A day late this week, my apologies but needs must. So the beautiful view above looking down on Eyebrook reservoir from a Rutland hillside gives a pointer to the type of weather we are expecting to come our way over the next 7-10 days as high pressure finally breaks up the run of Bay of Biscay low pressure systems that have been pretty much set fair for the last month or so. After a dry start to June, it started raining on the 14th over here (though Ireland and Scotland were drier for longer) and we have had some pretty heavy downpours during that period, intense humidity and obviously high disease pressure.
Speaking of downpours there was some really heavy rainfall around yesterday with parts of London getting 40 mm + in the space of a few hours causing widespread flooding.
You can see yesterdays intense rainfall band over London and the south east on Netweather’s radar image below.
Well we pick up our own heat plume this weekend (see GFS output below), thankfully more short-lived than the one that affected Canada and the north west of America. That said I’ve seen colours on the heat maps across Africa that I’ve never seen before representing intense heat and I think it’s only a matter of time before we see one of these head our way.
If so, it’ll be a game changer temperature-wise. Away from the weather, plenty has been going on, but we won’t talk about the football eh ?
So we are due to pick up some sunshine and some warmth over the next 7-10 days and the good news for Ireland is that they are closest to the centre of the high pressure, so you’ll get some cracking weather. When the sun is out, there’s few better places to be than out west in Sligo, Mayo or Kerry….That said, it’s not often you see a run of temperatures like this for Dublin 🙂
General Weather Situation and weather outlook
So a pretty easy forecast for this week as we see high pressure building and cloud cover decreasing culminating in the highest temperatures over the weekend with low twenties during this week for the U.K and Ireland before pushing up to mid-twenties for Ireland and high twenties possibly even touching thirty degrees over the weekend in the U.K, with clear unbroken sunshine. I’d expect a few showers in the north east to bubble up today and move southwards but other than that, pretty dry. Now you might all be sun worshippers, but personally I’m not, it’s crap for fishing. This run of ‘lovely’ weather extends into the start of next week but I think we will see the temperatures drop back to low to mid-twenties as the high pressure turns on its side and pulls north winds down across the U.K. Not cold north winds just cooler ones than the weekend. Next week continues this pattern, fine and settled, not soaring high temperatures, probably more in the way of cloud cover due to the wind direction but fine and dandy nonetheless with I think low to mid-twenties.
So no sooner has fine weather arrived than I am asking how long it’s going to stay for ?
Well that all depends on the formation and ‘behaviour’ meteorologically-speaking of a Bay of Biscay low pressure system (which I will affectionately refer to as ‘Bob’ in future blogs in deference to a cracking episode of Black Adder many years ago for those that can remember it :)). This system may be lurking around towards the end of next week. Now the pattern and projections at the 7-10-day range are changing daily so I don’t think we know one way or another quite yet how it’s going to go. This mornings output has a BOB low pressure system forming from Thursday onwards and then linking in with another low pressure over Eastern Europe. Together they form a bridge which pulls in rain and cooler temperatures to the U.K & Ireland, with the latter receiving any rain showers first before they move into the U.K at the end of next week. Now we all know how fragile this scenario is, the high pressure could continue to build or the BOB low pressure won’t form and link up with the one over eastern Europe. Interestingly the ECMWF output shows low pressure forming but not as significant a breakdown in the weather as the GFS output. So with 2 models pointing that way I think we are safe to say we have 10 days of this warm, dry and sunny weather before a subtle or not so subtle change, with the highest temperatures over this coming weekend.
So I’ll do my usual look back on June before everyone has forgotten it from a GDD, G.P and rainfall perspective and then talk about where we are now….
June GDD Summary – Thame, U.K location
I covered this last week so won’t dwell other than to say June 2021 represented a really good growth month from a temperature perspective though rainfall was lacking in some areas (Ireland and Scotland in particular). So good that in the early part of the month an application of Trinexapac-ethyl would be lasting 12 days working on the U.S model of 200GDD and 0°C base temperature.
Y.T.D we were actually a good way down from a total GDD perspective from January 1st to June 30th, 2021 at 565.5. If you look at the graph above that is the 3rd lowest y.t.d total we have measured and is a legacy from the cold April and cool May we endured this year.
It’ll be interesting to see how this changes through the year but where I stand now I can’t see 2021 coming in as a warm year and continuing the 2,000+ total GDD trend.
That said we are only half way through the year and who knows what’s coming down the line ?
U.K Locations – Total Monthly G.P and Rainfall data
The above figures to me are impressively consistent in terms of total G.P for the month, with the exception of Fife, all of the other locations are between 25-28 total G.P for the month. Out of a possible of 30 (30 x 1.0 optimum G.P per day), that means growth was at a pretty much near optimum level for most of June.
For example if we take the Harlech location at 25.29 for the month, that works out as 25.29 / 30 = 84.5% of optimum.
Of course the parameter there is variability in the most is rainfall and we see a very clear north-south divide across the U.K with northerly locations coming in with much lower monthly rainfall totals than southerly ones.
Why is that ?
Well it’s our old friend ‘Bob’…(said in a Rowan Atkinson voice). June’s rainfall totals were very much dictated by southerly BOB low pressure systems rather than Atlantic ones and that’s why you’ll see some pretty low rainfall totals for Ireland following on from this. The demarcation line I think was south of The Humber estuary sort of way but it’s clear in some areas of the U.K, growth would have been limited by moisture availability.
Not a phrase I would often use when I move on to discuss Ireland’s June weather but actually…..
Irish Locations – Total Monthly G.P and Rainfall data
So for Ireland we can see that the monthly G.P levels were a factor of 20-25% lower than those for the U.K and similar to our Scottish location.
The surprise (well at least to me) was the rainfall or more precisely, the lack of it….A really dry month which judging by the stats I have processed (thanks to all) only started to correct itself right at the end of June, so some locations experienced over 3 weeks without meaningful rainfall.
That’s very strange for Ireland and is really to do with the way rainfall patterns formed to the south of the U.K, rather than to the west of Ireland.
So we have a dry, warm, sometimes hot outlook with pretty high E.T figures expected so it is going to be a case of keeping the plant healthy, optimising growth without pushing it on too much (because with higher N, you increase the plant’s requirement for moisture and create a puffy, soft turf) and making good use of quality biostimulants, surfactants and moisture meters. Keeping the plant in the sweet spot nitrogen-wise ( 3.2 – 4.0% in the clippings) so you don’t provide a calling card for Anthracnose by putting the plant under N deficiency(remembering that it isn’t only Poa that can be affected) and also encouraging it to prolong seedhead formation (which incidentally took a bit of a hike upwards last week after the rain). So nice and simple, good greenkeeping.
Hopefully with this run of weather we will see a decrease in disease pressure as daily humidity levels drop, certainly we are due it !!!
Now I did promise you a special blog for this week but I’ve ran out of time so it’ll have to wait till next week as we know tempus fugit and all that….
So enjoy the nice weather, slap on the factor 30 when required and look after the grass as well…
All the best.