I'm a fan of the way Kevin has put that formula together as it is fairly simple and the data is not too difficult to collect

I take the point about a burst of 1mm of rain on an otherwise sunny day compared to a dank drizzly day with 1mm spread over several hours but the following will mostly mitigate this effect in the overall index

Most summers have a "statistical" mix of both types of rain day so roundabouts and swings

The dank and drizzly day will also reduce the sun hours by more and this is also in the formula

The dank and drizzly day will often have a lower maximum temp (in summer) also in the formula

So I would endorse the relatively simple method being used

It’s not easy to add anything emotive to a statistic and that’s fine as long as we accept that it is what it is.  It’s great as a statistic for comparison over time and I think we’d just over complicate things by trying to make it a more accurate representation and as SC pointed out, the data isn’t always available. 

We're having 2/3 days of less good weather. But that's normal for summer. As long as we don't regress back to the unrelenting crapfest of June, it won't be too bad - although I'd like a 3-4 week spell of warm & sunny as we go into August.

I was thinking purely in terms of the rain, as funnily enough I've had a lot of months in recent years with most of a near-average rain total falling in the space of a few days max. Curiously, this was not always the case; there used to be a more even mix here.

I agree that Kevin's summer index as it stands does a mighty fine job .

So back onto the thread topic - after a couple of breezier, fresher days, it's calmer and more humid here today. In fact I was impressed at how warm it felt when stepping out for lunch. Temps are now rising slowly through the 23s thanks to sunny spells.

Hints of the sea breeze are starting to appear now; a rustling of the leaves outside the window. I can also see the blue skies to the south that tend to accompany it.

Striking that Bournemouth Airport's still almost as warm as here, despite a 10 mph southerly breeze. That usually drops the temp by 1-3*C at this time of year.

http://ghrsst-pp.metoffice.com/pages/latest_analysis/sst_monitor/ostia/anom_plot.html?i=34&j=2

The nearshore waters of the Channel are responding well to the intermittently sunny and mostly warm weather, despite some quite cool nights for the time of year. SST anomalies are somewhere near +3.5*C in the Solent waters. Strangely, that's only a little short of what they were this time last year after that blazing June .

It's felt like a typical July to me - mostly fine, but with the odd day of rubbish thrown in

Manchester Summer Indices 

1954 143
1907 147
1956 155
1912 156
1924 158
2012 164
2008 168
1987 169
1946 170
1909 171
1931 173
1978 173
1980 173
1920 174
1923 174
2007 174
1927 175
1948 176
1938 177
1922 178
2011 179
1985 180
2019 181 (up to 9th July)
1958 184
1972 185
1916 188
1986 189
1965 189
2016 189
1910 190
1936 190
1988 191
2010 191
1966 192
1998 192
2017 192
1953 193
1963 194
1993 194
2009 194 

Yes you're right these, nothing extreme or even significantly warmer than average but mostly very 'useable'.

Well certainly moving in the right direction. At what point would it be classed as an 'average' summer?

One way of doing that would be to take an average of all of the Manchester Indexes and then compare this year's value so far with that average. If we are above that average, Manchester is having a decent summer otherwise they are having a poor summer there and we can also define an average summer as being one where the Manchester Index value was less than a certain amount either above or below that average.

The official Met Office way of doing that is to go by some 30 year LTA and currently, this is the 1981-2010 Average when we are doing that for the likes of temperature or rainfall. Because of that, I have looked backed on Kev's posts both here on TWO and over at Netweather where he has listed all of the Manchester Indexes for each year. From that, I worked out that average Manchester Index for the 30 period between 1981 and 2010 inclusive is 216.07 to two decimal places.

If we then take that to the nearest whole number, this means that we can then unofficially (since this hasn't actually defined by the Met Office) define the 1981-2010 LTA for the Manchester Index as 216. Since this year's Manchester Index up to 9th July was 181, we can then say that the Manchester Index Anomaly at that point in time was -35 since the latest reported Manchester Index is 35 points below that 1981-2010 LTA which I have just defined.

Since that anomaly is negative, this means that the city of Manchester was experiencing a poor summer overall up until 9 July in terms of the Manchester Index. it is worth remembering though, that this is only valid for Manchester, but there is no reason why this exercise can't then be repeated for other towns and cities within the UK to determine whether or not, that particular location is experiencing a decent summer according that location's corresponding index.

I wonder if we could technically reach last year’s figure of 272, if August turned out to be a good one.  Bearing in mind it let the index down last year and we’re still only half way through summer.

Last year's figure of 272 is 56 points above the 1981-2010 average which I have just defined in my last post here. This means that we can say that last year's Manchester Index Anomaly was +56. I suppose that it is technically possible to beat that this year but even though last August was fairly poor, that didn't prevent last summer from being a really decent summer overall.

The Manchester Index Anomaly which I have quoted shows that really well and although we may or may not technically be able to beat that this year, I reckon that this would probably be quite huge ask even if this was actually possible (although there's nothing to stop us from being optimistic on that front).

If I was in the Manchester area then for me, I would just be happy enough if this year's Manchester Temperature anomaly (as defined in my last post here) ended up being positive which will happen if this year's Manchester Index ends up being at or above 217.

This summer has got better over time as has been shown by the fact that the Manchester Index is going up, so there's no reason why this can't end up happening.

We would need an index of 339 for the period 10/7/19 up to 31/8/19 to equal last year

This equates to no rain in that period, 12 hours of sun every day and an average maximum temperature of 24.5C

So yes it is technically possible but I wouldn't rush down to Ladbrokes to put a bet on

Here we were right in the middle of a yellow warning area for thunderstorms which was issued by the Met Office and yet, this has been yet another day where all of the "interesting" weather has happened elsewhere in the UK other than here whilst where I live, once again lives up to its usual reputation of being the most boring part of the UK when it comes to our weather.

This is shown by the fact that a number of other locations within the UK got some thunderstorms today, whilst we got absolutely nothing at all in that department which shows yet again that getting any kind of "interesting" weather in these parts virtually always seems to be too much to ask for.

It is true that a yellow warning means to be aware that the weather event in question could possibly happen, but the impacts v likelihood matrix which went with that warning showed that this particular event was actually unlikely to happen as it turned out. To me, I don't really see the point in issuing that warning in the first place under those circumstances because if the Met Office are going to go down that road, they would be as well to just give a yellow warning for every other type of weather as well on the sole basis that it is possible to get those other types of weather, even though this is unlikely to happen.

To me, issuing that yellow warning for this area under these circumstances has therefore been a complete and utter waste of time because to me, I don't really see the point in a yellow warning being awarded for anything unless that particular weather event in question is actually likely to happen. On the same token, it is at times like this that I wonder whether or not these folks at the Met Office who actually issue these warnings actually have any sort of clue as what they are actually doing when they issue these warnings.

Instead of the thunderstorms which were forecast for today, we actually had a warm and increasingly sunny day and in fact, today has been the warmest day of this month so far at all three of my local stations with only the very wet start to today (without any thunder or lightning) preventing today from being our best day of proper summer weather overall so far this year.

As someone who likes to see a decent summer, I will happily welcome that sudden unexpected burst of summer which we have seen during today but then, I went into today expecting thunderstorms (since that was what the warning was for) and because of that, I'm really disappointed that we didn't get those thunderstorms which were forecast especially since other places down south did get them (why is at as well, that the English always have to get just about everything when it comes to any sort of "interesting" weather).

Finally, I am going to be down in the Scottish Borders for a week starting from next Monday and until now, I was interested in what the model output was like for next week in terms of what the weather in that part of the world is likely to be like next week. After today's dismal performance by the Met Office in particular though in terms of today's weather, next week's model output isn't even worth looking at because at the end of the day, there is certainly no chance of them being able to get next week's weather right if they can't even get today's weather right.

And you wonder, why I often feel that any sort of model output is a complete waste of time at the best of times?

The BBC forecast was looking just about ok here for the next couple of weeks but it's looking quite disappointing this morning. Lots of rain days. Today and tomorrow now looking wet. The last couple of days have been poor. Urgh

I'd take that!!

Technically speaking, it is possible to get 12 hours of sunshine per day in every day during the rest of this summer, although this is only possible up until around the Autumn Equinox.

It should also be noted that we are already into the time of the year when the days have started to get shorter once again. This will reduce the maximum amount of sunshine over time which is possible on any given day and thus, make it increasingly difficult to actually get 12 hours of sunshine on any given day.

That in turn means that the maximum possible Manchester Index for any given day is going down as a result which over time, will make it increasing difficult for those values for the Manchester Index to be achieved which are required for this summer to go down as a decent one overall.

Just 0.4mm of drizzle down here since 19th June and with temperatures having exceeded 20c everyday this month there are no complaints from me. 

Sunshine has been at a premium here this week, but still plenty of pleasant weather and no rain at all.

Today is one of those where it looks different to what it feels when you step out; it's breezy with a lot of large cumulus allowing only a few sunny spells, yet the temperature's in the mid-20s!

This is my 7th of days of the month to reach 24.0*C or more. Not bad going considering there's nothing special driving the weather at this time.

Especially with the complete absence of daytime rain so far .

So far this summer can be described as patchy at best here in the south of East Anglia. This past week being fairly typical. Eventually the sun cam out for a couple of days but despite promising forecasts earlier in the week the thick cloud has returned. It has been very, very cloudy here past two months. Summer to me is about sunshine more than temperature or dryness.

Maybe you need to have a word with johncs?

Roger