Model Output Discussion 06Z, 13 Sep. 2013 ---->

[Captain Shortwave]

The one good thing the models have done over the past 12/24 hours is that they have all dropped that pesky deep Scandi troughing which looked like it could become a feature from the middle of next week. That looks unlikely now 

The pattern looks pretty slack over the Atlantic and with an upper ridge over us when the pattern slows to a crawl then we could be settled for quite a while (warm if the high sets up favourably)

Edited September 19, 2013 by Captain shortwave

[No Balls Like Snow Balls]

T120 is where the uncertainty begins. UKMO and GFS 12z completely different at this time frame.

 

 

 

Not even worth trying to make a forecast after Tuesday at the moment.

 

 

 

 

[Gaz1985]

Well what can you say? brilliant! 

 

[Summer Sun]

No change from ECM so far for next week

 

 

+15 uppers remain on course to move in this weekend

 

 

Interesting to see where we go from here

 

 

The high stays at t144 but it becomes cooler away from the SW

 

Edited September 19, 2013 by Summer Sun

[Mark Neal.]

+144hrs ECM. Still settled but low pressure not 100 million miles away to the SW. Still pleasant.

Edited September 19, 2013 by Mark Neal.

[Captain Shortwave]

I cursed the output again didn't I 

 

[AWD]

So at T144 we have;

UKMO settled and warm

ECM settled but cooler

GFS less settled/showery but warm

Take your pick!

[Mark Neal.]

Lose the really warm uppers by 144hrs aswell. Some chillier air to the North not far away from Scotland, though still benign. 

[Mark Neal.]

168hrs, the high starts to lose its grip it seems, still pleasant but not as settled as previous model runs.. 

Edited September 19, 2013 by Mark Neal.

[Summer Sun]

So at T144 we have;

UKMO settled and warm

ECM settled but cooler

GFS less settled/showery but warm

Take your pick!

 

Yep its a right old mess at the moment

 

GFS unsettled but warm

 

 

UKMO settled and warm

 

 

GEM settled and warm

 

 

ECM settled but cooler away from the SW

 

 

Take your pick from that lot

[Frosty.]

The GEFS 12z mean shows rock solid support for the very warm and anticyclonic spell which really begins to click into gear by sunday and go through the gears early next week with very warm weather for most of next week, especially for the south but pretty warm further north too, temps in the south are looking like they will soar into the mid to upper 20's celsius, especially across southern, central, eastern & southeast england, it also looks like sunshine amounts will increase as time goes on with less cloud around by early next week, the warmer uppers flood in on saturday and then it just builds and builds from there, this is a bonus anticyclonic spell and we should make the most of it in case it's the last time we see weather like this until next april at the earliest. The longevity of this fine spell is still unclear although the mean maintains a ridge across most areas until at least the end of next week, it may well be that once this anticyclonic spell becomes firmly established, it may prove very reluctant to leave us until october.

Edited September 19, 2013 by Frosty.

[Mark Neal.]

+198hrs ECM shows the following, pressure falling away and lower heights to the North. 

Edited September 19, 2013 by Mark Neal.

[Summer Sun]

Low pressure taking over at t216

 

 

Warm in the south cooler in the north

 

Edited September 19, 2013 by Summer Sun

[Mark Neal.]

216hrs has Cooler conditions with low pressure to the SW ( Still mild in South), looks alot less settled to me. Uppers less mild and colder air filtering to the North of UK. 

 

So as people have alluded to looking at all current model output, on where we go after Tuesday, Midweek as pressure tends to fall away and we see cooler temperatures still settled at that time. Interesting to watch next few model runs and see if they continue to show pressure falling away and a return to unsettled by this time next week. Alot of watching for now..

 

In mean time a lovely couple of days to come. Sunshine at times, warmer and lighter winds 

Edited September 19, 2013 by Mark Neal.

[Mark Neal.]

240hrs low pressure taking charge with a system to the SW sliding along southern districts. Uppers cool in North, 0c line into Northern England. 

[Summer Sun]

Cooler for all at t240

 

 

Not agreement from t144 onwards this evening so where we go next week is anyone's guess

Edited September 19, 2013 by Summer Sun

[Captain Shortwave]

Well if the ECM verified then the metoffice would have to rewrite pretty much all their forecast, though it's not the first time this week that's happened.

Lets hope the ECM is off on one 

[Frosty.]

I think steve murr will be lurking

 

There has been warning signs that there could be a much cooler and unsettled spell as northern europe cools down significantly, the Gfs 6z (op & control) showed the trend the Ecm 12z has run with tonight but it's still outside the reliable timeframe, we now have a very warm anticyclonic spell set in stone, let's enjoy it while we can.

[Frosty.]

 

 

 

Thereafter subtle movements in the high pressure could mean the Uk engages colder air into the circulation as the cold surge in northern Europe becomes perilously close to the East on some output. ECM goes one step further with a particularly chilly looking 10 day chart with rain on a vigorous cold front slipping SE would be followed by a marked drop in temperature with potentially wintry showers over Northern hills and frost at night in the days that follow. So enjoy the warmth and sunshine early in the week because it might not last too long after midweek.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

 

 

Gibby mentioned this risk earlier, the Ecm 12z has delivered it, as did the GEFS 06z control run. Good spot by gibby, top man.

[Cheshire Freeze]

Gibby mentioned this risk earlier, the Ecm 12z has delivered it, as did the GEFS 06z control run. Good spot by gibby, top man.

 

To be fair, signs that the NAO may be about to go negative have been there for days. The GFS has shown the Scandi trough on several occasions in FI with pressure rising to the N and NW. Some people just chose to harp on about temperatures into the mid- high 20's etc etc.

Edited September 19, 2013 by CreweCold

[ANYWEATHER]

Yep it looks like a settled and warm outlook is still on track, a rogue 6z control run showing unsettled is nothing to be concerned about, looking forward to summer coming back now, have to say the models picked this trend weeks and weeks ago, ran with it dropped it, ran with it, dropped it and now it's reality, although at no stage has the 500 mb anomaly charts been fully behind it, indeed for most of the time it's been against it, until very recently. This is going to be like July weather next week.

There is not going to be any July weather next week, if you look at the models closely ,a lot of cloud during this weekend  and perhaps next week .before the weather turns more unsettled from  midweek onwards...gfs and ecm show what I mean....  

Edited September 19, 2013 by ANYWEATHER

[Captain Shortwave]

To be fair, signs that the NAO may be about to go negative have been there for days. The GFS has shown the Scandi trough on several occasions in FI with pressure rising to the N and NW. Some people just chose to harp on about temperatures into the mid- high 20's etc etc.

To be honest I see little point of looking at day 10 and beyond if the models are struggling to get day 4/5 correct as how that pans out is more than likely to determine how things play out later on. I mean the coming weekend is tantamount to that point.

So the split flow is causing the models problems with huge differences even at 5 days out. ECM is usually best at this timeframe but it's run this morning had support whilst tonight any other model support has moved to different options. I guess more runs are needed.

Mid twenties for Sunday, Monday and possibly Tuesday at least still

@Anyweather, I wouldn't exactly call the GFS unsettled now. I mean if that's unsettled, the ECM would be apocalyptic

Edited September 19, 2013 by Captain shortwave

[Cheshire Freeze]

To be honest I see little point of looking at day 10 and beyond if the models are struggling to get day 4/5 correct as how that pans out is more than likely to determine how things play out later on. I mean the coming weekend is tantamount to that point.

So the split flow is causing the models problems with huge differences even at 5 days out. ECM is usually best at this timeframe but it's run this morning had support whilst tonight any other model support has moved to different options. I guess more runs are needed.

Mid twenties for Sunday, Monday and possibly Tuesday at least still

@Anyweather, I wouldn't exactly call the GFS unsettled now. I mean if that's unsettled, the ECM would be apocalyptic

 

Aye, not too unsettled but possibly cold for the time of year with subdued daytime maxima and overnight frosts, possible air frosts in prone locations if we're affected by the coldest of the uppers. Anyhoo, some warmth to be had before then

[Summer Sun]

Latest from Gibby

 

Good evening. Here is the report on the 12 midday output of GFS, UKMO, GEM, NAVGEM and ECM for today Thursday September 19th 2013.All models show the pattern that's been shown for days now continues on schedule with the last rain for a time has now recently cleared SE England leading to steadily rising pressure from now on from the South and SW. A ridge crosses East tomorrow with dry and fine weather for most in a light to moderate Westerly breeze with sunshine and passing clouds and temperatures around average. By Saturday a warm front will be moving NE across Northern and Western Britain carrying a lot of cloud and some drizzly rain in places for a time before drier air reaches the SE later and works it's way further North across the UK on Sunday and Monday. It's from that point on that the pattern between the models diverge.

 

GFS shows High pressure declining away slowly SE through the week with pleasant weather remaining intact for most of Britain for quite a while. Late in the week pressure will of fallen sufficiently to allow fronts to push in from the West and SW with rain a risk for many next weekend as temperatures fall. Then through the rest of the run Low pressure areas from the SW then North come into play for the UK with an ever cooling air mass covering the UK to bring very cool and unsettled conditions to end the run.

 

UKMO shows High pressure over the top of the UK next Wednesday with sunny and warm daytime weather with clear, cool and potentially foggy nights.GEM shows pressure falling after midweek with the UK declining away as fronts push up from the SW with some rain and cooler conditions reaching many areas over the weekend.

 

NAVGEM is looking very isolated tonight in that it shows a rapidly deepening Low near Southern Ireland as early as Tuesday with strong winds and rain developing for many by midweek as the Low ambles around Ireland before sliding slowly back South late in the week. The rain would be most prolific in the South and West with the North and East less likely to see much rain from this scenario closer to High pressure.

 

ECM tonight shows a large High having developed South of Iceland next Tuesday absorbing our weekend High into a ridge early next week. After a few warm days temperatures would likely steadily fall back to average levels with night's cool and misty with some radiation fog formation under light winds. Later in the week things show signs of turning more unsettled as pressure falls and Low pressure develops to the SW and with a cold feed not far to the NE with rain likely for many next weekend in much cooler air.

 

The GFS Ensembles show good support for a warm period over the weekend and start of next week before cooler conditions look like developing as well as more unsettled conditions with rain at times from the 27th in the South. The North show a rapid cool off earlier than further South with a huge spread between members from as early as midweek next week.

 

The Jet Stream shows the flow migrating North of the UK over the next few days with a cut off circulation down to the SW. As this small feature expands it draws down the SW to NE flow more and more SE on its trajectory through the UK so that indications are shown tonight of the flow perhaps moving South of the UK in the outer limits of the run.

 

In Summary the weather shows two phases tonight. the first phase will occur between now and Tuesday when gradually warmer conditions are likely to develop with some warm daytime sunshine with cool and misty nights. The second phase is from Tuesday onward when indications are that High pressure will re-position or decline sufficiently enough to allow lowering temperatures, cloudier and eventually more unsettled conditions to develop across the UK as a whole. It is too early to say whether this trend will be maintained or dropped over the coming days but there are growing indications that the fine and warm conditions that looked like lasting some considerable time a few days ago may be a rather shorter spell than we might of hoped.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

 

 

[Frosty.]

There is not going to be any July weather next week, if you look at the models closely ,a lot of cloud during this weekend  and perhaps next week .before the weather turns more unsettled from  midweek onwards...gfs and ecm show what I mean....  

Yes but the met office update sounds great as does most of the output with just a few exceptions, potential heatwave next week for the south I reckon, by late september definition, 19c is the average temp in the south at this time of year, could be 6,7,8 degrees celsius higher than that early to mid next week