Model Discussion - 10th March Onwards

[johnholmes]

I always can find something of interest on the weather front-one does not have to restrict information, actual or forecast to this country to find something of interest.

The weekend has been an interesting exercise hardly mentioned on the model thread. The two models we see rainfall totals for have had a bit of a struggle at times before they now seem to have come to agreement of when/where and how much. Looking at the Met Fax charts has been quite illuminating as the changes on the cold front caused Exeter to alter the shape, position and movement over the last 3 days.

Its a bit sad when the only real interest shown on this and other forums is for cold and snow or heat and storms-still each to their own.

Edited March 16, 2012 by johnholmes

[Krakatoa01]

You don't work for the met anymore john so I think it's fair to say many of us would pay more credence to the met offices 32 day opinions to your own. Just a bit of perspective for you. Something to think about before you post dude

Just a quick psychological breakdown. "I restrict "MY" forecast to 20 days. Don't talk like you know more than the met. You don't.

see my post in the model thread in response to the same post you made as the one here

see my post in the model thread in response to the same post you made as the one here

Sadly I do not have access to the ECMWF 32 day outlook. I have to say though there have been, to my recollection, at least a couple of changes suggested by folk with access to it which have not come to fruition. Its not infallible just like any other model or human forecast.

I restrict my outlooks to about 20 days, a bit beyond the 500mb anomaly outputs.

Taking the last 5 days or so, which take us out to the end of March, and there is little to suggest an upper ridge being anywhere other than either over or close by the UK, east/north east of, not west or north west in that time scale.

The overall predicted movement of the +ve 500mb anomaly IS west of north though over the past 5-6 days. Maybe this is something the ECMWF longer outlook is taking and expanding on?

Edited March 17, 2012 by Krakatoa01

[andy100]

I love cloudy highs

[johnholmes]

wow-nothing since 0012-the 2 posts deleted

Looking 10-15 days ahead and there are some interesting things happening on the 500mb anomaly charts. Noaa changes little last evening from its last outputs over about the last week.

Changes are showing in the ECMWF and GFS output though.

This morning ECMF has the Atlantic trough as a disrupted centre around 30 west with GFS keeping it as a marked trough around 40 west. The ridge to the east also has differing positions for its centre of gravity, them having about 10 degrees difference in longitude.

Beyond the Atlantic trough and even more differences, as one would expect with their trough treatment, so some degree of uncertainty creeping in on the outlook for the genral weather pattern in this time scale. It will be interesting to see how all 3 look in about 3 days time.

My own view, for what its worth, is that as the upper ridge is very slowly nudged NNW this will allow the Atlantic trough, aided by events upstream of it, to edge/move east. Possibly in some kind of elongation SE'wards, maybe even as ECMWF is hinting at this morning, as a cut off feature. Thus the flow would be unblocked for southern areas and less settled as a result with the blocking and more settled weather tending to transfer further north. If it does happen then southern areas may see some welcome rain. How cold it might get is also something to watch although its way way too far ahead to really think about that.

links to NOAA 8-14 and ECMWF-GFS are below

http://www.cpc.ncep....10day/500mb.php

Not sure why but i get about 2 out of 3 times a message saying it will not load?

http://www.meteo.psu...0z/hgtcomp.html

Edited March 17, 2012 by johnholmes

[coldwinter]

GFS looks to bring in the potential for some thunderstorms next weekend as warmer air is drawn up from Africa next weekend as the air is quite unstable. Temperatures could be upto 18 or 19C, the strength of the sun should begin to really show soon.

Ryan.

[Summer Sun]

GFS has high pressure dominating for the next 2 weeks tonight

Looks like next weekend could be nice and warm for a good few, will be even better if the sun could get out

[Geordiesnow]

The models are indicating a sort of half and half spanish plume type set up where we get some unstable thicknesses embedded in the flow and the risk of some rain(perhaps thundery?) heading for more South-Western areas, not convincing admittedly but again something to keep an eye on.

Before that, a mostly dry week coming up but as per ususal western Scotland does appear an exception but as I stated yesterday, Western Scotland may finally get some useful sunshine later on in the week if the high positions itself correctly allowing a more ESE'ly-SE'ly flow coming.

[Milhouse]

Some differences emerging in the placement of the high for the end of next week and into the weekend. The UKMO has a more north-south tilt to the high which would bring warm and fairly settled conditions to much of England and Wales. Although there would be the threat of showers breaking out the further west you are.

The GFS/ECM bring easterlies so the warmth would be restricted to southern and western parts while the east coast would be cooler and prone to north sea mist and low cloud. Both models bring the chance of some convective potential moving northwards next weekend.

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

http://www.wetterzentrale.de/pics/Recm1441.html

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

[damianslaw]

Just 5 posts today - preety low it has to be said at anytime of year. Saturday does tend to be the quietest day in the thread mind.. but not normally this quiet.

I've been sporadic in my postings over the past 2-3 weeks largely because the outlook has been so benign with nothing particularly interesting to discuss. Sure enough the next week looks to see high pressure once again taking hold of things quietening things down - but there are hints of convection taking hold in southwestern areas as we begin to bring in some unstable warm air from the south - thanks to cut off low feature and splitting of the trough, remains to be seen whether SW parts turn unsettled by the end of the week as we see heights building strongly to the NE as opposed to lingering across the centre of the country as they have done this week.

Before then we will see some unsettled conditions for northern parts - as further fronts make inroads early next week.

Longer term - both ECM and GFS suggesting heights will slowly advect NW in time as we head towards the end of the month, could this be the suggested pattern change thanks to the PV finally moving away from East Greenland. Very plausible and perfectly normally for the time of year, April is renowned for its could northerlies! (last year was an exception) and I am sticking my neck out here by saying this April could be notably chilly and increasingly wet. Meto forecast suggesting a chilly unsettled start to April - yes its a long way off, but its a long time since we have been looking at the potential of colder and wetter than normal conditions - last summer was probably the last time! - early feb though cold was dry and most of our wet weather since last summer has been associated with mild southwesterly/westerly airstreams and only very shortlived polar outbreaks at times in Dec mostly reserved for the north. The anomalous warmth has to break at some stage.

[Chris K]

With regards to possible convection type weather near the end of the coming week, the most recent meto fax charts look interesting for T+96 and T+120 (see attached - T+120 being left image, T+96 right). If this was to happen, would there be a possibility of a thundery element within those fronts as the low moves up from Spain & the Bay of Biscay? I guess if it was mid-summer with more heat available from the continent, this setup could of been very exciting?

Edited March 18, 2012 by Bugganuts

[bluearmy]

With regards to possible convection type weather near the end of the coming week, the most recent meto fax charts look interesting for T+96 and T+120 (see attached - T+120 being left image, T+96 right). If this was to happen, would there be a possibility of a thundery element within those fronts as the low moves up from Spain & the Bay of Biscay? I guess if it was mid-summer with more heat available from the continent, this setup could of been very exciting?

and if it were 4 weeks ago, it would be even more exciting !! ever more evidence in the longer range ens that the main part of the decaying p/v will transfer from northwest of greenland towards nw siberia/northeast of scandi. i have been thinking about a chilly easter period for a while now and i think the nwp is beginning to settle on an evolution towards this. very early days yet but the dropping of heights towards the azores in the next week with the trough digging well south is something we haven't seen for a fair while. lets hope the azores high fights back yet again and pushes any mean flow north of west well to our east.

[Polar Maritime]

After the much needed rain this weekend the GFS is showing High Pressure takeing over once again, giving us pretty much a repeat of last week with some warm sunshine and settled conditions throughout with no notable rainfall showing untill the end of the month. Things could turn much more interesting according to the CFS during April with more unsettled colder N N/E winds showing. Somethings got to give sooner or later.

[Snow Shoes]

and if it were 4 weeks ago, it would be even more exciting !! ever more evidence in the longer range ens that the main part of the decaying p/v will transfer from northwest of greenland towards nw siberia/northeast of scandi. i have been thinking about a chilly easter period for a while now and i think the nwp is beginning to settle on an evolution towards this. very early days yet but the dropping of heights towards the azores in the next week with the trough digging well south is something we haven't seen for a fair while. lets hope the azores high fights back yet again and pushes any mean flow north of west well to our east.

Given the sustained drought we're currently experiencing here in the South, I think we should be actively welcoming, not mourning, any potential retreat of the Azores high and putting any IMBY "hopecasts" firmly on hold

[ANYWEATHER]

Given the sustained drought we're currently experiencing here in the South, I think we should be actively welcoming, not mourning, any potential retreat of the Azores high and putting any IMBY "hopecasts" firmly on hold

Totally agree. The 18 month dry spell in the SouthEast of the Uk looks like going on for some time yet after todays welcome rain for some. Mr High Pressure controling our weather for the forseeable future according to the Model outputs. Encouraging signs though, from the Cfs model of a big pattern change , with some unsettled and above average rainfall for those who are so dry now , in the month of April and beyond. Until then its a matter of chasing the Clouds!!! :lazy:

[bluearmy]

Given the sustained drought we're currently experiencing here in the South, I think we should be actively welcoming, not mourning, any potential retreat of the Azores high and putting any IMBY "hopecasts" firmly on hold

from a strategic perspective you are right. you will not find solace in the latest NAEFS update which, in FI, is 'plus ca change' with the vortex stuck west of greenland, a western russian trough and a ural ridge. the azores high ridging towards nw europe. spread, though, is high across the NH.

[Alex]

As long as any pattern change into April consisting of rain and cool weather doesn't last into summer I will be content.

However its worth mentioning the GFS 00z backed away from any pattern change within the realms of its run.

[Summer Sun]

Looks like by the end of this week the high should bring in some nice warm weather for many

I wouldn't rule out 20c somewhere next weekend if the sun is out of any prolonged periods

[Scorcher]

Yes GFS showing temperatures widely into the high teens for central and western parts by the end of the week, also looks good for the south coast with the winds being more easterly. However I for one am not getting my hopes up this time after last week's debacle, just keeping my fingers crossed for more sunshine and warmth this week.

[summer blizzard]

The models once again look great, high pressure all this week with no rain and abundant sunshine.

Stratosphere still with a cold wedge at 10hpa preventing down-welling of any final warming so i do not see a major change anytime soon.

Ensembles say it all really..

[MP-R]

Ugh, my interest in weather is really being tested now - when will this boring drivel end!

Right, that's that off my chest. GFS 06Z showing a dry picture for next week but I don't think it's quite as a clear cut as just sunny and warm everywhere. A few 'T's seem to dotted around the place by the end of the week ensuring it won't be a simple dry and warm picture. Cloud amounts will vary, sunshine will often be hazy with air increasingly coming from the south and with a 52% chance of a storm for Bristol on Friday and Saturday, nobody can rule out the odd shower.

Beyond that is of course FI and there are tentative signs of a pattern change so maybe a more traditional April showers scenario as the final week of March arrives. Bring on the 12Z.

[mulzy]

Ugh, my interest in weather is really being tested now - when will this boring drivel end!

Right, that's that off my chest. GFS 06Z showing a dry picture for next week but I don't think it's quite as a clear cut as just sunny and warm everywhere. A few 'T's seem to dotted around the place by the end of the week ensuring it won't be a simple dry and warm picture. Cloud amounts will vary, sunshine will often be hazy with air increasingly coming from the south and with a 52% chance of a storm for Bristol on Friday and Saturday, nobody can rule out the odd shower.

Beyond that is of course FI and there are tentative signs of a pattern change so maybe a more traditional April showers scenario as the final week of March arrives. Bring on the 12Z.

Why is this boring? Probably the most appreciated type of weather expected over the next week or so - warm(ish), sunny and dry.

Yes, there is a worry that like last year we may waste these superb synoptics in the wrong months, but as far as I'm concerned bring it (warm and sunny weather) on!!

[ukpaul]

Why is this boring? Probably the most appreciated type of weather expected over the next week or so - warm(ish), sunny and dry.

Yes, there is a worry that like last year we may waste these superb synoptics in the wrong months, but as far as I'm concerned bring it (warm and sunny weather) on!!

I doubt that anyone here in the south east who understands the situation wants dry weather anymore, I suppose many don't look beyond the next day forecasts so imagine that rain is around the corner though, so they don't really understand the full picture.

I sometimes wish that the broadcast forecasts gave an idea of a fortnight ahead so people could see what we can extrapolate from the models, I know they don't want to be seen to be wrong but some indication is useful and puts the print media froth into perspective. The GFS accumulated rainfall for the South East is just shockingly low, all going into Southern France instead.

[Thundery wintry showers]

This sort of weather tends to be good for outdoor activities (especially in the areas that see sunshine) but on the other hand settled weather by definition lacks variety, hence the way some find it boring, so there's a case for both points of view really. I'm not convinced that most parts of the country will be especially sunny during the working week but sunshine amounts do look set to increase generally as the week progresses.

Sunshine will probably be quite limited for many during Monday and Tuesday, because a tropical maritime airmass on the northern flank of the high will send a lot of moisture in off the Atlantic. There will also be some light rain and drizzle in western Scotland and Cumbria and possibly the western Pennines and western Welsh mountains. By Wednesday we will lose the supply of moist Atlantic air as the winds swing around to the south, so sunshine amounts will probably increase although it didn't really work that way last week (the cloudiest days were actually the two days after the moist Atlantic airflow was replaced by more of a southerly).

There is strong model agreement that we will draw in more of a continental influence from Thursday onwards than we saw during the previous anticyclonic spell. Therefore it will probably become sunny in central and western areas with warm daytime temperatures but with increased chance of low cloud heading into districts bordering the North Sea. Beyond the end of the week the models differ with the ECMWF going for a sustained easterly flow, probably meaning sunny and warm in the west but cloudy in the east, whereas GFS and UKMO keep more of an anticyclonic/southerly type which would mean plenty of warmth and sunshine for most. The ECMWF ensemble mean is more in line with UKMO/GFS, so it remains to be seen whether the operational will back down tonight or stick to its guns.

[MP-R]

Why is this boring? Probably the most appreciated type of weather expected over the next week or so - warm(ish), sunny and dry.

Yes, there is a worry that like last year we may waste these superb synoptics in the wrong months, but as far as I'm concerned bring it (warm and sunny weather) on!!

Had we had seasonal weather leading up to this week, I may possibly be welcoming a change but as it's been like this pretty much since the end of January, it's getting quite testing. The main problem is that the highs all look cloudy, last week's 'sunny' high was in fact cloudy and certainly this week looks much the same in reliable timeframe. Give me sunshine and active showers any day - emphasis on both rain and sun rather than cloud and dry.

The models themselves seem to show a lot of the rain diving into France and Spain, much like last spring with bits and bobs flirting with the northwest when pressure falls slightly here.

[phil nw.]

This coming week does look predominantly dry except perhaps for the north west of Scotland where Atlantic fronts continue to edge close by at times.

It will be quite pleasant for outdoor activities especially when clearer drier air moves in from the continent as the week goes on bringing with it more widespread sunshine.

Yes the drought goes on but it is what it is and if spring sunshine floats your boat then some days this week look quite promising.

http://www.wetterzen...ics/Rukm721.gif

It`s a little early to be certain but the indications of heights situating further north or north east towards the end of March is being suggested by MJO forecasts and later frames of the daily model runs.

So maybe something cooler with an easterly element to the flow as we start April.

Edited March 18, 2012 by phil n.warks.