April CET

[Optimus Prime]

and even colder than average Jans / Febs / Mar are often a favourable pattern to lead to a cold April. Sadly after a favourable pattern last year, a cold April still failed to materialise.

Again and again, very little proof to support that argument. The only examples in the last hundred years or so were 1917 and 1986. Two examples is really enough evidence out of many I can give you to support your hypothesis? No, the only connection I can see is mild Aprils often proceed cold winters. And less so, mild Marches too.

[Iceberg]

It's now looking more about how much the April Record will be broken by IMO, with some warmer night I can see a daily CET range of maybe as high as 14C, which will certaintly cause the April CET value to increase on a quick upward trend.

I struggle to see any CET's below 10-11 now until the end of the month even if we get an easterly feed for the last month it will likely lead to cloud cover keeping night time temps in double figures.

[TonyH]

The most amazing thing about this month is that Craig Evans could well win

[summer blizzard]

www.climate-uk.com

Phillip Eden seems to think that we have recorded over 100 hours of sunshine already. How many Aprils have seen over 200 hours of sunshine.

http://www.metoffice.gov.uk/hadobs/hadukp/data/ranked_monthly/HadEWP_ranked_mly.txt

Unlikely to match 2007 in terms of lack of precipitation however there is a good chance that April could be drier than March which would be something given that March 2011 was the driest in 50 years (20th driest on record).

The lack of precipitation is notable considering that December 2010 was the 22nd driest, March 2011 the 20th driest and a very dry April 2011 looks likely.

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Forget about any cold spell, with agreement like that i will say this now...

The record is gone!!!!

[Summer of 95]

It will be a travesty if this month beats 2007, just like May 2008 had no right to lace May 1992's shoes. Very disappointing not to have reached 21C this month here, considering all the warm synoptics and 21Cs recorded in the east of the country.

And the sunshine has been very disappointing, considering all the high pressure and dryness. It just can't stop clouding over in the afternoons having lured us out with warm sunny mornings, today I'd swear it was 3C warner at 12 noon than 3pm.

[Snowyowl9]

April has changed so much in the last 10 years theres no doubt about it.

Another record warm april looks on just 4 years after 2007,oops that was a summer and a half record wet.

very hazy this spring almost polution looking.

Edited April 18, 2011 by Snowyowl9

[Upgrade]

April and September seem to be the months which have changed the most over the years. this year's spring has been freakily perfect in the south east. we've just had weeks of endless sunshine.

[stewfox]

Will we ever see a cold April again? We just don't seem to be able to get northern blocking and / or cold polar maritime zonality to give us cold weather in April any more - all we seem to be able to get now is high pressure sat over the UK, refusing to ever move north of the UK to let cooler airflows in.

This reminds me of 3/4 yrs ago of will we ever see a cold December again etc

Maybe warm April come in clusters

1783 1794 1796 1798

1798 April hit 10.4c in the top 12 warmest as are the rest mention above. The forums back in 1798 were saying the same then and then guess what happened the following year.

1799 April hit 5.4c 6th coldest in 330 yrs

[Optimus Prime]

This reminds me of 3/4 yrs ago of will we ever see a cold December again etc

Will we ever see a sub 3.0c winter

Will we ever see a winter lower than 2005/2006

Will we ever see a winter month below 4.0c

Will we ever see a month below 2.0c

Will we ever beat February 1991

A month below 0c

Will we ever get widespread snowfall and low temperatures similar to December 1981 and January 1982

Those questions have all been asked and have all been answered.

Will we ever see an April below 7.0?

Yes.

Edited April 18, 2011 by Optimus Prime

[damianslaw]

There is no denying the fact that this April is turning into an exceptional month for sustained warmth. I do believe we have a very high chance now of beating April 2007 and probably by quite some margin, and whilst we have not and unlikely will see the extreme warmth of that month, because the warmth started right from the outset we have been able to outshine 2007 simply down to the length of the warm spell. It is quite amazing how we are talking once again about a very warm April - only four years since the last. Why has this month been so exceptional put it down to La Nina and the persistance of the polar vortex stuck like a broken record over Greenland - it shouldn't be where it is right now, but it is and it is down to it that we have seen such warmth.

Could April beat May 2011 for CET I think there is a very good chance.

Out of interest with temps expected to reach daily highs of 24 and 25 degrees in London over the coming days - does anyone have the daily maxima that London saw during the very warm spell of mid April 2007. Will be interesting to see just how sustained and intense the upcoming warmth for London will be compared to April 2007.

People should remember average maxima for London at this time of year is about 13 degrees - to see a sustained maxima at least 10 degrees above this figure is exceptional. If it was July or August the equivalent would be daily highs of about 34 degrees - to see a run of more than 3-4 days of this heat is quite exceptional. As I said these are potentially exceptional days ahead in terms of temps for London. Compare with the cold of Dec 2010 which was extreme but we didn't see maxima some 10 degrees below what it should be.. how do we manage to see greater deviation from normal temps in the spring and summer compared to the winter.

Edited April 18, 2011 by damianslaw

[Weather-history]

Will we ever see a sub 3.0c winter

Will we ever see a winter lower than 2005/2006

Will we ever see a winter month below 4.0c

Will we ever see a month below 2.0c

Will we ever beat February 1991

A month below 0c

Will we ever get widespread snowfall and low temperatures similar to December 1981 and January 1982

Those questions have all been asked and have all been answered.

Will we ever see an April below 7.0?

Yes.

Another one you can add to the list, will we ever see a sub 9C year again

Yes we did.

[Weather-history]

.

Could April beat May 2011 for CET I think there is a very good chance.

Something I have been wondering about, the higher the April value is, the greater the chance.

It has happened only 6 times

1755, 1814, 1821, 1869, 1894, 1987

The 1814 one is interesting, after such a severe winter that lasted well into the March, April returned a CET of 9.6, so it must have been a real shock to the system.

The difference between the January and April of 1814 was a huge 12.5C

[North-Easterly Blast]

Another one you can add to the list, will we ever see a sub 9C year again

Yes we did.

We were lucky there. The cold of 2010 exactly co-incided with the calendar year. The 12 month rolling average ending in Jan 2011 was above 9*C again, the 12 month rolling average ending in Nov 2010 was above 9*C.

Another question could be:

Will we ever see a sub zero month again, that is not part of the mildest winter on record containing a sub zero month, and in a winter that is not a pear shaped winter let alone the most pear shaped winter on record like 2010-11 was?

We may think Dec 2010 was exceptional, but look how pear shaped and dissapointing the rest of the winter was.

Almost all the other sub zero months if not all of them occurred in a winter that wasn't a pear shaped one. The rest of the winter in all other winters that have had sub zero months was most likely far better than the rest of the 2010-11 winter. At the end of the day Dec 2010 was just an exceptional early cold spell in an otherwise winter that was nothing special, and had a mild February, just a long long weeks / months after Xmas with nothing other than what we have become used to in the 1990s and 2000s - it certainly was dissappointing overall and far from a classic.

Edited April 19, 2011 by North-Easterly Blast

[Weather-history]

Again and again, very little proof to support that argument. The only examples in the last hundred years or so were 1917 and 1986. Two examples is really enough evidence out of many I can give you to support your hypothesis? No, the only connection I can see is mild Aprils often proceed cold winters. And less so, mild Marches too.

Just look at some of the the "cooler" Aprils since that last cold one of 1989

April 1990 had a CET of 8.0 and yet the 3 months preceding it and the following May were very warm.

April 1998 had a CET of 7.7C and yet like with 1990, the months surrounding it were on the warm side.

The same again with 2000.

So why did Aprils in those years did not turn out as warm as you think they should have been considering they were surrounded by warm months?

Then you got 1996, which was the inverse. Why didn't that April turn out colder than it did? February and March were on the cold side, May was exceptional cool but April was above average.

April seems to have been a bit of "maverick" in the last 20 years, bucking small trends, turning out less warm in a warm period, and warmer in a cool period.

[Optimus Prime]

My local average now stands at 12.7c which is equal with 2007. With the heat building this week and no signs of a cooldown i'm thinking somewhere around the mid to high 13.0s as the finishing point. Warmer then the warmest CET for October on record....remrkable. More unprecendented then December for sure.

[reef]

Hadley on 11.2C to the 18th. Yesterday came in at 12.3C.

It looks pretty likely the record will go for the second time in four years. How much by depends on just how warm it gets this weekend and whether the low cloud from the North Sea afterwards penetrates inland.

[North-Easterly Blast]

Just look at some of the the "cooler" Aprils since that last cold one of 1989

April 1990 had a CET of 8.0 and yet the 3 months preceding it and the following May were very warm.

April 1998 had a CET of 7.7C and yet like with 1990, the months surrounding it were on the warm side.

The same again with 2000.

So why did Aprils in those years did not turn out as warm as you think they should have been considering they were surrounded by warm months?

Then you got 1996, which was the inverse. Why didn't that April turn out colder than it did? February and March were on the cold side, May was exceptional cool but April was above average.

April seems to have been a bit of "maverick" in the last 20 years, bucking small trends, turning out less warm in a warm period, and warmer in a cool period.

A bit like the Decembers in the 1970s and 1980s - in a run of much cooler years overall, the Decembers in those two decades were much milder overall than the Decembers in the very warm decades of the 1990s and 2000s - it is in the last two decades that December has bucked the trend and swung the other way to most if not all the other months in the year.

Hadley on 11.2C to the 18th. Yesterday came in at 12.3C.

It looks pretty likely the record will go for the second time in four years. How much by depends on just how warm it gets this weekend and whether the low cloud from the North Sea afterwards penetrates inland.

Before 2007 the record April CET was 10.6 in 1865 - quite something when that was only 1.4 above the March record considering April's long term average is over 2*C higher than March.

[Snowyowl9]

After a record la nina year I expected to see some cold this spring.

Last may gave cold but nothing like the mid-90`s

[Duncan McAlister]

We were lucky there. The cold of 2010 exactly co-incided with the calendar year. The 12 month rolling average ending in Jan 2011 was above 9*C again, the 12 month rolling average ending in Nov 2010 was above 9*C.

Another question could be:

Will we ever see a sub zero month again, that is not part of the mildest winter on record containing a sub zero month, and in a winter that is not a pear shaped winter let alone the most pear shaped winter on record like 2010-11 was?

We may think Dec 2010 was exceptional, but look how pear shaped and dissapointing the rest of the winter was.

Almost all the other sub zero months if not all of them occurred in a winter that wasn't a pear shaped one. The rest of the winter in all other winters that have had sub zero months was most likely far better than the rest of the 2010-11 winter. At the end of the day Dec 2010 was just an exceptional early cold spell in an otherwise winter that was nothing special, and had a mild February, just a long long weeks / months after Xmas with nothing other than what we have become used to in the 1990s and 2000s - it certainly was dissappointing overall and far from a classic.

Do I hear goalposts being shifted?

People should remember average maxima for London at this time of year is about 13 degrees - to see a sustained maxima at least 10 degrees above this figure is exceptional. If it was July or August the equivalent would be daily highs of about 34 degrees - to see a run of more than 3-4 days of this heat is quite exceptional. As I said these are potentially exceptional days ahead in terms of temps for London. Compare with the cold of Dec 2010 which was extreme but we didn't see maxima some 10 degrees below what it should be.. how do we manage to see greater deviation from normal temps in the spring and summer compared to the winter.

There is less tendency to deviate from the maximum in winter but very large scope for deviation from the minimum. Temperatures of around -15C are a bigger deviation from the average minimum (in England at least) than just about any record high temperature in the summer. And yet such temperatures were recorded quite widely in December. Assuming the average is around 1-2C, this represents a difference of 16-17C from the average. We've only seen that kind of deviation from the max in summer on two or three occasions (I'm thinking August 1990 and 2003). Of course even lower minima were experienced widely in Highland Scotland.

Edited April 19, 2011 by Duncan McAlister

[Jack Wales]

We may think Dec 2010 was exceptional, but look how pear shaped and dissapointing the rest of the winter was.

I tend to think differently, the cold we experienced during the six weeks from mid November to the end of December was unprecedented. Yes, the rest of winter was fairly benign but I certainly would prefer a long cold spell like we had rather than two days of cold followed by a toppler.

Anyway, back on topic! It looks like we could top a 12C CET this month, Here's a question for Mr Data perhaps... What's the record maximum temperature for the UK in April?

[North-Easterly Blast]

I tend to think differently, the cold we experienced during the six weeks from mid November to the end of December was unprecedented. Yes, the rest of winter was fairly benign but I certainly would prefer a long cold spell like we had rather than two days of cold followed by a toppler.

Anyway, back on topic! It looks like we could top a 12C CET this month, Here's a question for Mr Data perhaps... What's the record maximum temperature for the UK in April?

I would prefer cold spells spread through the winter rather than a big one so ludicrously early like in 2010-11 only for the rest of the winter post Xmas to deliver next to nothing. Certainly no other winter since the CET record began in 1659 has been so pear shaped - no other winter has ever seen the combination of an exceptional month long cold spell to fade in late December into nothing, and then the rest of the winter deliver so little, and such a mild February, and moving into the spring, into the warmest April on record.

If we do top a 12*C CET this month, that would be every bit as exceptional as May 1833 or June 1846.

[damianslaw]

After a record la nina year I expected to see some cold this spring.

Last may gave cold but nothing like the mid-90`s

Spring isn't over yet, we still have May to go and there are signs of some cooler conditions as we enter May so la nina may well deliver the cold I think many of us were predicting it would bring this spring - but alas has failed to do so yet. Anyone know why we are seeing such warmth this spring?

April is our most fickle month and the one month which can produce the greatest extremes of temps in very short spaces - it is renowned for its major switcharounds from cold arctic northerlies temps barely getting above freezing and then warm southerlies - its just this year it has decided to stay positively warm.

The seas are still relatively cool and the land is still taking its time to heat up hence we see much less convection in April than at any stage during May - Sept and thus much less cloud and therefore greater chance of sunny days, it is the sun which is the real big player in anticyclonic conditions in April - it is now as strong as it is in August but as I said because the land is still relatively cool it isn't strong enough to trigger temps conducive to cloud and storm build up, thus we can see large diurnal temp ranges favouring some very warm maxima for the time of year. A similiar synoptical pattern we have now occuring in July and August would I believe be much more conducive to major convection and heavy cloud build up inland with severe thunderstorms.

[Weather-history]

Here's a question for Mr Data perhaps... What's the record maximum temperature for the UK in April?

29.4C on the 16th April 1949

[Isolated Frost]

The coldest December in 120 years and in some parts, forever, and now possibly the warmest or second warmest April ever?!

Amazing.

[Snowyowl9]

I tend to think differently, the cold we experienced during the six weeks from mid November to the end of December was unprecedented.

Anyway, back on topic! It looks like we could top a 12C CET this month.

Coldest december since 1890.

This is unprecidented if april reaches higher than 2007 which I thought couldn`t be topped.

What next worms falling from a cloudless sky in scotland. :huh:

http://news.scotsman.com/odd/Never-mind-cats-and-dogs.6744480.jp

Edited April 20, 2011 by Snowyowl9