Model Output discussion 1st September 00z------->

[Frosty.]

It's a great looking outlook as far ahead as the second week of October for the majority of the uk, the exception being the far northwest, no downgrades from the latest Met Office update, most of the model output so far today paint a settled picture from this weekend onwards with daytime temps rising at least a little above average and warmer than that for some areas. Nights look chilly with clear skies allowing mist and fog patches to form but sunshine totals are expected to be well above average during late Sept / early October...it couldn't be better.

Edited September 23, 2015 by Frosty.

[knocker]

Except thr GFS of course.

[joggs]

Daily comparison using the GFS, ECM, UKMO, JMA, ICON, GEM, NAVGEM, NASA, CMA, FIM and the CFS all up to 240 hours along with the ECM and GFS ensembles. For each day whatever model has the most support will be shown for that time.

 

24 Hours Thursday (GEM)

Low pressure sits to the North West of the UK and will slowly move East during the day across the far North of Scotland.

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48 Hours Friday (GFS)

Low pressure remains over most of Scotland while the rest of the UK starts to see high pressure moving in from the South West.

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72 Hours Saturday (ECM)

High pressure around 1025mb covers most of the UK and Ireland as a low pressure system to the South West of Iceland develops.

3.png

 

96 Hours Sunday (NAVGEM)

High pressure of 1025mb now covers all of the UK and Ireland.

4.png

 

120 Hours Monday (ECM)

The high pressure starts to gain strength up to 1035mb as another low pressure system starts to develop in the Atlantic.

5.png

 

144 Hours Tuesday (ECM)

High pressure remains over the UK and moves East just slightly as the low in the Atlantic gains strength as it moves North.

6.png

 

168 Hours Wednesday (CFS)

High pressure continues to move East but still mostly covers all of the UK and Ireland.

7.png

 

192 Hours Thursday (CFS)

High pressure shows a sign of gaining even more strength and moving West.

8.png

 

216 & 240 Hours Friday and Saturday (FIM & GEM)

Most of the models at this range showed high pressure extending North into Greenland.

9.png 10.png

oh for these charts in December,sigh.

[phil nw.]

An entertaining series of later frames from the 12z GFS- for cold lovers.

Plenty of cold air spilling into Scandinavia and N.Europe/Russia around a Greenland block.Widespread snowfall up there if that were to verify.

I should quickly add -just for fun at that range.

[mountain shadow]

If only if it was Winter charts on tonights GFS. Copious Northerly blocking, Southerly Jet.  Mainly dry throughout with low pressure pushing in from the South West towards the end.

[I remember Atlantic 252]

An entertaining series of later frames from the 12z GFS- for cold lovers.

Plenty of cold air spilling into Scandinavia and N.Europe/Russia around a Greenland block.Widespread snowfall up there if that were to verify.

I should quickly add -just for fun at that range.

 

Not entertaining for me, well in FI, hope these charts fail, 0ct the 9th or so will never give snow here

[Scorcher]

If only if it was Winter charts on tonights GFS. Copious Northerly blocking, Southerly Jet.  Mainly dry throughout with low pressure pushing in from the South West towards the end.

 

If only it was summer with the last few ECM runs. The GFS is still on its own to a large degree.

[Frosty.]

The end of the Gfs 12z has really got me in the mood for winter, it just shows if we get the right conditions, the arctic cold packs a real punch, even in early october..super charts, I pray we see plenty of charts like this in the reliable timeframe  as we go into deeper autumn and then winter.

Edited September 23, 2015 by Frosty.

[knocker]

An entertaining series of later frames from the 12z GFS- for cold lovers.

Plenty of cold air spilling into Scandinavia and N.Europe/Russia around a Greenland block.Widespread snowfall up there if that were to verify.

I should quickly add -just for fun at that range.

 

You have to say the GFS is playing a complicated scenario after moving the HP east the middle of next week/

[Frosty.]

Looks like a lovely weekend on the way with a big fat high settling down over the uk according to the Ukmo 12z and there should be plenty of sunshine for all areas once early patchy fog disperses, high pressure dominates next week too with warm and sunny days and cool clear nights with patchy mist and fog.

Edited September 23, 2015 by Frosty.

[phil nw.]

You have to say the GFS is playing a complicated scenario after moving the HP east the middle of next week/

A parcel of colder upper air coming west around the high, by the looks Knocker, meeting the TM air to our south west.

 

I see the 12z ECM op has the block a little further south and west at that timeframe so any low pressure development further away over the continent on that model.This looks more in line with the GFS mean so i would think more likely the block would hold across our locale through next week based on what i have seen so far.

Edited September 23, 2015 by phil nw.

[SMU]

Well the cobwebs are being dusted off

The much touted 'indian summer, thats appeared in the models for the past few days looks on course now, maybe the last fine weekend for BBQs !!

There is some hints though that for the south & SE at least a bit of a cooler breeze will develop, possible even a drop in temps if we get lower uppers-

The ECM at day 7 has uppers in the SE dropping to 6c-

http://www.meteociel.com/modeles/ecmwf.php?ech=72&mode=0&map=3&type=0&archive=0

& then by day 10 as low as 1c in the SE again

http://www.meteociel.com/modeles/ecmwf.php?ech=72&mode=0&map=3&type=0&archive=0

The best location for this projected fine spell of weather seem to be the North /North west/ ireland & parts of Scotland-

An unexpected bonus for this time of year -

A hint of retrogression from the GFS & ECM generating the first 'cool' plunge into Northern europe ready for october-

I noticed on the hadley CET the other day that we are in a string of months below ave with sept expected to be 4/5 months -

This ties in with the flip in the AO to negative

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/month_ao_index.shtml

Lets hope the trough of negative can stay throughout winter ....

S

[Captain Shortwave]

That cold pool running into Europe around the flank of the high is a real pain, this really is the moment where you curse our climate as this situation would not have occured during the summer (the cold pool would have warmed through and weakened very quickly).

A chance for some pleasant warmth, if the ridge is strong enough then you could get a 25C day potentially early next week if you get a dry enough flow from the south/south east coupled with some very warm air.

Not perfect but this is the day which has been consistently pointed at producing some summer-like conditions. Beyond this a cool down looks likely with potentially the risk of rain in the far south/south east if any developing area of low pressure from the cold pool drifts close enough to us. Beyond that, only speculation of where the high could go to be honest. 

[Frosty.]

Awesome Ecm 12z, first of all we get the high in place for the weekend with plenty of warm sunshine but with chilly nights and an increasing risk of fog patches which continues through next week but then towards the end of next week our uk based high pulls westwards into the atlantic and T+240 shows the first cold blast of the autumn about to sweep south..now that was a run worth waiting for.

[legritter]

Awesome Ecm 12z, first of all we get the high in place for the weekend with plenty of warm sunshine but with chilly nights and an increasing risk of fog patches which continues through next week but then towards the end of next week our uk based high pulls westwards into the atlantic and T+240 shows the first cold blast of the autumn about to sweep south..now that was a run worth waiting for.

I was half expecting a chart like this to pop up from ECM soon .

I think the further outlook is far from nailed ,so still good potential for some summery type of weather then i have a gut feeling that some real autumn type set up with some colder temp could be on the cards .

expect last few frames of ECM to have big variations on each run ,here we go an interesting period coming up .cheers 

[ANYWEATHER]

Both ecm and and gfs at t+240 are showing the high pressure retrogressing .Interesting!

[Scorcher]

The ECM looks great until midweek at least- it's certainly not as keen as the GFS to introduce that cooler air westward around the high. It's not until the end of next week on this run that the cooler air finally makes it to our shores.

 

It's a bit of a shame for those of us looking for some final warmth of the year that it appears to develop into a rather bizarre setup, with everything seemingly moving westwards, just when we finally get high pressure to settle over the top of us. Let's see if the signals for retrogression continue or not as they are still in FI.

[Man With Beard]

This is one of the rare set ups now that can flick from hot to cold in a couple of days, just in these three weeks of the year. A potentially warm start to next week (low 20s I suspect, not enough of a southerly to get higher) could easily nosedive into the low teens as the continental feed flips into winter mode. This kind of set-up leads to a dramatic season changing experience, in a country where we usually get a gentle glide into autumn due to our warming sea influence. Could be sunshine and t-shirts on Monday, but sunshine and coats by Thursday.

[Scorcher]

This is one of the rare set ups now that can flick from hot to cold in a couple of days, just in these three weeks of the year. A potentially warm start to next week (low 20s I suspect, not enough of a southerly to get higher) could easily nosedive into the low teens as the continental feed flips into winter mode. This kind of set-up leads to a dramatic season changing experience, in a country where we usually get a gentle glide into autumn due to our warming sea influence. Could be sunshine and t-shirts on Monday, but sunshine and coats by Thursday.

 

Personally I don't see it as being anything like that dramatic next week- it's a possibility if the GFS is on the money, but even the GFS is suggesting high teens for most of England and Wales and even low 20s for the SE next Friday. The irony is as we lose the high on this run, the continent warms up behind it and we begin to import some warmer air from France.

[Captain Shortwave]

Interesting to see retrogression signals from the operations, but the ensembles tending to hold high pressure near to just to the east/north east of the UK.

 

There does seem to be a decline in heights during the later stages of week 2, though again no real retrogression signal (A slight westward shift in the anomalies but not particularly much). This could be a natural return to default conditions (going by the gfs ens at least). Either way the warmest weather seems to be during the first half of next week with temperatures probably returning to near normal levels, it could turn quite chilly along southern and eastern coasts if we do pick up a noticeable easterly wind though.

Edited September 23, 2015 by Captain shortwave

[knocker]

Looking at tonight's anomalies it would seem they are all in agreement keeping the HP very close to the UK with the LP area to the SW. although the detail varies. NOAA is quite emphatic about this.albeit with the configuration changing between 6-10 and 8-14. The GEFs leaves open the option for possible lp intrusions from the south The ecm is on board more or less to the end of the ext period with the GEFS keener to introduce the Atlantic trough. The detail regarding temps is a bit irrelevant at this stage of the proceedings.

http://www.tropicaltidbits.com/

Edited September 23, 2015 by knocker

[damianslaw]

Models showing quite a continental outlook, far from atlantic domination, quite interesting set up for the time of year, not because it is anything unusual, more because this is when the atlantic tends to fire into gear and westerly airstreams gain the upper hand.

 

Lots of speculation where the high pressure will eventually end up. It now looks less likely we will see a warm southerly surge and instead import a slightly cooler southeasterly/easterly feed with the high elongating and stretching westwards, in response to the position of the jet which is very elongated and low pressure over the atlantic taking an unusually south-north path, but also firing the jet somewhat, all that energy has to go somewhere and ECM and GFS are suggesting it will attack scandanavia eventually hence why we are seeing a retrogression of heights to Greenland - its certainly a very plausible evolution given the state of the jet.

 

A fine spell ahead for most after tomorrow, plenty of dry weather, chilly nights with possible fog and warmish days, though a stiff easterly breeze could take the edge off things in the south come early next week bringing in some cloud.

[Midlands Ice Age]

Well the cobwebs are being dusted off

S

 

 

Steve ...

Is this your method of prediction?. Can the spiders really see up to one week ahead!

 

Its just that I've been inundated the last few days.

 

Could it be that they are GFS fans too. I'd better make sure I turn my Laptop off at night. Don't want them to be better than the MO.

I even had one going right to left across my laptop. Was it following the retrogression! 

 

MIA

:D .

Edited September 23, 2015 by Midlands Ice Age

[Penrith Snow]

My God what a waste of a good high pressure, in summer it would be hot and sunny, in winter cold and frosty but in Late September it's just going to be cool and misty.

All summer we have waited for a UK High and now we get one that could last 4 weeks and be as boring as watching paint dry.

Andy

[Polar Maritime]

The GFS continues to show a cool slack Easterly flow for the turn of the Month.