October 2007 CET

[Stratos Ferric]

Certainly all to play for this month. If the 0z and 18z GFS were to verify the second half of the month would have a CET around 7C.

Those looking for cold pooling will be delighted to see the marked cooldown in eastern and central Europe.

WiB, I think you're comfortably beyond the margins of the probable there I'm afraid.

Summer was cool because of zonality and the southwards displacement of the jet. It wasn't that what we had was especially cool, so much as that we were denied any of the usual warm source air.

We're now in a rather different pattern. Even had we had the summer set up, the absence of warmth would be less notable this time of year: a run like the one we had in summer, occurring now, would tend to give us something closer to norm. The best this pattern offers is occasional cold feeds, like the two we briefly had in September, and if anythign we're slightly beyond that now because HP is more dominant to our E.

The best hope for a cool H2 would be something like October 03 when we got a continental feed, but the models are not consitently indicating that.

Re cold pooling: I do believe we start to get these comments at this time of year every year: it's continental interior - it ALWAYS cools down. Somebody will be surprised that Christnas is coming next.

[SMU]

Im thinking the current CET is approx 12.6- Taking us out to the 15th & the mid way point I think we will arrive at 13c give or take-

that is 15 x 13 = 195C for the month thus far-

To achieve a CET of 11C we need to average out the following for H2-

31x 11C = 341C

341-195 Over 16 = 9.125C

To get to the 71-00 ave of 10.4 we require

31x10.4c= 322.4

322.4-195 over 16 = 7.96C

That is a TALL order - maybe for 5-7 days but the cooler air would have to hang on for over 2 weeks with no mild breaks-

I would say SF's mid months projection should come in around the mid 11's......

S

Edited October 13, 2007 by Steve Murr

[West is Best]

WiB, I think you're comfortably beyond the margins of the probable there I'm afraid.

Hey, watch my lips ... or in this case my fingers. I wrote if the 0z and 18z GFS verify . I didn't say I thought that would be the outcome. Steve's pretty much right there I reckon. A very sharp cooldown can't be ruled out, but something gently falling away into the 11's is likeliest I'd have thought. Would be nice to see something sharper though.

Edited October 13, 2007 by West is Best

[Snowly does it]

Steve, don't disagree with much there however - if we are at 12.6 today, then 15.6 is required to hit 13 by the 15th - that looks unlikely with maxes tomorrow in the 17-18 range with a slightly cooler night to follow and similar maxes Monday. I'd say 12.8 on the 15th, maybe 12.9 (unless last nights swelterthon has pushed us over the 12.7 today already)

[SMU]

Steve, don't disagree with much there however - if we are at 12.6 today, then 15.6 is required to hit 13 by the 15th - that looks unlikely with maxes tomorrow in the 17-18 range with a slightly cooler night to follow and similar maxes Monday. I'd say 12.8 on the 15th, maybe 12.9 (unless last nights swelterthon has pushed us over the 12.7 today already)

No worries- I wasnt sure of the starting point due to Philips site not updating the Current CET- so what I was using was a hearsay value-

Anyone got the link to the Manley one if its current...

If 12.8 is the case then the recalc is

9.31C for 11C

8.15C for 10.4C

regards

Steve

Edited October 13, 2007 by Steve Murr

[SP1986]

Interesting, if only the month ended now I might bump up my score on the CET table, unfortunately, it looks like its going to cool down generally, within the CET area, but as it stands it will probably still be 1C above average. Does looks like the incoming high after the northerly will give us a few cold nights, probably a good bet for frosts. However the northerly follows a modified sea track, so no frost up to that point, but a rise to possibly 13C before dropping to 11C by say the 20th? I would suggest, after that anything could happen.

[SMU]

Interesting, if only the month ended now I might bump up my score on the CET table, unfortunately, it looks like its going to cool down generally, within the CET area, but as it stands it will probably still be 1C above average. Does looks like the incoming high after the northerly will give us a few cold nights, probably a good bet for frosts. However the northerly follows a modified sea track, so no frost up to that point, but a rise to possibly 13C before dropping to 11C by say the 20th? I would suggest, after that anything could happen.

Steve seeing as the calculator is still out- if as you suggest the CET is up to 13C by the 15th it would require a 5 day CET of 5C from 15th-20th to bring it down to 11c----

thats a little low- With the modified Northerly your looking around 9c in the CET zone which from 13C on the 15th would bring it down to 12C

S

Edited October 13, 2007 by Steve Murr

[SP1986]

Steve seeing as the calculator is still out- if as you suggest the CET is up to 13C by the 15th it would require a 5 day CET of 5C from 15th-20th to bring it down to 11c----

thats a little low- With the modified Northerly your looking around 9c in the CET zone which from 13C on the 15th would bring it down to 12C

S

Thanks Steve, so just perhaps, if the following week was to continue the current cooling spell, we may achieve 11C by the end of the month? By no means certain and we could see a further warm up especially if the high moves east and drags up warmer air again - I can only see the current spell being predictable up the the 20th at the most. These months just fly by though it wasnt long ago we were deliberating the September CET!

[Snowly does it]

No worries- I wasnt sure of the starting point due to Philips site not updating the Current CET- so what I was using was a hearsay value-

Anyone got the link to the Manley one if its current...

If 12.8 is the case then the recalc is

9.31C for 11C

8.15C for 10.4C

regards

Steve

11 looks the low end really wouldn't you say Steve? Can't see a 10 from here. Well, unless we get some sharp air frosts in the CET zone lingering for a few days.

[SMU]

11 looks the low end really wouldn't you say Steve? Can't see a 10 from here. Well, unless we get some sharp air frosts in the CET zone lingering for a few days.

Yep mid to High 11's................

Cant see where we would tap any more Cold air from Post day 7...

S

Edited October 13, 2007 by Steve Murr

[Optimus Prime]

It does look as if things are really going to cool down next week. The 14th-20th looks to have an average temperature of around 10.2c.

The CET by the 20th should be around 11.9c.

Still possible we could have a sub 10c month. Odds stand at around 20% i'd say.

[Snowly does it]

Yep mid to High 11's................

Cant see where we would tap any more Cold air from Post day 7...

S

Could the HP not move northwards and allow a draw of relatively cold air from the East? Or could we sit under an inversion?

Looking at T168 - I am thinking the colde drop into Europe, could that not be drawn more in our direction?

Edited October 13, 2007 by snowmaiden

[SMU]

Could the HP not move northwards and allow a draw of relatively cold air from the East? Or could we sit under an inversion?

Looking at T168 - I am thinking the colde drop into Europe, could that not be drawn more in our direction?

It could, but for that you need amplitude in the jet, not a fast easterly flowing one, Also look at the 500mb charts for that time period, the Low heights towards Iceland & Svalbard are cundusive to a retrograde High...

S

[Glacier Point]

It could, but for that you need amplitude in the jet, not a fast easterly flowing one, Also look at the 500mb charts for that time period, the Low heights towards Iceland & Svalbard are cundusive to a retrograde High...

S

question is, have the models got the position of that cold upper air right ? Some grounds for thinking that it could be a little lower than shown - in which case, GFS 18Z and 00Z are plausible for progressive high latitude blocking.

[Snowly does it]

It could, but for that you need amplitude in the jet, not a fast easterly flowing one, Also look at the 500mb charts for that time period, the Low heights towards Iceland & Svalbard are cundusive to a retrograde High...

S

I'll bow to your (far) superior knowledge on that one!

[SMU]

I'll bow to your (far) superior knowledge on that one!

Well, THanks...

Although GP does have a point- the current projection does go with what Im thinking, which covers 10 days- thats ushering in the colder air & time for the High pressure to subside, Will will only get a retrograde when the PV & Low heights over svalbard relax-

The latter being our biggest problem in recent years..

S

[Snowly does it]

Well, THanks...

Although GP does have a point- the current projection does go with what Im thinking, which covers 10 days- thats ushering in the colder air & time for the High pressure to subside, Will will only get a retrograde when the PV & Low heights over svalbard relax-

The latter being our biggest problem in recent years..

S

So, out of interest, if pressure is higher over Svalbard, what does this do? Force troughs to form further south over Scandi?

[kold weather]

Its a shame that the set-up the 12z models show between 144-216hrs didn't happen later in Autumn/early winter as to me its got the classic cold throug ht eback door look to it, reminds me actually of the late December cold snap/spell in 2006:

http://www.wetterzentrale.de/archive/2006/...00120061224.png

Of course the upper air temps are higher this time round however I wouldn't be at all surprised to see a fairly stromng inversion set-up and with fairly low mins we could see surpressed maxes if any fog can linger long enough, though at this time of year thats still a real uncertainty. If we were in November though I'd be more interested.

[AtlanticFlamethrower]

Sea Surface temps closest to CET area.

October CET 10.5C. The temperatures reflect anomalies +1.0C above the average.

[Stratos Ferric]

Hey, watch my lips ... or in this case my fingers. I wrote if the 0z and 18z GFS verify . I didn't say I thought that would be the outcome. Steve's pretty much right there I reckon. A very sharp cooldown can't be ruled out, but something gently falling away into the 11's is likeliest I'd have thought. Would be nice to see something sharper though.

You wrote 'if' and I said 'i doubt it'. Sometimes, WiB, I really struggle to understand why you get so touchy.

[Stratos Ferric]

It does look as if things are really going to cool down next week. The 14th-20th looks to have an average temperature of around 10.2c.

The CET by the 20th should be around 11.9c.

Still possible we could have a sub 10c month. Odds stand at around 20% i'd say.

OP, can't help thinking you're being skewed by your own guess there. If we were 11.9 at the 20th it would require around 6C per day thereafter to get down under 10. That's a huge ask, and I'd have to say rather less than 1:4 likelihood, though it has happened three times in the christmas pudding, and as recently as 2003.

I don't think you're going to get a persistent northerly: perhaps your best chance is a 2003 like set-up feeding dry continental air giving cold clear nights.

[West is Best]

I don't think you're going to get a persistent northerly: perhaps your best chance is a 2003 like set-up feeding dry continental air giving cold clear nights.

It's not impossible towards the end of the month ... some cold minima ahead next week. But the cold easterly is no longer showing up.

Very interesting synoptics still, and I continue to think this may be a case of a little pain for a lot of gain.

(p.s. not touchy SF. Just about being correct. You have often been a one for semantic accuracy when you've been on the receiving end of misquotation, so don't take umbrage when it's served back to you with a side salad and dressing)

[BLAST FROM THE PAST]

It's not impossible towards the end of the month ... some cold minima ahead next week. But the cold easterly is no longer showing up.

Very interesting synoptics still, and I continue to think this may be a case of a little pain for a lot of gain.

(p.s. not touchy SF. Just about being correct. You have often been a one for semantic accuracy when you've been on the receiving end of misquotation, so don't take umbrage when it's served back to you with a side salad and dressing)

Very chilly here this morning and off a southerly feed. My feeling is 11 to 11.5 but still holding out for sub 11c as FI is by no means set yet.

BFTP

[kold weather]

Yeah I'm tending to think between 11-11.5C based on the current models, may well be quite a good deal cooler in the last few days of the month depending on whether or not we can get a cut-off upper low to get further east and south then where its currently located, would open the chance of a repeat weak northerly shot which while not going to take the CET too far down it will reduce it from where it currently is fairly neatly.

[Kentish Man]

Todays Hadley update shows October CET currently standing at a fairly balmy 12.7C which is 0.9C above the rolling mean.