[Model output discussion - into 2018]

1 minute ago, Daniel* said:

UKMO is not far from being very good but it looks doomed to sink not long after, not enough northerly latitude on HP. South East Europe is very mild, there’s the danger - GFS 12z brings a ‘warm’ aloft easterly. 

I must being seeing different charts? It warms up because the winds are not easterly, they veer around to almost southerly! 

[Model output discussion - into 2018]

3 minutes ago, Ali1977 said:

1501 I’m afraid - grabdual return to milder next week - still sounding v cold till mon/Tue. 

I don't intend on cluttering this thread (Sorry John), but none of the models have been predicting the notably below average temperatures to stay for more than around 4/5 days. Despite the ECM being the road we would preferably want to go down, it does still bring *slightly* LESS COLD conditions as the wind has more of a South Easterly component around mid week (Next week) before the blocking re - orientates itself and PERHAPS gives us chances further down the line. 

[South West and Central Southern England Regional Weather Discussion 09/12/2017 onwards]

2 minutes ago, *Stormforce~beka* said:

Same here! Bonkers innit! Just dropped to 5.4c. Took hours though! 3c in Bristol according to XC

Temp dropped from 6 to 4 in under an hour without precipitation here so it changes very quickly 

[South West and Central Southern England Regional Weather Discussion 09/12/2017 onwards]

What are the temperatures guys? And did they drop quickly at one point. 

[Model output discussion - heading into 2018]

2 minutes ago, northwestsnow said:

Indeed as i have been mentioning for days Knocker

UKMO tho - yuk, cold rain away from northern scotland.

There is actually only minor difference's, granted on local basis it makes a big difference. Also the UKMO only has the feature just approaching my 144hrs so that judgement is a little premature. 

[Wales/Cymru Regional Weather Discussion]

5 minutes ago, CRACKPOT said:

I know this front is supposed to pivot - but if you check the radar the intensity has gone and seems to be fragmenting?

Doesn't look on the face of it much life in this after mid morning. Hopefully I'm wrong.

JK

Essentially that is what is forecast, probably like another 4 - 5 hours of decreasing intensity (Probably add about 2- 3 cm). Especially where snow has already settled. 

[Wales/Cymru Regional Weather Discussion]

Literally in like 30 seconds its gone from pure rain to very wet snow.

[Wales/Cymru Regional Weather Discussion]

6 minutes ago, Jayfromcardiff said:

So we're in the firing line now for snow?

I think any snow for you/southern coastal areas will be when the front begins to push back south later in the afternoon. I can see most seeing some wet snow in the late afternoon/evening with temperatures around 1 - 3. Intensity of precipitation will be decisive. 

[Model Output Discussion - cold spell to end Autumn]

2 minutes ago, Steve Murr said:

Perfect allignment of the cold so far brings a second bout of -10c over the UK

how close will the slider get....

62% phone charge Steve....

In all seriousness, the West Coast would look very wintry if it came off as this. 

[Model Output Discussion - cold spell to end Autumn]

6 minutes ago, feb1991blizzard said:

I don't know for definite but I read somewhere on the GEFS that 10 are tweaked to show milder outcome and 10 a colder one, I don't buy into that because they are global models, surely if one place is mild, it will be balanced out by somewhere being cold, I have noticed though when you go through them chasing an amplified pattern - the GEFS usually have a good number in the first few more amplified (particularly with an Easterly) don't know about the ECM as ive only been using them the last few days.

FWIW number 45 on the eps is the best over the widest area, upwards of 10 inches over the whole of the midlands, however, they are great fun but I really wouldn't be paying to much attention to these in a serious manner, one had 10inches sslap bang over Manchester, Manchester had 6 inches in Jan 10 but that was the most in the City Center since 1980-81 so theres basically zilch chance of that happening!!

Interesting stuff. From some quick research, it seems that the ECM & GEFS use different manners for creating the perturbations. The GEFS uses something called 'Bred Vector' ( https://en.wikipedia.org/wiki/Bred_vector).

[Model Output Discussion - cold spell to end Autumn]

Just now, feb1991blizzard said:

No, but the Control does show a hefty snow event as well though, just for the North, its like the reverse of number 1, all the areas that get pasted on the control are the ones that don't on 1.

This is a question for anyone. The alteration of initial data, do the first perturbations have closer initial conditions than say number 20 to the raw operational data? Or does it work in different manner? 

[Model Output Discussion - cold spell to end Autumn]

Just now, karlos1983 said:

Ah yes , member #1 AKA the trend setter 

Yeah absolutely 

[Model Output Discussion - cold spell to end Autumn]

Just now, karlos1983 said:

Yes they generally overdo snow accumulations by around an inch I’ve found 

nice one MWB, I will run down the street naked if that happens, (after the watershed) 

It wasn't the control which showed this snow event. It was the 1st member. 

[Model Output Discussion - cold spell to end Autumn]

The Jet Stream profile is notably different on this run. The 6z run has more energy going into the southern arm, the 12z has more going into northern arm combining with a higher latitude based northern arm jet. The net result is the low pressure traversing a more northerly route in contrast to that of the 6z. 

[Model Output Discussion - cold spell to end Autumn]

This thread has been somewhat hostile at the moment. This is a 'model output' thread, not a thread to display your weather wishes. I think people really need to consider whether what there posting is of any use (Ie contains some scientific knowledge to it, or more importantly some more open minded analysis). 

[Model Output Discussion 01/09/17]

2 minutes ago, Geordiesnow said:

Personally I rather this mess of a set up for Friday does not occur because the air is just simply no where near cold enough for snow apart from the top of the hills, yesterday's output had a nice clean airflow heading into the UK, todays output is now showing this shallow low and all it does is delays any cold from the North West and deliver a lot of cloud and rain, only the ECM kind of keep it well to the South but even this model has backtracked slightly.

I agree with the begins of your statement, the length of source is too high for there to be sufficient cold for there to be snow down to low levels. Unless there is a perfect combination of undercutting cold air and adiabatic cooling (Unlikely). With regards to the latter of your points, the front actually clears sufficiently to allow respectable uppers for a North West flow (Though still not enough for snow anyway from areas with reasonable height).

[Model Output Discussion 01/09/17]

6 minutes ago, Steve Murr said:

A reasonable start to the 18z GFS pushing the colder air further SE at 72-84

Looking for some potential mild V cold interaction along the wave @96...

This run doesn't develop the wave feature as much so no sign of any leading edge snow (If any limited to the highest ground in Wales). Sure not to be settled on however for at least another 24hrs.

[Model Output Discussion 01/09/17]

5 minutes ago, jules216 said:

Hi guys, sorry for maybe off topic question, but I think it might be model related as we stand, is it true that models have lack of satellite data over Greenland?

I saw it written here before when models had no clue during blocking period,could that contribute to the fact of huge swings and forecast uncertainty even at 5 days range?

If so, is there any link to official sources that could confirm this?

 

thanks 

https://www.metcheck.com/WEATHER/discussion.asp?DiscussionID=971&DiscussionTitle=Model+Blind+Spots

Read this from Metcheck which gives a good insight to the input of data. 

[Model Output Discussion 01/09/17]

Just now, CreweCold said:

Get a decently rigid block between Greenland and Scandi and the Atlantic is all but buggered for the foreseeable. 18z wants to try and give it a go

As Knocker has recently mentioned frequently in the last day or so, the GFS has constantly been causing cyclogenesis in the later period of its runs. Caution required obviously all round, one positive is the higher resistance to the energy (Low Pressure) upstream which Nick mentioned would be critical to the process the ECM was trying earlier. 

[Model Output Discussion 01/09/17]

2 minutes ago, Allseasons-si said:

Destination....pete tong

no heights in the polar regions what so ever on this run.hopefully not a trend,do we discount it?

No, but the pub run rarely fails to bring a surprise (Normally disappointing).

[Model Output Discussion 01/09/17]

Just to input a sense of humor and pretend this run will verify....

[Hurricane Ophelia]

4 minutes ago, WelshWanderer said:

Good point Crimsone about not much people in Swansea can do to prepare but in case of power cuts I was thinking about grabbing some batteries, candles etc and in my case clearing their balconies of random stuff to prevent the stuff flying around and pelting windows and people lol

I would love it if the DVLA building was taken out-give them an excuse to put something nicer there instead of that monstrosity!! ;-) 

Just to calm you down a bit, the models are not predicting 70/80 mph gusts in Swansea. Unless you live up on Mumbles Head then gusts will probably stay down at 60/65 max. Obviously any slight east deviation to the track would bring the risk of higher gusts of >70mph.

[Hurricane Ophelia]

1 minute ago, OPHELIA said:

Really? Is this how you treat people with open minds who have studied the weather since child birth :(, I am not a troll I promise you this....Go ahead do your research, come on prove me wrong...what happens when water becomes warmer. I'm not a conspiracy theorist, the only thing that is stopping these storms from becoming more powerful is in fact....salt and maybe just maybe the tilt of the earth during autumn.   

 

I've had enough already. I thought this generation would be more open minded.

 

Depressions will increase, ex tropical storms can or could increase again it depends on the salt deposits in the atlantic and currents.

Please stop. This forum is predominantly good with discussion, there will always disagreement but your taking it to a new level. Your essentially saying those whom do research in these fields (Likely have PhD's) are completely wrong and in denial? 

[Where have the long fetch northerlies gone?]

Interesting thoughts indeed. What Phil mentioned yesterday (Strictly relevant to Northerlies) was excellent. It will be interesting to see the extent of Ice Sheets this winter and the possible role it could play. 

[Where have the long fetch northerlies gone?]

1 minute ago, northwestsnow said:

Well after much consideration my 'expectations' when winter approaches are now very low.

We can talk all we want about the ENSO, SSTs, QBO but the harsh reality for a cold weather fan in much of Europe is the landscape has changed.I do not profess to know for how long the change will be but to deny winters are now mild and wet in the main is denying reality.

Of course there will be cold snaps / spells in future winters but they are becoming rarer and rarer (just like the easterlies) 

I would expect this coming winter to be in the main, wet,and mild.Yes there could be cold snaps but for my money, the chances of a stable block over scandy or greeny recede year in year out, there is just too much energy in the blasted Atlantic nowadays for any block to survive!

What do you mean by 'Landscape has changed'? Please elaborate.