Model output discussion 25th Jan onwards

[Methuselah]

Welcome to NW Eastwoods... 

[phil nw.]

While it is quiet in here I will chance my first post. I would just like to thank all the posters in here for their contributions to this thread during what has been a fascinating winter weatherwise albeit poor for cold/snow, the instructive commentary of the models by yourselves has been excellent,informative,useful and humourous. For the professionals amongst you a special thanks as that extra insight from the products not available to most is invaluable plus my scrabble scores have increased no end(snowballz).

I do still hope that the weather is not as severe as progged for those areas already struggling with flooding and that maybe we can get a more settled looking output from the models over the next couple of weeks, perhaps even a "WTF" moment from IB,anyway thanks again and back to lurking!!!

Hi Eastwoods,

Welcome to the forum.

I am sure your positive comments are appreciated by all.

I hope you continue to find the thread useful and eventually feel you can add your views on the charts.

[Paul_1978]

Well the Atlantic onslaught seems unprecedented......or is it? When was the last time we had low after low after low after low barrelling towards us over a period of a number of weeks?

Mr Data (Weather-History) is sure to know. I can't remember a period like it.

[Mark Neal.]

Well the Atlantic onslaught seems unprecedented......or is it? When was the last time we had low after low after low after low barrelling towards us over a period of a number of weeks?

Mr Data (Weather-History) is sure to know. I can't remember a period like it.

 

December 2013-January 2014    18z coming out... Not much of hope for us coldies/snow lovers now but plenty of weather to happen this week. Some largely unusually powerful low pressure systems spawning in the Atlantic and cutting right through us not gonna be pretty with all models showing rinse and repeat scenario. There is a little window on Friday for potential of back edge snow with cold uppers and lower dew points there could be some snow for some southern areas that however is 6 days away and many model runs before then to enroll..

 

I'd happily for once in my life at this time of year take the Azores to pay us a visit... It really is a worrying time for many of the SW and other areas. 

Edited February 1, 2014 by Mark N

[Mapantz]

Well the Atlantic onslaught seems unprecedented......or is it? When was the last time we had low after low after low after low barrelling towards us over a period of a number of weeks?

Mr Data (Weather-History) is sure to know. I can't remember a period like it.

 

^ DOH! Mark beat me to it.

 

December 2013

Edited February 1, 2014 by Mapantz

[Weather-history]

Mr Data (Weather-History) is sure to know. I can't remember a period like it.

Autumn 2000, I don't think this winter will top those rainfall totals at the national level.

[mountain shadow]

Tamara, your post regarding the PNA confuses me. It seems to say that neither a positive PNA nor a negative PNA assists in bringing cold air to here.

Therefore isn't the PNA phase irrelevant to our weather?

[Staffordshire]

The fact no words have been spoke about the 18z, itself, speaks many words....

[Fred Sykes]

18z = wet and windy

[john pike]

fax chart for 96 tonight

 

the south - south east and south west

 

very strong winds

 

heavy rain scattered throughout the uk

 

lets hope for downgrades on this

Edited February 1, 2014 by john pike

[kumquat]

I count six deep lows (some are powerful secondary lows spawning off the main mamas) in the next 384 hrs on the 18z on a collision course with Southern UK (and Eire, of course). With what we've had already it's not a good picture.

 

Edit: BTW - great post earlier by Tamara giving the low down on the longer wave teleconnections affecting our current (and, unfortunately, future) predicaments. 

Edited February 2, 2014 by kumquat

[syed2878]

as a fan of snow and cold the model runs over the last few days hasn't been inspiring. However the nwp has been giving us alot to talk about and at times even gave pro forecasters a head scraching moments. Again all outputs today showed the salvos the atlantics going be firing at us and has been since dec 2013. Now all u good folks down in the south west take care and most of all keep safe. Interestingly some of the models showing there could be chance of back edg snow for friday 6day's away. Before that we have alot of weather to get thru before we even think of those snow chances.

[shaky]

Ecm sends that low pressure at 120 houre further south now!!well done to ukmo amd gfs on that one cos if you compare todays 120 hour chart to yesterday mornings ecm 144 hour chart you will see how much further north ecm had it!

[Weather-history]

The irony is that we didn't want the Azores high to ridge northwards so lows could go underneath the block, now the block seems to be disappearing and when we want the Azores high to ridge northwards to decrease precipitation amounts, it's nowhere to be seen!

[bluearmy]

The irony is that we didn't want the Azores high to ridge northwards so lows could go underneath the block, now the block seems to be disappearing and when we want the Azores high to ridge northwards to decrease precipitation amounts, it's nowhere to be seen!

The extension of the Canadian vortex into the n Atlantic suppresses the Azores ridge. The upcoming 10 days certainly look concerning to say the least and some of these systems originating way south in the Atlantic will carry more moisture - add to that the thermal gradient across them, contributing further to the amounts that may fall from the sky.

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

looking horrible  plenty of rain heading our  way  but     in  f1  by Feb 15  could be  under  snow by then well we can dream !!

[johnholmes]

The extension of the Canadian vortex into the n Atlantic suppresses the Azores ridge. The upcoming 10 days certainly look concerning to say the least and some of these systems originating way south in the Atlantic will carry more moisture - add to that the thermal gradient across them, contributing further to the amounts that may fall from the sky.

It is this eastward lobe of the Candian main trough/vortex that has been the main governing feature of the upper air pattern for 10-12 days and it, according to the anomaly charts, shows little sign of changing in any major fashion so far as I can see for another 6-15 days. Been away so my data is a bit sketchy but will do a fuller update later today after time to check things more thoroughly.

below is the latest ec-gfs output this morning

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

and below this the NOAA 6-10 and 8-14 from last evening

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

now anyone looking at those 3 sets of charts and having access to data from 7-10 days ago may notice not much change. There has been some minor shifts but nothing, for cold/snow lovers, that suggests any major pattern change.

Nor does it look any better for the awful situation so many folk continue to have to endure for flooding and wind effects, or so it seems to me. I will do an in depth look sometime later today not only with the anomaly charts.

Edited February 2, 2014 by johnholmes

[IDO]

The GEFS at T300 are all zonal, the degree the flow slips north allows some to have temporary ridges for the far south but overall looking like an extended period of wet weather with no cold. There are none showing a MLB let alone any signal for a HLB. The mean:

 

 

By T384 that propensity to have transient ridges is still there, slightly more common with a trend to edge slightly further north, but we are really clutching at straws as the flow remains Atlantic dominated (95%).

 

Nothing of interest on London ens, no cold: 

 

They continue to show the slacker flow in week 2, less rainfall spikes, so a modicum of respite.

 

The GFS op struggles with the block on this run and the LP system next Saturday stalls over the UK and remains in situ for 4-5 days as the following LP's slide into it:

 

Saturday:   Wednesday: 

 

That appears to be due to pressure rises in SE Europe linking with the Russian/Siberian High and stalling the Atlantic.

 

Certainly this is a signal on the GEFS as the mean at T200 show: 

 

GEM also sees this with a log jam close to the UK at D9: 

 

ECM thinking that way, but less intense: 

 

So just when you thought it couldn't get worse, not only is the Russian high wasting 7 more days with a holding pattern, we have further height rises to our SE, also delaying the flushing of that PV build up to our NW. You just know this winter was not meant to be.

Edited February 2, 2014 by i'm dreaming of...

[Gibby]

Good morning. Here is the report on the outputs of the NWP based on their midnight outputs on Sunday February 2nd 2014 and featured on my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models continue to show a very volatile and mobile setup across the UK through the coming week. With winds from between South and West through the week and Low pressure areas and trough moving across the UK tomorrow, Wednesday and again towards the weekend over the South there will continue to be spells of sometimes heavy rain coupled with strong winds which could reach severe gale force on Wednesday as a particularly deep Low speeds NE across the UK through the day. The rain will be heaviest in areas adjacent to the wind, especially the high ground of the South and West. In between the main rain bands brighter or clearer air with blustery showers will occur most likely over Tuesday and Thursday with temperatures largely near average for all but perhaps rather chilly at times over the North where some mountain snow is likely.

 

GFS then moves through next weekend with no changes with further windy spells with heavy rain at times as Low pressure remains close to the NW. Through the latter stages of the output the weather remains very volatile and Atlantic driven with yesterday's improvements muted today with further low pressure areas maintaining the wet and windy theme right out to the end of the run for all in average temperatures.

 

The GFS Ensembles today show continued very changeable conditions preferred over the period with a lot of rain possible for a good portion of the run though perhaps a trend towards less rain by the end of the run. The recent strong milder surge in uppers have been scaled back this morning with the likelihood of more average temperatures at the surface being most likely for all areas for the next two weeks with solid agreement from most members.

 

UKMO shows the end of the week and start to next weekend with a new depression rattling in towards Western Ireland bringing another set of troughs in from the SW to all areas by the end of Saturday with rain and strong winds followed by showers the likely sequence of events through the day for the UK.

 

GEM today shows deep Low pressure areas continuing to cross the UK next weekend and the start of the second week with more very heavy rain and gales all too frequently affecting all areas with the West and SW continuing to suffer the worst of the conditions with wind too newsworthy too at times.

 

NAVGEM shows a vicious little Low crossing Southern England next weekend with very heavy and prolonged rainfall moving East over the day and followed by more unsettled and windy Westerly breezes with further rain and showers in very average temperatures.

 

ECM today has removed the hint of somewhat drier conditions late in the run and replaced it with a continuation of wind and rain at times, sometimes heavy and prolonged at times as the run continues to show areas of Low pressure and fronts running in from a very active Atlantic Ocean.

 

The ECM 9 and 10 Day Mean Charts have deepened the trough still more over the UK in 9 and 10 Days time with undoubtedly no chane in the wet and windy wether under Low pressure to the North and West late in its run so no improvent from this model.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

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

 

The Jet Stream continues to pump Eastwards over the Atlantic and across Southern Britain and Northern France and apart from temporary and slight migrations away from this pattern as Low pressure areas wax and wane over the UK little overall change is shown that would in any way release the UK from the current wet and windy theme.

 

In Summary the weather remains locked in this pattern of wet and windy weather which is rapidly heading towards the wettest winter of all time if we continue down this never ending tunnel of Low pressure through the periods covered by this morning's output. The amounts of rain and wind remain rediculously high again this morning with absolutely no chance of the very short drier interludes between the rain areas being long enough for any alleviation in conditions to flooded areas before any improvements are removed by the next storm but unfortunately that's how it looks again this morning. Winds too feature strongly at times with severe gales likely at times giving rise to their own disruptive recipe almost anywhere. The one consolation that while these conditions prevail there will be little or no risk from snow with ice, frost and fog no more than a local issue on the rare occasions when clearing skies between systems overnight allow patchy ground frost to be possible.

[bluearmy]

It is this eastward lobe of the Candian main trough/vortex that has been the main governing feature of the upper air pattern for 10-12 days and it, according to the anomaly charts, shows little sign of changing in any major fashion so far as I can see for another 6-15 days. Been away so my data is a bit sketchy but will do a fuller update later today after time to check things more thoroughly.

below is the latest ec-gfs output this morning

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

and below this the NOAA 6-10 and 8-14 from last evening

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

now anyone looking at those 3 sets of charts and having access to data from 7-10 days ago may notice not much change. There has been some minor shifts but nothing, for cold/snow lovers, that suggests any major pattern change.

Nor does it look any better for the awaful situation so many folk continue to have to endure for flooding and wind effects, or so it seems to me. I will do an in depth look sometime later today not only with the anomaly charts.

 

that lobe has waxed and waned over the past few weeks john and each time it waxed, it threw out another piece of low heights into the n atlantic which put pressure on the block. the difference now is that we see a persistent lobe of the vortex driven out to sit in the n atlantic which, in effect, sounds the death knell for the blocking as it cannot rebuild between the waxing/waning.

[Nick F]

At least the deep secondary low that the models threatened southern Britain with later in the week has now been shunted south across France, for now, though needs to be closely watched. UKMO had it much further south than GFS and EC yesterday, incidentally.

 

Wednesday's deep low shown to be past its deepest phase too as it continues to fill while tracking NE across Ireland and Scotland, but GFS still shows a swathe of 60-70mph(+) gusts across many areas Tuesday night with frontal system moving through ahead of the low, strong winds across the southern flank of low as it arrives after - but winds not as bad as shown on earlier runs. The rain and frequent showers this system brings more of an issue inland, though big Atlantic swell this storm generates could bring more coastal flooding in the west.

 

Another potential deep low threatening NW Britain for next weekend on the big three models. 

 

Trying to find a glimmer of light at the end of the tunnel and all I can find is an increase in +ve height anomalies across Greenland on the 00z EC H500 anomalies for 8-10 day period, but the low heights and zonal flow stretching from Alaska across Canada all the way into N Europe still prevails:

 

Edited February 2, 2014 by Nick F

[summer blizzard]

After 7 consecutive operational runs the 18z last night dropped the pressure build from the 13th, the 0z has followed it.

 

Are there any ensembles still going for such a pressure build.

[Summer Sun]

Hints again from the ensembles of less rain as we get towards mid month

 

[bluearmy]

With the northern half of scotland sitting north of the pfj over the next two weeks, we could see some impressive depths of snow over the hills by the time this disturbed period relents.

Signs that in around a fortnight, the mean torugh will have worked its way east to sit across the uk. in the meantime, mean slp on the ecm ens fails to raise above 1000mb across the uk. The flooding by mid month likely to be the story. Through week 2, upstream looks to try and stretch the n american vortex from hudsons to alaska which will hopefully mean less energy to be thrown east into the n atlantic. I wonder if this possible slight easing in the n atlantic jet will allow it to buckle somewhat to our west as the mean trough edges east.

[cooling climate]

Although stuck on t192 the GFS 06z chart clearly shows the effects of

wave 2 strat warming filtering down into the troposphere.Can not

remember when I last saw high pressure where the vortex has sat most of

the winter.

FI starting to look a lot colder than we have been use to with lows

tracking further south and higher pressure then trying to ridge north.

Of course by this time we are into the middle of February and to have

laying snow you really need the colder uppers but I feel that we are

beginning to see a positive feed back of the warming in the strat down

into the NWP models. Hopefully this will now continue in future runs and

we will see an increasingly colder outlook for around the middle of February

onwards.

Edited February 2, 2014 by cooling climate