Model Output Discussion - Early November Onwards

[winter watcher]

Way too much bickering going on in here c'mon guys and girls its bonfire night have some fun and chilax the weather will do what it likes. We are speculators and by no means experts. My view is as the likes of BFTP ( Fred ) & Steve M. We need to see this euro high disappear which is no mean feat but signs are for a change to emerge after mid November where signs are for things to get a little more interesting for us golden coldies however as we all know nothing is for certain in this business until it happens. So in the mean time we stay stuck in a rut awaiting the change. Next week we see above average temps and cloudy overcast conditions with the odd shower or longer spell of rain in the south and for once in the early part of next week up north will be pleasant with sunny spells and a chance of frost by night if sky's stay clear. Either way we should see by mid to late next week where we go once the pattern change does happen.

[wolvesfan]

In response to your post WF is your opinion one that would support a pattern change to something cooler in the next couple of weeks? My knowledge of the NAO is very limited. When it turns negative as you state what usually happens the the weather/temperature etc around our parts. Thanks GSL

HI GSL,my knowledge of the NAO also very limited but i believe its forecast to go negative shortly, this can result in a less active icelandic low and also the same principal applies to the sub tropical ridge i believe.if i'm correct this would be more conjusive for rising heights to our north.maybe one of the more experienced members could explain better though.thanks.

[Grimsby Snow Lover]

HI GSL,my knowledge of the NAO also very limited but i believe its forecast to go negative shortly, this can result in a less active icelandic low and also the same principal applies to the sub tropical ridge i believe.if i'm correct this would be more conjusive for rising heights to our north.maybe one of the more experienced members could explain better though.thanks.

Thanks WF, I have a better understanding now. I know the NAO is discussed a lot on here so any explanation is appreciated by me

[Paul]

The NAO doesn't drive anything - it's effectively just an indicator of the pressure differences between the Azores High and Icelandic low - so a high gradient (eg a strong Azores high and a Strong Icelandic low) means a positive NAO.

More here:

http://www.ldeo.columbia.edu/res/pi/NAO/

[Frosty.]

Good cross model agreement that next week will start mild and then become milder, it also looks like a cloudy week and although dry early in the week, some rain looks like spreading in from the west through to midweek and a similar pattern through to next weekend but increasingly warm with a S'ly airflow and some brighter weather developing in sheltered areas, especially to the east of high ground. Initially it looks sunny across more northern parts of britain, especially towards the far north west and monday could be another sunny day up there, tuesday brings cloudier weather from the east to all but the nw corner of scotland by the end of the day but it does seem at this stage that sunshine will be at a premium next week but mild temps will be widespread although a few more nights of slight frosts for scotland & n. ireland but thats the most wintry it's going to get in the next 10-15 days at least.

[wolvesfan]

The NAO doesn't drive anything - it's effectively just an indicator of the pressure differences between the Azores High and Icelandic low - so a high gradient (eg a strong Azores high and a Strong Icelandic low) means a positive NAO.

More here:

http://www.ldeo.colu...edu/res/pi/NAO/

HI Paul,This would be beneficial to a pattern change would it not?,thats if it did go negative,thanks.

[phil nw.]

HI Paul,This would be beneficial to a pattern change would it not?,thats if it did go negative,thanks.

High pressure to the North,say Greenland/Iceland area and Low pressure to the South of the UK around the Azores would be a negative NAO state -NAO and yes would be good for cold.

As Paul said earlier NAO is just a reflection of a sypnotic pattern-ie where the Highs and lows are placed in the model out put at any particular time--it doesn`t drive the pattern.

I hope that helps.

Regards,Phil.

[nick sussex]

Wow that limpet euro high is getting as annoying as the euro itself. You know much discussion and the problem still never gets sorted out!

Relating to wolvesfan regarding the NAO the ECM is a good example of how you get a negative NAO but still end up running around in shorts and a t-shirt !

I expect people are becoming frustrated with seeing a relatively weak jet with no PV stuck over southern Greenland but still somehow feeling like this is Groundhog Day regarding the mild conditions, changes will come but this is going to need some time.

There are some signs of encouragement this evening but it's going to need some patience as the models are in no hurry to end the Euro high soap opera!

[kev238]

As far as I can see, it looks mild all then way at the moment. Inevitably it will have to cool at some point, but I don't see all the pattern changes that others do.

To be honest, I am enjoying the mild weather; still not switched on heating and sat in a t shirt this evening... The cold weather can wait a bit longer for me.

It was highly unlikely that this November coukd match last time and judging by met office long ranger, they see mild or very mild trending average as the month progresses.

[phil nw.]

Wow that limpet euro high is getting as annoying as the euro itself. You know much discussion and the problem still never gets sorted out!

Relating to wolvesfan regarding the NAO the ECM is a good example of how you get a negative NAO but still end up running around in shorts and a t-shirt !

I expect people are becoming frustrated with seeing a relatively weak jet with no PV stuck over southern Greenland but still somehow feeling like this is Groundhog Day regarding the mild conditions, changes will come but this is going to need some time.

There are some signs of encouragement this evening but it's going to need some patience as the models are in no hurry to end the Euro high soap opera!

Hi Nick,

I agree with your general view re,stuck in this mild stagnant pattern,but to suggest ECM is modelling a -NAO state is stretching it somewhat imo.

Only in a couple of frames is the any upper hts to our north west on the ECM output.

At best i would think we are more in a neutral state of the NAO,--that block to the East and the Atlantic trough keeping things pretty even at least for the next week with that Southerly draw.

Regards,Phil.

[damianslaw]

Wasn't expecting much difference in todays models for the foreseeable future - as I keep saying the current pattern is a stuck record and will only very slowly eventually be played out to death until its time for something new. Longer term signs of strengthening heights to our north - the longwave trough can only stay in its current position for so long - how long is anyone's guess at this stage but would be very very surprised if by the end of the month we are still in this same pattern, which is actually quite an unusual one for the time of year it has to be said - southerlies don't normally tend to stick around as long as they have done.

Must say though recent days of model watching have been very trying indeed and I suspect the next few will be equally so - a good time to go on holiday and hope on return that they are showing something difference - that one week off I suggested this time last week should have been two!

[Cheshire Freeze]

Wasn't expecting much difference in todays models for the foreseeable future - as I keep saying the current pattern is a stuck record and will only very slowly eventually be played out to death until its time for something new. Longer term signs of strengthening heights to our north - the longwave trough can only stay in its current position for so long - how long is anyone's guess at this stage but would be very very surprised if by the end of the month we are still in this same pattern, which is actually quite an unusual one for the time of year it has to be said - southerlies don't normally tend to stick around as long as they have done.

Must say though recent days of model watching have been very trying indeed and I suspect the next few will be equally so - a good time to go on holiday and hope on return that they are showing something difference - that one week off I suggested this time last week should have been two!

Put it this way, I would be extremely surprised if in a week from now there isn't a change in model output to a prevelance of high latitude blocking

[stewfox]

I think that this post is slightly misleading. Here are the Aberdeen 850 hPa temperature ensembles from the GFS 12Z run.

My comments would be that the temperature is consistently above average and only gets close to average at the extreme of FI in 15 days time. Even at the end of the run the mean is well above the -5ºC line. it is certainly not a trend I would be getting excited about.

We may get a temperature drop close to average in around 15 days time is how I would view these!

Happy to see a down ward trend with not huge variation to get to as you say probably average temperatures by mid Month. We can't stay in the current pattern with a cement High over Europe for ever. Half full for me. If it was a upwards trend or even flat trend thats a different story.

Edited November 6, 2011 by stewfox

[summer blizzard]

I think that while we are all looking for the next pattern change, we are missing the fact that almost no rain looks to fall in eastern England for the next week or so. Exceptionally dry.

[NorthYorksWeather]

I think that while we are all looking for the next pattern change, we are missing the fact that almost no rain looks to fall in eastern England for the next week or so. Exceptionally dry.

.

Glad to have a dry week here. Our garden is a mudbath and extremely saturated. 18z ensembles still keeping the cooler trend with more members going even colder in F.I. Mean still around average but still positive signs heading into the latter part of the month. Also worth noting that the pub run is on the warm side throughout the run.

Edited November 6, 2011 by vizzy2004

[ZONE 51]

GFS 18z

I know its a long way off but i am tracking this, around the 19th GFS is indicating colder air to reach Scotland and this shows on the 850 Esembles(my purple line to show its around -3 850s?) looks about that,

The surface pressure,

and the 850hpa, -5c line very close to the far north

is gfs just flirting? :lol:

Edited November 6, 2011 by ElectricSnowStorm

[scotty_boy_winter]

Your going to be extremely surprised then

Put it this way, I would be extremely surprised if in a week from now there isn't a change in model output to a prevelance of high latitude blocking

[ZONE 51]

No one is certain of what would be in effect in 3/4wks time..but just an idea, alot can happen in 3wks as we know last winter.

Taking a look at sunday on the GFS 18z

Some areas would be in for sunny periods,

Top and tail getting stronger winds,wind charts and surface pressure

NAE 00z temperatures,

it is likely to feel cold in the cloudy areas especially, with maybe some light rain drizzle in to the SE/EA,

it does look dry for most, just a risk of light rain in East Anglia/Southeast in thicker cloud areas,

NAE 00z winds

NAE 00z cloud cover for period 1200-1800hrs

I wont be posting loads of charts everytime but il try and post some info when i can.

Edited November 6, 2011 by ElectricSnowStorm

[Weather-history]

The fohn effect could be a player next weekend if ECM comes to fruition. North Wales and the north coast of Devon look favoured in this set-up

http://www.wetterzentrale.de/pics/Recm1682.gif

[ICETAB]

GEM @ 240 h looks interesting to me. It could go on to develop a GH. After viewing this mornings model output I have no reason to change my current view of a cold spell ariving from around the 18th, maybe a little later. I think the models should start to pick up on this over the next few days.

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

Edited November 6, 2011 by ICETAB

[Frosty.]

Absolutely nothing on the gfs or ecm 00z to get excited about for cold lovers, the ecm 00z shows a mild week ahead and then becoming extremely mild through next weekend with some very warm T850's pumping northwards followed by a very mild and anticyclonic spell with probable mist and fog overnight, the gfs 00z not quite as full on with the warm up but still a mild outlook with no sign of anything cold even beyond mid november, so a backward step or two from this gfs run in terms of a cold snap before december. To add to the gloom..quite literally, a very cloudy week ahead with patchy rain spreading from the west, a lot of dull and misty, drizzly type weather but with temps on the mild side although not as high as recently but then probably warming up next weekend, more like late summer than close to winter.

[trisnow]

Not sure whether I should post this as I'm not adding anything to the discussion but just would like to say, from a utter novice point of view that it can be incredibly confusing reading this thread! Obviously love reading everyone's input but I keep seeing comments about it getting colder and then comments about no sign of cold in the models so not quite sure what to believe!

Are the folk who say they can see signs of cold using data not shown in the charts? A lot of the people who say they can't see cold coming tend to back it up with evidence, (not that I understand it when they do as a novice) but I don't see it happening with folk who predict cold so are they going on more of a hunch? Or is it that the charts out in FI have that much info packed in that some people can see a slight hint of cold?

Anyway, I love reading the posts as I'm sure a lot of novices do like me who are all looking for and wanting it to get colder so please don't take this as a dig as it isn't meant that way, just looking to understand a bit more.

Thanks

[chionomaniac]

Not sure whether I should post this as I'm not adding anything to the discussion but just would like to say, from a utter novice point of view that it can be incredibly confusing reading this thread! Obviously love reading everyone's input but I keep seeing comments about it getting colder and then comments about no sign of cold in the models so not quite sure what to believe!

Are the folk who say they can see signs of cold using data not shown in the charts? A lot of the people who say they can't see cold coming tend to back it up with evidence, (not that I understand it when they do as a novice) but I don't see it happening with folk who predict cold so are they going on more of a hunch? Or is it that the charts out in FI have that much info packed in that some people can see a slight hint of cold?

Anyway, I love reading the posts as I'm sure a lot of novices do like me who are all looking for and wanting it to get colder so please don't take this as a dig as it isn't meant that way, just looking to understand a bit more.

Thanks

It's called hopecasting!

[wolvesfan]

High pressure to the North,say Greenland/Iceland area and Low pressure to the South of the UK around the Azores would be a negative NAO state -NAO and yes would be good for cold.

As Paul said earlier NAO is just a reflection of a sypnotic pattern-ie where the Highs and lows are placed in the model out put at any particular time--it doesn`t drive the pattern.

I hope that helps.

Regards,Phil.

HI phil,Thanks for taking the time to explain.

[lorenzo]

Trisnow - what you have eloquently described is hope casting, another ailment as common as flu in Winter.

FI can throw up all manner of charts and on occasion can deliver exactly what someone wants to see then disappear on the next run.There are also posters who bias a milder set up in Winter and will champion Zonal weather, where there is none, so the coin itself has 2 sides.

My advice would be to pick out the posters whose comments you trust as technically accurate and work from there to learn.

Looking at GFS today there are some signs for tentative blocking signals, but these are in the lower resolution end of the run and a long way from fruition.

As for looking for cold - we are moving into the second half of November, so I would be expecting it to get chillier !

Meanwhile our anomaly remains to our East . It really isn't for shifting !