December CET

[Eugene]

Current charts have rescued my CET forecast, HP would do it no good at all, still chilly charts though and i could be slightly too high but in with a much better chance than if HP took over.

[Weather-history]

Yes, don't forget that the Januarys of 1978 and 1984 (two of the starkest examples of cold zonal months) still came out with a close to average CET, despite much below average temperatures across Scotland and Ireland. January 1952 was another good example of a cold zonal month, but it only managed a below average CET because of a blocked last third with some northerlies.

Another example is December 1993, the mildest December for the CET since 1988 but the coldest December in Scotland since 1981.

[Thundery wintry showers]

Yes, and judging by the current model outputs this December could easily pan out similarly to December 1993- jet on a similar track, and some pretty big depressions.

[Great Plum]

A point made on TWO in their model thread was that if the 12z gfs came off, it would be really quite below average for much of the BI... I recall the temp only rising above 6c once in the CET zone over the next 14 days!

[BornFromTheVoid]

5.8C to the 3rd

Yesterday was 4.0C. Minimum today is 1.8C, while maxima were around 8C, so a drop to 5.7C is possible on tomorrows update.

After that, the 12z GFS has the CET at

5.7C to the 7th (5.6)

6.0C to the 8th (7.9)

5.8C to the 9th (4.1)

5.3C to the 10th (0.5)

4.9C to the 11th (1.3)

4.8C to the 12th (3.9)

4.8C to the 13th (5.2)

[summer blizzard]

5.8C to the 3rd

Yesterday was 4.0C. Minimum today is 1.8C, while maxima were around 8C, so a drop to 5.7C is possible on tomorrows update.

After that, the 12z GFS has the CET at

5.7C to the 7th (5.6)

6.0C to the 8th (7.9)

5.8C to the 9th (4.1)

5.3C to the 10th (0.5)

4.9C to the 11th (1.3)

4.8C to the 12th (3.9)

4.8C to the 13th (5.2)

Looks very good with an outside chance of a ice day on the 10th.

Any idea what the rolling 30 year average to the 13th is?

[Isolated Frost]

At Durham Uni to the 6th:

Overall 3.9c (0.0c), av.max 6.2c (-0.5c), av.min 1.5c (+0.4c).

Bang on average so far... 7th and the 8th should be rises, around 4.5c to the 8th due to the exceptionally mild thursday, and then friday and saturday below average by a fair bit, possibly below 4c to the 10th again here.

Going to be a very large north-south split this month methinks.

[reef]

Hadley is 5.6C to the 5th. Yesterday was 4.7C.

Pretty close to average in the CET zone so far.

[Optimus Prime]

It is probably more likely for the CET zone than much else, reef. Already, this 'cold snap' is producing above average in the CET zone. And with no major blocking on the horizon the likelihood is that the CET zone will continue above average.

Not anymore its not lol

[summer blizzard]

Any update for the CET?

[BornFromTheVoid]

6.1C to the 8th

http://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

Yesterday was 7.8C. Minimum today is 3.4C while maxima should be around 7C, so a drop to 6.0C tomorrow is likely.

After that, the 06z GFS has us at

5.7C to the 10th (3.2)

5.6C to the 11th (4.7)

5.5C to the 12th (4.0)

5.5C to the 13th (5.9)

5.4C to the 14th (4.1)

5.3C to the 15th (4.4)

5.2C to the 16th (2.5)

Average, slightly cool for the time of year. CET about average by mid-month.

[reef]

6.1C to the 8th

http://www.metoffice..._info_mean.html

Yesterday was 7.8C. Minimum today is 3.4C while maxima should be around 7C, so a drop to 6.0C tomorrow is likely.

After that, the 06z GFS has us at

5.7C to the 10th (3.2)

5.6C to the 11th (4.7)

5.5C to the 12th (4.0)

5.5C to the 13th (5.9)

5.4C to the 14th (4.1)

5.3C to the 15th (4.4)

5.2C to the 16th (2.5)

Average, slightly cool for the time of year. CET about average by mid-month.

Temperatures in the CET zone are often higher in this sort of setup than the GFS suggests (especially minima), so much like the first 8 days we might be higher than expected by mid-month.

[Isolated Frost]

A similar pattern for at least the next wind... two lows, one on Tuesday and Friday according to the latest gfs, bring severe gusts again, possibly worse than yesterday's. Upper air temps range between 5 and -5c for London and most of the nation... generally cool and wet for the north, more close to the average and drier for the south, with some very mild weather for all under warm sectors, temps nearing 12-13c possible in the south and east. I'd expect the CET to be around average for the next week.

[Roger J Smith]

Will the contest be void if the CET zone ends up in Scandinavia?

[BornFromTheVoid]

5.6C to the 10th

http://www.metoffice..._info_mean.html

Yesterday was 3.0C. Minimum for today is 1.2C, while maxima look like being around 8.0C, so we should stay at 5.6C tomorrow.

After that, the 06z GFS has the CET at

5.5C to the 12th (4.9)

5.5C to the 13th (5.2)

5.4C to the 14th (3.2)

5.3C to the 15th (4.8]

5.3C to the 16th (5.3)

5.2C to the 17th (4.0)

5.1C to the 18th (2.1)

[reef]

5.6C to the 10th

http://www.metoffice..._info_mean.html

Yesterday was 3.0C. Minimum for today is 1.2C, while maxima look like being around 8.0C, so we should stay at 5.6C tomorrow.

After that, the 06z GFS has the CET at

5.5C to the 12th (4.9)

5.5C to the 13th (5.2)

5.4C to the 14th (3.2)

5.3C to the 15th (4.8]

5.3C to the 16th (5.3)

5.2C to the 17th (4.0)

5.1C to the 18th (2.1)

GFS is almost certainly underestimating on the temperature side of things. It looks very windy indeed, so Ill be very suprised if we see widespread minima of 0-1C like it is showing. Maxima also look equally underestimated, rather than the 4-5C its showing I think 5-8C is more likely. Uppers rarely dip to -5C or so.

It'll be interesting to see how close the model ends up being.

[TonyH]

Shaping up for a (slightly) above average month.

[damianslaw]

Its been a preety average start to the month CET wise - the first 10 days of the month tend to bring the mildest conditions in December as the atlantic normally rules the roost..

Can't see much change in values in the coming days, cloud and wind will prevent any particularly cold nights but also any particularly mild days. Scotland and N England will remain colder thanks to colder uppers..

I do feel a very near average CET will be the end result but at this juncture far from certain whether it will be on the plus or minus side..

[Snowyowl9]

I did read that december will turn out at around average temps at 4.5c

So far it has been very much different to the last couple of years with raging mainly SW-ly to west atlantic,with some colder zonality,looks like a cold NW-ly after fridays s-ly tracking less intense storm shown to yesterday but still one to watch,followed by much milder with HP coming from the south I would think looking at the current setup.

A different december this year so far thats for sure.

I would say above average,but things can and do change.

[reef]

Hadley is 5.6C to the 12th. A small rise on yesterday.

http://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

[kold weather]

I suspect the 5-6C range is looking a decent bet at the moment, so probably a little above average but hardly a blow torch set-up unless the 06z GFS actually comes off!

[summer blizzard]

I suspect the 5-6C range is looking a decent bet at the moment, so probably a little above average but hardly a blow torch set-up unless the 06z GFS actually comes off!

I am still fairly confident for something near my 4.1C prediction after adjustments.

December is still a coolling month which should put downward pressure on the CET and in addition to that the majority of model runs have shown good inversion potential from high pressure afterward.

In addition, the northerly this weekend looks fairly potent.

[Optimus Prime]

Last December at this stage we were discussing the likely outcome December would be sub-zero. This year couldn't be more different.

Possibilities are endless on where this one will end up. A range between 6.6c (a result of a very mild remaining week or so) or under 4.0c resulting in some kind of cold spell after this weekends potential notable in terms of cold (when comparing to what we've had this year in general)

At this stage something inbetween looks likely. Cooler RPM air looks like a strong possibility. Colder than average yet again for Northern Ireland and Scotland (4th December in a row) but mild elsewhere. Somewhere in the 5.0's is what I'm thinking. Not particularly mild and in fact the 2nd coldest month of the year.

[summer blizzard]

Hadley is 5.6C to the 12th. A small rise on yesterday.

http://www.metoffice..._info_mean.html

Manley is at 5.2C which is -0.3C below the rolling average to the 12th (so Hadley 0.1C above).

With the upcoming cold weekend i would say that below the 1971-2000 average is looking ever more likely.

I would also add that the ensemble mean even for London was below average throughout the GFS6z run.

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

[damianslaw]

Some colder nights on the cards later this week and into early next week which will have a knock on effect to the CET moving it downwards - one of the key reasons this month so far in the CET zone has remained so consistent has been the weak diurnal ranges thanks to cloudy windy nights.

If heights do develop near/over the country next week - inversion conditions will occur and I suspect daytime highs will be suppressed markedly after the cold nights which will in turn bring CET values slightly below average. We would then still have another week which could bump the CET up, but near average still looks a good bet with an ever increasing chance of it being below rather than above thanks to the colder prospects for this weekend and potentially in the run up to christmas.