January CET

[Nick L]

Actually it's the weather which changes. Bitterly cold first 1/3rd, followed by a complete flip-flop to above average second third. The problem on this forum tends not to be people who change, but people who don't: hence they will find the next 1947 out of charts which have moved on and which show nothing of the sort any longer. Our weather is capricious. My own fault is not that I change with the weather, but a tendency to be too extreme about it and, heads up, that criticism I completely accept.

The estimated air frosts tonight from the GFS proved out by between 2C and 4C yet again. With climate-uk posting a 0.2C increase yesterday Hadley should be on 3C by the reading on Saturday. That will leave 8 days' data, or more than a quarter of the month, for the remaining rise of 0.5C to occur, which I happen to think is pretty much a shoo-in.

The best hope of staying under 3.5C now remains Hadley's habit of correcting its figures by 0.2C to 0.3C after the end of most months. Otherwise 3.5C to 4C looks 80% likely to me from here. To remain this side of 3.5C will require air frosts and they don't look all that likely right now, at least not with potency.

I don't know what country you are from but from where I am it has been far from consistently above average. Most days are average at best. And besides, after the first 10 days a complete "flip flop" would be exceptionally mild, opposite to the exceptionally cold we saw a few weeks ago.

[Stu_London]

Hadley has nudged up to 2.8C to the 22nd

GFS 06z would indicate that the CET will land at 3.1C (way below some of the outlandish dreams posted on here of late).

I think the tendancy for GFS to undercook maxes will be offset by a downward correction at month end.

Therefore if we are more than 0.2C either side of that, I would be very suprised.

[Optimus Prime]

It won't be as high as 3.5c. period 23rd-28th averages 3.1c from the GFS run. It should be around 2.9c by the 28th. Low pressure may return after this, but I suspect the mobile pattern is slowly giving way to a blocked pattern now.

[reef]

It won't be as high as 3.5c. period 23rd-28th averages 3.1c from the GFS run. It should be around 2.9c by the 28th. Low pressure may return after this, but I suspect the mobile pattern is slowly giving way to a blocked pattern now.

Only two of the last 12 days have had means below 4C and those were with upper air temperatures colder than we're forecast to have over the next few days. Hadley's update today took us to 2.84C and today's min is down as 3.2C, so we'll see that 2.9C tomorrow.

The range is looking like 3.3C - 3.7C before adjustment. How the weekend pans out temperature-wise will be a big indication. The GFS is going for supressed temperatures, but the Metoffice are going for average or slightly above average in the southern half of the CET zone.

[Optimus Prime]

Tonight will see minimum temperatures down to -1c or -2c in the CET land, with a maximum of 5c or 6c tomorrow, there will be a slight drop back to 2.8c. High pressure could well play a part as the month ends, giving some frosts and lower temperatures.

To get 3.7c, 6.0c is required daily from tomorrow to end of month. This isn't reached once on the 2m profile upto 28th

And to get 3.3c, 5.0c daily. Maybe reached Twice at the most.

3.7c is far too high. 2.8c - 3.3c is the range for me.

Edited January 23, 2009 by Optimus Prime

[The PIT]

Tonight will see minimum temperatures down to -1c or -2c in the CET land, with a maximum of 5c or 6c tomorrow, there will be a slight drop back to 2.8c. High pressure could well play a part as the month ends, giving some frosts and lower temperatures.

To get 3.7c, 6.0c is required daily from tomorrow to end of month. This isn't reached once on the 2m profile upto 28th

And to get 3.3c, 5.0c daily. Maybe reached Twice at the most.

3.7c is far too high. 2.8c - 3.3c is the range for me.

Dunno about -1c. We're just outside the CET zone and it's 4.6C and pretty level. Cloud keep the temps up.

[Stratos Ferric]

Very slow drift up in GFS projections continues. Average error at t-24 is around -0.3C, which if continued would mean around 2-3C upwards correction by the month end on top of the current projected running mean (3.1C). WIB's suggestion of 3.5C or higher doesn't seem so outlandish on that basis, though much now depends on how far north the milder warm sector passages get over the next week.

[high ground birmingham]

Actually it's the weather which changes. Bitterly cold first 1/3rd, followed by a complete flip-flop to above average second third. The problem on this forum tends not to be people who change, but people who don't: hence they will find the next 1947 out of charts which have moved on and which show nothing of the sort any longer. Our weather is capricious. My own fault is not that I change with the weather, but a tendency to be too extreme about it and, heads up, that criticism I completely accept.

The estimated air frosts tonight from the GFS proved out by between 2C and 4C yet again. With climate-uk posting a 0.2C increase yesterday Hadley should be on 3C by the reading on Saturday. That will leave 8 days' data, or more than a quarter of the month, for the remaining rise of 0.5C to occur, which I happen to think is pretty much a shoo-in.

The best hope of staying under 3.5C now remains Hadley's habit of correcting its figures by 0.2C to 0.3C after the end of most months. Otherwise 3.5C to 4C looks 80% likely to me from here. To remain this side of 3.5C will require air frosts and they don't look all that likely right now, at least not with potency.

I cannot believe that the last 10 days can be called above average. Above average it has certainly not been. In fact in this January, only 1 or 2 days have been above average. Looks like some frosty nights too next week.

There is 0% chance of the January CET of 4C plus coming off. I think the January CET will end up close to 3.3C.

[Stratos Ferric]

I cannot believe that the last 10 days can be called above average. Above average it has certainly not been. In fact in this January, only 1 or 2 days have been above average. Looks like some frosty nights too next week.

There is 0% chance of the January CET of 4C plus coming off. I think the January CET will end up close to 3.3C.

The average for 11-20th Jan (WiB said middle third, not last ten days) was about 5.3C (for what it's worth the mean for the last ten days is around 5.1C); the thirty year rolling mean for Jan is 4.5C. The average to the 10th was about -0.1C. Some of what WiB has said regarding projections to the month end is a tad, shall we say "gassy", but as to the undisputed facts his qualitative assessment looks spot on.

[West is Best]

The average for 11-20th Jan (WiB said middle third, not last ten days) was about 5.3C (for what it's worth the mean for the last ten days is around 5.1C); the thirty year rolling mean for Jan is 4.5C. The average to the 10th was about -0.1C. Some of what WiB has said regarding projections to the month end is a tad, shall we say "gassy", but as to the undisputed facts his qualitative assessment looks spot on.

Thanks SF. It's one of those cases of the difference between what it feels like and the empirical data. Combined with this we perhaps also forget what an average day in January should be like according to the mean, so used to mild winters have we become.

As for my 3.5C, I really don't see how the difference of 0.4C and Stu's 3.1C could be described by him as outlandish. More to do with personalities than the CET that remark. This having been said, we have seen a CET frost tonight, even up in the Lancashire plain at Hawarden. I mentioned to Snowmaiden some time back that the best hope for staying inside the 3C to 3.5C band would be overnight frosts, so it's going to be very interesting to see how this pans out. I still think 3.5C to 4C is the marker, but it's much closer than I thought a day or two back, and I certainly wouldn't be surprised to see a Hadley post-month correction take it back just under.

[Snowly does it]

Thanks SF. It's one of those cases of the difference between what it feels like and the empirical data. Combined with this we perhaps also forget what an average day in January should be like according to the mean, so used to mild winters have we become.

As for my 3.5C, I really don't see how the difference of 0.4C and Stu's 3.1C could be described by him as outlandish. More to do with personalities than the CET that remark. This having been said, we have seen a CET frost tonight, even up in the Lancashire plain at Hawarden. I mentioned to Snowmaiden some time back that the best hope for staying inside the 3C to 3.5C band would be overnight frosts, so it's going to be very interesting to see how this pans out. I still think 3.5C to 4C is the marker, but it's much closer than I thought a day or two back, and I certainly wouldn't be surprised to see a Hadley post-month correction take it back just under.

Worth noting however that the average, further to the discussion on the 'last 10 days' includes the milder tropical maritime interlude which ended last Sunday - since then we were slightly below the 71-00 mean until Thursday from Sunday, and probably now slightly above given the mild day Thursday - probably 4.6 or thereabouts including Thursday and yesterday I'd estimate - it has not been a flat CZ period since the 10th, its been a mix. Generally the CZ has panned out exactly as it probably should - the January average would come about from above average periods (SWrly, 'dirty' azores high, southerly and NWrly around a mild mid atlantic HP) versus 'cold' (Easterly and Northerly based synoptics and inversion highs) with the average being what I expect form NWrly LP systems and cool westerlies. Hence, noting unusual about the last few days - standard winter fayre producing standard temperatures skewed either side of average by the level of cloud or clear and number of mild sectors and their timing.

As for this month, 4 is silly. To hit 4 from here requires 61.3 cumulative degrees (assuming Hadley is 2.85 rather than 2.8 which it likely is) - 6.8 per day for the sake of argument - I thi nk thats what Thursday managed thereabouts and nothing looks sustainably as mild as that - yestedray wasnt so add some to the cumulative requirement, today won't be and neither will tomorrow - add some more.

The Meto forecasts get nowhere near enough to get above 3.5 at absolute best and thats fairly wishful - you need 2.3 degrees above the runnign mean to add 0.1 and tat increases by the 0.1 f the running mean and 0.1 for another day in Jan each day from here - doing that (which is highly unlikely and won't happen today with an air frost on the CET) gets you to 3.6 excluding todays no way) - thats before any adjustments

I'll say it again 3.0 to 3.4 inclusive of any adjustments. Very little chance of 3.5, no chance of 4.0 or above 4 or any of the other figures mentioned previously on the upside.

Second coldest or coldest month of C21

[stewfox]

Dunno about -1c. We're just outside the CET zone and it's 4.6C and pretty level. Cloud keep the temps up.

Bang in the middle of the CET zone and its currently 0c frost everywhere. Nearly 10am and high cloud has come in. Clear skies last night

Max forcast is 5c today but I cant see that

[Snowly does it]

2.9 to the 23rd, 66.7 cumulative degrees

3.0 for the month = 93 cumulative - average next 8 days 3.2 or thereabouts

3.5 for the month = 108.5 cumulative - average next 8 days 5.2 or thereabouts

4.0 for the month = 124 cumulative - average next 8 days 7.2 or thereabouts

GFS and MetO outlook for the next 5 days suggestive of an outturn in the 4s

3.3 looks a good bet from here - before adjustments

[West is Best]

Tonight will see minimum temperatures down to -1c or -2c in the CET land, with a maximum of 5c or 6c tomorrow, there will be a slight drop back to 2.8c.

OP to get a drop from 2.9C to 2.8C like you suggest would require a mean min-max of 0.5C. The 24hr temp is just not playing ball with that sort of figure. Indeed it's touch and go whether it will actually rise. The minima last night were quite cold: something around 0C to -1C is possible overall, but the maxima are already rising. If Northolt increases from 3c at noon to the sort of figures Pershore and Hawarden are already showing (5C and 6C) then we will have a mean of around 3C, which is above the current running mean.

I'm currently favouring an outcome between 3.5C and 3.7C unadjusted. but we still have a quarter of the month to go (amazingly) so there's plenty of room for things to go either way, particularly in the mild direction given the synoptics. Night frosts are now the key to trying to peg it back to that 3.5C marker.

[Snowly does it]

OP to get a drop from 2.9C to 2.8C like you suggest would require a mean min-max of 0.5C. The 24hr temp is just not playing ball with that sort of figure. Indeed it's touch and go whether it will actually rise. The minima last night were quite cold: something around 0C to -1C is possible overall, but the maxima are already rising. If Northolt increases from 3c at noon to the sort of figures Pershore and Hawarden are already showing (5C and 6C) then we will have a mean of around 3C, which is above the current running mean.

I'm currently favouring an outcome between 3.5C and 3.7C unadjusted. but we still have a quarter of the month to go (amazingly) so there's plenty of room for things to go either way, particularly in the mild direction given the synoptics. Night frosts are now the key to trying to peg it back to that 3.5C marker.

Out of interest, why do you use the coastal Hawarden? Stonyhurst is on a paralell 50 miles inland form Blackpool isn't it? So Woodford or Bingley would be a better comparison.

The minima suggest last night was about -0.5 i think so it would take a return of about 1.7 today to get a drop with roundings - unlikely

Maxima are about 4.5 in Pershore and on the Lancashire plain and lower at Northolt (which is not ideal for Rothamsted but near enough) - maxima will probably be around 6 so a return of 2.75 for the day. The CET will be 2.9 tomorrow.

There is almost no chance of 3.7 coming off Richard and I suspect you know that - it needs every single day to be at least 2.5 degrees above the running mean and one of them double that, so after today the run in would need to be something like 7.9, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6

[Snowyowl9]

3.3 looks a good bet from here - before adjustments

Thats exactly what I went for.

If GFS Oz run would`ve come off nearer 3c,I still think it may end up a touch lower than 3.3c with those adjustments at the very cold beginning.

It`s still running colder than Jan 1997 here still by quite a reasonable margin.

[reef]

I cannot believe that the last 10 days can be called above average. Above average it has certainly not been. In fact in this January, only 1 or 2 days have been above average. Looks like some frosty nights too next week.

There is 0% chance of the January CET of 4C plus coming off. I think the January CET will end up close to 3.3C.

This is a perfect example of what I mentioned earlier in the month of how we can 'sleepwalk into milder weather' when cooler zonality is progged.

Contrary to belief, from the 11th-23rd January only two days were actually below the 1971-2000 mean for the month of 4.2C. These days were the 14th (3.3C) and 20th (3.6C). In there were also some very mild days: 12th (8.1C), 16th (7.6C), 17th (7.0C).

The mean for the period 11th-23rd is 5.3C, so comfortably above average.

[Optimus Prime]

Hasn't felt at all cold in my opinion, only the last few days. Your stats there are for Central England, for Scotland and Northern Ireland, it has been cold and wintry.

[Stu_London]

I can't see anything to change my view of yesterday that 3.1C will be the landing point (including any adjustment). If anything the last day of the month looks a little colder on todays charts than yesterdays

[Snowly does it]

This is a perfect example of what I mentioned earlier in the month of how we can 'sleepwalk into milder weather' when cooler zonality is progged.

Contrary to belief, from the 11th-23rd January only two days were actually below the 1971-2000 mean for the month of 4.2C. These days were the 14th (3.3C) and 20th (3.6C). In there were also some very mild days: 12th (8.1C), 16th (7.6C), 17th (7.0C).

The mean for the period 11th-23rd is 5.3C, so comfortably above average.

Yes, this is true, however cool zonality only started to move in on the 17th late on through the 18th - I would wager a guess that (including todays likely output) the average since cool zonality started up is rather closer to the long term average and indeed where one would epect a westerly to nor westerly flow across average sea temps to be - low to mid 4s

[West is Best]

This is a perfect example of what I mentioned earlier in the month of how we can 'sleepwalk into milder weather' when cooler zonality is progged.

Contrary to belief, from the 11th-23rd January only two days were actually below the 1971-2000 mean for the month of 4.2C. These days were the 14th (3.3C) and 20th (3.6C). In there were also some very mild days: 12th (8.1C), 16th (7.6C), 17th (7.0C).

The mean for the period 11th-23rd is 5.3C, so comfortably above average.

Spot on Reef.

Today's maxima amongst the relevant stations were between 6C and 8C.

I'm anticipating the finale to the month to come in around 5.5C, just a little above the last 10 days with less cool upper air temps and that will land us on 3.6C at close of play (note Charlotte).

[Stratos Ferric]

Bang in the middle of the CET zone and its currently 0c frost everywhere. Nearly 10am and high cloud has come in. Clear skies last night

Max forcast is 5c today but I cant see that

Careful, you'll have a certain member opening a thread about catastrophically incorrect forecasts...6C plus widely across CET land. And you're projecting within 4-5 hours of it happening!

[West is Best]

Out of interest, why do you use the coastal Hawarden? Stonyhurst is on a paralell 50 miles inland form Blackpool isn't it? So Woodford or Bingley would be a better comparison.

It's 25 miles from Blackpool. I think it's topographically closest to Hawarden. Woodford or Bingley? Well definitely not the latter which is 35 miles east across the moors - a totally different micro-climate (I know that area fairly well). Woodford's ok, and I do keep an eye on the Manchester readings but I'm a little wary about urban warming. On the other hand, Hawarden is probably a bit of a nod to Philip Eden who makes a slightly better effort of keeping the original Lancashire plain reading.

CET maxima today were, indeed, in the 6-8C range.

I read back through this thread and it's amusing how many of us move goalposts surreptitiously. 'Certain sub 3C' quietly become '3C to 3.5C' without a bat of an eyelid. And I include myself here: afterall have I self-flaggellated for not attaining exactly the 3C by the weekend that I predicted?!

Keep it humourous folks. It's only weather!

[Snowly does it]

Spot on Reef.

Today's maxima amongst the relevant stations were between 6C and 8C.

I'm anticipating the finale to the month to come in around 5.5C, just a little above the last 10 days with less cool upper air temps and that will land us on 3.6C at close of play (note Charlotte).

given that today is about 3, so completely neutral in terms of the running mean, 5.5 per day would bring us in at 3.5

I make todays maxima as follows

Pershore 6.6

Northolt 6.1

Then you can take your pick - Hawarden is 8.2 but is not really representative of Stonyhurst which is further North and further fror the coast, it did get down to -0.9 over night however, or somewhere like Woodford which only managed 0.2 overnight but restricted to 6.1 today - whatever we go for the CET remains unchanged I'd say.

Maxima 6.5, minima -0.5, maybe a little lower - average 3 or a little lower - no net change to the running mean

I am going for 3.3 close of play, adjusted down to 3.2 or 3.1

however - if the mild secotr showing for arlound the last 3 days of the month keeps minima up, that might rise 0.1.... I am doubtful of a 3,5 pre-adjustment finish, but it is at least on the radar, 3.6 for me, isn't

I read back through this thread and it's amusing how many of us move goalposts surreptitiously. 'Certain sub 3C' quietly become '3C to 3.5C' without a bat of an eyelid. And I include myself here: afterall have I self-flaggellated for not attaining exactly the 3C by the weekend that I predicted?!

Keep it humourous folks. It's only weather!

I think I have been fairly consistent - I have trended up maybe 0.3 at most - I have been saying 3ish all along

It remains a stone-cold nailed on, for sure, never wrong, utterly definite 3 to 3.49 pre adjustment

[high ground birmingham]

This is a perfect example of what I mentioned earlier in the month of how we can 'sleepwalk into milder weather' when cooler zonality is progged.

Contrary to belief, from the 11th-23rd January only two days were actually below the 1971-2000 mean for the month of 4.2C. These days were the 14th (3.3C) and 20th (3.6C). In there were also some very mild days: 12th (8.1C), 16th (7.6C), 17th (7.0C).

The mean for the period 11th-23rd is 5.3C, so comfortably above average.

OK i take your point but you have to agree with my point that this January has hardly seen double digit maxima throughout central and southern england apart from London on a few days. It has been extremely different compared to the likes of January 2005 and January 2007. There has been NO blowtorch southwesterlies atleast.

next week some frosts are likely in CET land so i do not think 3.5C will be breached.

Edited January 24, 2009 by high ground birmingham