[Model Output Discussion - the cold has arrived]

7 minutes ago, 38.7°C said:

Pretty good model agreement on a pattern change by next weekend for the UK to a milder SW'ly orientated flow and staying dry but cold before that, but yes the freezing, snowless spell looks like coming to an end in around 8 days time

 

6 minutes ago, Turnedoutniceagain said:

Christmas Eve and still well and truly in the freezer....

Just bonkers on the different opinions on here sometimes. No wonder newbies struggle to follow some of it.

[Model discussion - hunt for cold - Christmas countdown]

Just now, MarkM said:

Nobody should talk about the Model Fight Room....

1st rule! 

[Model discussion - hunt for cold - Christmas countdown]

Another quick question as the ICON is coming out. On Meteociel web site is there a setting to get the chart to update automatically or can I view all of the model runs here on Netweather? Will they update automatically? TIA again 

[Model discussion - hunt for cold - Christmas countdown]

Just now, Kasim Awan said:

I miss Laura Tobin

She's still with the Met Office

[Model discussion - hunt for cold - Christmas countdown]

1 minute ago, Kasim Awan said:

Icon to be released by 15.00.

Sorry to clog the thread, but what are the release times of the other models today? TIA

[Model output discussion 11/12/21]

8 minutes ago, Bradley in Kent said:

Good evening all, 

I have not been participating in the Netweather forums for that long, especially compared to many others. However, like all forums it's okay to make comments about comments.

Something I find odd are the occasional comments about models not being as good as others or people being disappointed with a model when it doesn't show what (I think) most of us want: hot summer weather / cold winter weather. Surely a good model or even model run are one's which stick with reality and don't overplay unusual features.

Yes, if I see runs showing BTFE galore with -20c 850s, I enjoy it as much as others, but it doesn't make it a good model / model run especially past day 3. IMO (and it is opinion of course), a true good model would be one which sticks as much with mobility and +NAO as possible, since that's what our weather is constantly trying to default to. Or in other words, a model which doesn't lead us up the garden path!

(open to replies if you disagree of course)

When the experts here have time to reply, you will understand as I did that you can have some of the biggest super computers and software available, but you still need a human that knows when data doesn’t look right and should be disregarded. 

[South East, London and East Anglia regional discussion - 8th February onwards]

Light snow in Woking. Sticking on roofs and grass. 
 

BBC weather app is an utter joke! Broken sunshine and cloud!

[Model output discussion 10/02/21]

6 minutes ago, wiltshire weather said:

What I have been trying out (just to aid my understanding) is to take NOAA 500MB Height Chart for a period such as this one for the 17-21 Feb issued yesterday:

then I look through the 500MB hPA Wind charts on WZ for instance to find one in that period that seems to match it as near as poss such as this one for the 19th Feb:

Then I look to see what the 500MB Geop Height chart looks like for the same timeframe:

Gives a good idea of what it could look like at the surface.

All very subjective of course as there are several patterns that could fit the NOAA chart through that period with much different surface conditions!

Now checking the NOAA 8-14 day chart:

A fairly similar 500hPA Wind chart for the 23rd:

And 500hPa Height chart for the 23rd:

If (and it's a big IF) those are correct then you could surmise that the GFS is developing the right pattern currently.

I have no idea if this is a valid way to interpret the various charts but will be fun to keep track of it to see how successful it is  

Brilliant WW. This is what I was chatting with @johnholmes last month whereas I was suggesting matching the closest permutation to the 500s, but your idea is a much better way of matching it using the jet. Great stuff

[South East, London and East Anglia regional discussion - 8th February onwards]

1 minute ago, Radiating Dendrite said:

Sounds good for my locale in NE Surrey.

Any chance this could mimic what was seen in 09 & 10 in terms of totals - possibly 25cm in some spots?

I hope you’re right RD. It’s not looking overly promising at the minute in Woking. But the main thing was to get the cold in and the snow will follow. We have definitely got that now, so just fingers and toes crossed and a stealie eye on the radar. 

[South East and East Anglia Weather Discussion February 2021 onwards]

Meto removed snow here overnight and tomorrow!!! I can’t be??? All the other weather apps still say snow tomorrow. Do the Meto know something??

[Winter 2020/21 chat, ramps, moans and banter]

4 minutes ago, Snowmut said:

Blimey after reading some of the posts above I just had to check I didn't imagine the ECM run....

 No I thought not!

I think I put on some REM to cheer myself up!

Only track that would fit is “The End of the World”! Love it! Sorry Mods

[Model output discussion - deep cold inbound?]

31 minutes ago, Cold Winter Night said:

It seems so, but not quite.

When we attempt to evaluate how reliable the output really is, it's best to look at a number of things (not exhaustive):

- Is an operational (high resolution) run more or less in line with its own ensemble mean or ensemble clusters?
- Is it in line with other models' operational and/or ensembles?
- Is it consistent with previous runs, or does it jump from one solution to another?
- Is it in line with background signals?
- At what timeframe does a specific model usually perform best?
- Are we talking about more reliable short term forecasts or is it the more fickle FI?
- Does the model have known biases that might be an issue?

ECM had many issues at the end of last week and early weekend, it jumped around quite a bit, was not in line with its ensembles, not in line with the other models and it was mostly FI.
That's why ECM was dismissed. GFS was more steady and in line with other output.

Now the situation is different. ECM is steady and in line with its ensemble and in line with UKMO and others. Those are usually very good at short range (up to day 5,6). GFS is suddenly jumping around, its ensemble is messy and it blows up lows, which is a known bias.
That's why this time GFS is, still cautiously, dismissed by many.

It would not be different if GFS/GEFS were the only ones forecasting cold, with EC/UKMO forecasting mild, so it's not about what we want to see.

For all newbies, please read this brilliant post! 
 

We don’t just discard a suit because it’s not showing what we want to see. That would be a layman’s response. We are, to a lesser extent, scientists and deal mostly in logic. 

[South East and East Anglia Weather Discussion January 2021 onwards]

Warnings for London & SE

 

Updated: 09:50 (UTC) on Fri 29 Jan 2021

Further details

An area of rain pushing in from the south-west overnight will turn to sleet and then snow during the course of Saturday morning, before the band stalls and starts to move south again in the afternoon as it eases. A few cm of snow are possible at low levels, but more persistent snow is expected across Wales and some hills elsewhere, with 3-7 cm of snow possible above 150 m elevation and 10-15 cm over higher ground (above 250 m), mainly in Wales. There is also a low chance of around 20 cm over the higher routes in the Brecon Beacons.

[Model output discussion 24/01/21]

23 minutes ago, Lord Grogon said:

It’s part of a special group of painfully frustrating terms including:

Uncertainty

Battleground

Midlands North

Downgrade

Pesky shortwave

Dew points too high

Usually correct south

Still waiting for the effects of the SSW.

Phasing issue

 

You forgot the M4!

[South East and East Anglia Weather Discussion January 2021 onwards]

Just started snowing in Woking
 

Heavy precipitation now

[South East and East Anglia Weather Discussion Sept 2020 onwards]

I’d actually be quite happy to see it falling from the sky. The bar is set very low at the mo 

[South East and East Anglia Weather Discussion Sept 2020 onwards]

Woking snow shield in full working order! Nothing is getting through

[South East and East Anglia Weather Discussion Sept 2020 onwards]

2 minutes ago, loafer said:

They use historic runs, and the models are upgrading the forecasts at the moment.

This should cheer you up;

 

Thanks loafer! Defo yes! I’m just looking for that confirmation in the ordinary gp tools. I’ve bored the wife stupid over the years with 10 day chart blizzards inbound most of which have never come to fruition. It’s just the usual 4-5 days worry that we’re chasing phantoms. I’ll feel better when the flakes are falling outside my window.

[South East and East Anglia Weather Discussion Sept 2020 onwards]

I know the weather apps (TWC, BBC & MetO) are renowned to be crap but none of them have any snow for my location next week. I keep looking for them to update but everyday nothing. Are they all wrong? I know they all use data in their apps that we have access to. Why don’t they see what we are seeing? 

[Model output discussion - Closing in on Christmas]

1 hour ago, mushymanrob said:

Using this method would save a lot of excitement/disappointment caused by the wilder swings of the ops.

It was mentioned above by @swfc that our weather looks like coming from the NNW, and the anomaly charts for several days now suggest a mean upper flow from the Northwestern quadrant. So cool unsettled likely imho.

Speculating, all anomaly suites suggest positive heights to latitudes north of the UK.  If we can get cyclogenesis to stop developing over the Eastern seaboard and subsequent energy injected into the jet stream, then maybe a more substantial Greenland block can develop. Im not "coldie" but imho that chances of a proper cold spell this winter are much higher then usual, ive been feeling this now for several weeks as northern blocking has developed.

You actually raise a really interesting question rob. 
 

I can’t read the anomaly charts yet at all, but could @johnholmes or another one of you learned fellows, cross reference the anomaly charts with the closest GFS/EMC Permutations to illustrate a clearer way forward +8 days. It seems the anomalies are more right than wrong at this time and we have enough data variables to possibly match up a way forward.

Apologies if this has been done before and proved not to work, but I can’t recall seeing it in the past. 
 

TIA

Mr. B

 

[Model Output Discussion - Colder spell ending, what's to follow?]

5 minutes ago, LRD said:

Last winter the IOD demolished cold chances. This winter it could be the MJO or lack of

Time to call this lad:

And if the ensembles are misreading MJO signals it could mean that the best set of ensembles so far come to nowt:

Which'd be a bloody shame as from 23rd/24th those 850s are dropping quickly

So does the MJO drive the ensembles or do the ensembles drive the MJO or do they independently read the background signals?
 

Sorry LRD not directed at you personally just interested. 

[Model Output Discussion - Colder spell ending, what's to follow?]

2 minutes ago, dragan said:

there is almost zero chance of cold weather in the next 10 days, temps especially at night will be a bit above average. I say almost zero chance, unless every forecaster and model are wrong, then really there is no chance 

Can you start backing up these assumptions with charts! #justsaying

[Storms and Convective discussion- 15th August onwards]

One of the trees at my mums house got struck by lightning over the weekend and it knocked off a large branch. Not sure whether the lightning carried down the tree and through the root system under the ground or they are burns on the surface, but left these amazing patterns. Not seen anything like this before. Can anyone shed any light on it? Apologies mods if this is not the correct place to post this.

[Storms and Convective discussion- 15th August onwards]

Looks like the best time for storms today in the South East will be 19:00.

Here is the CAPE and the Lifted Index for the South East

 

And for the UK at the same time

[South East and East Anglia Weather Discussion Sept 2019 onwards]

6 hours ago, Stabilo19 said:

N London is no longer stormless 

30 mins of moderate to heavy rain here with some lightning and loud cracks of thunder. Still seeing flashes of lightning every few minutes even though the storm passed a while ago. 

Seems like S/SE London have yet to see any direct action.. 

Yep! Storm starved here!