UK Synops?

[Keith (Southend)]

Over the last few months some of the UK Synops have been updated to include Tx & Tn data after the 333 climate marker at 6z, 9z, 18z & 21z.

What time frames do these cover as often when looking at the Tt (dry bulb hourly temperatures) it doesn't stack up.

Usually these are either 12 or 24 hour timeframes.

I would be interested if anyone has the full breakdown. I realise the synops have been converted from bufa code.

Many thanks

Keith (Southend)

[Metman2012]

When I was an observer (60s and 70s), I think they all went back 12 hours. The 09 and 21 were climatological and have been around for a loooong time. The 06 and 18 were synoptic and were a comparative recent addition (comparative to the 60s!). No maxes and mins were done at midnight and midday. I'm prepared for someone to say I'm wrong and I've no idea if they still have those periods. There were some stations that only reported at 09 and they went back 24 hours.

[Keith (Southend)]

Thanks for the reply.

Currently to try to establish the max/min for the day from the synops with these latest codings I use the highest (max) reading from 18z & 21z and the lowest (min) reading from 06z and 09z, as I was assuming they are 24 hourly figures, if they are 12 hourly maybe I should use 18z, 21z & 06z (next day) for (max) and 06z, 09z and 18z (mins).

A bit of a  conundrum. :-)

Keith (Southend)

[Metman2012]

Well, perhaps i should have looked at the synop decode I have. Here's the relevant explanation:

333 Group - Special / Climatological Data

• 0.... -- Regionally developed data
• 1sTTT -- Maximum temperature over previous 24 hours
  s -- sign of temperature (0=positive, 1=negative)
  TTT -- Temperature in .1 C
• 2sTTT -- Minimum temperature over previous 24 hours
  s -- sign of temperature (0=positive, 1=negative)
  TTT -- Temperature in .1 C

Taken from this page. I don't know if this has ever been updated. There's not many hits when synop code is Googled. Which stations report extremes at 09/21?

[Keith (Southend)]

Quite a few now:

3031,3044,3080,3088,3144,3153,3155,3212, 3220, 3226,3230,3305,3316,3330,3344,3346,3379,3392,3409,3410,3488,3520,3529,3535,3544,3560,3609,3647,3740,3743,3770,3796,3827,3844,3882,3904,3907,3915,3923.

You'll see what I mean if you look at them together with the hourly readings.

Regards

Keith (Southend)

[Metman2012]

Thanks, I would assume that the 09 and 21 obs only go back 12 hours each (and if you find one that only reports at 09, then that would be 24 hours). I was hoping that someone more up to date than me would have chimed in by now!

[Keith (Southend)]

Thanks for your replies. No on else has chimed in and I also posted the same on uk.sci.weather. I don't think there are many of us that use and take a close look at the climatic data, the majority just pile on on the model uncertainty, plenty of that atm, so probably sulking atm. :-)

I have a closer look through some of those 18z & 21z data see if your hunch fits (fingers crossed).

There is someone on Twitter I will ask as well later.

Many thanks

Keith (Southend)

[Freddie]

I'll ask on Tuesday when I'm next at work.  These new extremes reporting times are a result of a new observation collection system being used.  I know people who developed the system so should be able to find you a definitive answer.

--
Freddie
Alcaston
Shropshire
148m AMSL
http://www.hosiene.co.uk/weather/
Stats for the month so far: https://www.hosiene.co.uk/weather/statistics/latest.xlsx

[Keith (Southend)]

Thank you Freddie, much appreciated.

Keith (Southend)

[Freddie]

On Monday, 20 December 2021 at 15:39:32 UTC Keith (Southend) wrote:

Thank you Freddie, much appreciated.

Keith (Southend)

On Sunday, December 19, 2021 at 10:32:38 PM UTC Freddie wrote:

I'll ask on Tuesday when I'm next at work.  These new extremes reporting times are a result of a new observation collection system being used.  I know people who developed the system so should be able to find you a definitive answer.

Hi Keith,

The period covered is always for the preceding 12 hours.  Reports are made at 0600 (covering 1800 to 0600), 0900 (covering 2100 to 0900), 1800 (covering 0600 to 1800) and 2100 (covering 0900 to 2100).  All times UTC of course.

[Metman2012]

Benson report a 7 group at 0600, but not at 1800, so does that mean it's 24 hours rather than 12? Similarity Brize Norton. However this might be Ogimet not converting the synop from bufr correctly.

[Freddie]

Where is the 7 group?  The maximum is reported as a 1 group in section 3 (after the 333), with the 2 group for minimum in the same section.

[Keith (Southend)]

Hi Freddie,

Thank you for confirming that for me.

Now when I look at the synops for both the original and the new coding and checking back at the hourly 1**** Tt readings, this seems to make to sense.. For some reason, I always had in the back of my mind that they were 24 hourly readings, but they're not for the UK ones at least. I was trying to see if there was somewhere else in the coding that told you this, similar to whether wind is in mph, knots or m/s, but I don't think it does.

Here my original breakdown for decoding I've had on a spreadsheet for many years, which states 12 or 24 hours.

333 Group - Special / Climatological Data                                                        
                                                       
0.... -- Regionally developed data                                                        

1sTTT -- Maximum temperature over previous 24 hours (sometimes 12 hourly)                                                        

s -- sign of temperature (0=positive, 1=negative)                                                        
TTT -- Temperature in .1 C                                                        
                                                       

2sTTT -- Minimum temperature over previous 24 hours (sometimes 12 hourly)                                                        

s -- sign of temperature (0=positive, 1=negative)                                                        

TTT -- Temperature in .1 C               

Metman2012  mentioned the 7 group, I assume you mean the 24 hourly rainfall:

    7RRRR -- 24 hour precipitation in mm                                        
        last R is 1/10th.                         eg       70123 = 12.3mm of rain in past 24 hours.
000        0 mm                               

999       Trace

(Reporting at 0000, 0600, 1200 and/or 1800 UTC)    *Just at 6z for UK*

I always use this when it's reported as it is to .1 or the 6***4 @ 6z + 18z etc, the downside is it's always a whole 1mm, unless 0.8mm or less total.

Finally, In your conversation did you get any idea when the rest, assuming they are, likely to be updated, as this is so much better, I'm particularily interested Shoeburyness (03693)?

It's a shame the grass minimum wasn't also included on the 09z observation 3****, but no I'm pushing my luck :-)

Many many thanks

Keith (Southend)

[Freddie]

Hi Keith,

Regarding the "when", the only info I have is that all will be done by the end of 2022 - covid permitting!

Your decode of the 1 and 2 groups looks good to me.  Time period of the max/min is a locally-agreed thing (at a country level) so likely differs between the UK and elsewhere.

[Keith (Southend)]

Great stuff.

Just gone below freezing for me at Southend-on-Sea. :-)

Many thanks

Keith (Southend)

[Metman2012]

It's in the 333 area, 0600 yesterday was 70000.

03658 16581 /0603 10038 20017 30182 40254 56006 60002 333 20035 3/002 70000 88/27==

[Keith (Southend)]

70000 is 24 hour rainfall, in this case none, the 60002 prior to the 333 is the 12 hour rainfall, which fall within the Land Based Observations (111 group).

     6RRRt -- Liquid precipitation                
     RRR -- Precipitation amount in mm                
               
1        1 mm        
2        2 mm        
          ...                  ...        
988        988 mm        
989        989 or more mm        
990        Trace        
991        0.1 mm        
992        0.2 mm        
          ...                  ...        
999        0.9 mm        
               
     t -- Duration over which precipitation amount measured                
               
1        6 hours        
2        12 hours        
3        18 hours        
4        24 hours        
5        1 hour        
6        2 hours        
7        3 hours        
8        9 hours        
9        15 hours        
          /        24 hours        

Keith (Southend)

[Metman2012]

You live and learn! I hadn't realised that. I wonder if that's where the flood check web page get their numbers from (at bottom of page)

[Freddie]

I think the rainfall figures are from EA gauges.

[Keith (Southend)]

I modified my spreadsheet for the UK stations so that ALL locations will run to the 06z/09z & 18z/21z reporting times. Fortunately I have the hourly Tt temperature for each hour shown on the spreadsheet so:

For 06z it will also pick up the minimum from 06z (Tn), 07z (Tt), 08z  (Tt) , 09z  (Tt) and 09z (Tn). So picks the lowest temperature from the 5 readings.

For 18z it will also pick up the maximum from 18x (Tx), 19z  (Tt) , 20z  (Tt) , 21z  (Tt) and 21z (Tx). So picks the highest temperature from the 5 readings.

This also means as soon as more stations come on board with the additional data it will automatically pick the Tx or Tn's up.

At a first glance many of the minimums on some mornings are lower, as the temperature has continued to fall after 6z. I would imagine the maximums won't be quite as noticeable, mainly happening when a warm front digs in for the evening, saying that, it's happened a couple of time lately here.

Over the festive period I will have a closer look at some of the other European locations as I'm sure this applies as well.

I hope this makes sense.

Keith (Southend)

On Tuesday, December 21, 2021 at 11:27:36 AM UTC Freddie wrote:

[Keith (Southend)]

Concentrating on my European spreadsheet atm and have spoted quite a few additions since I last updated it. One unusual one I just found is Portugal, which includes the Azores and Maderia, that they report 24 hour rainfall 7**** at 09z, infact they seem to do at 6, 7, 8 in some cases. Fortunate adding this to csv file that gets created it sits right at the end and I have a free column, so I haven't got to shuffle the columns of the spreadshet along.

Great to have some time to do this, can't wait for retirement in 3 years time.

Keith (Southend)

[Metman2012]

Hi Keith, don't wish your life away. I was looking forward to retirement not all that long ago - but suddenly it's nearly ten years ago now - hence the 2012 in my handle!

[Keith (Southend)]

Indeed you are right, just looking forward to when time is my own, just hopeI/we get some good few years of it.

Keith (Southend)