Model Output Discussion

[Cecil Hogmanay Melchett]

Looking like a poor gfs operational coming out.We just cant shake off that Atlantic its forcing the AH to ridge across but nowhere near as far north as we need it to be.

ecm looking a bit lonely now.

[NorthantsSnow]

thats why i cant understand the met o widespread warnings.

some will get snowfall but its not a major event

The last update was yesterday morning, at which point the models were suggesting fairly widespread precipitation.

However in recent model output the tenancy has been to push it west, or at least stall its progress eastwards until it eventually fizzles out.

I can understand why they issued a weather advisory for my area yesterday but I would fully expect them to remove it today and adjust their warning zone further west.

I agree that it's not a major event, and I cannot see >5cm snowcover anywhere except perhaps higher ground over Wales.

[D KARLSON]

There is low confidence in the model outputs at the moment and i cant see that changing in the near future as long as that stubborn high stays to the northeast and if you add these high pressure cells moving up from the souwest to join the main high the situation is likely to remain protracted with neither the cold or the mild winning out, with the chance of some very cold air returnig from the continent before the months out

[Optimus Prime]

Certainly a more easterly orientated feed on the latest GFS run. Higher risk of snowfall.

[grab my graupel]

Looking like a poor gfs operational coming out.We just cant shake off that Atlantic its forcing the AH to ridge across but nowhere near as far north as we need it to be.

ecm looking a bit lonely now.

Hi HD, if you take a look at the jet pattern it demonstrates quite nicely why that is.

[BLAST FROM THE PAST]

Hi HD, if you take a look at the jet pattern it demonstrates quite nicely why that is.

Blimey Brian, you ever seen a jet pattern like that. I hope the flights coming from the states don't follow the jetstream on the 25th if it comes off....they'll double their flight time Lol!!!

BFTP

[weather eater]

The warning out for snow on Wednesday by the MO is a advisory warning, the MO would be aware that details would need to firm up before issuing a be prepared warning or changing the areas effected or removing altogether, all pretty standard stuff from the MO at any time of year, its not really their fault if some NW members wish to read more into it.

Lots of chopping and changing with model output but the 06z again wants to develop a mid Atlantic block a feature that keeps appearing.

[Thundery wintry showers]

Looking towards Wednesday I stand by my earlier assessment of snow on high ground with sleet or rain at low levels, but I could turn out to be wrong. The MetO warning is, indeed, just an advisory and I think they are right to give one just in case.

Looking at the longer term, while I would normally back the ECMWF over the GFS, the GFS has support from the UKMO in this case, bringing a Euro High into play- the kind of evolution suggested by some of the teleconnections, albeit rather more progressive than they suggest. ECMWF is out on its own, but with all of the chopping and changing I don't think the GFS and UKMO have necessarily "nailed it".

[bluearmy]

the continuity, day to day isnt at all good at the moment. maybe exeter would like to defer updating their 15 dayer on the grounds that 'no one has a clue'. i expect thsi thread will be fairly quiet due to not many having the confidence to comment on something that they dont really believe in. time to take a 'break' after 6 weeks i reckon.

[Steve Edgefield]

the continuity, day to day isnt at all good at the moment. maybe exeter would like to defer updating their 15 dayer on the grounds that 'no one has a clue'. i expect thsi thread will be fairly quiet due to not many having the confidence to comment on something that they dont really believe in. time to take a 'break' after 6 weeks i reckon.

Couldn't agree more. Lots of uncertainty in the medium to longer term and it's hard to get terribly excited at the moment. I think GP has been pretty accurate with his forecast so far this winter. The output does seem to suggest something colder at the end of the month (possibly) but I get the feeling that this will be replaced quite quickly by something benign and mild (e.g a euro high). Hope I'm wrong though..

[TEITS]

the continuity, day to day isnt at all good at the moment. maybe exeter would like to defer updating their 15 dayer on the grounds that 'no one has a clue'. i expect thsi thread will be fairly quiet due to not many having the confidence to comment on something that they dont really believe in. time to take a 'break' after 6 weeks i reckon.

Yes if I was the Met O I wouldn't even bother with a 6-15 day forecast!

At the moment based on all the runs I have seen and also using a bit of instinct I would suggest the following.

The beginning of next week is likely to be influenced by HP rather than LP. During the weekend we're likely to see a SW track SE down the N Sea. Into the beginning of next week we're likely to see the HP to our S merge with the block to the NE bringing a fairly slack E,ly flow. For the rest of the week its difficult to say but at the moment it looks more likely to be cold than mild with Jan ending on a cold note. However how cold and how this exactly develops synoptically is difficult to say.

I will finally add that don't be surprised if a cold spell suddenly develops around +144/+168 timeframe on all the models. For example the 0Z had a pool of sub -10C uppers just off the E coast at +168.

[Frosty.]

Another potent Northerly blast shown on the GFS 06z in FI, the gfs has been showing a cold plunge on most of it's recent output for the period late Jan / early Feb so it might be on to something there but who really knows as this model is a very ordinary performer this winter so far. The ECM 00z looks very isolated now with it's wintry theme for late this week into next week with the ukmo and gem to name but a few which look very disappointing in comparison if you are wanting more very cold weather.

[Paul Sherman]

Yep

No continuity between all the Models which says to me we are stuck and stuck for a while in "No Mans Land" as it has been termed.

Interesting on the Meto Update just now that they hint at a low probability of Cold returning from the NE At the end of the month.

[Mark Burton]

Have been watching this thread for a few days now, with much interest. In my experience of winters over the past 40 odd years, when deep cold makes an early appearence as it has - in fact twice, early on in the season, we don't usually see a fast return to cold weather. If I remember rightly, February and March are usually mild with the odd sleety/ snowy incursions - but they are short lived.

My gut feeling is that we have seen the worst of the winter, and any future cold spells will be 'normal' short lived affairs - I hope to be proved wrong though! I am not a model watcher, but I enjoy reading your opinions and learning from your expertise.

[sandstorm2]

I am just amazed at the lenght of time the HP has almost stayed in the same position for so long, it really has been knife edge stuff, a couple of hundred miles further west and we would really have had something to talk about. At the moment though the models look to have reahed a stalemate, but if I was a betting man I would go for an avearge winter from here on in.

SS2

[KTtom]

Yep

No continuity between all the Models which says to me we are stuck and stuck for a while in "No Mans Land" as it has been termed.

Interesting on the Meto Update just now that they hint at a low probability of Cold returning from the NE At the end of the month.

Do they say what the high probability option is then

[Paul Sherman]

Do they say what the high probability option is then

Lol

Yes and it involves a Fence and some Backsides

Better not stray onto this subject or Mr Holmes will beat me with his Stick!

The good thing is that they are mentioning it at all - They did the same around Xmas Time with the extended for 2nd Jan until the 8th Janury

[KTtom]

Lol

Yes and it involves a Fence and some Backsides

Better not stray onto this subject or Mr Holmes will beat me with his Stick!

The good thing is that they are mentioning it at all - They did the same around Xmas Time with the extended for 2nd Jan until the 8th Janury

Well, the updated BBC Monthly forecast also hints at the prospect of a returning easterly in a couple of weeks. Time will tell as always

[bluearmy]

Do they say what the high probability option is then

there isnt one at the moment

[MR EXTREMES]

Yep

No continuity between all the Models which says to me we are stuck and stuck for a while in "No Mans Land" as it has been termed.

Interesting on the Meto Update just now that they hint at a low probability of Cold returning from the NE At the end of the month.

im not sure how that fits with any of the model outputs lol.

but its always a possibility.

[Tom D]

Not sure if it's of any significance but the ECM at +192, the GFS mean at +180 and the GEM at +180 are generally very similar, with high pressure over most of Europe and us with low pressure over Greenland. I guess it wouldn't be wet and mild shortly before or long after this set up with such an expanse of high pressure? Or would the position/origin of the dominant high give dramatic temperature differences? (Clear and frosty or mild and cloudy)

Maybe someone else can use these charts better than me...

http://91.121.94.83/modeles/gens/run/gens-21-1-180.png?6

http://91.121.94.83/modeles/gem/run/gem-0-180.png

Edited January 18, 2010 by Tommyd1258

[Thundery wintry showers]

GFS and GEM would be fairly mild and cloudy towards the NW but probably sunny towards the SE because of the position of the high pressure. Conversely ECM's version would be fairly cold, sunny in the NW and cloudier towards the SE- perhaps with a few wintry showers if the upper air is cold enough.

In all three cases a pretty quiet spell of weather is indicated although GFS has the low move over to Scandinavia in FI bringing northerlies.

[Matty M]

GFS and GEM would be fairly mild and cloudy towards the NW but probably sunny towards the SE because of the position of the high pressure. Conversely ECM's version would be fairly cold, sunny in the NW and cloudier towards the SE- perhaps with a few wintry showers if the upper air is cold enough.

In all three cases a pretty quiet spell of weather is indicated although GFS has the low move over to Scandinavia in FI bringing northerlies.

Indeed i wouldnt be surprised to see some wildly changing output in the next few days.

I expect the model to latch onto it at some stage towards the weekend.

With the Arctic High shifting towards Scandy bringing the PV towards western Russia/East Europe.

[Eugene]

The front looks like fizzling out before it reaches the midlands, that block to our east is having more of an influence in the very short range than many suggested

With charts like this you can understand why me and others were going for cold to continue all week, it was a VERY close call indeed.

http://www.wetterzen...cs/Rtavn481.png

Edited January 18, 2010 by Eugene

[cooling climate]

Convection looks a lot stronger over the date line today which should be picked up

by the MJO graphs tomorrow.

This should have an impact on the model outputs as well.

http://www.cawcr.gov.au/bmrc/clfor/cfstaff/matw/maproom/OLR/m.3d.html