Mike Poole

In my opinion, the GEM has been the most consistent producing blocked runs in the 8-10 day timeframe for quite a few days now. And more to the point, blocking in the right places. That doesn’t mean it is right, but it certainly means it shouldn’t be ignored.

Very interesting set up, the lows are sliding but against the most slight block you could imagine, GFS // T150: GFS is even slighter, but goes on to deliver a promising pattern later. We are really seeing the lack of a strong vortex driving the systems off the Atlantic - in a way it is more like a summer setup.

ICON 12z at T132 and T180 I’m finding this quite educational, it didn’t look like the low would slide to start with, but such a weak ridge seems to be sufficient, hence T180 chart. The early evolution of this is so important and i wonder if the 12z suite today sorts this out in favour of the weak block. T850s far too warm, but it is about the start of an evolution to cold.

Well I used to @Vikos , haven’t had a single gamble or bet since the lockdown in March, so I’ve saved some money but I’m not sure what for! Anyway this from the GFS // at T276 is probably the most ridiculous NH chart I have ever seen (not claiming anything specific for the UK here): Just noting i guess what might happen if the arctic high connected with the increased amplification we are now seeing in the Atlantic sector...

Christ, we’re almost into the fluffy bunny rabbit split in two scenario here, GFS // T180:

Not sure what you mean Vikos! But GFS // looks to me like it is taking the faster route, just out to T162:

Well there’s the scandi high i was on about an hour or so ago, great run this, and it shouldn’t just be discounted because its the 18z, this is exactly the evolution we should expect now given the SSW and MJO resurgence into phase 7. It won’t go away on the 0z’s.

Pub run T270 and this is the real deal cold:

Are you a dentist?

Only one way from here on GFS pub run T240: And it is cold

Can’t see it into Greenland, Scandi looks more likely to me, with brief Azores link up, we will see...

GFS 18z T168, and the combination of the amplification upstream and the wedge is causing trough disruption and the lows tracking NW-SE. Good holding pattern this but I think the eventual outcome will be a scandi high.

Yeah, I’ve just edited my post .

GFS 18z T108 compared to 12z at T114: This one isn’t going under, it has blown up and there is no wedge for it to go under (it was better on the 12z but still didn’t undercut). I think, however, the undercut is actually the more likely outcome at this timescale and the run has gone wrong earlier. Edit, this post is total nonsense, see @Allseasons-si post above, it only I’d waited a couple of frames!! It still doesn’t go under, but my point above was largely wrong!

Hi folks! Busy early evening today so just catching up. Really positive output on the 12s today, yes the models haven’t nailed a proper cold spell yet but are edging towards it, which as good as we can expect given recent output. ECM clusters are out, T192-T240, all charts are green border (-NAO) and so all show some kind of high latitude blocking, and undercutting lows: Moving on the T264-T360 charts show some charts with red border (Scandi blocking) and you can see this in the 2nd cluster in particular. It would be a brave person to predict a mild outlook for the UK based on that...we will see.

GFS // 18z at T144, is this really going to go under such a small wedge of heights: If it is, it kind of sets the benchmark for what systems might get deflected SE on the jet...no matter the rest of the run, I think it shows we are very much in the game re sliders until something more meaty comes along, which it well might.

GFS 18z // T120 -will it or won’t it go under?

Well, yes for fun @Griff but probably not for meaningful analysis! Won’t stop us I’m sure.....

You could. In fact that is one of the interesting features of model watching this year, isn’t it, without a Greenland centered vortex powering things, what is coming off the Atlantic is, it seems to me, a bit more like summer, a bit random. If that makes sense. We won’t know re the ICON, but eyes down for the pub run...

ICON T120 v 0z T132 A rare post in here. A big downgrade! But still it is only the ICON!

ECM clusters T192-T240 are interesting. No big high lat heights on the first two, but both suggest a wedge - and we know at this time of year wedges mean sledges (I know that’s copyright @northwestsnow!) highlighted. The third cluster has more substantial blocking: All are green border -NAO!!

I’m not sure but I may be about to say in many paragraphs what @tight isobar has just said above in two lines, but hey ho! I think it is pretty clear that FI is T96 or maybe even earlier and that the models are struggling with this situation. Let’s start with the strat, here NAM plot based on the GFS 0z: The downwelling from the SSW seemed to hit a block and will continue to do so as forecast, but not for long, with the -NAM taking hold at the surface at the end of the run. This must be linked to the MJO story - others have posted the MJO phase diagram, but I expect MJO into phase 7 at reasonable amplitude is a big part of the uptick in AAM as per CFS forecast, and it isn’t coming from a low base now: This would discount any idea of a La Niña end to winter. As the op runs are struggling, the ensembles are a better guide at day 10, ECM T240: So with the mean plot, Azores displaced, UK trough into Europe, so potential for sliders there if even slightly higher heights can hold over or near Iceland. Spread plot, uncertainty near the tip of Greenland is relevant, and SE of us in Europe, suggests there might be a signal for more southerly tracking lows on some members. All of which says, cold February to me. All the best, Mike

GFS 18z // already got all sorts of options on the table at T120:

You know, I kind of look at this and think, no this isn’t going to happen...GFS T174: Where is the system in the Atlantic getting its drivers from? Numerical modelling errors compounding is my take...this one is for the bin...

Didn’t even look at the 0z runs (apart from HARMONIE for the regional thread) too busy enjoying the snow, glad I missed a stinker!