A lot of you have had quite a wet spring so far, although that's not been the case here in Edinburgh.

As I have said in last month's post, we could really do with some much need rainfall in order to at least make up some of our rainfall deficit which has built up quite a lot since last year.

However, I am also aware that more rain is probably the last thing that most of the rest of you will be looking for after a wet spring so far.

This month is important in many ways. It is of course, the final weekend of the meteorological spring and there are also a number of big events taking place during this month such as the King's Coronation which takes place next weekend.

These are occasions for which we will obviously be looking for some decent weather but regardless of how everything pans out during this month, this is the place to report those all important rainfall totals for your area.

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Could be quite lively in spots on Friday with some decent downpours 

I've just noticed that SEPA released their latest water scarcity report on 27 April 2023.

This report shows that despite the continued low levels of rainfall over recent months, the current water scarcity level is actually at normal across most of Scotland.

There are a number of areas which are already at early warning status for that but rather interestingly, these areas are all in the west of Scotland, so SE Scotland is rather unexpectedly coming out as normal in that regard.

In those regions which are at early warning status, river levels and groundwater levels are classed as being exceptionally low in places, but the groundwater levels are actually normal across most of the rest of Scotland with the exception of Fife and Angus where groundwater levels are quite low.

First of all, it is interesting that it is actually the west of Scotland rather than the east or SE which is considered to be at the greatest risk just now. Those are the areas which had a wetter than average February whilst the rest of the UK (including here in Edinburgh) was much drier than average but this has clearly not been enough tp prevent any concerns about water shortages being raised there.

For the rest of us, I'm surprised that the water scarcity level is still at normal despite the almost constant low levels of rainfall here. Having said that though, we did have a wetter than average autumn followed by a wetter than average start to both the winter and spring.

None of those wetter than average months were excessively wet here but when it has been drier than average here, it has never actually been excessively so at any time. Our driest month over the last few months was in February but even then, it wasn't quite as excessively dry here as it was down south during that same month.

The overall result is that our rainfall deficit has continued to grow over recent months but it seems that it doesn't actually take all that much in the way of rainfall to properly replenish our groundwater and river levels which means that our rainfall totals clearly don't actually need to be at or above our long-term average in order for that to happen.

Furthermore, SEPA are confident that there is enough in the way of rainfall coming up according to the latest model output to be able to see things through for a while longer yet without any major issues, although I am always a bit nervous about that, especially when our rainfall totals are continuing to be below average for most of the time.
 

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The overall result is that our rainfall deficit has continued to grow but it seems that it doesn't actually take all that much in the way of rainfall to properly replenish our groundwater and river levels which means that our rainfall totals clearly don't actually need to be at or above our long-term average in order for that to happen.

 

I think you need to factor in the effect of vegetation. Once trees and bushes are in leaf, it takes a lot of (preferably) heavy rain to reach the ground, and what does get through is immediately used up by grass and herbaceous plants. So even if there wasn't a great deal of rain , anything before the end of March, even April, would have gone direct to topping up groundwater and reservoirs.

I was filling in teaching Geography A level one year - not my specialist subject but I'm interested in physical geography - and I came across a textbook statement that in high summer it takes an inch of rain before any recharges rivers or groundwater. This I didn't believe, so coming from experimental science, I set up a test. The class were sent out with secateurs to gather vegetation from the school grounds, much to their embarrassment. We made a pile of it and sprinkled on an amount of water from a watering can and measured how much reached the sheet of polythene underneath. This crude experiment suggested that about 3/4" could be held up on the vegetation.

It's probably the only geography lesson they'll remember, 30 years on 😀

 

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I think you need to factor in the effect of vegetation. Once trees and bushes are in leaf, it takes a lot of (preferably) heavy rain to reach the ground, and what does get through is immediately used up by grass and herbaceous plants. So even if there wasn't a great deal of rain , anything before the end of March, even April, would have gone direct to topping up groundwater and reservoirs.

I was filling in teaching Geography A level one year - not my specialist subject but I'm interested in physical geography - and I came across a textbook statement that in high summer it takes an inch of rain before any recharges rivers or groundwater. This I didn't believe, so coming from experimental science, I set up a test. The class were sent out with secateurs to gather vegetation from the school grounds, much to their embarrassment. We made a pile of it and sprinkled on an amount of water from a watering can and measured how much reached the sheet of polythene underneath. This crude experiment suggested that about 3/4" could be held up on the vegetation.

It's probably the only geography lesson they'll remember, 30 years on 😀

 

One great thing about this forum is that I am always learning something new from it, and here is yet another example of that.

I suppose that the big takeaway from all of this is that if rainfall totals continue to be low here once all of the trees are in full leaf, then I can start to worry about possible water shortages arising from that. That is most likely to be the case during the summer and yet since most of us are usually looking for decent summer every year, more rainfall during that period is usually the last thing which we then all want to be seeing as one of the main aspects of a decent summer is that it should be drier than average overall.

That is why I would much rather have had more in the way of rainfall beforehand so that our rivers and reservoirs could be filled up by enough during this period for us to then to be able to enjoy a decent summer without any possible resulting concerns about water shortages arising from that.
 

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I think you need to factor in the effect of vegetation. Once trees and bushes are in leaf, it takes a lot of (preferably) heavy rain to reach the ground, and what does get through is immediately used up by grass and herbaceous plants. So even if there wasn't a great deal of rain , anything before the end of March, even April, would have gone direct to topping up groundwater and reservoirs.
 

...and the knock-on effect of that is that trees help enormously with moderating flash-flooding. It's why I despair at the modern trend for fake grass in back gardens and paving over front gardens, if you get a summer thunderstorm you get flash flooding (and the drains often can't cope, hence it ends up in the sea).

Just 0.2mm of rain so far here this month, but I suspect that'll have gone up a fair bit by this time next week.

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7.4mm to date 

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15.2mm for the day, 19.8 MTD

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The latest rainfall data for Edinburgh Gogarbank and the botanic gardens in Edinburgh are as follows:

Data For Recent Days

24 Hour Total up to 10am BST (09:00 UTC) yesterday morning: 0.4 mm at Edinburgh Gogarbank, along with 0.4 mm at the botanic gardens in Edinburgh mm at the botanic gardens in Edinburgh.

Total since 10am BST (09:00 UTC) yesterday morning: 7.8 mm at Edinburgh Gogarbank along with 7.8 mm at the botanic gardens in Edinburgh (as at 8am BST (07:00 UTC) this morning on Sunday 7 May 2023).

Monthly Data

Total for this month so far: 8.2 mm (16.3% of 1991-2020 May average) at Edinburgh Gogarbank along with 8.2 mm (17.2% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of rain days during this month so far: 1 (9.3% of 1991-2020 May average) at Edinburgh Gogarbank along with 1 (10.4% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of dry days during this month so far: 4 at Edinburgh Gogarbank along with 4 at the botanic gardens in Edinburgh.

Seasonal Data

Total for this spring so far: 100.4 mm (67.6% of 1991-2020 spring average) at Edinburgh Gogarbank along with 109.2 mm (79.8% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of rain days during this spring so far: 21 (69.4% of 1991-2020 spring average) at Edinburgh Gogarbank along with 24 (85.4% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of dry days during this spring so far: 30 at Edinburgh Gogarbank along with 29 at the botanic gardens in Edinburgh.

This means that just at least another 5 rain days now need to be recorded at the botanic gardens in Edinburgh between now and the end of this month in order for this spring to go down as being wetter than average there in terms of the number of rain days.

Annual Data

Total for this year so far: 176.4 mm (22.5% of 1991-2020 annual average) at Edinburgh Gogarbank along with 176.6 mm (24.3% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of rain days during this year so far: 39 (28.4% of annual average) at Edinburgh Gogarbank along with 40 (31.2% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of dry days during this year so far: 61 at Edinburgh Gogarbank along with 59 at the botanic gardens in Edinburgh.

Note

This data has been obtained from the Scottish Environmental Protection Agency (SEPA).
 

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10.8mm

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The Coronation didn't rack up massive totals of rain (5.6mm at Kew, for instance), just enough to spoil the occasion. The south coast and much of Central Southern England got totals in the mid-teens (14mm at Chichester, and it felt much wetter!)

EDIT - a friend reports no measurable rain in the extreme east of Essex (Clacton) on Coronation Day

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21.30 mm This Month.

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11.5mm to date.

24.30 mm This Month.

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The latest rainfall data for Edinburgh Gogarbank and the botanic gardens in Edinburgh are as follows:

Data For Recent Days

24 Hour Total up to 10am BST (09:00 UTC) this morning: 1.4 mm at Edinburgh Gogarbank, along with 4.8 mm at the botanic gardens in Edinburgh mm at the botanic gardens in Edinburgh.

Total since 10am BST (09:00 UTC) this morning: 0.4 mm at Edinburgh Gogarbank along with 0.4 mm at the botanic gardens in Edinburgh (as at 12pm BST (11:00 UTC) noon on Monday 8 May 2023).

Monthly Data

Total for this month so far: 10.0 mm (19.9% of 1991-2020 May average) at Edinburgh Gogarbank along with 13.4 mm (28.2% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of rain days during this month so far: 2 (18.6% of 1991-2020 May average) at Edinburgh Gogarbank along with 2 (20.8% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of dry days during this month so far: 4 at Edinburgh Gogarbank along with 4 at the botanic gardens in Edinburgh.

Seasonal Data

Total for this spring so far: 102.2 mm (68.8% of 1991-2020 spring average) at Edinburgh Gogarbank along with 114.4 mm (83.6% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of rain days during this spring so far: 22 (72.7% of 1991-2020 spring average) at Edinburgh Gogarbank along with 25 (89.0% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of dry days during this spring so far: 30 at Edinburgh Gogarbank along with 29 at the botanic gardens in Edinburgh.

This means that only at least another 4 rain days need to be recorded at the botanic gardens in Edinburgh between now and the end of this month in order for this spring to go down as being wetter than average there in terms of the number of rain days.

Annual Data

Total for this year so far: 178.2 mm (22.7% of 1991-2020 annual average) at Edinburgh Gogarbank along with 181.8 mm (25.0% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of rain days during this year so far: 40 (29.1% of annual average) at Edinburgh Gogarbank along with 41 (32.0% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of dry days during this year so far: 61 at Edinburgh Gogarbank along with 59 at the botanic gardens in Edinburgh.

Note

This data has been obtained from the Scottish Environmental Protection Agency (SEPA) by using a beta version of their latest upcoming API system.
 

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Now up to 17mm.

Difficult to keep up. 19mm now.

15.6mm to date

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The latest rainfall data for Edinburgh Gogarbank and the botanic gardens in Edinburgh are as follows:

Data For Recent Days

Total since 10am BST (09:00 UTC) yesterday morning: 4.0 mm at Edinburgh Gogarbank along with 3.8 mm at the botanic gardens in Edinburgh (as at 8am BST (07:00 UTC) this morning on Tuesday 9 May 2023).

Monthly Data

Total for this month so far: 13.6 mm (27.1% of 1991-2020 May average) at Edinburgh Gogarbank along with 16.8 mm (35.3% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of rain days during this month so far: 3 (27.9% of 1991-2020 May average) at Edinburgh Gogarbank along with 3 (31.2% of 1991-2020 May average) at the botanic gardens in Edinburgh.

Number of dry days during this month so far: 4 at Edinburgh Gogarbank along with 4 at the botanic gardens in Edinburgh.

Seasonal Data

Total for this spring so far: 105.8 mm (71.2% of 1991-2020 spring average) at Edinburgh Gogarbank along with 117.8 mm (86.1% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of rain days during this spring so far: 23 (76.0% of 1991-2020 spring average) at Edinburgh Gogarbank along with 26 (92.6% of 1991-2020 spring average) at the botanic gardens in Edinburgh.

Number of dry days during this spring so far: 30 at Edinburgh Gogarbank along with 29 at the botanic gardens in Edinburgh.

This means that just at least another 19.0 mm of rain now needs to fall at the botanic gardens in Edinburgh between now and the end of this month in order for this spring to go down as being wetter than average there in terms of the actual amounts.

In addition to that, at least another 3 rain days now need to be recorded at the botanic gardens in Edinburgh between now and the end of this month in order for this spring to go down as being wetter than average there in terms of the number of rain days.

Annual Data

Total for this year so far: 181.8 mm (23.2% of 1991-2020 annual average) at Edinburgh Gogarbank along with 185.2 mm (25.5% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of rain days during this year so far: 41 (29.8% of annual average) at Edinburgh Gogarbank along with 42 (32.7% of 1991-2020 annual average) at the botanic gardens in Edinburgh.

Number of dry days during this year so far: 61 at Edinburgh Gogarbank along with 59 at the botanic gardens in Edinburgh.

Note

This data has been obtained from the Scottish Environmental Protection Agency (SEPA) by using a beta version of their latest upcoming API system.
 

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10mm today, more thunder and lightning than rain which makes a change.

42.00mm MTD and 350mm YTD so a good splash, hopefully it doesn't do a volte face and dry up all summer like last year.

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