rwtwm

Thanks for sharing this. I'll read down to the correlations, and then realised I'd been distracted from work for some time. I'll update here when I finish absorbing, rather than clogging up the other thread!

Thanks @Catacol & @bluearmy for the responses. So (checking I understand) the BOM interpretation is preferred, both because it lines up better with the background signals and because the model has a better perceived skill in that part of the world. If the plot posted by @Met4Cast is to be believed, I guess the question of lag times and amplitude duration are moot. But I think the question is still worth considering. If the MJO rattles through 4 phases on short order, does that mean the effects don't have a chance to propagate, or does it just look like enhanced mobility to us? I can't say I'm blown away by the velocity potential chart, because I'm not sure quite what it means. From what I've read in the last 20 or so mins, it looks like it might be to do with the jet slowing down and spreading out over the Pacific? I think the MJO plots I'm used to are showing convection. But maybe I've been seeing them both and not realising there are distinct measures?

While the thread is likely to be a little quieter between chases, I have a question for the teleconnections experts. I've heard lots of talk about the MJO in the last couple of weeks, with (if I'm remembering correctly, I don't know where to find the composites) phases 7&8 likely to lead to more blocked weather in this part of the world. (Model content incoming...) Looking at the ECM and NCEP MJO forecasts for yesterday, the ECM has no amplitude through phases 7 or 8. NCEP has convection come to life in phase 8. To the question. Are the expectations that the models are understating the amplitude of this move? Or are these low amplitude phases enough in an otherwise conducive environment for blocking? Or have I got completely the wrong end of the stick, and something else is going on?

I think you're in the wrong thread... This belongs here. I think any optimism on climate progress that I had after Paris has long since faded. Unless CO2 sensitivity is variable (we've emitted enough that we have empirical evidence of the bounds, troubling in itself given how long we've known of the issue), we only have around 8-10 years to dramatically slow global net emissions. There are too many people still denying it's a problem, combined with too many accepting it's a problem and carrying on anyway for sufficient progress to be made.

5.1c and 98mm please.

Pretty much every possible December condition seems to be represented there!

Really good use of the minimum chart there that never really occurred to me. It's effectively a Dalmatian plot when used like that.

You're not the only person to make this statement. But it's worth reminding everyone that the first half of last December was the coldest since 2010 - sample analysis charts from Dec '22 below. Separately, was it 2019/20 that started with a really disorganised vortex, then an SSW threw us into a mild high? Can't help but be reminded of that (even if I have the year wrong), when I see excited posts about an SSW against this starting point. Of course, there's still time for everything to flatten out. But looking naively at the 00z ensembles it's looking promising that a second consecutive winter will start with a below average spell. *Edit to save clogging the thread* Excellent post from @Met4Cast above. I've struggled to get my head around AAM (not what it is, but what it's impacts are likely to be). That discussion has helped me massively.

I can't help but think that these two things are related though... We watch the GFS mess around with various solutions from 15 days out, and then the ECM and GEM join in the wild flailing from day 10. From a week away we start to see the met office output, by which time the broader uncertainty is often mostly gone, and the disputes are about the details. Then often the Met Office model gets congratulated for not demonstrating the wild swings of the other models! I'm aware that even at that range the MO is often the most accurate. But, conversely to your point, I sometimes think we give the models that give us access to more data an unfair knock, because we get to see those 8+ day charts where chaos tends to reign. Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4955246

I can't help but think that these two things are related though... We watch the GFS mess around with various solutions from 15 days out, and then the ECM and GEM join in the wild flailing from day 10. From a week away we start to see the met office output, by which time the broader uncertainty is often mostly gone, and the disputes are about the details. Then often the Met Office model gets congratulated for not demonstrating the wild swings of the other models! I'm aware that even at that range the MO is often the most accurate. But, conversely to your point, I sometimes think we give the models that give us access to more data an unfair knock, because we get to see those 8+ day charts where chaos tends to reign.

I was intrigued, so I went and had a dig through the ECM documentation. Confluence Mobile - ECMWF Confluence Wiki CONFLUENCE.ECMWF.INT They are apparently basically the same and only diverge due to "small technical differences and the chaotic nature of the atmosphere"... There's no more detail than that. Maybe floating point truncation plays a part? Edit* I see I was beaten to the punch

I can think of two this decade! Dec '22 and Feb '21 both had notably cold 2 week spells. They were both fairly dry, so not memorable to those for whom snow is the key feature. Even so, I think both were in the bottom 10% for the time of year in terms of mean temp?

I think we might just break the run of above average months here. And if I'm miles out the new comp starts next month anyway! 6.3°C & 124mm please

I stumbled upon this discussion of the intensification this evening. Thought it might be of interest. Trying to make sense of why Otis exploded en route to Acapulco this week – The Eyewall THEEYEWALL.COM One-sentence summary Scroll to the bottom for a couple notes on current weather, but in today’s post, I want to try to make some sense of what just happened in Mexico this week. Otis’s …

I didn't see the impact matrix. If the amber was highest impact, but down one notch on probability that makes sense. Once you get so close to the event, it becomes up to police and local authorities IMO. Now, could the distinction between high likelihood, strong impact and moderate likelihood, severe impact be clearer? I'd have sympathy for that argument, but believe an amber could have been justified given the existing scale.

I was checking the radar as the day progressed. I was maybe 30-40 miles from being trapped under a blustery front for about 6 hours. It seems like a bad forecast if you compare conditions, but if you compare positions it makes a lot more sense.

I went through the 6z Ops for rain accumulation up until 6am Saturday. For London, the lowest estimate was about 6mm, and the highest over 50mm! In Hampshire it was even worse. Some outputs have it almost completely dry, others have over 100mm. I haven't had time to check ensembles too to see which pattern looks most likely.

They are two different questions IMO. Comparing to more modern average is checking how big a departure the temperature is from what one might expect given AGW. The question here is looking at the departure from a long term average, therefore measuring the impact of a warming climate. I think both are relevant, and to continually update the reference mean without showing the long term context is only telling half the story.

Kachelmannwetter.com :vd:: "++BREAKING++ Im äußersten Südwesten wurde in der …" - Meteo.Social - Die Mastodon-Instanz für alle Wetterverrückten METEO.SOCIAL ++BREAKING++ Im äußersten Südwesten wurde in der letzten Stunde tatsächlich die 30 Grad-Marke geknackt. Es ist der späteste #Hitzetag seit Aufzeichnungsbeginn. /LD Hier die... Provisionally the latest 30°C day in Germany since records began. The link in the 'Toot' shows a little pocket of 30c temps in the the South West https://kachelmannwetter.com/de/messwerte/deutschland/hoechsttemperatur-1h/20231013-1400z.html

A couple of days ago I was worried I'd undershot with my guess. It looked like we'd get a quasi-stationary low just off to the west. Not massively warm by day, but virtually no diurnal range. In just 2/3 days the script has completely flipped!

Not necessarily, as they often use UK wide figures rather than CET for Met Office press releases. Seems likely it was though.

Furious with myself for bottling September's guess. I talked myself out of going for a record breaker at the last. I don't think October will break records but I'm going big. 13C please, but grim second half so 150mm EWP.

14.8c and 49mm please

If I could freeze the angle of the earth relative to the sun, I'd do it this week. For me (in my current location) the day length feels just about perfect. Unfortunately it's at a time when the nights are starting to close in rapidly. I don't get to enjoy it for very long at all.

It really depends on what kind of weather were having, and how much detail you want! We can normally be fairly confident of the broad scale pattern at 5 days. So, are we under high or low pressure? Is the flow west-east (Zonal) or more aligned with the country (meridional). If we are under a high, then in most cases sun/cloud amounts can be reasonably estimated, and depending on the speed and direction of the prevailing flow we should have a decent idea of the temperature. Under low pressure situations, or mobile ones (where you get low/ridge/low in quick succession). It can be a lot harder at 5 days, as a being 6/12 hours out can make quite a difference on how a day feels. Rain arriving at 7am and lasting a few hours gives a different feel to the day than if it arrived at 1am. It's going to be very difficult under any circumstance to work out exactly where and when any rain might fall at 5 days. Even if you can be quite sure it will rain at some point. And on more showery days you might struggle to identify the weather for a particular location at all. It could be sunny and a little windy in one place, and 15 miles up the road it could be miserable cold and wet most of the day. At 5 days you'll never be able to tell which one you'll be. (Actually it can be difficult at 24 hours!)