Model Output Discussion 01/06/2012

[Gavin P]

Interesting discrepency between GFS and NAE for late tonight and tomorrow morning

NAE wants to take an area of pretty heavy rain from Bristol to The Humber in the morning;

http://www.weatheronline...ES=0&WMO=&PERIOD=

http://www.weatheronline...ES=0&WMO=&PERIOD=

GFS doesn't really show much at all. Maybe some showers over East Anglia by lunchtime, but certainly nothing that significant;

http://www.wetterzentrale.de/pics/Rtavn124.png

http://www.wetterzentrale.de/pics/Rtavn184.png

Unusual to have a differance like that at such a short time out.

[Chris K]

How come the 18z isn't rolling out here? Most of 12z is missing to? Anyone else got this or is it just my internet being silly?

[Snowy Easterly]

how unlucky are we, the whole of europe is under high pressure next week while we have that little low slap bang over us, im not bothered if it rains i just hope its not cool, what will temps be like ? the GFS charts on netweather are not working

[Cheese Rice]

The 18z is a horror show, this summer really is turning out to be a repeat of the last few.

Hopefully mid July onwards will garner some settled weather.

[Supacell]

How come the 18z isn't rolling out here? Most of 12z is missing to? Anyone else got this or is it just my internet being silly?

Its the same for me. Pity as i dont really understand the pressure maps, i need colours on maps of the uk to know what is happening. Not sure what is going on with them.

[ZONE 51]

Parameter - GFS - Thck 850-1000 hPa - 18z

starting of with - Sat 30.06 15 GMT

Sun 01.07 15 GMT

Mon 02.07 15 GMT

Tue 03.07 12 GMT

Wed 04.07 12 GMT

Thu 05.07 12 GMT

Fri 06.07 12 GMT

Sat 07.07 12 GMT

The next chart is an idea of where the largest amounts of rainfall could be, this is the accumulated total precipitation from friday 29/6-2100hrs to 6/7-1200hrs-this could change,

GFS - 18z - the next 7 days-thundery at times, rain and showers for all, some heavy downpours and thunderstorms possible in places, especially next week, we will have unstable air at times, mostly warm generally next week, and perhaps very warm late next week, most likely in the south although some warmth pushing north.

[Frosty.]

This morning's UKMO 00z shows all of the uk controlled by low pressure centred close to ireland next week but at least it looks fairly warm and humid but with more heavy slow moving showers and storms although there will also be sunny periods and the low fills towards the end of next week with the uk within a slack pressure field so it looks warm and showery next week with some storms and temps into the low to mid 70's F.

[mushymanrob]

theres no agreement on the track/behaviour of the next system, slip into france (ukmo) hang about over us (gfs00z) or migrate slowly northeast (ecm). no real sign of pressure rise (although hinted at in fi) but as things are so unstable nothing past about t60 can be taken to seriously.

[Summer Sun]

All models remain unsettled for next week only ECM in deep FI shows pressure building

http://www.jp2webdes...o.uk/ds/gfs.htm

http://www.jp2webdes...o.uk/ds/ecm.htm

http://www.jp2webdes....uk/ds/ukmo.htm

All areas can expect to see rain at some point

Edited June 30, 2012 by Summer Sun

[snowmadchrisuk]

Last night's Models showed Next Thursday having Some Crazy storms at least as good as last Thursday , but this seems to have been toned down this morning with it not getting as Hot over the UK as was predicted. However there is still a lot of Hot air to our South and we could quite easy tap in to the Hot unstable air at fairly short notice. I predict 2 more weeks of Rain/Showers before we get a 2 Week dry spell around final third of July.

Edited June 30, 2012 by snowmadchrisuk

[johnholmes]

Its the same for me. Pity as i dont really understand the pressure maps, i need colours on maps of the uk to know what is happening. Not sure what is going on with them.

hi S

Why not have a look in the Net Wx Guides for help in explaining what the charts show. I'm sure you would get more enjoyment once you are able to develop more understanding of the charts.

If you want any help please pm me I'm always happy to talk 'weather'.

John

[William of Walworth]

Last night's Models showed Next Thursday having Some Crazy storms at least as good as last Thursday , but this seems to have been toned down this morning with it not getting as Hot over the UK as was predicted. However there is still a lot of Hot air to our South and we could quite easy tap in to the Hot unstable air at fairly short notice. I predict 2 more weeks of Rain/Showers before we get a 2 Week dry spell around final third of July.

theres no agreement on the track/behaviour of the next system, slip into france (ukmo) hang about over us (gfs00z) or migrate slowly northeast (ecm). no real sign of pressure rise (although hinted at in fi) but as things are so unstable nothing past about t60 can be taken to seriously.

I can see exactly, from recent outout, why snowmadchris is predicting continued instability/unsettledness, but I've bolded the bit of mushy's post that should provide the cautionary note against extrapolating too far ahead at the moment.

Edited June 30, 2012 by William of Walworth

[William of Walworth]

Which is why I can't possibly say yet what next Friday and Saturday** will be like ... let alone the rest of the month ...

**(we''ll be camping once again, this time in Hereford),

Some sunshine with frequent showers and reasonably warm seems as good a punt as any, but this far out it's guesswork only. We can't even altogether rule out something drier than that by then. Yet.

Edited June 30, 2012 by William of Walworth

[phil nw.]

Looking at the overnight modelling we would be tempted into thinking there are just a few signs from the ECM Op. run of some improvements in week 2.

Both runs show the Azores High nosing in-the ECM more so-similar to it`s 12z yesterday.GFS keeping the AH further west.

Here the mean heights from both runs for day 8-10 illustrate this

When glancing at some other data we can see more uncertainty.

GFS percipitation ens graph shows a higher mean total for London for the first part of July than the ECM which would reflect a more suppressed Azores High than the more settled ECM outputs.

Add into the mix the NOAA 8-14 day H500 forecast and the NAEF`s at Day 10

both indicating the persistence of a NW European trough,but perhaps less pronounced and signs of some splitting.

It does appear the ECM Op.run is still at odds with the GFS and indeed it`s own mean output and taking the other data above there`s no strong trend away from this showery and changeable regime yet.

Edited June 30, 2012 by phil n.warks.

[Bobby]

The GFS 06z looks more like the UKMO with a cut off low/stalled low over us. ECM takes the low further North, allowing pressure to build and would produce the most settled weather of the summer so far.

The GFS/UKMO however means more rain and heavy/thundery showers for most for a while yet. The NAEFS anomaly maps and ensembles suggest to me the GFS/UKMO is more likely. Towards the end of the run the NAEFS maps show a strong signal for low pressure dominate again, so even if the ECM is right it might not last

GFS 06z

NAEFS anomalies at the end of run

Still strong heights Greenland way as they have been for ages now it seems

ECM's hope for summer lovers

[phil nw.]

I see we are reading the same script Barb,lol.

Indeed no across the board signs of real Summer-only in the later ECM Op run.

Those of us who would enjoy a decent spell of Sun and warmth can only hope that the ECM has picked up a new trend and that other outputs will catch on in future runs.

Yesterday`s ECM 12z Op and the 00z ECM Op both show the building Azores High in week 2-so you never know.

Edited June 30, 2012 by phil n.warks.

[bluearmy]

we have clear uncertainty regarding the behaviour of the troughing this week - will it sink and become cut off or not ?

beyond this and we have seen two ecm ops building the azores ridge into nw europe in fi whilst gfs op runs are playing around with this option somewhat whilst the gefs hold the ridging in the atlantic and the troughing in our vicinity (hence the naefs output above).

to look at the varying output at day 10 between ecm ens 00z and naefs 00z

mean and spread for each model

conclusions:

ecm mean approx 5mb higher than naefs over the uk

look at the shape and position of the atlantic ridge on the two models. naefs has it positioned much as it has been for the past month standing tall and proud with the subsequent troughing into nw europe. not looking particularly sharp but certainly not settled for us. ecm has the ridging under pressure off the eastern seaboard (much as the op showed) which pushes the ridge more ne towards iceland. the spread on ecm showing support for the mean with the lighter area se of greenland where lower heights are clustered and the darker shape of the low spread reflecting the ridge shape towards iceland.

so the key to the shape of the atlantic ridge will be the trajectory and strength of the jet off the eastern seaboard. neafs banks on it being much as it has been for the past month whilst ecm goes for a change of direction.

to our east, both models have a ridge, ecm more pronounced than naefs (Infact the models are almost a straight reversal of shape for the sceuro ridge and atlantic ridge with naefs having the sceuro ridge under more pressure from the nw euro trough - that would indicate to me that we see a stronger jet near us on naefs than ecm.

both models have their spreads fairly inline with their means. however, naefs spreads seem to be trending slightly towards ecm to our west and that just gives the edge to the chances that ecm is likely to be closer come day 10 than naefs.

fairly inconclusive re likely surface conditions but the lowish spread for se uk and the direction of that spread sw/ne says that maybe week 2 might be not too bad for the se quarter of the uk.

[Summer Sun]

GFS 06z remains unsettled all next week

http://www.null/ds/gfs.htm

[Frosty.]

There are crumbs of comfort from the ecm 00z in FI for the first settled spell of the summer but otherwise it looks like unsettled weather will dominate for the next few weeks at least and if it wasn't for the recent flooding chaos, the idea of sunshine punctuated with heavy thundery showers and temps around 22-24c would seem like a popular type of summer weather if we can't have baking heat and wall to wall sunshine..all I can say is, the current pattern will change eventually so let's hope we see something more settled from mid to late july onwards.

[BLAST FROM THE PAST]

Signs of this low pressure next week becoming slow moving and warm air being sucked up to mix with cooler air concerns me. I think we should look out for torrential downpours again. Who will cop it....anyone's guess but IMO there is a real risk ahead of us for 1st week of July. This type of setup leads to very slow moving showers so flash floods may be a news item again.

BFTP

[johnholmes]

Picking up on what has been posted above using the various model longer term predictions.

Using, as ever, for the 7-15 day period, the 500mb anomaly versions. They still show little sign of any marked let alone major upper air pattern change in the time scale in the previous sentence. This is my short hand comment I made this morning once I had seen the NOAA issue from last evening and the ECMWF-GFS output this morning.

Both fairly similar to their last issue although gfs is building the ridge to the nw more than on 29^th

Looking at the 29^th noaa issue and the ec-gfs this morning there is some similarity but also some differences. Noaa looks more like the ec issue and has no cut off over uk, similarity to both is the build of heights west of uk

Summing up, the noaa-ec version suggests more of the same with gfs POSSIBLY giving a slightly different version but still unsettled but possibly warmer?

There is just a glimmer, no more than that, of a possible SLIGHT shift in the pattern that MIGHT lead to more than a couple of days settled warmth but I would not if I was a betting man put any money on that yet.

Edited June 30, 2012 by johnholmes

[Summer Sun]

GFS 06z continues to show a wet week coming up, storm risk though is low at the moment

July looks like starting where June finished, anyone with holiday plans could be dissapointed as sunshine looks hard to find for any long periods next week

[Frosty.]

Having just had a good read of the latest meto update, it would seem that the Ecm 00z evolution of the azores high ridging across the uk could be premature but with just a small delay of 3-5 days. The meto are hinting at a pattern change around mid July but more likely towards the last 7-10 days rather than mid month with a chance of very warm and dry weather in that period. So there may be light at the end of the tunnel with a hint of fine summery weather after mid july and hopefully extending into august but until then it looks like either showers or persistent rain are going to feature strongly in the forecast but at least it should be on the warm side with some sun between the downpours.

[Frosty.]

Signs of this low pressure next week becoming slow moving and warm air being sucked up to mix with cooler air concerns me. I think we should look out for torrential downpours again. Who will cop it....anyone's guess but IMO there is a real risk ahead of us for 1st week of July. This type of setup leads to very slow moving showers so flash floods may be a news item again.

BFTP

Agreed but perhaps not as severe as thursday with no repeat of the supercells as hot continental air met the colder air aloft, but it does look disturbed with more traditional heavy showers and some thunder activity but probably no giant hail next time..or tornados!

[phil nw.]

As it`s very quiet in here this afternoon it`s seems a good time to lock this thread and start a new one for July.

Link to new thread

http://forum.netweather.tv/topic/73729-model-output-discussion-30062012/page__pid__2327631#entry2327631

Edited June 30, 2012 by phil n.warks.