April 2017 C.E.T. forecasts

[Summer Sun]

9.9 to the 3rd

3.4 above the 61 to 90 average

2.0 above the 81 to 10 average

[cheeky_monkey]

5 hours ago, Summer Sun said:

9.9 to the 3rd

3.4 above the 61 to 90 average

2.0 above the 81 to 10 average

why does nobody ever quote the 71-00 average?..why are we still using 61-90?

[Optimus Prime]

1 hour ago, cheeky_monkey said:

why does nobody ever quote the 71-00 average?..why are we still using 61-90?

61-90 is an important reference period because the WMO swear by it.

[BornFromTheVoid]

1 hour ago, cheeky_monkey said:

why does nobody ever quote the 71-00 average?..why are we still using 61-90?

The standard reference periods for long term climate analysis are generally updated every 30 years, so 1961-1990 is the current one and the next one will be 1991 to 2020. Many met agencies currently use 1981-2010 to compare with the recent climate averages too.

[cheeky_monkey]

11 minutes ago, BornFromTheVoid said:

The standard reference periods for long term climate analysis are generally updated every 30 years, so 1961-1990 is the current one and the next one will be 1991 to 2020. Many met agencies currently use 1981-2010 to compare with the recent climate averages too.

it seems however we have been using the 1961-90 average for as long as i can remember...when did we stop using the 1931-60 Average then?

[BornFromTheVoid]

33 minutes ago, cheeky_monkey said:

it seems however we have been using the 1961-90 average for as long as i can remember...when did we stop using the 1931-60 Average then?

Some time in the early 1960s I assume. Though I don't know when the guidelines were put in place

[cheeky_monkey]

3 minutes ago, BornFromTheVoid said:

Some time in the early 1960s I assume. Though I don't know when the guidelines were put in place

This is where im confused?...if 1961-90 is still current and we are way past 1990 why wasn't 31-60 used up until 1990?

[BornFromTheVoid]

Just now, cheeky_monkey said:

This is where im confused?...if 1961-90 is still current and we are way past 1990 why wasn't 31-60 used up until 1990?

Sorry, I meant 31-60 would have started in in the early 60s, and 61-90 should have started in the early 90s. So 91-20 will start in the early 2020s.

[Roger J Smith]

Also, the contest uses 1981-2010 to determine above or below normal (you get a point for your forecast having the right sign) and the Met Office quote 1961-90 on their update page; this is why Summer Sun chose to report these two periods and not 1971-2000. I could calculate the means for that decade so we could see that data point as well (we go off cumulative means, the April 1981-2010 cumulative are in a table I posted earlier and look rather odd because they go down from a higher start, just the way things have been in that period). We can assume that the Met Office use a similar running cumulative mean for the anomalies they report. (1st to day of last report, at the end of the month this slides into the better known 30-year "normal" for the month).

[damianslaw]

Once again another month starting on a notably above average note, in what is a significantly warming month as well.. I don't though foresee the rate of warmth persisting unlike March. How many of our months since April last year have been at least 1 degree above the average, most I think expect Nov, Oct and Jan.

[Roger J Smith]

Okay, if you would like to track the CET against 1971-2000 cumulative normals, here they are on a daily basis:

01 __ 7.6 _____ 11 __ 7.2 _____ 21 __ 7.6

02 __ 7.5 _____ 12 __ 7.2 _____ 22 __ 7.7

03 __ 7.1 _____ 13 __ 7.2 _____ 23 __ 7.8

04 __ 7.0 _____ 14 __ 7.3 _____ 24 __ 7.8

05 __ 6.9 _____ 15 __ 7.3 _____ 25 __ 7.8

06 __ 7.0 _____ 16 __ 7.4 _____ 26 __ 7.9

07 __ 7.0 _____ 17 __ 7.4 _____ 27 __ 7.9

08 __ 7.0 _____ 18 __ 7.5 _____ 28 __ 8.0

09 __ 7.0 _____ 19 __ 7.5 _____ 29 __ 8.0

10 __ 7.1 _____ 20 __ 7.6 _____ 30 __ 8.1

Note, the trend goes down from 1st to 5th much like 1981-2010. Of course these periods share 20 years (1981-2000) so I looked at them and found that the downward trend 1st-5th is particularly influenced by these years: 1981, 1990, 1991, 1994, and also 1979 which was only in this data set and not 1981-2010, The means for the first five days of 1981,90,91 and 94 were 8.8, 8.2, 6.3, 5.1, 5.4 and adding in 1979 this becomes 8.4, 7.5, 5.6, 4.6, 5.1. 

So that largely explains the odd decline in CET in early April. The other years were six times as frequent but were only boosting the running means by 0.1-0.2 on average, That was overcompensated by these large falls in five or so years. 

So, for the provisional report on the 3rd, it would be:

 

9.9 to the 3rd

3.4 above the 61 to 90 average

2.8 above the 71 to 00 average

2.0 above the 81 to 10 average

 

Edited April 4, 2017 by Roger J Smith

[Weather-history]

7 hours ago, damianslaw said:

Once again another month starting on a notably above average note, in what is a significantly warming month as well.. I don't though foresee the rate of warmth persisting unlike March. How many of our months since April last year have been at least 1 degree above the average, most I think expect Nov, Oct and Jan.

One peculiarity about April is the lack of particularly high maxima during the last few days of the month. For instance the highest maximum ever recorded on the 29th April is just 25.8C, that's just 0.2C higher than the all time March maximum. 

[Summer Sun]

10.0 to the 4th

3.7 above the 61 to 90 average

2.3 above the 81 to 10 average

[Roger J Smith]

also 3.0 above the 1971-2000 average for 1st-4th.

[The PIT]

Sunny Sheffield at 9.8C and with zero rainfall.

[Summer Sun]

9.6 to the 5th

3.2 above the 61 to 90 average

2.0 above the 81 to 10 average

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Current high this month 10.0 to the 4th

[Matthew.]

It's hard to believe at the moment the warmest spring on record could be challenged yet again this year after 2007 and 2011 and not long since one of the warmest winters on record

[Relativistic]

1 hour ago, Summer 1976 said:

It's hard to believe at the moment the warmest spring on record could be challenged yet again this year after 2007 and 2011 and not long since one of the warmest winters on record

And, as out of place as it sounds, only four years after the coldest Spring in 122 years.

[Don]

2 hours ago, Summer 1976 said:

It's hard to believe at the moment the warmest spring on record could be challenged yet again this year after 2007 and 2011 and not long since one of the warmest winters on record

It wouldn't surprise me if this spring turns out be one of if not, the warmest on record.

[NorthYorksWeather]

9.7c here to the 5th, 1.9c above the 1981-2010 average.

Looking like a warm up peaking on Sunday, then quite a drop next week and beyond if the models are to believe.

[ARTDEMOLE]

Met Office Hadley    9.32c.     Anomaly       2.9c. Provisional to 6th.

[Summer Sun]

9.3 to the 6th

2.9 above the 61 to 90 average

1.7 above the 81 to 10 average

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Current high this month 10.0 to the 4th

[The PIT]

Sunny Sheffield down to 9.2C.  +0.8C above normal. Next week should batter if the GFS is correct.

[The PIT]

Sunny Sheffield down to 9C courtesy of a cold night.

[Summer Sun]

9.4 to the 7th

2.9 above the 61 to 90 average

1.9 above the 81 to 10 average

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Current high this month 10.0 to the 4th