Model Output Discussion - 1st July Onwards 18z--->

[summer blizzard]

....in which case, why do they even put them up? I don't like the bashing the met office get from people who know nothing about the weather at all, but placing these extended outlooks up sets themselves up to be shot at!

Back to the models, maybe the huge cold pool in the Atlantic is squeezing the thermal gradients further south this year - ie the jet is more southerly as the cold boundary is more to the south than it should be? I'm sure that's a simplistic was of looking at it, but maybe it'll help us out with some decent winter weather!

Its not as important in summer when we have a low amplitude vortex. This is more to due with a background pattern and this month a -AO.

[summer blizzard]

I would have thought the other way, jet to the south surely means more low pressure, more rain? at low levels in the south

You can get lots of rain from such situations but in winter you want the jet south because the easterlies on the northern edge will drag in colder air.

The cold pool where it is now though is more likely to produce a strong thermal gradient and when we get a vortex going in October-December I'd wager a stormier than normal period.

[Bristawl Si]

I'm guessing, like GP and Tamara they look at other things like the GWO and Mountain torques etc…, these appeared to be pointing to a more settled August, unfortunately, something must be over riding those signals.

 

El Nino perhaps?

We're an island. The Atlantic rules....usually.

And our geographical position continues to confound the more technically-minded weather enthusiasts.

[len]

I'm not sure how accurate the JMA composites are but taken at face value, they would indicate a very warm region 1+2 in August should translate to the exact opposite of what we see being modelled for the UK.

 

 

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/newoceanindex/index.html

 

Hi Nouska

 

That red (as I understand it, having visited the page) might mean a high "positive circulation anomaly"

Which might mean "unusually vigorous altantic flow"???

Therefore depressingly confirming more of what we've got

This is a layman's reading of it.....and I don't know what  "element z500latlon" means?

Can someone clarify please?

 

Len

Edited July 25, 2015 by len

[seaside 60]

....in which case, why do they even put them up? I don't like the bashing the met office get from people who know nothing about the weather at all, but placing these extended outlooks up sets themselves up to be shot at!

Back to the models, maybe the huge cold pool in the Atlantic is squeezing the thermal gradients further south this year - ie the jet is more southerly as the cold boundary is more to the south than it should be? I'm sure that's a simplistic was of looking at it, but maybe it'll help us out with some decent winter weather!

Well I hope you dont live in the south east, as the MO has been pretty spot on for several months now.

However we dont know where you are so cant comment on your area.

[summer blizzard]

GFS still poor to day 10..

 

[Polar Maritime]

An unsettled end/start to the new Month looks likely, With Lows feeding in off the Atlantic from the N/W, Driven by quite a powerful Jet Stream buckled over the UK.

Edited July 25, 2015 by Polar Maritime

[Milhouse]

Well if no one else is going to mention it then i will. GFS 12z has a nice window of settled weather Fri-Sun (nicely coinciding with the weekend) Temps up to 23c in the SE on Saturday.

 

[Milhouse]

GEFS ensemble mean supports a mini plume next Sunday

 

[knocker]

Well I was going to mention it but not in the same context. I'm afraid I've no idea where you get this mini plume from with a raging depression in the offing.

Looking at the GEFS anomalies for 12z the last three days starting at T240 you can see it has suddenly conjured up a deep upper low which accounts for the surface analysis.

http://www.tropicaltidbits.com/

Edited July 25, 2015 by knocker

[legritter]

Evening gang ,I was going to wait till tonights ecm run before posting but family ties pending so here goes .

All i can see at this moment is plenty of interesting weather ,a touch of autumn and at times even winter ,but looking further ahead to the months end its even possible to drag some very warm air over us from time to time .

We have generally had  a dry few months so i expect mother nature to make up which current charts are showing .

g

reat that we are able to put all our knowledge together .But a thought ,long range and mid range forecasts are updated every day ,thats what makes our science so interesting ,[go too sleep wake up all change .]my interest at the moment is what will the weather be doing this wednesday ,only 4 days away ,if this low hits it could be a total washout again ,but on the grand scale of things if it slips a little further south ,a complete different story .certainly not boring charts at the moment ,cheers gang 

[Milhouse]

 I'm afraid I've no idea where you get this mini plume from with a raging depression in the offing.

 

I was going to say its the smallest of mini plumes but the GEFS mean still shows warmer air moving northwards before it gets swept away eastwards. The 10C isotherm just about making it into southern England

 

[knocker]

I was going to say its the smallest of mini plumes but the GEFS mean still shows warmer air moving northwards before it gets swept away eastwards. The 10C isotherm just about making it into southern England

 

 

Don't take this as a criticism as it's not meant to be but it seems to me 'plume' became in vogue this summer and is frequently used when really it's just fluctuations of temp in a mobile situation. I think that this can be quite confusing. Just my opinion of course.

[Nouska]

I was going to say its the smallest of mini plumes but the GEFS mean still shows warmer air moving northwards before it gets swept away eastwards. The 10C isotherm just about making it into southern England

 

 

Love your optimism, that's things just returning to normal!

 

Hi Nouska

 

That red (as I understand it, having visited the page) might mean a high "positive circulation anomaly"

Which might mean "unusually vigorous altantic flow"???

Therefore depressingly confirming more of what we've got

This is a layman's reading of it.....and I don't know what  "element z500latlon" means?

Can someone clarify please?

 

Len

 

Hi Len, the chart is for the 500mb geopotential height anomaly - same type as the ones Knocker posts regularly. Red, in this example, indicates positive anomalies over the UK; blue would be what we would see if it was going to be trough dominated (just as it is at the moment - see up the page). Lation is just the whole global view - can change to NH view.

Edited July 25, 2015 by Nouska

[knocker]

Abandon hope all ye who enter here

 

[ANYWEATHER]

Evening Folks, well lets tart the forecast up and put lipstick on as well      I would imagine these are the worst summer charts since 2012! On a lighter note , southern Britain does need the rain, but not excessive rain as the models paint,,,, Ive posted the unreliable time frame at T+240  , it does not look a lot different from the reliable timeframe   :rofl:  

[Milhouse]

At least with this sort of mean chart it raises the chances of higher temperatures returning to the UK, more especially to the SE which should also enjoy the best of any dry weather. Same old story for the NW however.

 

[knocker]

Well don't look at the ext ECM anomaly for any relief as it has the upper trough over the UK.

[Man With Beard]

Abandon hope all ye who enter here

NOAA 8-14 is not good but 6-10 day at least gives 30-40% chance of a stalling front IMO. Could get 2 or 3 warmer days out of that ... OK it isn't that good at all, then!

[knocker]

Quite and regarding next Sunday the GEFS isn't alone with the upper low.

Edited July 25, 2015 by knocker

[Milhouse]

No such concerns regarding the 18z. Temps up into the low to mid 20s on Sunday and as high as 27c on Monday. Quite a few 12z ensemble members went for a big warm up at the weekend too.

[knocker]

Yes that's because on this run it's tracking the low NNE and that might turn out to be more correct.

Edited July 25, 2015 by knocker

[Captain Shortwave]

Last one from me for a while (jetting off for Florida with their current drought likely to break down as soon as I arrive, how typical).

As some have pointed out there seems to be a window of opportunity next weekend where low pressure could dig south in the eastern Atlantic allowing a chance of the heights over Europe to become more influential again.

Day 6 charts

 

GFS

 

UKMO

 

GEM

 

The GFS and GEM start to stall the low heights beyond this point offering some form of southerly source flow, though it isn't exactly settled so the risk of thundery activity would be there. But at least signs of some kind of warm up occurring after a spell of unseasonably cool and at times wet weather for many areas.

[knocker]

yes does look a bit damp in parts Cs.

After this current depression is out  of the way a mainly dry, cool, week, but warming up a tad in the south by the weekend but more rain creeping into the NW.

Chart weatherbell

 

Edited July 26, 2015 by knocker

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON SUNDAY JULY 26TH 2015.

 

THE CURRENT GENERAL SITUATION. An Atlantic depression will move East into Ireland today with associated fronts crossing most areas and becoming slow moving over Scotland tomorrow in the developing cyclonic flow across the British Isles, strong in the South.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif 

 

MODELS-2 WEEK HEADLINE Still rather changeable with some dry and bright conditions mixed with occasional rain or showers. Generally on the cool side but a few warmer interludes possible in the South.

 

THE GFS JET STREAM FORECAST  The GFS Jet Stream Forecast continues to blow strongly on a much more Southerly trajectory than is normal for this time of year, currently over Southern England and Northern France. Through this coming week it weakens and becomes less defined. It then moves North to Scotland briefly and increases in strength again next weekend before weakening once more and still lying too far South to guarantee dry conditions for the UK.

 

http://www.netweather.tv/index.cgi?action=jetstream 

 

GFS OPERATIONAL The GFS Operational Run today continues to indicate an unsettled week to come though after midweek things look better and somewhat warmer for the South as a ridge from the SW holds sway. Then a NW/SE split seems likely to re-establish across the UK with some fine and at times warm weather in the SE while the North and West sees windy and wet weather at times as deep Low pressure passes by to the NW. Towards the end of the run Low pressure sinks further South again to end the period with rain at times for all.

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The GFS Control Run looks very similar to the operational this morning with some decent weather coming up for the South and East once we leave the current unsettled phase around midweek. It will likely become very warm in the SE next weekend with only a slow decline back into cooler and more unsettled weather experienced elsewhere shown thereafter towards the end of the period.

 

THE GFS CLUSTERS(14 Days) The GFS Clusters at 14 days still indicate High pressure out to the SW in two weeks time with varying degrees of influence shown for the British isles with some members showing a lot of fine and dry weather with warm weather in the SE to others with a strong Atlantic influence with rain at times especially over the North.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows a period of slack conditions from midweek under a weak ridge. A lot of dry and bright weather is likely across the UK but with local showers, warming up in the SE towards the weekend but eyes will have to watch for thundery developments from an upper cool pool of air to the SW of the UK at the weekend. 

 

http://www.wetterzentrale.de/pics/Rukm1441.gif 

 

THE FAX CHARTS The Fax Charts this morning show the first half of the week changeable and windy with showers as the deep Low crosses the UK and away into Europe by midweek. Pressure then builds from the SW, stronger than last nights charts, making the threat of rain for the South after midweek much lower.

 

http://www.weathercharts.org/ukmomslp.htm#t120.

 

GEM GEM is gone with the GFS route this morning indicating unsettled and windy conditions for all until midweek when pressure builds across Southern Britain from the SW. A NW/SE split is then likely to develop with fine and warm conditions likely for the South and East with just brief interruptions from any rain while the North and West see windy and more changeable conditions as deep Low pressure remains to the NW

 

http://www.wetterzentrale.de/pics/Rgem2401.gif 

 

NAVGEM NAVGEM today still shows a threat of more extensive rainfall in the South for a time midweek but then moves into a similar phase as GEM with a build of pressure from the South introducing warm and humid conditions down here towards next weekend. Pressure remains Low to the NW with rain at times in these regions and this shows signs of pushing East into the humid air towards the South and East later next weekend.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

 

ECM ECM looks much better this morning too with the same NW/SE split in the weather developing from later this coming week. The next few days will remain unsettled and windy with rain at times in all regions but as pressure builds somewhat across the South of the UK later this week the South and East will become dry and eventually warmer with only the threat of flirtations of rain from the more changeable NW at times and maybe from a thundery SE late in the period.

 

http://www.wetterzentrale.de/pics/Recm2401.gif

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last night reflects that Low pressure will lie somewhere to the NW of the UK with a SW flow across the UK, warmest towards the SE where only small amounts of rain are likely.

 

http://www.wetterzentrale.de/pics/Reem2401.gif 

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning is focusing on a return to a more NW/SE split to develop in the weather with the driest and warmest conditions towards the SE

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 95.6 pts followed by UKMO at 95.0 pts and GFS at 94.2 pts. At 5 days ECM is stll king at 84.9 pts followed by UKMO at 81.8 and GFS at 81.6 pts. Then at 8 Days ECM still leads at 55.7 pts over GFS's 49.1 pts. Finally at Day 10 ECM leads GFS at 35.1 pts to 28.9 pts from GFS.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png 

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig

 

MY THOUGHTS The models have seemed to jostle around with synoptics which always seemed to lead to conditions over the UK to be poor in recent days so it's nice to see that they have come to some sort of togetherness this morning in that conditions might not become too bad again for parts of the South and East once this current universally unsettled and windy phase of weather over the UK moves away towards midweek. It looks like the rise of pressure from the SW later in the week may hold dominance for a lot longer than was previously documented as the predicted deep Low which was highlighted to end it is now scheduled on a course further to the NW leaving the South and East largely unscathed and possibly scooping up some warm and muggy air into the SE next weekend. This leaves the North and West with the standard weather fayre that has afflicted these regions all summer with further rain and showers in strong and blustery SW winds at times. However, further South and East look like seeing a fair amount of very useable conditions for outside events and activities with only the occasional threat of an intervention from the West by a cold front and a little rain or indeed a thundery shower from mainland Europe. Perhaps the most encouraging thing shown this morning is the feed of warm air over Europe able to make some inroads into the UK and not be bottled up in situ by Low pressure events across the UK. Let's hope this is the first steps towards a better August predicted by the UKMO for some while now and that the models continue to expand their improvements to include those folk up North soon. 

 

Next update from 09:00 Monday July 27th 2015