Rain All Night

12z deterministic runs, Sat 24th to Fri 1st (day 7) The models seem to be finding more amplification this afternoon (GEM excepted), which gives me some hope for drier times ahead. 12z ensemble means, Sat 24th to Sat 9th (day 15) The ECM ensemble mean is nice to see, with a mean Atlantic shutdown from 3rd March through to the end of the run. The other two models look like they need a little more convincing, though the GEFS mean is still a good one (unless you're only interested in a cold outcome, which is not on the table in this timeframe).

0z deterministic runs, Fri 23rd to Fri 1st (day 7) 0z ensemble means, Fri 23rd to Sat 9th (day 15) Still a slow learning process. From 3rd March (day 9), the ensemble means tell us that a lot of member runs feature raised heights to our east, but the means remain too blurry to indicate what pattern might be setting up just yet, and by 7th March (day 13), the signal fades back to noise. None of the ECM ensemble cluster representative members at day 10 convince me that a strong blocking pattern is emerging, but perhaps there could be some opportunities for drier weather ahead:

12z/18z deterministic runs, Fri 23rd to Thu 29th (day 7) 12z/18z ensemble means, Fri 23rd to Fri 8th (day 15) Seeing more of that signal for heights to build to the east or even northeast after that next trough comes in at the turn of the month, kind of interesting.

That was a LONG silence for this thread in winter!

0z deterministic runs, Thu 22nd to Thu 29th (day 7) Nothing new here really, though I note from other posts that there's some interest in whether the low on Sunday could miss us to the south entirely. Regardless, pressure contours looking slack over much of Britain for a while on Saturday and Sunday. 0z ensemble means, Thu 22nd to Fri 8th (day 15) It feels like we're learning ever so slowly at the moment. We've known about the next trough attack around 29th Feb/1st Mar for days, but still have little signal beyond that. My one concern, based on the raised heights to the east that have been showing up on some of the ensemble means into the first week of March, is that we could end up with troughs getting stuck over, or just to the west of, the UK with no way to exit. I hope the upcoming stratospheric event can do something to get rid of the tedious TPV to the northwest.

What does this actually mean?

0z deterministic runs, Wed 21st to Wed 28th (day 7) GFS has this morning 'capitulated' to the ECM's depiction of the toppling Atlantic ridge - but of course, nobody is paying much attention to that, since none of the suggested outcomes on either side have been especially interesting for the UK. 0z ensemble means, Wed 21st to Thu 7th (day 15) As with the op runs, the shift of the GFS ensemble towards the other two models is noticeable this morning. They're all now showing similar progressions into the first week of March. We have a new signal emerging in that first week of March, which is for a build of heights to our east. It's too early for me to guess at the possible impact of this at present. The GFS ensemble allows this signal to fade away into deep FI, but the ECM and GEM hold it in place.

Metwatch And why is that, I'm assuming the reduced solar input compared to mid-July?

Sod's law, the second strongest background driver after global warming!

Metwatch Do you not think 40C would be possible now in early August?

GFS continues to want to be different, its 18z run tries to link the Azores high to Scandinavia

raz.org.rain The SSW, and any subsequent impacts on us, will be in spring...

WYorksWeather That looks nice...

Is anyone else not looking forward to the consequences of this happening so late?

12z deterministic runs, Wed 21st to Tue 27th (day 7) Divergence after 96 hours (Sat 24th), though the difference between the outcomes on offer is not likely to be of great interest to many here since there are no deep cold air masses in the mix. 12z ensemble means, Wed 21st to Wed 6th (day 15) Looking back at my posts over the past week or so, I think our three 15-day ensembles have, as a team, given us good guidance on the progression through our upcoming battering: 21st Feb - round 1 25th Feb - round 1.5 (with GEFS making much more of the trough going into Europe after this point) 29th Feb - round 2 What happens beyond that (day 10+, the first days of March) remains unclear for now - as illustrated by the rather different directions each of the three ensemble means take after this point - but personally I'm not going to count on it being anything settled.

0z deterministic runs, Tue 20th to Tue 27th (day 7) GFS op runs, like its ensemble means, continue to make more of the trough going down into Europe, with the Atlantic high more reluctant to topple over it. 0z ensemble means, Tue 20th to Wed 6th (day 15) ECM and GEM still seem to send in a second big low behind the toppling Atlantic ridge by around 29th Feb (day 9), which may be followed by a second toppling ridge behind it. GFS continues to want to sink, rather than topple, the Atlantic ridge (and make more of the trough going into Europe), which appears to delay the arrival of the next big low by perhaps a day or two, and possibly hinder its progress through the UK.

RJBingham len You can get an annotated versions of ECMWF charts that are better for copying and pasting into your posts here: click the share button at the edge of the chart, choose "Copy link", paste the copied link into your browser's address bar, and the annotated version of the chart will load, which you can then right-click on and copy as normal, for pasting into your forum post.

I haven't in recent months been looking at height anomaly charts for the ensemble means like I used to, but this evening I did, and I'd forgotten how much the mean height anomalies from climate average can leave one with a different impression than the mean heights alone. "Lower than average heights over Iberia" was not one of my main takeaways from looking at the ensemble mean height charts from this afternoon's model runs on Meteociel, but that is one of the more prominent features highlighted by the anomaly charts for 5th March (day 15). And then, I look at all the members of the ECM ensemble on that day, and sure enough, I do indeed see more members than you'd typically expect to see showing lower than usual heights over Iberia, so the anomaly isn't misleading me (assuming that the ensemble members themselves are any good in the first place):

12z deterministic runs, Tue 20th to Mon 26th (day 7) Choose your toppler! 12z ensemble means, Tue 20th to Tue 5th (day 15) All agree on the signal for a further polar maritime low to be thrown at us after the Atlantic ridge has toppled (or sunk), with differing timing. From day 13 onwards we see agreement on a continued Azores high presence (especially on GEFS) and a general rise in heights (especially on ECM). Could the ultimate legacy of the stratosphere this year, after apparently denying us a cold heart of winter, be to condemn us to a late spring?

Penguin16 They've actually done the opposite and expanded the reach of those forecasts by adding them to their mobile app recently

bluearmy Update: GFS and GEM don't look like this, they're just regular topplers

In Absence of True Seasons Has there been any particular skew towards an increase in the number of wet days compared to average vs. an increase in the amount of precipitation on wet days compared to average, or has it been a fairly balanced combination of both those things?

Summer8906 Are we actually in a notably long series of wetter than average months? I know it feels like it sometimes...

summer blizzard Thanks, how was spring 2016? I don't recall it

I assume we would not actually notice any direct effects from the SPV being directly above us?