May CET

[Optimus Prime]

Well, things have changed. Just look at the northern hemisphere ice;

That's about, 300,000 sq miles below average! And that's in comparison to recent averages.

Something must be melting all that ice, and it ain't cold air B)

A few of days of exceptional heat would see a rapid rise in the CET.

At this time of the year it's usually night time minima that causes extreme rise in the CET. Average maxima is around 17c now. So 27c is only 10c above average. Yet minima should be around 6c right now, if temperatures were not to get below 19c at night (like last year) that would make it 13c above average.

[kold weather]

Yep, thats sure worrying OP, I'm pretty sure that there is a very meridional patterns across the globe at the moment though I have no proof of that.

Scorcher, your right, we could get a Spainish plume, but I don't think we will. We've got a set-up dominated by a LP to our west:

http://www.wetterzentrale.de/pics/Rtavn781.png

Eventually, by the jet, it'll be forced to move eastwards. Once it does then instead of a southerly flow, you get this type of flow:

http://www.wetterzentrale.de/pics/Rtavn2641.png

How long it'll take is certainly up for debate, and it certainly won't be cold either, but once the more average temps arrive, it'll be here for every bit as long as this warmth has been here and you'll be lucky to see anymore heawaves this month after this one, hence my comment of doubting a month with a CET of 13.8C, simply becuase the slow moving pattern changes won't allow it UNLESS things were to get more mobil towards the end of May in terms of the jet.

Most likely outcome CEt wise will probably be something around the 12.5c mark, til labove average by quite a way.

[summer blizzard]

Sorry Kold Weather, but i must disagree with you, this pattern is locked in and sea surface temperatures support this pattern aside from a cooler interlude between the 20th and 25th May, have just had a look at the summer of 1976, and the ITCZ was in a average position and while the ITCZ may be below its average position, its orientation means that heat is favoured to build over southern Spain as high pressure over north Africa is in such a position.

http://www.nhc.noaa.gov/tafb/ATSA_12Z.gif

[West is Best]

The CET is rising sharply today. On the NW tracker it's pushing 13.5C. I guess Manley will go up another 0.2C or so today to 13C.

The weekend should I suppose see some correction, but next week still looks above average because of the relatively high minima. I don't really see where this cooler correction is going to come from at the moment. 14C for the final figure anyone?

Edited May 12, 2006 by West is Best

[kold weather]

I shouldn't think it'll get any higher West then what it'll be tommorow, simply because temps aren't expected to get this high again for a while.

Remember, the temps WILL coo lrelative to what they are presently, so don't think they wil lrise and rise, because after this, the temp will stablise and prehaps even fall a tad down to about 12.5c by the end of the month, and a few days like the 06z FI is suggesting will soon see the CEt reduce a little more down to my suggested 12.5c mark...

I'm willing to say that 14c is about as likely as seeing May with a CEt below 12c, with neither being at al llikely.

Manley CET should end up at 13c tommorow I agree West.

[West is Best]

I shouldn't think it'll get any higher West then what it'll be tommorow, simply because temps aren't expected to get this high again for a while.

Remember, the temps WILL coo lrelative to what they are presently, so don't think they wil lrise and rise, because after this, the temp will stablise and prehaps even fall a tad down to about 12.5c by the end of the month, and a few days like the 06z FI is suggesting will soon see the CEt reduce a little more down to my suggested 12.5c mark...

I'm willing to say that 14c is about as likely as seeing May with a CEt below 12c, with neither being at al llikely.

Manley CET should end up at 13c tommorow I agree West.

Well Manley is currently on 13C http://www.climate-uk.com/. I can't see the overall falling to 12.5C. That would take an amazing correction, which doesn't really look on the cards. It's more likely to be up at 13.5C by the end of next week, or at least little down on this 13C. The nightime minima are the key from now on.

Edited May 12, 2006 by West is Best

[Weather-history]

Well Manley is currently on 13C http://www.climate-uk.com/. I can't see the overall falling to 12.5C. That would take an amazing correction, which doesn't really look on the cards.

All it would need for the next 19 days to average 12.2C daily for this month to end on 12.5C, nothing amazing about that all. The overall average for May is about 11.3

The second half of the month could still be above the average but just less warm than the first half. I think May 1990 might have fallen into that category.

Edited May 13, 2006 by Mr_Data

[kold weather]

Models this morning suggests exactly what I thought what would happen. Looking at the output there is now just aobut no chance of a month with a CET of 14c occuring now, with a set-up like this occuring:

http://www.wetterzentrale.de/pics/Rtavn2161.png

A CEtof 12.5C is looking highly likely to even be too high looking at the northerly set-up pushing in. Still as i did say before. Once the set-up does change from warm to cooler, the cool will stay with us for a while as well.

[West is Best]

Models this morning suggests exactly what I thought what would happen. Looking at the output there is now just aobut no chance of a month with a CET of 14c occuring now, with a set-up like this occuring:

http://www.wetterzentrale.de/pics/Rtavn2161.png

A CEtof 12.5C is looking highly likely to even be too high looking at the northerly set-up pushing in. Still as i did say before. Once the set-up does change from warm to cooler, the cool will stay with us for a while as well.

I'd be cautious about that my friend KW - that's 10 days away. This week is still going to see above average temps still, especially night-time minima. If you run the GFS min-max sequence it looks like another mild week, at least through to Friday when we might begin to see the first signs of a correction. Up to then, those high night-time minima and still often above average daytimes (eg 21C on Tuesday) will keep the CET well up around the 13C level. The week after this one is just too uncertain at the moment to be able to post definitively about 'no chance' - afterall the FI on the 0z is as contrasting as the runs yesterday, so I'd say they need to be treated with great care. This is doubly the case because there's HUGE scatter in the 0z ensembles from next weekend:

There's a 20C temperature variation in FI! So I'd say from that it's just impossible to be certain. We've got a pretty good idea what's happening up to Friday, but after that it's much too difficult to call the synoptics, let alone the temperatures.

Edited May 14, 2006 by West is Best

[kold weather]

The teleconnections will mean that the set-up will change, and we wil leither see Lp ovcer the top of us or the LP to our north feeding down northerlies of some sort, either way will see below average day-time maxes and mins close to average.

Your right, the next 5-7 days do look like having temps above average but if you follow through the logical progression of tghe set-up from now onto the 144hr mark, you'll see that the stuff that happens after will lead to a cool-down one way or another and any type of cool-down from now on in will prevent the CEt of 14c being reached I think.

[West is Best]

The teleconnections will mean that the set-up will change,

Hmm ... wish I could place the same trust as you in the teleconnections! I don't have the same confidence in them, even though it ought to be the way forward.

But you're right - we ought to see a correction. I'm just not certain about calling it as certain, but you may be right. Next weekend could be the harbinger of some seriously unsettled weather but we'll see!

By the way, a 14C was always a long shot, so I agree with you! I favour something around 13C at the moment which would be around 1.7C above average. If the AZH does ridge up though as was showing on yesterday's runs then we could have a very warm finale to the month. But I reckon it could be mid-June before that happens.

Edited May 14, 2006 by West is Best

[Thundery wintry showers]

Looks like a fairly potent northerly for the time of year is being consistently progged- on most of the models- at around T+144, and even if it doesn't come off, it should at least cool down somewhat.

I think I still have a decent chance with my 12.8C prediction.

[Scorcher]

I still think the CET will end up above 13C. The amount of cloud is likely to keep night time minima comfortably above average over the next few days and daytime temperatures will probably be slightly above average. So I don't really see the CET being dented over the next few days. Obviously the outlook is rather uncertain after this week and there could be cooler conditions, but despite no signs of it at the moment I think there may be another warm spell before the end of the month. In my opinion 13-13.5C looks the likely value at the moment for this May.

[Dave J]

I reckon (looking at recent model output and trends) that the month will end up around 1C above average (12.3C) by the end due to a significantly colder and wetter 2nd half.

[Optimus Prime]

Going by the current gfs run, from the 1st May - 30th the CET would end up at 11.6c. 0.3c above average.

Due to a cold end with mean temperatures around 10.1c or 1.8c below average for the second half.

[kold weather]

I personally suspect that the GFS is a little too cold in the mid-term and it'll be warmer then it shows, though I agree OP, I think there will be a downwar correction of the CET. At least for the next few days the CEt should remian close to the 13c mark, as night-time mins look like staying abiove average and with day-time maxes at 18-20c.

I suspect that a CET mark somewhere around the 12.3c mark is likely now, maybe lower or higher but I shouldn't think it'll be much higher as I think 12.5c will be the upper limit considering we are at 12.9c still now.

[West is Best]

I personally suspect that the GFS is a little too cold in the mid-term and it'll be warmer then it shows, though I agree OP, I think there will be a downwar correction of the CET. At least for the next few days the CEt should remian close to the 13c mark, as night-time mins look like staying abiove average and with day-time maxes at 18-20c.

I suspect that a CET mark somewhere around the 12.3c mark is likely now, maybe lower or higher but I shouldn't think it'll be much higher as I think 12.5c will be the upper limit considering we are at 12.9c still now.

I don't know KW ... a downward correction is reliant on temp predictions from next weekend onwards which is pretty iffy. There's such a lot of scatter in the ensembles: for example if 'my' Azores high ridging comes into play it will start to turn very warm later next week.

This week as you say isn't going to dent the CET. In fact if anything it will continue upwards - with night-times of around 9C to 12C and days of around 16C to 20C you're looking at a CET this week of between 13.5C and 14C - at least until Friday.

You are also right to caution about the GFS temps. For example, we've already got 19C today in London which even the GFS this morning only had at 17C. I don't place too much faith in the GFS temperatures. The BBC national forecasts in conjunction with the Met Office seem to me to be far more accurate.

It's important to remember that as this month wears on it really only takes Mr Sun to pop out for 20 minutes and the temp will push upward sharply. As Manley and Hadley work on the min/max basis rather than trackers it doesn't take much to get above average.

Although at the beginning of the month I went for 12.6C I think this will be much too low: above 13C looks very on to me.

Edited May 15, 2006 by West is Best

[Guest Mike W]

I agree with WIB, things do look very bad, especially now that a very hot summer looks certain like 1995, 76 and other like that. It doesn't look like this global warming is ever going to stop, if anything it looks likes it's getting worse.

Edited May 15, 2006 by Mike W

[The PIT]

Net-Weather CEt is now 2c above normal. Yet the low temps the past few days here have made a nice dent in the figures for our area.

[reef]

Net-Weather CEt is now 2c above normal. Yet the low temps the past few days here have made a nice dent in the figures for our area.

The last 3 days have made my average here drop by half a degree aswell. I suspect with the northerly next weekend this will fall further as this week doesnt look particularly warm here. Hence my comment above of a possible north/south split.

[Weather-history]

Although at the beginning of the month I went for 12.6C I think this will be much too low: above 13C looks very on to me.

I think the question has now become will it get above 13.0C again. It has been more or less static for the last few days and as each day goes by the harder it is to raise the CET by 0.1C

CET: (May 1-16): 12.9°C (+2.4 degC)

E&W Rain: (May 1-16): 34.0mm (107 per cent)

E&W Sun: (May 1-16): 102.5hr (101 per cent)

http://www.climate-uk.com/index.html

[West is Best]

I think the question has now become will it get above 13.0C again. It has been more or less static for the last few days and as each day goes by the harder it is to raise the CET by 0.1C

Not so sure Mr D. I wouldn't be surprised to see it nudge up to 13C from 12.9C this week. The high night-time minima are keeping it up.

We'll see!!!

[kold weather]

Though equally Mr.D, it gets harder and harder for us to drop the CET as well.

Looking at the models the next 2 days should see the CEt hiold at about 12.9-13c thanks to above average night-time temps.

I should expect the CEt to remian possibly around the same as it is now roughly.

[Weather-history]

Though equally Mr.D, it gets harder and harder for us to drop the CET as well.

Looking at the models the next 2 days should see the CEt hiold at about 12.9-13c thanks to above average night-time temps.

I should expect the CEt to remian possibly around the same as it is now roughly.

Yes, it is going to be harder and harder for it to drop as well. I think the interest now is going to turn away how warm May this turns out to be into how wet this May could turn out to be.

May is one of the driest months of the year on average

Here's the decadal rainfall average for May

1990s: 51.4mm

1980s: 64.0mm

1970s: 60.8mm

1960s: 73.2mm

1950s: 62.9mm

1940s: 69.8mm

1930s: 63.0mm

1920s: 65.3mm

1910s: 56.0mm

1900s: 61.6mm

1890s: 55.2mm

1880s: 61.9mm

1870s: 58.6mm

1860s: 67.3mm

1850s: 59.8mm

1840s: 67.8mm

1830s: 49.6mm

1820s: 61.5mm

1810s: 82.3mm

1800s: 67.6mm

1790s: 64.1mm

1780s: 66.2mm

[Joneseye]

Does anyone fancy doing a list of the predictions and the daily average needed to reach this by month-end?