January C.E.T

[eddie]

Hadley CET now at 6.2C.

Yesterday was a crazy 10.8C which makes it the joint 10th warmest January day in the CET series.

[Weather-history]

The second half of January 1846 had a CET of 8.3 I wonder how close the second half of January 2008 will get to this value.

[Snowyowl9]

What is noticeable in that chart is how the GFS underestimates the temperatures in very mild tropical maritime setups like the last few days. I have a sneaky suspicion that after Thursday's brief cold interlude, we could be seeing temperatures far above what the GFS is currently showing.

Take the T+168 chart for example, its out of the reliable timeframe, but looks like a perfect example of how the GFS underestimates.

A mainly south-westerly flow and upper air temperatures approaching 10C. The GFS also goes for cloudless skies:

However, at the surface are temperatures of 9-10C:

In such a setup you'd expect temperatures many degrees above that. The high is not in a suitable position for inversions or fog. I just cant see how a temperature of 10C at the surface in almost 10C upper air could occur when even weak sunshine is in the equation.

Interesting.

Looks like theres some slightly cooler surface air mixed into the high making temps look less mild than the uppers suggest and also lighter winds.

http://85.214.49.20/pics/Rtavn1442.png

http://85.214.49.20/pics/Rtavn1447.png

http://85.214.49.20/pics/Rtavn14417.png

[ukmoose]

I'm a little surprised that Hadley is as 'low' as 6.2

I suppose the colder incursions further north in the CET have managed to take the edge off the overall CET because down here in the south it has been a fair bit milder than that I would think.

7 is looking a pretty good bet now given the location of that high pressure to our south continuing to feed in warm air. But I suppose anywhere from 6.5 to as high as 7.9 can't be ruled out?

Moose

Edited January 21, 2008 by ukmoose

[Snowly does it]

I'm a little surprised that Hadley is as 'low' as 6.2

I suppose the colder incursions further north in the CET have managed to take the edge off the overall CET because down here in the south it has been a fair bit milder than that I would think.

7 is looking a pretty good bet now given the location of that high pressure to our south continuing to feed in warm air. But I suppose anywhere from 6.5 to as high as 7.9 can't be ruled out?

Moose

I think 7.9 can be very safely ruled out Moose - it would require 10.6 per day on Manley, let alone Hadley.

7.5 would require 9.5 - highly improbable

over 7 will be difficult to achieve especially as we do not look like seeing very high returns until at least Saturday (Weds and Fri have cooler nights preceeding them)

As for the current position, its not that surprising, the very mild temps did not arrive until this weekend, before that it was just a little warmer than 'cool'

[shuggee]

Away from the CET zone up here - a very near average month continues:

N Scot 0.0

E Scot 0.0

W Scot +0.6

C.ScotTemp +0.5

From: http://www.climate-uk.com/page2.html

However I suspect that will change by month end with more northerly tracking lows and more frequent encroachment of warm sectors this far north.

[Stu_London]

Away from the CET zone up here - a very near average month continues:

From: http://www.climate-uk.com/page2.html

However I suspect that will change by month end with more northerly tracking lows and more frequent encroachment of warm sectors this far north.

Might be partially offset by a couple of very keen frosts this week

[shuggee]

Maybe Stu - but only two instances this calendar month of temps in double figures here:

And I suspect there's a few more to come before month end.

Meanwhile minimum temps have included 16 ground frosts (sub 2ºC as an arbitary figure) or 8 air frosts (0ºC or below):

So I'd suggest it's the maximums that swing it.

[Stratos Ferric]

What is noticeable in that chart is how the GFS underestimates the temperatures in very mild tropical maritime setups like the last few days. I have a sneaky suspicion that after Thursday's brief cold interlude, we could be seeing temperatures far above what the GFS is currently showing.

Take the T+168 chart for example, its out of the reliable timeframe, but looks like a perfect example of how the GFS underestimates.

A mainly south-westerly flow and upper air temperatures approaching 10C. The GFS also goes for cloudless skies:

However, at the surface are temperatures of 9-10C:

In such a setup you'd expect temperatures many degrees above that. The high is not in a suitable position for inversions or fog. I just cant see how a temperature of 10C at the surface in almost 10C upper air could occur when even weak sunshine is in the equation.

I agree Reef, and we shall see (if we get that synoptic). My projection did add a tad above the GFS projection for the same reason. The one modifying factor is that under descending air the RH should be lower than in a pure mT feed off a LP, reducing the effect of any fohn. Certainly agree that 10-11 underplays things though. London was like April again today, and the Standard was running a story on the record warm night (Friday) and flowers in bud.

It is even feasible that a maximum temperature of 20C could be achieved in London.

No chance. Not outdoors anyway.

I'm a little surprised that Hadley is as 'low' as 6.2

I suppose the colder incursions further north in the CET have managed to take the edge off the overall CET because down here in the south it has been a fair bit milder than that I would think.

7 is looking a pretty good bet now given the location of that high pressure to our south continuing to feed in warm air. But I suppose anywhere from 6.5 to as high as 7.9 can't be ruled out?

Moose

That'll be that pesky northern station holding things back a bit. I have to agree, particularly as I spend a lot of time scuttling north and south, that events in the south this month belong to a very different season to those further north.

[Roger J Smith]

Never say never in this climatic regime, I don't know about 20 C but 18 is probably do-able nowadays in central London in January if you got the right combination of air mass and mixing. We may find out before this month is over.

Just as an analogy, Toronto with its long period of record (1840-present) had recorded 15 or 16 a number of times in January as far back as 1876 and more recently in 1950 and 1967. Daily records in the "global warming" period starting in the later 1980s were not able to crack this long-standing record, but when everything set up just right in Jan 2005, it hit 19.5 C and shattered the monthly record.

The same thing had already happened to the December record back in 1982, that one was blown away by 4 C degrees.

For a weather station with good exposure and a long period of record, those are very large monthly record changes.

A similar event, March 1990, mid-month temps broke daily records by 5 or 6 degrees. That didn't apply to the monthly because those came near the end of the month, although I think the old monthly for March was recently nipped out as well.

These events seem to apply mainly to winter months so far, summer monthly records have not been broken and just to give some idea of how long-standing they are, starting in April and running to November, Toronto's all-time monthly records date to 1842, 1962, 1964, 1936, 1918, 1953, 1963 and 1950.

I think a very warm January day is probably long overdue given the regime since 1988, and it would not surprise me in the least if somewhere hit 18 or even 19 C this month. Not sure what your existing UK all-time January record is, imagine it is 19 or so, but I am not talking about some foehn location in north Wales here, I'm talking about relatively flat southeastern England where the all-time record I would imagine is 16 to 17 C.

Meanwhile, the Hadley CET has my very firm encouragement to go conservative from here to the end, now even I'm looking for a cold spell ! :lol:

[Kentish Man]

The all time record at East Malling Kent, my local weather station, is 17.4C on 27 January 2003. Toronto by virtue of being 44 deg N as opposed to 51 deg N presumably has a better chance of reaching 20C in Jan.

[Roger J Smith]

That latitude is a factor from March to November, but consider this, from December to February, there is relatively little warmth to be gained from the low solar angle at 44 N, Toronto is surrounded by Great Lakes that average 2-4 C in those months if not ice-covered in some cases, and large parts of the upwind region are often snow covered even in a relatively mild winter (which is the sort that produces these daily records, typically, a daily record at Toronto will follow a period of at least two weeks of snow-free ground conditions, and not the other 50% possibility, snow cover).

I accept your point but I think that southern England through the years has always managed slightly higher winter record max temperatures than the Toronto region, so this new departure in 2005 is probably a good sign of what could happen in that region sooner or later.

Now if the climate of North America ever switched around to some flow pattern that involved a persistent mid-continent ridge in winter, then you might start to see average temperatures like southern France and daily records around 20-21 C. But that never happens, the flow is always some variation on a trough near 90 W, it seems, the cold winters have a deep trough and the mild winters have a shallow one. I attribute this to the arctic conditions around Hudson Bay and the magnetic field forcing of the upper atmosphere.

[acbrixton]

The all time record at East Malling Kent, my local weather station, is 17.4C on 27 January 2003. Toronto by virtue of being 44 deg N as opposed to 51 deg N presumably has a better chance of reaching 20C in Jan.

Interesting stat KM. I imagine that the all time UK non-foehn January record cannot be much higher than that. The record maxima for Toronto for January is 14c and the winter record is 16c. Even taking into account the greater variability that Toronto as a continental city can expect I doubt that 20c is an easier record for Toronto than anywhere in the UK.

As regards future UK January maxima, 'even larger teapot' or not, there must be an absolute limit for such maxima imposed by reduced insolation. I would guess at 19c under foehn conditions (existing record 18.3c) and 18c under non-foehn conditions.

regards

ACB

[osmposm]

The record maxima for Toronto for January is 14c and the winter record is 16c. Even taking into account the greater variability that Toronto as a continental city can expect I doubt that 20c is an easier record for Toronto than anywhere in the UK.

Um, ACB, I'm confused: Roger has just quoted max figures of 15 & 16 for January in Toronto occasionally since 1876.....and a high of 19.5 in Jan 2005 !? Are you disagreeing with his stats?

[acbrixton]

Um, ACB, I'm confused: Roger has just quoted max figures of 15 & 16 for January in Toronto occasionally since 1876.....and a high of 19.5 in Jan 2005 !? Are you disagreeing with his stats?

Ah, I had not read Roger's post.

My assertion was based upon BBC News online data ('average conditions'). I have found some dubious data there before. I will have to find alternative sources!

regards

ACB

[Roger J Smith]

Those BBC stats may have been based on a shorter period of record, they look like they would be true for about 1981 to 2000 for example, but mine are from the official records which extend from 1840 to 2008. The recent 19 C reading was at Toronto airport which on past occasions ran a degree or so colder than downtown Toronto in very mild winter weather, but the downtown readings were discontinued before this observation.

In general, southern Ontario stations with long periods of record have seen readings like 18 C in January before, but Toronto had never been above 61 F while they were measuring in that scale up to 1977. And they had not been past 16 C afterwards until 2005.

I don't have the records at hand, but I recall seeing a 70 F reading in the records for Jan 1906 somewhere in Ontario, probably Windsor or Chatham, but they are closer to 42 degrees N.

Most daily records at Toronto in winter are above 10 C but there are days in early February which have never broken 10 C. To give you an idea of the variability of climate in that region, while it was 16 C on 26 Jan 1967, it was -33 C close to Toronto on 23 Jan 1976 and -42 C about a hundred miles to the north.

Edited January 22, 2008 by Roger J Smith

[reef]

Another 0.2C increase in the CET today on both the Hadley and Manley figures.

Manley is currently at 6.6C:

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

Hadley at 6.4C:

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

Only 7.8C for the remaining 10 days required now on the Hadley to finish the month on 7C. 8.3C is required on the Hadley. Possible, but it does look a little less mild than we've had.

[Norrance]

Signs of a cool down from about Tuesday possibly due to as high pressure building to the North. Latest Met O outlook for the last few days of Jan a bit cooler than previously indicated.

UK Outlook for Sunday 27 Jan 2008 to Tuesday 5 Feb 2008:

Many parts should be fine at first with some sunny spells, as high pressure is expected to be centered to the south of the UK. Northern and some western parts will be more unsettled though with cloud and outbreaks of rain as well as some strong winds, perhaps gales over northwest Scotland. It will be mild generally. However, some colder air is expected to spread across the UK from next Tuesday onwards, and this will bring showers or spells of rain, with wintry falls over hills, and perhaps to low levels in the north. It is likely to be windy at times too. The driest and sunniest conditions are most likely in the south and east. Temperatures will be near normal to rather cold after the mild start.

Updated: 1158 on Tue 22 Jan 2008

[Stratos Ferric]

The all time record at East Malling Kent, my local weather station, is 17.4C on 27 January 2003. Toronto by virtue of being 44 deg N as opposed to 51 deg N presumably has a better chance of reaching 20C in Jan.

That's definitely one factor; it's the equivalent of almost a full month of apparent solar elevation. The other 'problem' is that the UK is essentially a maritime climate; the sea moderates in both directions. I would guess that record warm in Toronto comes of a W / SW'ly feed, and then when aresa south have also been warmed. Because land could warm anomalously (you don't have to head that far south and you're verging on sub-tropical) it would be easier to get a large upside than a feed off the ocean, where thermal lag is more pronounced.

I think I can fairly safely say "never [for January 20C]" Roger until SSTs get a lot higher.

Signs of a cool down from about Tuesday possibly due to as high pressure building to the North. Latest Met O outlook for the last few days of Jan a bit cooler than previously indicated.

UK Outlook for Sunday 27 Jan 2008 to Tuesday 5 Feb 2008:

Many parts should be fine at first with some sunny spells, as high pressure is expected to be centered to the south of the UK. Northern and some western parts will be more unsettled though with cloud and outbreaks of rain as well as some strong winds, perhaps gales over northwest Scotland. It will be mild generally. However, some colder air is expected to spread across the UK from next Tuesday onwards, and this will bring showers or spells of rain, with wintry falls over hills, and perhaps to low levels in the north. It is likely to be windy at times too. The driest and sunniest conditions are most likely in the south and east. Temperatures will be near normal to rather cold after the mild start.

Updated: 1158 on Tue 22 Jan 2008

It may cool down as we cusp into February, but the remainder of this month looks predominantly mild in CET-land. 7 - remarkably - is still not out of the question, though personally I'd favour high 6s.

[Roger J Smith]

I agree SF, 20 is a degree or perhaps two, higher than it could probably reach in southern England, but maybe we'll know better after tomorrow, which looks pretty toasty with this westerly wind giving a long land fetch too.

Yep, when it gets record warm in Toronto, it is almost always 3-5 C cooler than in Cleveland or Buffalo, showing the cooling effects of Lakes Erie and Huron on southwest Ontario, and also the wind has to come in from WSW or very cold Lake Ontario will cut the temperature down further. Many days in spring around western Lake Ontario, there is a stronger lake breeze than any sea breeze you would ever see in East Anglia or Kent. I've seen cases where it would be 4 C in fog at the lakefront and 21 C in sunshine about 30 kms inland. The western end of Lake Ontario also anchors fronts in some cases so that the whole region stays cold when it warms significantly further to the west, above the Niagara escarpment which is the feature over which Niagara Falls, fall. I think.

As for the landing point, I would say Hadley 6.6, Manley 6.8, NW 7.0 at this rate. It will get above those by this weekend, then probably slide back down (and I'm happy about that).

[BLAST FROM THE PAST]

As for the landing point, I would say Hadley 6.6, Manley 6.8, NW 7.0 at this rate. It will get above those by this weekend, then probably slide back down (and I'm happy about that).

Very few are or will be Roger

BFTP

[Mammatus]

It may cool down as we cusp into February, but the remainder of this month looks predominantly mild in CET-land. 7 - remarkably - is still not out of the question, though personally I'd favour high 6s.

Agree SF. Another very mild January looks certain now with a CET in the high 6's, although as you say above, 7 is still not out of the question . It's felt like March/April down here in Suffolk, extraordinary/barmy warmth lately.

Mammatus

[damianslaw]

Getting a CET above 7 degrees this month whilst still very possible will depend very much on whether clearer skies develop as we head into next week or not, i think we will need persistant cloud cover at night for the rest of the month to deliver an above 7 degree as i don't foresee very high maxima i.e. average above 10 degrees occuring after the weekend.

[eddie]

Hadley CET now 6.4C. Yesterday was recorded at 5.5C.

8.4C required for the rest of the month to reach 7C. Looking at the 06z GFS I would rate the chances of that happening as slim to none.

[Duncan McAlister]

Sorry if this has been mentioned before - but it looks to be the first month with an above average second half since May.