The GFS 18hz Discussion Thread

[grab my graupel]

I posted some thoughts earlier, but they have been buried now under the ramping - lol.

Will the jet overcome the high? I really don't know.

More runs needed.

Yes,

This is my worry also,

As the Jet to me does seem to me to be steadily edging more Northerley again at

times.

The only thing is I never trust the Jet forecasts these days and like you

haven't a clue what will happen.

By the way have you had a chance to look at the GEFS ensembles tonight.

I haven't really had the chance yet like I normally would, with the board being

so lively tonight.

OOPs Just seen Johns post about the jet.

Edited February 4, 2007 by grab my graupels

[The PIT]

He has been enjoying the nice and sunny (but very cold) Icelandic weather at the mo.

I'm sure theres a few volcanoa's that can warm him up a bit. Hows he got there??? Vacation????

[wellington boot]

18z is a bit weird; as temp wise it doesn't seem to be an outlier, but there is some considerable member divergence as to the pressure building to our NE heading towards the F.I. range. I'm not getting my hopes up yet; as the 18z has little support and really depends upon a multitude of factors towards our side of the Atlantic and up towards northern Europe.

I think the 00z may backtrack slightly on the strengthening of this Scandi-high and head slightly more towards the UKMO solution.

You say that it's an outlier, but I would suggest that it's only the result of a devloping trend. Ive been very busy the last couple of days so havent really been posting, but ive been checking the model runs run by run all the same. The main thing i noticed, which i drew attention to recently in fact, was the fact that the high pressure to the east was being progged stronger and stronger, creating a more prolonged battleground situation. This is a trend, and especially if we take into the runs whihc were flying around a few days ago, which showed high pressure to our north and east, like a few of the ensemble runs, and those jma runs, i would not be surprised if the LP was held off and heights increased again to the north and east.

[PersianPaladin]

You say that it's an outlier, but I would suggest that it's only the result of a devloping trend. Ive been very busy the last couple of days so havent really been posting, but ive been checking the model runs run by run all the same. The main thing i noticed, which i drew attention to recently in fact, was the fact that the high pressure to the east was being progged stronger and stronger, creating a more prolonged battleground situation. This is a trend, and especially if we take into the runs whihc were flying around a few days ago, which showed high pressure to our north and east, like a few of the ensemble runs, and those jma runs, i would not be surprised if the LP was held off and heights increased again to the north and east.

I didn't say it was an outlier; but there doesn't seem to have been any significant build in member agreement for the pressure to continue rising to our NE. If anything, the UKMO picked-up on a lower-level high first.

[yamkin]

*passes cookies and hot chocolate around*

Great charts and many more upgrades to come !

Robert

Definitely more upgrades to come. Very interseting times to come :lol:

Goodnight all :lol:

[PersianPaladin]

Definitely more upgrades to come. Very interseting times to come :lol:

Goodnight all

How can you be so sure?

[wellington boot]

I didn't say it was an outlier; but there doesn't seem to have been any significant build in member agreement for the pressure to continue rising to our NE. If anything, the UKMO picked-up on a lower-level high first.

Well it's not quite true that there hasn't been a significant build in member agreement for the pressure rise, because it wasnt really predicted by the gfs at all previously. Your right that the ukmo did previously show an HP edging westwards from our north east, but it was a different evolution and didnt appear to be coming to much. This is much mroe convincing. Each gfs run recently, with few exceptions, has shown the battle lastiung longer and longer. And high pressure to the east , if it can hold off the atlantic for long enough, will begin to fight back. I talked about this a couple of days ago. Battleground situations are among the only ones (if not the only ones) which can change on the models at very short range. Even last yesr, the same happened to some extent, when it looked like the atlantic would steam straight through, but there was a battle which lasted a couple of days in the end. Perhaps we can get it even better this time

[PersianPaladin]

Well it's not quite true that there hasn't been a significant build in member agreement for the pressure rise, because it wasnt really predicted by the gfs at all previously.

On the operationals perhaps....but it was hinted at by some of the ensemble members. I only wish I had saved those European ensemble graphs.

Lots of uncertainty still at the moment....and I think a lot of people are struggling to handle the whole evolution of this set-up (including me).

Edited February 4, 2007 by PersianPaladin

[Tim Bland]

A word of warning to the rampers... the 18Z control run is a rapid, rainy breakdown for most:

http://91.121.0.76/modeles/gens/run/gens-0-2-108.png

Don't get carried away with WZ's "operational", whatever that may be (cant be up to much if they don't even put it on the ensembles )

[wolvo weather]

guys calm it dow there nothing to see ATM to far out just see what happens friday saturday i have as being hello atlantic we didnt miss you

sign of things to come me thinks winter nearly done now so look forward to the summer storms only weather we are most likely to be sure of

[PersianPaladin]

A word of warning to the rampers... the 18Z control run is a rapid, rainy breakdown for most:

http://91.121.0.76/modeles/gens/run/gens-0-2-108.png

Don't get carried away with WZ's "operational", whatever that may be (cant be up to much if they don't even put it on the ensembles )

Not for those east of the pennines. Look at the GFS 850's, dew points, wet bulb temps, lower-level flow and 0C isotherm as a guide, etc, etc.

[wellington boot]

On the operationals perhaps....but it was hinted at by some of the ensemble members. I only wish I had saved those European ensemble graphs.

No dont worry i remember them too. I know it was hinet at. Everything is hinted at by the ensembles though. Evolutions were very different though, even where it did come up. The important point here is not that the high pressure resists a couple of low pressure systems swinging in off the PV before finally giving way, nor is it that high pressure never dies in the first place and ridging happens to the north, nor is it that the Pv just doesnt want to move and the high pressure has no trouble holding its ground.

In this situation, we see LP after LP swinging round the south side of the PV mass and bashing against a high pressure zone which stands completely solid. The heights only start rising later, completely afresh, to the north. It's not a question of the high pressure sticking around to the north in the first place, which it became obvious would not happen. Not is it a question of the PV not wanting to move east at all, which it also became obvious was not likely.

These new maps are suggesting that the jet is simply not strong enough/too far south (or a bit of both) to get through, and furthermore, that the general situation at the northern latitudes is still conducive to blocking, because it shows pressure rising again.

And this is a trend, which is crucial, rather than a one off run.

This is as usual not a ramp, just an honest appraisal of the situation, which i feel is looking pretty good at the moment. Certainly by comparison with what we've seen recently this winter (apart from the cold snap).

And by the way, i wouldnt go with those people saying we should just hope for heavy snow for a few hours and then raging atlantic. We've got a great chance here (or as good a chance as it can be while still at this range). And a few hours of snow frankly wouldn't satisfy me.

By the way, this is my 500th post. Woohoo. :lol:

[wolvo weather]

pmsl at u lot

[TEITS]

A word of warning to the rampers... the 18Z control run is a rapid, rainy breakdown for most:

http://91.121.0.76/modeles/gens/run/gens-0-2-108.png

Don't get carried away with WZ's "operational", whatever that may be (cant be up to much if they don't even put it on the ensembles )

No that link was taken from the GEFS model and the run we saw tonight is from the GFS so you won't see this run on the ensembles because the GEFS has it's control run and 14 ensemble members.

[grab my graupel]

pmsl at u lot

What :lol:

[TEITS]

Haven't looked at the AO ensembles for a couple of days but was surprised when I viewed them.

http://www.cpc.ncep.noaa.gov/products/prec...ex/ao.sprd2.gif

Two days ago the ensembles indicated a return to positive values +1.5 but now they seem to be clustering towards negative values. What with some of the recent GEFS ensembles indicating the posssiblity of a negative NAO this coupled with the AO could mean some significant N blocking towards mid month. I know this may sound silly what with this weeks weather uncertain but a cold Feb looks on the cards to me :lol:

[PersianPaladin]

What :lol:

It was an acronym for "p*ssing myself laughing"

[grab my graupel]

Haven't looked at the AO ensembles for a couple of days but was surprised when I viewed them.

http://www.cpc.ncep.noaa.gov/products/prec...ex/ao.sprd2.gif

Two days ago the ensembles indicated a return to positive values +1.5 but now they seem to be clustering towards negative values. What with some of the recent GEFS ensembles indicating the posssiblity of a negative NAO this coupled with the AO could mean some significant N blocking towards mid month. I know this may sound silly what with this weeks weather uncertain but a cold Feb looks on the cards to me

Yeah your right I haven't taken any notice of those recently, with been side tracked.

It takes up a lot of time going through all these things.

Particularly with these ensembles on Meteociel.

But as you say could be an interesting end to the winter.

It's amazing how things have turned around in just a couple of weeks.

It was an acronym for "p*ssing myself laughing"

Ahhh! Gotya. :lol:

[wellington boot]

Yes i had forgotten to look at those too! But i guess i assumed the AO was going to take a dip, because there are all these indications, even on some of the worse ensembles, that heights rise a bit, or at least dont fall as low as some areas to the north, in the near future. Its definately good news. Battleground period equals ao closer to zero or positive, and then plunges again, and we free fall from an already cool situation into the depths of winter, with whole days lost to blizzards, sub -10 temps, and constant darkness...

Im upset no one has said anything about my 500 posts btw. 500 POSTS 500 POSTS 500 POSTS. Its the second landmark after 100. and i deserve a few beer symbols. :lol:

[sundog]

i hope your right. hopefully the nao might be negative going into early spring aswell. after the winter weve had so far i find it depressing to think that spring is only a few weeks away now. But if the nao was negative in march that would be good and delay spring so to speak

[grab my graupel]

Yes i had forgotten to look at those too! But i guess i assumed the AO was going to take a dip, because there are all these indications, even on some of the worse ensembles, that heights rise a bit, or at least dont fall as low as some areas to the north, in the near future. Its definately good news. Battleground period equals ao closer to zero or positive, and then plunges again, and we free fall from an already cool situation into the depths of winter, with whole days lost to blizzards, sub -10 temps, and constant darkness...

Im upset no one has said anything about my 500 posts btw. 500 POSTS 500 POSTS 500 POSTS. Its the second landmark after 100. and i deserve a few beer symbols.

Sorry but you have to get to a thousand first W.B.

Can I suggest doing 500 ramping posts on the other thread :lol:

On topic, yeah things seem to be coming together nicely now.

I'm hoping that we can play catch up and rescue this winter.

It's funny because Ive always had the feeling that this winter is kind of running a

month behind all the time.

I mean late December/ Jan resembled Autumn to me.

Edited February 4, 2007 by grab my graupels

[PersianPaladin]

(chants triple-jinx mantra)

I think the 00z is going to be a massive upgrade in the mid-term.

:lol:

Edited February 4, 2007 by PersianPaladin

[TEITS]

I think the 00z is going to be a massive upgrade in the mid-term.

:lol:

You crazy lot aren't staying up for the 0Z are you

I would but I don't have enough cigarettes to last me through the night .

[PersianPaladin]

You crazy lot aren't staying up for the 0Z are you

I would but I don't have enough cigarettes to last me through the night :lol: .

Smoking is bad for your health and won't keep you awake.

How about this crazy stuff? LOL

[grab my graupel]

I think the 00z is going to be a massive upgrade in the mid-term.

:lol:

I hope so P.P.

I'll be pleased as long as the blocking remains to the East.

and with it the potential for something better further down the line.