAO must be reflective of the high being centred further north than the means show and close to our west stretching back into the mid Atlantic. I think we can expect it pull back a little from time to time and also to ridge north towards Iceland. It wouldn't be a big neg return. It does allow for the potential incursion we see next weekend. Nothing wintry on offer from these incursions unless we can retrogress upstream a bit and amplify to draw the ridge further west and north. very few gefs members show that but it remains a possibility. Quiet on the whole looks favoured but how convinced are you, especially given the outlier op that ECM threw out yesterday. Clearly that block isn't as strong as it might look. Btw, the control also split the block and dropped another trough in later in the run.

[mushymanrob]

Whilst the ECM  is rolling out I want to highlight the GEFS control.

 

 

Before anyone says I am merely highlighting the chart below towards all those posts saying "Winter is over", "No chance of snow anymore for low lying areas"!!

 

 

GEFS control.png

 

Just add how the ECM differs with regards to the low pressure in the Atlantic between +120 & +168 shows our outlook is far from certain. The ECM has this tracking SE into the Med, other models NE into Scandi!

 

but that chart has 0 chance of verifying as the anomaly charts dont suggest/allow a large scandi high and a strong easterly.

 

i really would urge people to view the anomaly charts first, then view the ops to see which solution is most likely. thats why john holmes has been so accurate as you yourself dave, acknowleged.

the anoms this morning suggest much as they did before.... high pressure sinking to our south, then building in again from the west? (or southwest), which to my untrained eye suggests pretty much what the ops are generally saying... this high drifts off but will be replaced by another over the next 10-14 day period.

compare yesterdays 8-14 dayer and todays (ok im a day out , todays isnt issued until this evening but go with the gist) and that appears to build in high ridging in off the azores ?

 

this morning

 

that does suggest (as has been mentioned) the uk under a nw upper flow, but where the surface air originates will make the difference between tm and pm air, with the high looking close to us, maybe a similar situation to what we have today?... a northern flow but sourced off the atlantic.

Edited February 7, 2015 by mushymanrob

[nick sussex]

Nick, I assume the - NAO must be reflective of the high being centred further north than the means show and close to our west stretching back into the mid Atlantic. I think we can expect it pull back a little from time to time and also to ridge north towards Iceland. It wouldn't be a big neg return. It does allow for the potential incursion we see next weekend. Nothing wintry on offer from these incursions unless we can retrogress upstream a bit and amplify to draw the ridge further west and north. very few gefs members show that but it remains a possibility. Quiet on the whole looks favoured but how convinced are you, especially given the outlier op that ECM threw out yesterday. Clearly that block isn't as strong as it might look. Btw, the control also split the block and dropped another trough in later in the run.

Morning BA, well I'm not convinced by the ECM and the high might end up further north but the overall theme is pretty underwhelming across the models. I thought the positive PNA helped by the MJO phase 8 might just tip things more favourably but unfortunately that Canadian PV chunk remains glued.

 

I shouldn't complain too much its been a lovely week here, the best since February 2012 in terms of cold and snow but I feel for those in the UK who really have once again drawn the short straw.

[fergieweather]

Some models can have a tendency to put unrealistic spotty showers under high pressure, looks like GEM is doing just that on this occasion.

...Plus some higher-resolution models also resolve moisture deposition through e.g. dew, hoar frost etc within their PPN tally. Either way, profiles do show very moist BL conditions next week under very pronounced inversion, with some patchy drizzle in places, mostly via weak (mostly west-facing) upslope forcing.

Edited February 7, 2015 by fergieweather

[TEITS]

but that chart has 0 chance of verifying as the anomaly charts dont suggest/allow a large scandi high and a strong easterly.

 

 

Mushy I only highlighted that chart to illustrate how cold spells remain possible and "Winter is over" posts are too premature. That is all my old mate.

 

Little to say about the model output this morning except they are shockingly poor from a coldies perspective.

[bluearmy]

but that chart has 0 chance of verifying as the anomaly charts dont suggest/allow a large scandi high and a strong easterly.

 

i really would urge people to view the anomaly charts first, then view the ops to see which solution is most likely. thats why john holmes has been so accurate as you yourself dave, acknowleged.

the anoms this morning suggest much as they did before.... high pressure sinking to our south, then building in again from the west? (or southwest), which to my untrained eye suggests pretty much what the ops are generally saying... this high drifts off but will be replaced by another over the next 10-14 day period.

compare yesterdays 8-14 dayer and todays (ok im a day out , todays isnt issued until this evening but go with the gist) and that appears to build in high ridging in off the azores ?

 

814day.03.gif this morning 814day.03b.gif

 

that does suggest (as has been mentioned) the uk under a nw upper flow, but where the surface air originates will make the difference between tm and pm air, with the high looking close to us, maybe a similar situation to what we have today?... a northern flow but sourced off the atlantic.

Rob - I'm a great supporter of the NOAA CPC charts but they are generally going to struggle ahead of any pattern change (the ncep ens are generally a bit slow on board) and also they will not show small detail which will be short lived. If yesterday's ECM 12z was to verify, those charts would look pretty well the same. the broad mean pattern remains the same averaged over a 6 day period.

does anyone have yesterday's 12z op mean heights/anoms 6/10 day charts to see how the ECM looked averaged out compared to the gfs? Wonder how different it looked.

[nick sussex]

In terms of next weekend unfortunately we don't have the normal ECM spreads because Meteociel hasn't updated but going by the standard deviations there suggests some solutions have the high further nw with a spread in the North Sea.

 

This supported by the 850's SD, any colder interlude however looks brief as the high nudges in once again.

[knocker]

Next weekends anomaly charts both put the HP around the SW of the UK with the ECM perhaps a tad further north and west.

Charts courtesy weatherbell

 

[Gibby]

A slight difference in my reports from today as by request of my website viewers who wanted me to include charts within my text so from this morning their wishes have been answered and shared by you folks on the forum too.

 

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS

THE CURRENT GENERAL SITUATION A High pressure to the West of Ireland will persists extending a ridge east across England.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE A lot of benign and quiet weather is expected across the UK with light winds and plenty of cloud but some sunshine or clear spells with some frosts at night especially in the South. Daytime temperatures close to average. Perhaps a short period of less settled weather next week.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows the flow now climbing North of the UK and being maintained there for most of the period though becoming more undulating later as weak Low pressure areas interact with it later on around the UK.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS operational today maintains it's High pressure based them with a slow relaxation of the centre to the SE next week before at mid run it reforms across the UK . Through week 2 the pattern remains quite slow changing with more intervention at times from Atlantic Low pressure especially towards the North and East as a couple of cold plunges of Northerly winds flirt with these areas at times.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run looks broadly similar to the operational with any intervention from the Atlantic brief and flirting in Week 2 with High pressure quickly making a return soon afterwards, centreing across Southern Britain.

THE GFS CLUSTERS The GFS Clusters show an array of options all basing their predictions upon High pressure lying to the South or SW of the UK with NW or West winds. If the High remains close as 40% of members do then it will be mainly dry but there is some shift of emphasis towards a more unsettled theme from the West or NW by the end of the run.

Gfs Clusters

UKMO UKMO this morning shows High pressure drifting slowly East across the UK next week and away slowly to the East. By the end of the run at Day 6 a deepening Low pressure area over the North Atlantic shows signs of bringing a more unsettled and windier spell by next weekend.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts show High pressure slowly shifting East across the UK and on into Europe leaving slack winds from the South or SE over the UK by the middle of next week.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM shows the UK based High slipping away into Europe through next week and followed by a strengthening West to NW flow as Low pressure develops to the North. The end of the run in 10 days time shows the UK bathed in a strong Westerly flow between High pressure to the South and Low to the North with troughs delivering rain at times to Northern areas in particular.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM also shows High pressure slipping away East through next week with benign conditions over the UK maintained as a result. A brief more changeable period is shown towards the end of the period as Low pressure to the North throws a trough East over the UK with some rain for all.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM continues to show High pressure moving away East next week as an active trough crosses the UK later in the working week. Pressure becomes High again close to the SW at the end of the run with a strong Westerly flow and occasional rain likely then over the North.

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

ECM 10 DAY MEAN The 10 Day Mean this morning indicates that High pressure will most likely lie to the South of the UK late next week and beyond. Conditions will be fairly typical of a Westerly flow over the UK in that the South will see the best of the dry and fine weather while the North will be more at risk of troughs from the Atlantic delivering rain at times in a stiffer Westerly flow.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The only notable trend shift this morning revolves around the extent of an interruption to the fine weather late next week as it looks increasingly likely that a trough or Low pressure will move east across the UK towards next weekend.

MY THOUGHTS Only small scale changes to report within the outputs this morning with High pressure continuing for the most part to drive the weather across the UK. In the 4-6 day term only small changes day to day are expected at the surface all centreing on amounts of cloud determining what levels of bright sunny spells we will get by day and clear spells with resultant frost by night. What is certain that there will be very little rainfall as pressure remains very High until at least later next week when models seem to be firming up on something of a hiatus in the fine weather as an active trough crosses West to East over the UK giving rise to a spell of windier and wetter conditions. However, it looks unlikely to last long as those models that show it go on to bring High pressure back close to the South of the UK and bring back a lot of fine weather by the end of next weekend. It then looks like something of a North/South split might develop with stronger Westerly winds over Northern areas perhaps bringing more changeable weather there while the South maintains fine if rather cloudy skies. Temperatures overall look like being close to average for many but perhaps a little below in the South under any prolonged clearer conditions however having said that there is little sign of anything significantly cold on the horizon with the Jet Stream programmed to remain near to the north of the UK on the Northern flank of high pressure longer term and any cold restricted to any clear frosty skies by night tempering the diurnal warming of daytime temperature values.

Issued at 08:30 Saturday February 7th 2015

Edited February 7, 2015 by Gibby

[Summer Sun]

The ECM ens isn't as keep as the Op to bring in the low later next week

 

Op

 

 

Ens

 

 

Unfortunately the GFS 10 day precip charts have gone back to 1979, 1980 & 1981 this morning so Its not worth posting them unless you wish to time travel back to the late 70's and early 80's.....

[johnholmes]

Rob - I'm a great supporter of the NOAA CPC charts but they are generally going to struggle ahead of any pattern change (the ncep ens are generally a bit slow on board) and also they will not show small detail which will be short lived. If yesterday's ECM 12z was to verify, those charts would look pretty well the same. the broad mean pattern remains the same averaged over a 6 day period.

does anyone have yesterday's 12z op mean heights/anoms 6/10 day charts to see how the ECM looked averaged out compared to the gfs? Wonder how different it looked.

not true ba, that is why they often consistently show such a thing, note the word it is significant. IF they are not consistent, across all 3 I use, for 2 preferably 3 outputs then NOAA is usually neaer to the actual upper flow 6-10 days on but it needs taking with a pinch of salt. Only if all 3 are pretty similar then they will show the continuation of a pattern OR a change in pattern just as well. If the 8-14 looks a decent pattern based on the 6-10 and especially if it fits the MJO idea then it will pick out changes at 8-14 days.

I certainly wish I had it to hand in my days of forecasting, sometimes my views disagree with UK Met beyond 15 days but in the 6-15 it is not usual. Okay we all get it wrong at times but, and I know some others don't agree, I find it the most reliable output I can get free for working out the 6-15 day, sometimes a few days further what the upper pattern is going to be. The ever so clever bit, as it always has been in forecasting is then to get the surface pattern correct in the UK area.

As for the anomaly guidance at the moment, ECMWF and GFS are varying from one day to the next, NOAA seems fairly solid both in the 6-10 and 8-14 day pattern, see below.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

I said 24 hours ago they left a 'slight' probability of maybe a mini type outbreak of deep cold from a N'ly point, but no more than a 25% and this still holds in my view, perhaps 35% after about 10 days?

[Polar Maritime]

I said 24 hours ago they left a 'slight' probability of maybe a mini type outbreak of deep cold from a N'ly point, but no more than a 25% and this still holds in my view, perhaps 35% after about 10 days?

 

The GFS 0z is certainly toying with this idea John.

 

Edited February 7, 2015 by Polar Maritime

[Captain Shortwave]

Disagreements again at day 6 today

 

GFS

 

UKMO

 

ECM

 

The Euros more keen on introducing an more unsettled spell from the end of next week. The GFS remaining stubborn on high pressure remaining solidly over the UK. So the Euros are being more progressive with the Atlantic for a change.

The GFS ens more in line with the GFS op 

ECM ens 

Similar to the GFS ens in fact.

So the UKMO and ECM ops seem to be on the progressive side of the suite overall this morning. No real sign of a potential cold outbreak, more a case of settled vs a brief spell of more unsettled weather for the UK.

[polar vortex]

From my experience the anomaly charts are not always first to the party when it comes to pattern 

changes. Taking them in isolation is not a good practise. Expecting to see a growing trend in mid

to long range for more amplified and much colder northerly incursions.

[bluearmy]

not true ba, that is why they often consistently show such a thing, note the word it is significant. IF they are not consistent, across all 3 I use, for 2 preferably 3 outputs then NOAA is usually neaer to the actual upper flow 6-10 days on but it needs taking with a pinch of salt. Only if all 3 are pretty similar then they will show the continuation of a pattern OR a change in pattern just as well. If the 8-14 looks a decent pattern based on the 6-10 and especially if it fits the MJO idea then it will pick out changes at 8-14 days.

I certainly wish I had it to hand in my days of forecasting, sometimes my views disagree with UK Met beyond 15 days but in the 6-15 it is not usual. Okay we all get it wrong at times but, and I know some others don't agree, I find it the most reliable output I can get free for working out the 6-15 day, sometimes a few days further what the upper pattern is going to be. The ever so clever bit, as it always has been in forecasting is then to get the surface pattern correct in the UK area.

As for the anomaly guidance at the moment, ECMWF and GFS are varying from one day to the next, NOAA seems fairly solid both in the 6-10 and 8-14 day pattern, see below.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

I said 24 hours ago they left a 'slight' probability of maybe a mini type outbreak of deep cold from a N'ly point, but no more than a 25% and this still holds in my view, perhaps 35% after about 10 days?

I probably haven't got my point across john. Because they are 6 day means and because they are further smoothed out by being cross model mostly ens mean representation, they will generally fail to show the depth of the likely pattern change. Ie - ridge or trough not emphasised enough. So just looking at them, one could get an impression that we will see a shallow trough or ridge when the truth is going to be something far stronger. This is, of course in the 8/14 day timeframe. We see enough of the ECM ens spreads and gefs in detail to make our own calls on the 6/10 day period.

they are, the best tool that us mere mortals have to make a broad call on the two week outlook.

[Nouska]

Next weekends anomaly charts both put the HP around the SW of the UK with the ECM perhaps a tad further north and west.

Charts courtesy weatherbell

 

The EPS show it to be such an outlier that it will not show up on the mean charts.

 

last night and this morning.

 

12Z    00Z 

[summer blizzard]

Return to normality on the 6z..

 

[bluearmy]

Although in deep lala land and with a few gefs having shown support on each suite, the back end of the gfs op is indeed a thing of synoptic beauty for coldies.

Judging by the gefs members, you won't see the like for another 24 hours at least!

And amidst all the certainty, Shannon is back for one one day only!

Edited February 7, 2015 by bluearmy