Model Output Discussion

[Slowpoke]

I know it's FI but it's ridiculous how far north those the 850 20C line gets in Northern Europe. They seem to be having a pretty brilliant summer.

Edited July 16, 2011 by Slowpoke

[shedhead]

Very similar synoptics to the final third of last summer, which saw persistent heatwave conditions in W Russia, while we in W Europe suffered cool, unsettled weather. Moscow woud again see the 100f

mark threatened IF those charts verify, meanwhile here average temps look about the best on offer. Frustrating enough for most, but come Jan when it's -25c in Moscow and 13c here this forum will go

into full on 'toys out the pram' mode... again!

Edited July 16, 2011 by shedhead

[SP1986]

Looking at the NOAA, the NAO looks like it finally enter positive at least for a time later in the month. The AO also is heading for neutral or slightly positive. Both of these have spent quite a while in a negative phase. Whilst these two aren't everything about the weather hopefully it is some sort of sign for a pattern change even if not that massive.

This is pretty much some of the basis I used for suggesting the upcoming spell won't be as bad as the current model outputs suggest. The NAO/AO combination have actually been flirting with prospect of positivity for some time now.

[mushymanrob]

very tentetive signs oh something more settled and high pressure driven into fi, the ecm is pretty hopeful and the anomoly charts are edging towards a similar picture.. so just maybe there are some straws to clutch!

[The Northern Ramper]

The gfs 0z has been pretty consistent over the last few days of high attempting to build in next weekend. It is down to 144 now and will soon be reliable.

[bluearmy]

very tentetive signs oh something more settled and high pressure driven into fi, the ecm is pretty hopeful and the anomoly charts are edging towards a similar picture.. so just maybe there are some straws to clutch!

you mean this one rob ?

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

given that the ecm ens are't quite out yet, its clear that this is a mean of the op runs days 8 thru 10 so the two will obviously edge towards a similar picture!! i'll try and post a link to the ecm 500mb mean flows at T168/T240 to compare whether its accurate

here you go

http://www.ecmwf.int/products/forecasts/d/charts/medium/eps/ensm/essential!Geopotential%20at%20500hPa!Europe!168!pop!od!enfo!plot_ensm_essential!2011071700!!/

if you flick through the timescales T168 to T240, you'll see the differences between the mean on the left and the op on the right. clear that the earlier chart reflects the op run but the ens isnt too far away, given that it is bound to be less amplified. exactly where will the trough sit and how quickly can it fill ????

changing the parameter to MSLP also shows that the pressure anomolies are fairly well reflected by the mean though again, with rather less gusto.

wonder if the naefs 00z update will be better than yesterdays 12z which was quite unenthusiastic about prolonging any improvement during the last week july. the spreads on the ecm 00z look interesting if we can get the trough to fill out as they lift the jet well north of where its been sitting.

Edited July 17, 2011 by bluearmy

[Weather Boy]

EDIT: SORRY MY LINKS DON'T WORK: INSTEAD I'VE POSTED THE CHARTS

Looking at the 0z, I prefer (by which I mean, I would like to see, not think is more likely) the ECM which sees good ridging and the prospect of a decent settled spell around next weekend, which is borderline FI.

The GFS meanwhile, is rather a frustrating run in that it starts to go the same way as the ECM but never seems to quite complete the job. See here on Thursday, actually ahead of the ECM evolution:

..you would expect to see some nice ridging in to complete the evolution, but then into early FI you end up with:

http://www.netweathe...ction=nwdc;sess=

the same pesky low comes back to haunt us with a chart that is only a little better than what we are promised for the coming couple of days. I'd like to say that it was unconvincing, but I said that about the current set up which came to pass (although I do think that the charts and indeed the weather are nowhere near as bad as the models would have had us believe at least in my location). Then deeper FI gives us a low pressure train to the north of Scotland suggesting the same old SE/NW split, although the SE being far from perfect.

Looking at the ensembles, I agree that there's virtual across the board agreement on a pressure rise from the middle of the week onwards, but that's hardly surprising as it would be extraordinary to see such sustained low pressure from now into FI at this time of year - even a train of lows would give us higher pressure than now-. However it's worth noting that no member gives us particularly high pressure (or indeed temperatures) with even the most optimistic member having pressure well south of 1030 for the whole of the run.

So it looks to me that whilst more benign weather is very likely after mid/end-week, hot and/or very sunny weather seems a bit of a distant dream, although the SW seems better placed to take what's on offer for the foreseeable.

Edited July 17, 2011 by Weather Boy

[shedhead]

Signs this morning that we may well see a switch to more settled, warmer conditions in the longer term, but it's still rather early to make to many assumptions. Certainly the 500mb anomoly charts do take the deep

troughing away from us, but they are still not suggestive of anything fine, warm and sunny, so any improvement that does emerge could simply be a blip rather than a pattern change. That said, the overnight runs

do offer the best hope for some time to those wanting a return to more summery conditions.

Edited July 17, 2011 by shedhead

[Gibby]

GFS shows the current very unettled weather improving from the SW through the latter stages of this week. Until we get there there is still plenty of scope for heavy sahowers and rain at times in the cool North or Northwest flow over Britain. Up unto Day 8 pressure remains Low well to the NE, still close enough to affect the North and East with showers while the south and west see the driest and brightest weather close to high pressure to the SW. From day 9 to day 15 GFS brings a weakening ridge across the UK briefly but quickly brings a return to Atlantic wind and rain to all with depressions moving east close to Northern Scotland at times.

UKMO also shows an improvement but we're going to have to wait until the weekend for many to see much benefit as Low pressure is shown to be well in control through the working week with heavy showers and some longer spells of rain at times. It's next saturday when the west and south become dry and bright for many with just a few showers towards the east as a ridge closes in towards Western Britain from off the Atlantic.

ECM this morning is very similar to UKMO with an unsettled week with low pressure close to Northern and Eastern parts with a wrap around of rain and showers affecting all areas at times through the working week. pressure is then building from the Atlantic Northeastwards towards NW Britain late in the week with a very slow influence of this gradually extending across the UK by next weekend and beyond, bringing drier and less showery conditions as well as warmer weather too across all areas bar the far east and southeast by next wednesday.

Improvements are going to be slow but if we're patient there are signs of somewhat better weather on the horizon but how long it will last is open to debate (not long if the GFS model is anything to go by). Through the working week it looks unsettled but slowly and surely showers and rain will become more and more restricted to eastern areas by the weekend with the west becoming dry and bright by next weekend. We could end up over next weekend with a ridge having its axis SW-NE over us which could end up being a benefit to us longer term if it can hold as the Euro low pulls south. It's a case of wait and see as patience will be a virtue this week with twists and turns likely along the way.

[William of Walworth]

Excellent summary Gibby, both in clarity and (more positive looking) content -- thank you.

[shedhead]

06GFS continues the improving theme, but with a distinct west/east split developing as the working week unfolds. IF it verifies Ireland and the western half of the mainland should see some decent amounts

of sunshine across the 2nd half of the week and into the weekend, with temperatures probably rising by a degree each day. Eastern areas closest to the LP look cloudier and anomolously cooler with showers,

but even here showers should become lighter and increasingly confined to North Sea coastal counties by this time next week, with the chance of summer returning for all after the 25th - at least temporarily!

[SP1986]

I'm not surprised it appears (for now) to be edging towards the high pressure scenario (albeit it would be short lived), as generally the low pressure would be expected to move into any space it can find (much like water filling a space), and the gap has generally been to the southeast where the low now moves into. The slack Scandinavian high essentially dissects the low as it tries to find area to move into, allowing high pressure to move in.

This is always the most likely scenario to occur.. much more likely than the low hanging around just to our east.

[Thundery wintry showers]

Looking at the near term, mostly cloudy with some showers and longer outbreaks of rain over the next two days, due to a deep area of low pressure. Tuesday looks like having sunshine and showers and significant thunder potential in eastern and southern areas, with the low pressure slackening off. There is some divergence regarding what happens towards the end of the week- broadly speaking if we see that high nudge in from the west giving a north to north-westerly flow, as per GFS, we will have sunshine and declining shower activity. However, my main point of disagreement with many recent posts is with the notion that the higher pressure on the UKMO/ECM will equate to more sunshine as well as less showers. In my experience when we get modified air coming down from the NE the result, particularly in eastern areas, is often drier but cloudier conditions, and while it usually turns warmer, the warmth tends to result from higher overnight minima.

The trend has been to place the high a little further east than on yesterday's runs, though, and it would only take a small further eastward shift for my assessment of the likely weather to nudge significantly in the direction of warmth and sunshine. The other significant factor is the high over Scandinavia- if we can keep that lodged there for a while, there's more chance of some sort of hot spell eventually arising, but I think if the Atlantic cranks up a few notches and blasts it away then hot spells are almost out of the question. I don't find the 8-14 day summaries from NOAA very encouraging in this regard, keeping high pressure locked to the N and NW and promoting cloudy and relatively cool weather in the east, though again, one could argue that if the trend of the last two days continues (placing the high further east with each set of runs) then the next update or two could promote a warmer sunnier outlook.

[paul tall]

06GFS continues the improving theme, but with a distinct west/east split developing as the working week unfolds. IF it verifies Ireland and the western half of the mainland should see some decent amounts

of sunshine across the 2nd half of the week and into the weekend, with temperatures probably rising by a degree each day. Eastern areas closest to the LP look cloudier and anomolously cooler with showers,

but even here showers should become lighter and increasingly confined to North Sea coastal counties by this time next week, with the chance of summer returning for all after the 25th - at least temporarily!

I'm liking that possibility.

[Summer Sun]

Nice to see more agreement from GFS and ECM this morning for later in the week,

http://www.wetterzen...s/Rtavn1561.png

http://www.wetterzen...s/Rtavn1801.png

http://www.wetterzen...s/Rtavn2041.png

http://www.wetterzentrale.de/pics/Rtavn2281.png

This pattern is shown to continue until late July though FI been FI it's mostly likely to change within a few day's, though the met office are hinting of low pressure moving in by August so who know's

[Sunny Android]

Now we are half way through July I think we'll have to keep an eye on tropical formations off the East coast of Florida and the northern Gulf of Mexico,

There's a 20% chance of one developing into a storm right now of the Florida coast which could have a bearing on the North Atlantic Models in a week !

Edited July 17, 2011 by Sunny Android

[Eugene]

HP ridging in as early as thursday, turning into a very decent summer here in the midlands.

Edited July 17, 2011 by Paul

[95 Degrees]

All models look very good into not so deep FI, hopefully they don't change for the worse as they all look promising for late July

[Summer Sun]

Slowly but surely the models are starting to be consistent with a slow return to high pressure by later on this week,

http://www.wetterzen...s/Rtavn1261.png

http://www.wetterzen...s/Rtavn1501.png

http://www.wetterzen...s/Rtavn1741.png

GFS 12Z has upgrade on the 06Z with the high pressure staying right through the remainder of July and into August (deep FI), I this does happen then it would be quite a decent spell of settled weather, however wind direction and cloud cover will have a big say in how warm it may get, don't expect any heat waves but maybe above seasonal averages in some areas. Parts of Scotland and Ireland could be the favored spots for any hot spells.

Edited July 17, 2011 by Gavin D

[95 Degrees]

Slowly but surely the models are starting to be consistent with a slow return to high pressure by later on this week,

http://www.wetterzen...s/Rtavn1261.png

http://www.wetterzen...s/Rtavn1501.png

http://www.wetterzen...s/Rtavn1741.png

GFS 12Z has upgrade on the 06Z with the high pressure staying right through the remainder of July and into August (deep FI), I this does happen then it would be quite a decent spell of settled weather, however wind direction and cloud cover will have a big say in how warm it may get, don't expect any heat waves but maybe above seasonal averages in some areas. Parts of Scotland and Ireland could be the favored spots for any hot spells.

Cloud cover doesn't bother me as such as I don't think it will be much of an occurance during the HP period, more worried that because GFS has pushed the heat back from 27th to 30th, that it stays in FI and never becomes reality in the reliable, only slightly worried about that though and hopefully the warmth no matter how intense, eventually comes.

[Summer Sun]

ECM takes a slightly different set up to GFS, for the weekend.

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzentrale.de/pics/Recm1681.gif

[Guest]

ECM takes a slightly different set up to GFS, for the weekend.

http://www.wetterzen...cs/Recm1201.gif

http://www.wetterzen...cs/Recm1681.gif

That low in the north sea really winds itself up during the weekend then - if I am reading those two charts correctly.

Retrogression on the cards? :unsure:

[Summer Sun]

No i think if i'm looking correctly, it dies a death by Monday or Tuesday

http://www.wetterzentrale.de/pics/Recm1921.gif

http://www.wetterzentrale.de/pics/Recm2161.gif

ECM is showing the pressure rise from the south west it's just doing it slower than GFS at present

[damianslaw]

A slowly improving picture as we head through the coming week. The current low pressure system will become a weaker affair by Wednesday and as heights remain strong over north scandi and NW russia - it will gradually transfer southeastwards into north germany/denmark allowing developing strong heights over the atlantic to ridge into western and especially southwest parts by the weekend.

So a cool showery week for all with trough/shortwave action from the north under what will be a particularly cold airmass for the time of year - look at those low uppers descending down from the arctic mid week. Hopefully any ridge development becomes a robust affair by the weekend heradling more typical 'high summer' conditions. Those heights over north scandi could do us a big favour as we end the month - merging with such building heights. The alternative sceanrio with greater probability is weak ridge development allowing the atlantic trough from the nw to attack. I did forecast a decent spell at some stage during the second half of July and if the former scenario occurs then that come come true.

[snowlover2009]

Slowly but surely the models are starting to be consistent with a slow return to high pressure by later on this week,

http://www.wetterzen...s/Rtavn1261.png

http://www.wetterzen...s/Rtavn1501.png

http://www.wetterzen...s/Rtavn1741.png

GFS 12Z has upgrade on the 06Z with the high pressure staying right through the remainder of July and into August (deep FI), I this does happen then it would be quite a decent spell of settled weather, however wind direction and cloud cover will have a big say in how warm it may get, don't expect any heat waves but maybe above seasonal averages in some areas. Parts of Scotland and Ireland could be the favored spots for any hot spells.

Yes a slow improvement, but the ecm is kind of different in regards to the trough in the east, it does improve to the very end.

Edited July 17, 2011 by snowlover2009