Model Output Discussion - Early November Onwards

[peterf]

i was luck i missed the first 20 mins lol.

I'm no moderator but surely all of this is in the wrong topic? I know this post is off-topic, but it's only to help prevent all of this. http://forum.netweat...20#entry2155582

Thanks

yes we know, and the mods will sort it when they get round to it.

[chionomaniac]

i was luck i missed the first 20 mins lol.

yes we know, and the mods will sort it when they get round to it.

They may have their own lives and things to do. They are not there to serve you.

[peterf]

They may have their own lives and things to do. They are not there to serve you.

who woke you up?

[Osbourne One-Nil]

Ahem.

[peterf]

They may have their own lives and things to do. They are not there to serve you.

iv'e pm'd you to save going off thread topic.

[nick sussex]

The GFS 18hrs run follows the UKMO and ECM at 144hrs and it looks like NOAA made the right call in sending the earlier GFS operational runs into the shredder.

Overall I'd be encouraged by this evenings output as it suggests a plausible way out of the current mild stalemate but it won't be quick!

I think it's crucial that we get another high amplitude trough in the eastern USA if we are to see a bigger change to colder conditions, if not it might be a case of the much maligned faux cold brought about by the Euro high retrogressing further nw.

[snowfall09]

The GFS 18hrs run follows the UKMO and ECM at 144hrs and it looks like NOAA made the right call in sending the earlier GFS operational runs into the shredder.

Overall I'd be encouraged by this evenings output as it suggests a plausible way out of the current mild stalemate but it won't be quick!

I think it's crucial that we get another high amplitude trough in the eastern USA if we are to see a bigger change to colder conditions, if not it might be a case of the much maligned faux cold brought about by the Euro high retrogressing further nw.

Either way will it end up cold?

[Snowstorm1]

Either way will it end up cold?

Yep surface cold looks most likely but that is what I expect then another bite of the cherry later this month which will set up a very cold and potentially snowy end to November is what I think

[nick sussex]

Either way will it end up cold?

If you look at the ECMs later output although the 850's might look mild it would turn colder because of the surface inversion.

To get to much colder given the expected pattern at that time we would need to see the upstream pattern amplify with troughing in the eastern USA, building pressure over Greenland this will force the cold into Scandi, probably pulling the limpet high a bit further nw, however I think it mlght need one more go after that in terms of retrogression to finally deliver real cold to the UK.

Of course we're dealing in post 240hrs and need alot to go right to get to that point, tonight the output is a little more encouraging, I think some faux cold at least seems likely but as for anything better than that we'll just have to wait and see.

[snowfall09]

If you look at the ECMs later output although the 850's might look mild it would turn colder because of the surface inversion.

To get to much colder given the expected pattern at that time we would need to see the upstream pattern amplify with troughing in the eastern USA, building pressure over Greenland this will force the cold into Scandi, probably pulling the limpet high a bit further nw, however I think it mlght need one more go after that in terms of retrogression to finally deliver real cold to the UK.

Of course we're dealing in post 240hrs and need alot to go right to get to that point, tonight the output is a little more encouraging, I think some faux cold at least seems likely but as for anything better than that we'll just have to wait and see.

Ok thank you for your explanation

[damianslaw]

If you look at the ECMs later output although the 850's might look mild it would turn colder because of the surface inversion.

To get to much colder given the expected pattern at that time we would need to see the upstream pattern amplify with troughing in the eastern USA, building pressure over Greenland this will force the cold into Scandi, probably pulling the limpet high a bit further nw, however I think it mlght need one more go after that in terms of retrogression to finally deliver real cold to the UK.

Of course we're dealing in post 240hrs and need alot to go right to get to that point, tonight the output is a little more encouraging, I think some faux cold at least seems likely but as for anything better than that we'll just have to wait and see.

Yes one step at a time... there is a signal for the current high to advect northwestwards in time as we head towards the middle of the month with heights developing to our north forcing the longwave trough to move southeastwards - however, uppers will still be quite warm, which will prevent suppressed daytime maxima, but conversely should mean some much colder nights for all - in fact very similiar conditions to what n england has seen today.

In order to import colder uppers from such a synoptic, yes this could only occur if upstream pattern changes in NE USA- really need a strong trough to develop here enablimg warm air advection up the west side of Greenland, enabling the strong pressure rises over Greenland/Iceland to build westwards and allowing scandi trough formation and therefore much colder uppers to descend down from the NE. So a lot of pieces of the jigsaw need to fall into place. What we could end up with is a very slow advection of heights westwards much on a more mid-high lattiude position than at a lattitude close to the pole.

This is all speculation.. in the reliable timeframe, a few preety dull days ahead with mild days and nights, lots of cloud, some rain for the west by middle of the week and some strong southerly winds, turning more settled again by the weekend but staying mild as we see a light southeast flow develop.

[summer blizzard]

Talk that the current mountain torque event over Aisa may provide a pattern change however with no stratospheric response yet and no pattern change forecast over the USA i suspect that the ECWMF12z solution is about the best we can hope for in the next 10-15 days.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/pna.sprd2.gif

Potentially getting cooler but no real wintry outlook.

http://www.wetterzentrale.de/pics/MT8_London_ens.png

GFS18z ensembles still indicating the possibility of a cold outbreak from the 17th onward.

[kold weather]

Pattern shift towards a stronger upper HIGH (NOT ridge as in the previous few weeks) forming and with the UK picking up SE winds. In Jan that could well evolve into a cold flow but we are still too early for that so unless we can get the HP over us like the latter part of the 12z ECM, we';; probably remain above average.

Going to be very interesting to see how the pattern evolves from this point...

[ITSY]

I suspect, at least till the very end of the month, we will see a return only to something more seasonal - rather than any prolonged or severe cold. I also keep forgetting that, now that the clocks have gone back, the runs roll out an hour earlier! there should be some kind of reminder!!!!

[rich1]

Slow decay of this present pattern and a gradual falling off of the warm temperatures as the month goes on

I still think the overall picture in the coming weeks is a fair bit away from the norm, which is the deaded greenland vortex, the belts of HP to the south and depressions travelling west to east. That isnt what we are seeing

all depends on where the blocks end up. Some hints they will move north, which is where we want them though I dont envisage much action before the last week of the month or so. its a case of biding your time at the moment

[bluearmy]

is the ecm too progressive this morning or will it really be this easy ?? as can often be the case with ecm, i reckon its rushing it a bit though the overall evolution looks plausible. incredible run.

[wolvesfan]

Morning all,

ECMWF 00Z this morning maintaning to build pressure in NW area,looks a lot better for cold prospects than it did a couple of days ago,shows how quick things can change.

[Isolated Frost]

Wow, what retrogression on the ECM 00z suite. Absolutely lovely. Would be very frosty and then potentially quite cooler and more wintry from the 18th/19th onwards or so. Interesting pattern changes from say, Saturday's runs. Mid-late November does in fact look quite cool, but still a long way to go for now. I'll be watching developments closely and nick sussex, Steve Murr's, chiono's and GP's posts are a must for anyone looking for signs of a change in mid-late November.

[wolvesfan]

Valid from 23/11 to 20/12 2011

Settled mid-November

Issued: Saturday 5th November 2011

Duty forecaster: Simon Keeling & Captain Bob

'Winter is on my head, but eternal spring is in my heart'. Victor Hugo (1802 - 1885)

There remains some confidence that the current unsettled conditions will abate through the middle of the month when a recovery in pressure takes place, the exact location of this is somewhat uncertain at the moment, although on current evidence an anticyclone is expected to build to the north before slipping into the UK and taking control of the pattern.

The latter stages of November see low pressure becoming more influential across the UK and a more Atlantic orientated flow establishing to carry us through to the end of the month. Colder air is anticipated to be drawn into the pattern from the north or northeast, so more of a wintry flavour to close the month into the beginning of December.

The first week of December should see these rather chilly conditions continuing for a while with low pressure in control, less cold air should move through the UK as a westerly Atlantic flow establishes behind a transient ridge of high pressure, rain and strong winds affecting all areas.

Morning,this is from weather online it seems to tie in well with where the ECMWF might be going.

Edited November 7, 2011 by wolvesfan

[johnholmes]

The 500mb anomaly charts continue with their suggested blocking across northern regions of the hemisphere, its a consistent signal and has been for about a week. Just what the evolution is going to be is not easy to pick. The ECMWF version is perhaps closer than GFS at the T+240 timeframe in my view.

[Isolated Frost]

The 500mb anomaly charts continue with their suggested blocking across northern regions of the hemisphere, its a consistent signal and has been for about a week. Just what the evolution is going to be is not easy to pick. The ECMWF version is perhaps closer than GFS at the T+240 timeframe in my view.

ECM has been just right. Wintry showers and maybe snow from the 20th onwards for the north of england and scotland I think. Maybe a slight tint with a ne'ly for a day or two. The jet really has moved south on recent runs and optimism is high.

So in summary, a mild week, turning quite dry after a wet start, especially in the west. Southeasterly flow followed by retrogression and a cooler, frostier flow. Maybe some wintry showers if low pressure begins to influence from the sw and snow becoming a larger possibility. The 500mb anomaly charts are consistent and interesting. I'm probably thinking that it's a smaller blip with a westerly flow coming in late in the month, but I think n blocking will be quite consistent and persistant. Maybe some early snow in December. My opinion of course but there is a lot of optimism in recent days and the ECM 00z suite is brilliant.

[Robbie Garrett]

I am guessing as we move closer, the more it hints to a repeat of last years 'epic' freeze!

Anyone have any charts for the ECM??

[Isolated Frost]

I am guessing as we move closer, the more it hints to a repeat of last years 'epic' freeze!

Anyone have any charts for the ECM??

[wolvesfan]

HI All, would the cold being shown for for Russia be unusual for the time of year if it varified?its just that i cant recall seeing any of the purple shading that far south of the arctic before,normally deep blue and further into winter.

[Isolated Frost]

HI All, would the cold being shown for for Russia be unusual for the time of year if it varified?its just that i cant recall seeing any of the purple shading that far south of the arctic before,normally deep blue and further into winter.

Not really. Quite normal for an arctic blast like so with the blocking pattern. It's that retrogression that interests me.