Model Output Discussions 12z 03/05/2016

[Faronstream]

Looks like we are in a period of low pressures during the period 15 June- 25 July the last 4-5 years, August last years has been the best month with most sun. ECMWF continues with cool temperatures and rain alost 50% of the week, i still remember the summers 2003,2006 and 2010 when we had long periods of dry and sunny weather

[mb018538]

Enjoy this week if you get any sun, from the weekend onwards things are looking truly awful, massive high pressure covering the pole, with low pressure slapped across or near the UK. Can't really see any light at the end of the tunnel either!

[Frosty.]

17 minutes ago, mb018538 said:

Can't really see any light at the end of the tunnel either!

It's not that bad, after the fine spell it looks like a return to sunshine and heavy, thundery showers with temps close to 70F. There is plenty of time for heatwaves yet, for all we know, August could be a sizzler chin up.

[Singularity]

I'm not allowed to post much these days (work permits little), but I just wanted to point out that the 500mb anomaly charts are misleading for this week due to the fact that we have an unusually weak ridge of high pressure, which gives negative height anomalies in our vicinity yet still manages to prevent an unsettled regime across England until Fri or Sat.

I'll leave you all to it now, have a good week  

[knocker]

9 minutes ago, Singularity said:

I'm not allowed to post much these days (work permits little), but I just wanted to point out that the 500mb anomaly charts are misleading for this week due to the fact that we have an unusually weak ridge of high pressure, which gives negative height anomalies in our vicinity yet still manages to prevent an unsettled regime across England until Fri or Sat.

I'll leave you all to it now, have a good week  

I'm not sure which anomaly charts you are looking at but the ecm gives positive height anomalies for this week

 

Edited July 3, 2016 by knocker

[Polar Maritime]

Some posts have disappeared again as off topic, And add nothing to discussion on what this threads intended for.

[mb018538]

Temps close to 70f are below average! This area in July should be around 22-23c at average. I know we will hit that this week, but looking beyond it appears temperatures will be suppressed once more. Depressing!!

[March]

42 minutes ago, mb018538 said:

Temps close to 70f are below average! This area in July should be around 22-23c at average. I know we will hit that this week, but looking beyond it appears temperatures will be suppressed once more. Depressing!!

That's the average high of all of July, thus it's lower than that at the start, and higher at the end. 

[knocker]

Mainly cloudy today with the rain progressing east mainly confined to N.England, N.Ireland and southern Scotland. For the rest of the week (this morning's GFS) is pretty much a N/S split as a transient ridge brings some drier weather to the southern half of the UK mid week whilst the north is still subject to systems running NE from the Atlantic before more general wet weather arrives for the weekend. Temps varying around the  mean but favouring the N/S split.

[Singularity]

9 hours ago, knocker said:

I'm not sure which anomaly charts you are looking at but the ecm gives positive height anomalies for this week

 

Ironically I was (due to being on mobile) basing it on your summaries (generally unsettled) so assumed the anomaly charts must be showing negative height anomalies all the way south. Perhaps you were only talking about the longer term i.e. After Fri/Sat?

Obviously I stand corrected on the anomalies. Although the ridge is pretty weak, the airmass is warm enough to raise the 500 mb heights above average.

 

[Summer Sun]

Taking a quick look at the end of the week the low does appear to have gone further north west compare to the previous 2 runs

ECM at t144 yesterday and today right

[northwestsnow]

Reasonable week for those in the south and east, cloud fest for us in the north west with temps in the mid to high teens, woooopy do! And it wont even feel warm under cloudy skies.

GFS0z offers hope long term but i'll not hold my breath.

Can August buck the trend of the last god knows how many years? 

[B87]

9 hours ago, March said:

That's the average high of all of July, thus it's lower than that at the start, and higher at the end. 

Average high here at the start of July is around 22.5c, the average for the month as a whole is 23.5c, and the average for the last week of July and first week of August is about 24.5c.

Average highs of 70f/21c at any point in July or August is below average.  21c is the average for June, or the first third of September.

[A.J]

model discussion only please......other threads are available for discussion average temperatures etc

[MP-R]

Last chart of FI on the 00Z GFS showed exactly what I'm sure many would like to see at this time of year:

Hoping for more runs to show an increasingly settled outlook into the second half of July. With this week also not looking too bad, more so further south, it would nice to continue to squeeze out anything autumnal/Atlantic-based. 

[Man With Beard]

Just looked at the extended GEFS. Really wish I hadn't:

    

The depth of that mean trough to our north indicates, correctly, that the vast majority of ensemble members go the same way. The July CET is going to suffer badly if that comes off, and indeed some of the ensembles wouldn't be out of place in November. I said last night that there was a 50/50 split between this scenario and a split trough one (much better for us) and unfortunately this morning the worse scenario has been picked. Not good at all!

The ECM mean goes down the same path but gets enough heights into Scandi to prevent the coldest air getting south:

Fortunately, there has been a marked pick-up for the coming weekend, not the first time this summer that the models have cancelled Armageddon at the last minute!

compared with this a few days ago:

that's three or four times since the start of June that the models have backtracked significantly on unsettled weather - something to hold onto as this mid-July nightmare approaches...

[mb018538]

Crumbs to hold onto for sure....but I think once the trough is sat over us, there won't be any wriggle room really! It'll either just be unsettled, or very unsettled at worst case scenario! No ridges for a while.
Doesn't matter if it's El Nino or La Nina, low pressure or high pressure over the pole, settled or unsettled over the eastern seaboard....you can nearly always rely on a truly dire British summer! I honestly thought that this summer would be decent. How wrong I was!

[knocker]

The GFS still has the transient ridge, mainly affecting the south, mid week before the depression tracking NE arrives to be NW of Scotland by Sunday 00z. It then, after some complicated manoeuvres moves the low pressure east to Scandinavia which introduces a cooler snap but I wouldn't bet the bank on this later evolution.

Edited July 4, 2016 by knocker

[Frosty.]

The GEFS 12z mean, longer term indicates the south has a good chance of being influenced by the Azores high (ridging) with spells of fine and warm weather and the met office update earlier mentioned something similar. There is also hope for the rest of the uk too from some of the 12z perturbations which show various anticyclonic scenarios from mid month onwards so although this summer so far could be politely called mixed, most of us could use stronger language to describe it....but hang in there. I remain hopeful that our luck will change before August!

[ANYWEATHER]

Good Evening! There is no doubt that the Atlantic is in control with a strong jet stream powering its way across the nation A very disturbed outlook as we meet High Summer!

[Matthew.]

This evenings ECM longer term isn't too bad. The continuing battle of HP to the south potentially building north and LP travelling east over the Atlantic towards Iceland. I'm hoping Knockers charts will support HP to the south pushing north from mid July. There's certainly potential for a settled spell. Just hopefully LP won't be pushed east but away Ne.

[Frosty.]

20 minutes ago, Matthew Wilson said:

I'm hoping Knockers charts will support HP to the south pushing north from mid July. 

That will truly be a day to cherish when knockers charts support high pressure..

[Weather Boy]

1 hour ago, ANYWEATHER said:

Good Evening! There is no doubt that the Atlantic is in control with a strong jet stream powering its way across the nation A very disturbed outlook as we meet High Summer!

This post is a very substantial over-simplification to the point of being misleading.  You have cherry picked the worst charts currently out there.  It depends where you are, when you are talking about and which model you are looking at.

The GFS is the worst of the biggies.  No need to post the worst, as you've done that.  Poor charts this weekend, especially for the north, followed by a cool flow thereafter which is borderline FI (although that is not Atlantic driven being more of a northerly outbreak).  Such as (although this is likely to change):

 

UKMO looks better for the south, poor in the north for the weekend:

ECM confines the poor weather over the weekend to the north-west, generally:

Not a bad chart for most of E+W.  Furthermore, for a lot of the country for much of this week, the weather looks generally fine.  It is the weekend and thereafter, FI that the position currently looks poor in some models, but as everyone knows that is likely to change run by run.  To sum up the model output as "very disturbed" is not correct. I see little evidence of storms as the air is largely Atlantic rather than continental sourced, although I wouldn't rule out a bit of convection on some days.  The jet stream tends to be over the northern UK until deep into FI when it fragments very much.

So, in summary it depends when or where you are.  This weekend in the north looks bad.  Further south, away from the weekend, variable to good.

I think that newer people would appreciate a little bit more balance, especially where the outlook is quite a bit more positive than it has been for some time (not that that's saying all that much)! Hope this helps.

[knocker]

The anomalies this evening don't indicate and significant change to the upper air pattern.The 6-10s all have the upper low adjacent to Scotland thus a continuation of the upper flow from the westerly quadrant. Ergo unsettled with temps in general a little below average but with the likelihood of the north and west being the main recipients of the worst of the weather with the south east the best. The detail of course to be resolved within this pattern

The ext period does see a weakening of the trough, albeit the GEFs does this rather more than the other two, but overall the pattern remains the same with the temps still a little depressed

 

Edited July 4, 2016 by knocker

[knocker]

Today mainly cloudy but the cloud will break in some places to give a pretty fair day. The showers mainly confined to NE Scotland. The rest of the week (GFS) brings a showery regime for Thursday before swinging a frontal system through Fri/Sat associated with the fairly deep depression to the west which is tracking NE and could bring some wet and windy conditions to Scotland. It's still liking the idea of hanging tthe  said depression around in the vacinity of Scotland for three days before tracking it into Scandinavia and introducing a cool northerly. Best take a rain check on this evolution for a time I feel.

Edited July 5, 2016 by knocker