Model Output Discussion

[johnholmes]

One thing I would love to see in Model Chat on this forum is an absence of this descriptive bias applied to the charts because of what YOU like. So what that you think the chart is "tasty" looking, we would prefer a professional objective look at charts and the POSSIBILITIES they indicate please. Not everyone loves freezing cold all year round (though that's not the point).

Nothing tasty about numb hands, lashing cold winds and a runny nose, unless you like the taste of your own snot dribbling into your mouth.

Richard

First your last para is not very nice reading, perhaps you might care to delete it or at least moderate your expression please?

Secondly, I long ago gave up hoping/expecting for unbiased contributions when people comment on charts. I've lost count of the number of times I've been effectively told to 'wind my neck in' as everyone has a right to express their opinion, which is, I suppose, fair enough.

I notice you have not been a member for very long, compared to some of us, but you will get used to those posters who prefer a biased comment on any chart from whichever is the model of their choice on that day, or those posters who do try to make objective posts about what those charts show.

[Frosty.]

Well I don't know if it's my imagination but the GFS 12z appears to be shortening the anticyclonic spell with every run! it now only stretches to T+168 hours with only a weak ridge remaining by next friday across england & wales with low pressure beginning to affect scotland by then with a chilly and unsettled spell thereafter, even before then it looks as though it will become cooler and cloudier during next week with a brisk E'ly wind blowing. Make the most of this weekends pleasant sunshine.

[Guest]

Falling snow is still possible even at low levels from a northerly at this time of year, it's only lasting snow cover that is invariably restricted to hills and mountains.

We had snow exactly four years ago today here which lasted a few hours but the best example I've ever seen is the one we talked about the other day, 12th May 1995:

That saw settled snow of a few inches down to sea level across the west of Scotland.

The possibility of a nice cold northerly has been on the cards for a good while now but the ensembles still look a little scattered at this range.

[Eugene]

Falling snow is possible anytime of year, the daylight length isnt as important as some say ,its the airmass origin that is most important, we lose any lingering arctic airmasses to our far north after lets say mid June but i'm sure if we did actually have arctic air left to tap into it could snow even in July and August to lower levels in england.

The pattern we are in currently is actually a cold one, today and tomorrows warmth are just what happens this time of year as HP retrogresses northwestwards.

[snowfish]

One thing I would love to see in Model Chat on this forum is an absence of this descriptive bias applied to the charts because of what YOU like. So what that you think the chart is "tasty" looking, we would prefer a professional objective look at charts and the POSSIBILITIES they indicate please. Not everyone loves freezing cold all year round (though that's not the point).

Nothing tasty about numb hands, lashing cold winds and a runny nose, unless you like the taste of your own snot dribbling into your mouth.

ROTFL

For me that would produce said result and cold northerly wind which would bring cold rain - Nah, not for me thanks - warm southerly yes please....

Edited April 9, 2010 by snowfish

[Milhouse]

Oh dear, thats just typical. I have nearly 3 weeks off work soon and was hoping to get outdoors to enjoy some warmth and sunshine. What comes along to spoil it, a cold northerly. Hopefully it will be brief, although in some cases we can be stuck in a cold northerly flow for weeks.

[Rob]

Oh dear, thats just typical. I have nearly 3 weeks off work soon and was hoping to get outdoors to enjoy some warmth and sunshine. What comes along to spoil it, a cold northerly. Hopefully it will be brief, although in some cases we can be stuck in a cold northerly flow for weeks.

knowing our luck when we don't want the northerly, it'll arrive and stick around for a while....

[Cheese Rice]

Oh dear, thats just typical. I have nearly 3 weeks off work soon and was hoping to get outdoors to enjoy some warmth and sunshine. What comes along to spoil it, a cold northerly. Hopefully it will be brief, although in some cases we can be stuck in a cold northerly flow for weeks.

I wish, northerlies tend to last no more than 2-3 days and never (?) last for weeks. It remains to be seen how long this northerly will last, if it happens. I think a brief northerly giving way to the Atlantic.

[Thundery wintry showers]

Indeed, the chart 10123 posted would bring cold rain because the Arctic airmass isn't properly established- note that the 850hPa charts still show values of -4C and above. However, I don't see where the lashing cold winds and numb hands would come from with the isobars that widely spaced.

The sunshine-and-wintry-showers scenario is typically associated with the polar air catching the UK full-on and bringing 850hPa temperatures of -5C or below for most, with snow showers more likely if they are around -8C or below. People are allowed to have their own preferences but it doesn't help discussion when preferences "cloud" perceptions of what the charts show. The Arctic northerly type has a bias towards bright and showery, but embedded fronts/shortwaves and mixing can easily tip the outcome towards raw and wet, so it's not enough to see a northerly and jump to conclusions without evaluating the chart on its own merits. All of these northerlies are out in the periphery of FI and are thus subject to major changes, though the trend for Arctic air to surge south should certainly be noted.

The next three days still look like being dry and sunny to me- some forecasts are going for low cloud in eastern areas on Sunday and Monday but I don't think it will be very extensive- humidity is progged by GFS to be reasonably low and winds are set to be light. By Tuesday the models are still suggesting a more pronounced easterly flow and more extensive cloud. Tomorrow still looks like being the warmest day for many, with 18C likely in some western and southern parts.

[RichardR]

I guess its a matter of opinion, no-one is looking forward to grey skies but at the same time most aren't dreading it either, if you don't like variety get out of the UK as the weather is as varied as you could possibly get.

Also a northerly doesn't just bring snow it brings an abundance of Sunshine across the whole of the UK, I'm quite sure wall to wall sunshine beats Atlantic driven weather of rain after rain.

If you bothered to read my post properly you would see I gave my own opinion on the chart and also what would occur ie. "plenty of sunshine", "low temperatures" and "convection".

Also how am I been biased, again if you read my post properly I said "I for one", this is my opinion. If you care to elaborate on how I am been biased I will happily listen but until then don't post until you read what I actually said.

OK here you go:

A tasty looking GFS with the northerly slowly but surely coming into the reliable time frame

It's akin to a heat lover saying " Oooh look at that delicious baking +20C 850hpa air surely and definitely brushing up the English channel in the reliable time frame", no bias indeed!!! That you recon a cold chart is "tasty looking" makes your bias self evident.

Admitting (see red text) your opinion (bias, same thing, if we see through the semantic twisting) does not absolve it, either.

Your opinion is not a logic and reason based interpretation of the model, from any objective standpoint.

I notice you have not been a member for very long, compared to some of us, but you will get used to those posters who prefer a biased comment on any chart from whichever is the model of their choice on that day, or those posters who do try to make objective posts about what those charts show.

Quickly come to the conclusion it's clearly better to stick to the more advanced Model Analysis available than sift through tonnes of bias laced detritus.

Edited April 9, 2010 by RichardR

[Thundersquall]

What happened to those temperatures of 22 to 26C over the SE UK and much of Europe to our East and Southeast

that were showing in the charts about four days ago, albeit in the unreliable timeframe of T+300 hours onwards?

[Cheese Rice]

What happened to those temperatures of 22 to 26C over the SE UK and much of Europe to our East and Southeast

that were showing in the charts about four days ago, albeit in the unreliable timeframe of T+300 hours onwards?

I commented yesterday on how Monday was showing maxes of 16-18.c and even that has been downgraded to 10-13.c for most of the country, so even in the most reliable of time frames there are still little details to be sorted.

Regarding the situation on low cloud next week, GFS humidity profiles suggest a fair amount of low cloud coming into eastern Scotland by Monday, and possibly featuring near the coast on Sunday, but eastern England should stay in the clear on both days. There are then strong indications of low cloud becoming much more widespread from Tuesday onwards.

Interestingly the NAE is showing widespread high cloud cover on Sunday covering all central and even most western areas, although I'm not too sure about the different effects between Low cloud and high cloud.

Edited April 9, 2010 by 10123

[Cheese Rice]

Look i was merely giving my own opinion on a chart which is perfectly acceptable on the "discussion thread", we would have nothing to discuss if we all had the same view as each other. Also you criticise me for been "biased", you are in essence not allowing me to have my own opinion, I am not imposing my views on to anyone so I really don't see the issue. As stated before I gave my opinion on a specific chart and then stated what the conditions may be.

"Nothing tasty about numb hands, lashing cold winds and a runny nose, unless you like the taste of your own snot dribbling into your mouth" - Opinion dressed as fact?

Edited April 9, 2010 by 10123

[Bottesford]

OK here you go:

It's akin to a heat lover saying " Oooh look at that delicious baking +20C 850hpa air surely and definitely brushing up the English channel in the reliable time frame", no bias indeed!!! That you recon a cold chart is "tasty looking" makes your bias self evident.

Admitting (see red text) your opinion (bias, same thing, if we see through the semantic twisting) does not absolve it, either.

Your opinion is not a logic and reason based interpretation of the model, from any objective standpoint.

Quickly come to the conclusion it's clearly better to stick to the more advanced Model Analysis available than sift through tonnes of bias laced detritus.

We all have our opinions (or 'bias' if you must) and we're all free to express them. But lets not start arguing about who is right or wrong since everyone and no one is correct- it's opinion!

And lets stick on topic discussing the models - there's nothing wrong with expressing an opinion or even wants/want nots in this thread so long as there's some analysis of the model output as well.

For me, a northerly sounds good - it means abundant sunshine and big night to day temperature gradients. No I don't want it all spring but I wouldn't have an April without one!

[damianslaw]

Current synoptics are text book retrogression of azores high out towards Scandanavia, oftena precursor to a generally settled spell and a blocked one, and in winter a cold blocked outlook, synoptics indicative of a very quiet altantic and very seasonal given the time of year , the alantic tends to hibernate between now and late May, this is when we normally expect our most settled and driest conditions and for this reason I always rate second half of April through to mid June as much better than high summer in terms of guaranteed settled conditions, well especially here in the north west.

Longer term - models still in agreement of the high retrogressing towards Greenland, how far it ridges is yet to be seen and will make all the difference between whether we catch a deep seated showery cold northely or a more modified affair.

Tomorrow is likely to be the warmest day so far for many, but not those in the SE, hotspots tomorrow will be very unusual locations such as northern ireland coast, north wales coast and east grampian regions - Aboyne could get the honours 19 degrees possible here.

[frostyjoe]

Current synoptics are text book retrogression of azores high out towards Scandanavia, oftena precursor to a generally settled spell and a blocked one, and in winter a cold blocked outlook, synoptics indicative of a very quiet altantic and very seasonal given the time of year , the alantic tends to hibernate between now and late May, this is when we normally expect our most settled and driest conditions and for this reason I always rate second half of April through to mid June as much better than high summer in terms of guaranteed settled conditions, well especially here in the north west.

Longer term - models still in agreement of the high retrogressing towards Greenland, how far it ridges is yet to be seen and will make all the difference between whether we catch a deep seated showery cold northely or a more modified affair.

Tomorrow is likely to be the warmest day so far for many, but not those in the SE, hotspots tomorrow will be very unusual locations such as northern ireland coast, north wales coast and east grampian regions - Aboyne could get the honours 19 degrees possible here.

yea isn't this great.. it was 18c today.. and it is still 10c at midnight!! I'd say 20c at least for me tomorrow if the haze isn't there which is predicted.. maybe warmer.. whats with this haze anyway.. when is it for clearing?

[Derp Patrol]

I don't want a northerly either, but it's better than an easterly at least. In the south a northerly wouldn't be too bad, because it would likely be sunny and thus not too cold, probably around average temperatures - low teens. Not as good as a southerly or the current synoptics, but better than a cold, cloudy and gloomy easterly.

[Frosty.]

Today looks the warmest day in the current anticyclonic spell with 18..possibly 19c occuring in parts of northwest england and 17-18c across southern england, even sheltered parts of northeast scotland could reach 17c, glorious unbroken sunshine, rather hazy across northern england and some fair weather cloud will bubble up in the south in response to the pleasantly warm temps, temps dipping quickly this evening and tomorrow looks cooler but still sunny with cooler air filtering in from the east across eastern england, next week still looks fairly settled but cooler with an E'ly wind and probably more in the way of cloud and the breakdown to more unsettled weather is around a week away according to the gfs 00z with a deep low near iceland becoming the main feature by next weekend and the chance of a brief cold snap is still there in FI.

[mushymanrob]

Made me laugh, yes a northerly in late april is so worrying :lol:

sorry but this type of reply really annoys me.... why? because this line i posted has been taken right out of context to make it look like i posted something that I DID NOT SAY. i qualified my statement by refering to the spring of 1975 which was northerly driven from mid march to early june, effectively by-passing 'spring' proper. of course a northerly in spring isnt worrying, its EXPECTED, but memories of spring 75 IS worrying IF that was ever to be repeated.

Hi If there wasn't snow, then yes I would be quite happy with acg in winter. Much better than wind and rain.

fair play

not that much change this morning, the north sea cloud is still probable into next week, but lets enjoy the superb spring sunshine on offer before that happens! the transitory northerly blast is still lurking in fi, and is likely out of these synoptics, before the high moves back in over us returning some very pleasant sunny dry warm weather .

[johnholmes]

Current synoptics are text book retrogression of azores high out towards Scandinavia,

a pedantic point perhaps but retrogression is a movement east to west-that is the opposite of the normal west to east movement of weather systems.

So a movement of the Azores high to Scandinavia not 'retrogression'

Edited April 10, 2010 by johnholmes

[MR EXTREMES]

its looking pretty normal for april to be honest.

loving the weather right now and guess what i got burnt yesterday.:lol:

[Guest North Sea Snow Convection]

not that much change this morning, the north sea cloud is still probable into next week, but lets enjoy the superb spring sunshine on offer before that happens! the transitory northerly blast is still lurking in fi, and is likely out of these synoptics, before the high moves back in over us returning some very pleasant sunny dry warm weather .

Yes the GFS returns the high back over us. Unfortunately both the ECM and GEM return us yet again to a very west based pattern with the northerly in the atlantic and that dreadful cyclonic low pressure back over the UK. It is in FI but this pattern has already repeated at least a couple of times and the worry, in view of the background factors that continue to give support to it, is that it would happen again.

Still, some glorious weather at the moment and better let 10 days ahead take care of itself.

[Frosty.]

The ECM 00z has ditched the FI Northerly for the time being at least although the gfs is still very bullish about the idea of a brief cold snap during FI with a chance of reloads and a nw/se jet axis but it's still unclear which model has the better grasp of next week but it's clear that the highest temps and best sunshine will be during the next couple of days with a tendancy for more cloud and cooler temps beyond that.

[MP-R]

Yes the GFS returns the high back over us. Unfortunately both the ECM and GEM return us yet again to a very west based pattern with the northerly in the atlantic and that dreadful cyclonic low pressure back over the UK. It is in FI but this pattern has already repeated at least a couple of times and the worry, in view of the background factors that continue to give support to it, is that it would happen again.

Still, some glorious weather at the moment and better let 10 days ahead take care of itself.

Well even if it did turn into a cyclonic pattern, after an anticyclonic period of so many days it would probably be a nice change. As it is, the GFS sort of flirts between an anticyclone just to the west and a northerly just missing and going into Europe so probably something in between.

Personally I hope for this anticyclonic pattern to last no longer than the end of next week then something more traditional for April such as sunshine and showers.

[Derp Patrol]

No sign of any real cold except for maybe Scotland.. looks like turning gradually cooler, and then out in FI there is a hint of a nice southerly plume with uppers of 10C up to the midlands, which would bring temps in the low to mid 20s probably, fingers crossed on that happening!