July 2016 C.E.T. Forecasts

[BornFromTheVoid]

Minimum today of 14.3C, while maxia look like reaching about 22C, so an increase to 15.5C is likely on tomorrows update.

After that, the 06z GFS has the CET at:

15.7C to the 17th (18.8: +2.5)
16.0C to the 18th (19.8: +3.3)
16.3C to the 19th (22.2: +5.3)
16.6C to the 20th (22.9: +5.7) [Record high: 22.9C]
16.7C to the 21st (17.5: +0.6)
16.7C to the 22nd (18.2: +1.3)
16.8C to the 23rd (18.8: +1.9)
16.9C to the 24th (18.5: +1.9)
16.9C to the 25th (18.0: +1.0)

The upcoming slowly changing to a heatwave, with even a chance of setting a new record on the 20th. We could see the CET swing from 1C below average to 0.5C above average over the next 10 days.

[Summer Sun]

15.5c to the 16th

0.4c below the 61 to 90 average

0.9c below the 81 to 10 average

[BornFromTheVoid]

Today's 06z GFS keeps the warmth up for the rest of the month, with the week of the 17th to the 23rd averaging 19.8C, and the rest of the month averaging the low to mid 17s.

[Summer Sun]

15.7c to the 17th

0.2c below the 61 to 90 average

0.7c below the 81 to 10 average

[BornFromTheVoid]

Minimum today of 14C, while maxima look like reaching the mid 25s, so an increase to 16.3C is likely on tomorrow's update.

After that, the 06z GFS has the CET at:

16.3C to the 19th (22.7: +5.8)
16.6C to the 20th (22.5: +5.3) [Record High: 22.9C]
16.7C to the 21st (17.6: +0.7)
16.7C to the 22nd (17.8: +0.9)
16.7C to the 23rd (17.2: +0.3)
16.8C to the 24th (19.0: +2.4)
16.8C to the 25th (16.8: -0.2)
16.8C to the 26th (15.3: -2.0)
16.7C to the 27th (16.3: -0.9)

After the warm few days, things look like returning to average straight after, with little movement in the CET.

[Roger J Smith]

This brief heat wave reminds me of the spell from 30 June to 2 July last year. And that got me thinking, was 2015 the coldest July that managed a record high daily CET value? This is the list I came up with, showing rank of monthly CET in each case ... as you would expect, the top 20 do well ... The warmest July not to establish a record was 2nd warmest 1983. After that, the next no-shows (by 2015 at least) were 1859 and 2013, tied for 10th. Years before 1772 have no daily data and are shown "no daily data" ... the table includes all years to 18.0 CET then only those years that established daily records. 

* for records and totals marked, a tie with one other year. ... the total is adjusted where applicable (e.g. 1976 had 2 ties so its total of 6 daily records is adjusted to 5). 

Year _______ Monthly CET _____ Records __________________total*

 1. 2006 ____ 19.7 ____________ 24.5 (19th), 22.7, 23.2 (25th-26th)_ 3

 2. 1983 ____ 19,5 ____________ none ________________________0

 3. 1783 ____ 18.8 ____________ 22.6 (11th) ___________________ 1

 4t 1976 ____ 18.7 ____________ 22.8,24.6,24.7 (2nd-4th), 

_ _ _ _ _ _ ___________________ 23.3, 22.6*, 21,4* (6th-8th) __ 6 ** (5)

 4t 1852 ____ 18.7 ____________ 24.0 (5th) ____________________ 1

 6 1995 ____ 18.6 _____________ 23.4*  (31st) _____________ 1*  (0.5)

 7 1921 ____ 18.5 _____________ 21.6, 22.1 (9th-10th) ___________ 2

 8t 1808 ____ 18.4 _____________24.5, 24.4 (13th-14th) __________ 2

 8t 1757 ____ 18.4 _____________ no daily data

10t 1868 ___ 18.3 _____________ 23.1, 23.2 (21st-22nd) _________ 2

10t  1859 & 2013 _ 18.3 _________ none _______________________0

10t 1701 &33 __ 18.3 ___________ no daily data

15t 1818 ___ 18.2 _____________ 23.9 (24th) __________________ 1

15t 1989 ___ 18.2 _____________ 22.4 (23rd) __________________ 1

15t 1911,34 __ 18.2 ____________ none ______________________ 0

15t 1759 ____ 18.2 ____________ no daily data

20 1794 ____ 18.1 _____________ none ______________________ 0

21t 1901 &94 __ 18.0 __________ none _______________________ 0

21t 1666,77, 1714,19 _ 18.0 _____ no daily data

(only years with records now in list)

36t 2003 ___ 17.6 _____________ 22.7 (16th) __________________ 1

39t 1923 ___ 17.5 _____________ 22.6* (7th), 23.7 (12th) ___ 2* (1.5)

39t 1870 ___ 17.5 _____________ 21.4* (8th) _____________ 1* (0.5)

55t 1825 ___ 17.2 _____________ 23.7 (15th), 23.3 (18th) ________ 2

73t 1834 ___ 16.9 _____________ 22.3 (17th) __________________ 1

96t 1878 ___ 16.6 _____________ 22.9 (20th) __________________ 1

106t 1943 __ 16.4 _____________ 23.4* (31st) _____________  1* (0.5)

170t 2015 __ 15.9 _____________ 24.5 (1st) ___________________ 1 

182t 1948 __ 15.8 _________ 21.9, 23.7, 25.2, 23.1 (27th-30th) ____ 4

____________________________________________________

Quite remarkable how a cold July up to 26th (1948) could then produce four daily records and the highest CET value all-time. Average must have been about 14.5 before that heat wave. So, 2015 and its hot start was not quite the coldest July with a record high after all.

Edited July 18, 2016 by Roger J Smith

[Relativistic]

3 hours ago, Roger J Smith said:

 

Quite remarkable how a cold July up to 26th (1948) could then produce four daily records and the highest CET value all-time. Average must have been about 14.5 before that heat wave. So, 2015 and its hot start was not quite the coldest July with a record high after all.

An extraordinary month was July 1948.

1st-15th: 13.2C (5th coldest such period)

16th-31st: 18.2C (19th warmest such period)

The three day spell that commenced on the 28th is particularly eye-catching, with a mean of 24.0(0)C. In July, only 1976 could better it: 2nd-4th was 24.0(3)C; 3rd-5th was 24.4C.

(The 1st-3rd August 1995 was also warmer, at 24.3C. No other three day  period in August was >24C.)

Edited July 18, 2016 by Relativistic

[Roger J Smith]

The CET stood at only 14.0 on 24th and 14.2 on 25th of July in 1948. The heat was very confined to the period 25th July -2nd August. The highest daily average outside of that nine day period was 18.2 on 14th of June and again on 7th of August. 

In July 1983, the highest daily mean was 22.7 (13th). All five of these days missed being a record from 12th to 16th -- 22.6, 22.7, 22.1, 22.4, 22.5 -- the amounts by which they missed being 1,1, 1.7, 2.3, 1.3, and 0.2 (2003 eclipsed the one day that may have been a record otherwise).

The warmest in 2013 was 21.6 on the 22nd which missed by 1.6 degrees (from 1868). 

[Summer Sun]

16.0c to the 18th

0.1c above the 61 to 90 average

0.4c below the 81 to 10 average

[Summer Sun]

16.4c to the 19th

0.5c above the 61 to 90 average

0.1c below the 81 to 10 average

[BornFromTheVoid]

The minimum today is 19.0C, provisionally the warmest CET minimum on record. Maxima today are likely to be up around 26C, so an increase in the CET to 16.7C is likely on tomorrows update.

After that, the 06z GFS has the CET at:

16.8C to the 21st (18.5: +1.6)
16.9C to the 22nd (19.1: +2.2)
17.0C to the 23rd (18.4: +1.5)
17.1C to the 24th (19.2: +2.6)
17.1C to the 25th (18.3: +1.3)
17.1C to the 26th (16.0: -1.2)
17.0C to the 27th (16.1: -1.1)
17.0C to the 28th (17.4: +0.0)
17.0C to the 29th (15.4: -2.3)

The minimum for the 19th is almost certainly a daily record, and could still be an all time record after corrections. The maximum yesterday of 31.5C is also the 7th warmest July maximum on record, but not a daily record due to the 2006 value of 32.9C.

[Roger J Smith]

What is the highest minimum for any day of the year? 

[Candice]

23.9c Brighton August 1990

[BornFromTheVoid]

2 hours ago, Roger J Smith said:

What is the highest minimum for any day of the year? 

For the CET, it's 18.8C from July 29th, 1948 and August 11th, 1997

Edited July 20, 2016 by BornFromTheVoid

[hillbilly]

1 hour ago, Roger J Smith said:

What is the highest minimum for any day of the year? 

Highest minimum was on the night of 3rd/4th August 1990 at Brighton recording 23.9 deg

[The PIT]

Sunny Sheffield zoomed up to 16.2C -0.5C below normal.

[seaside 60]

3 days of over 30c and high minima in the central parts must have rocketed the CET.

I see Net Weather is running the CET at 16.99c just over 0.5c over ave.

[Relativistic]

1 hour ago, BornFromTheVoid said:

For the CET, it's 18.8C from July 29th, 1948 and August 11th, *1998*

* I suspect this is a typographical error but this should be 1997.

Edited July 20, 2016 by Relativistic

[BornFromTheVoid]

8 minutes ago, Relativistic said:

* I suspect this is a typographical error but this should be 1997.

Yep, you're right. Will edit!

[Roger J Smith]

Thanks in each case for those stats. Surprised that the CET has never stayed above 20 but I suppose it's a composite that includes some rural and fairly northerly locations, even so, short nights between two hot days, I would often have mins of 22-24 in heat waves in my rural setting even between days that topped out at 30 or 31. The higher humidity I suppose keeps things warmer. 

[BornFromTheVoid]

I think it's the 9am to 9am measurement time too, so it relies on the previous morning also being exceptionally mild/warm.

Edited July 20, 2016 by BornFromTheVoid

[Roger J Smith]

Agreed for the provisional values, but my understanding is that the final values reset the CET to the calendar day and this is the main reason why various days go up and down as we see. Days turning colder will go down with those evening lows and days that are warmer than previous days will go up when they lose the previous day's minimum. This is my theory, and it is mine. Maybe the people who run the CET can confirm this. (I am not saying that adjustments are entirely based on this, some may be based on more complete data from more sites too). 

[BornFromTheVoid]

6 hours ago, Roger J Smith said:

Agreed for the provisional values, but my understanding is that the final values reset the CET to the calendar day and this is the main reason why various days go up and down as we see. Days turning colder will go down with those evening lows and days that are warmer than previous days will go up when they lose the previous day's minimum. This is my theory, and it is mine. Maybe the people who run the CET can confirm this. (I am not saying that adjustments are entirely based on this, some may be based on more complete data from more sites too). 

Interesting about reverting to the calendar day. Where did you read about it? I thought the corrections were mainly down to UHI, station moves, things like that.

[Summer Sun]

16.7c to the 20th

0.8c above the 61 to 90 average

0.2c above the 81 to 10 average

[Roger J Smith]

Re the calendar day, I worked this out from two principles, one being the actual changes that were made to various days when I was thinking about the subject in 2010-2011, and two, just the belief that the CET would be eventually standardized to what all data sets should be based on, namely a close approximation of the calendar day (some slight variations are allowed by WMO, I understand that some North American data runs 06z to 06z and some data is midnight to midnight standard time all year, those sorts of minor adjustments won't make much difference. I think this was discussed in a CET thread years ago, can't remember who participated in the discussion now, and we got to the point of saying somebody should e-mail Hadley and find out, and maybe somebody did, I just don't remember.

This three-day heat wave has shifted the outcome considerably and I am now predicting 16.5 the most likely end point after adjustments. The contest will tighten up considerably and I will drop from first to about fifth, I would expect. Going to have to put some subs on the pitch for the last thirty minutes.