June 1st

Hi All,

Well, some of us will be starting June nervously looking at our water capacity, parched fairways and outfield, and with the memory of summer 2018 still fresh in our minds. (see image above)

I’ve seen similar pictures for 2020 already, the problem is we are only just in June and the above was August, so still 3 months to go. (gulp)

May 2020, was the sunniest since the 1800’s and I am sure they’ll be a raft of meteorological announcements in the media today…driest this, warmest that, brightest thing-me-bob….

The semi-good news is we do indeed have a break from this run of hot, dry and sometimes windy weather that has incurred a sizeable moisture deficit on soils so early in the year, but it takes a lot of rain to bring areas back and I don’t think we are going to get that just yet. We will have a significant drop in E.T though so any water applied will be available for longer to the grass plant rather than the current situation of it evaporating while you watch.

Out walking yesterday it was evident how the last week of high temperatures, wind and high E.T had really knocked crops back in the fields, the grass now crisp underfoot.

It is not surprising really because looking at the evapotranspiration data from The Oxfordshire, over the last week we lost the equivalent of 37.74mm of moisture and on the last day of May, topped 6mm of E.T loss in a single day (6.06mm on 31/05/20). Now that is going some…..

Taps on, Taps off…….that’s the weather story of 2020 so far.

General Weather Situation

So we start the week a bit like groundhog day, same old, same old, sunshine, bright skies and dry. Monday looks to be a dry, bright and sunny day just about everywhere with temperatures pushing up into the mid-twenties across the U.K and just breaking into the twenties across The Irish Sea. Once again we will be treated to lots of sunshine, a strong to moderate easterly wind and some cloud cover around the middle of the day pushed in off The North Sea. Not much else to say really, you know the form by now. Thankfully cool at night though with temperatures dipping down into the high single figures over Scotland and a couple of degrees higher further south.

Tuesday sees the beginning of the change as more cloud cover is pushed into Scotland and the northern counties of Ireland with rain into the north west of Scotland arriving by lunchtime. Up there the wind will swing round during the day to a north westerly direction. Later this rain will push south and east across Central Scotland and into the parched east of Scotland. Further south and west it’ll be a similar day to Monday, so lots of sunshine, that easterly breeze continuing and temperatures pushing up into the mid-twenties. Ireland looks to run up to similar temperatures to the south of the U.K and Wales. So warm, bright and sunny for Ireland, Wales and England, duller and cooler for Scotland.

By Wednesday that rain will have drifted south and pushed more cloud cover over Ireland, Scotland and the north of England. They’ll be rain for the east side of Ireland, the north west and north east of England as that front sinks south first thing on Wednesday. Currently the projection is for this rain to sink down the western side of the U.K across The Lakes and Wales as we move through Wednesday with very little for The Midlands and east of England though some showers may make it down that side of the country during the afternoon. The South West should see some of this rainfall for the 2nd half of Wednesday as will Wales. Indeed these two areas will be the main recipients with a line drawn west of The Isle of Wight the likely area to see rain later on Wednesday. After those early showers, Ireland and Scotland look to have a dull and cooler day, but still with the chance of some showers across the east of Ireland for the 2nd part of the day. The wind will be light and from the north east in most areas but you’ll notice the cooler feel to the weather as we drop down into the high teens for the north of England, Scotland, Wales and Ireland with only the south of England nudging into the twenties. A breezy and cool evening then for mid-week.

Thursday sees that cooler air push further south with the wind swinging round to the north west. This will introduce more cloud cover across the U.K and Ireland though still with a few bright interludes further south and west. They’ll be a bit of rain around across the west and eastern coasts of England and Scotland through the course of Thursday but it’ll be more noticeable for being dull and cool with temperatures 8-10° C cooler than the start of the week. Ireland looks to have a mainly dry, cool and dull day with temperatures nudging up into the mid-teens. So mainly dry, dull and cool is the outlook for Thursday with a freshening north westerly wind. Later on Thursday evening we see more rain arrive across the north west of Scotland and overnight this will push south across England though amounts will be light.

Closing out the week on Friday we start the day windy, dull and cool with the wind mainly from the west / north west. As the centre of the low pressure passes over the north of England it’ll introduce plenty of showers to Scotland and the north of England but sadly not many further south of this. So the bulk of the rain for Friday will be across Scotland and the north of the U.K with a few showers filtering south over Ireland, England and Wales. Windy on Friday with a pronounced north westerly wind and cloudy / dull as well. As we approach Friday evening that rain will consolidate over Scotland and then push southwards across the north and south of England / Midlands through the course of the night. Amounts don’t look to be much at this stage. Temperature-wise, expect 13-15° C for Ireland and Scotland and 16-19° C for Wales and England.

Unlike most weekends of late, next weekend looks cool and unsettled with a strong chance of rain across The Midlands and south of England for the 2nd part of Saturday. This rain will push down from The North West through the course of Saturday morning. So a sunshine and showers type of day. Ireland will also see some of those showers but they’ll be less frequent than across The Irish Sea. Still breezy from the north west and that rain will persist across the north of the country through till dusk when a new front pushes into Scotland. Sunday then will see that rain sink southwards overnight into The Midlands, Wales and across Ireland as well so Sunday could be a wet one (haven’t written that for awhile!) and likely to ease the lack of social distancing fears on beaches, parks and in the countryside in general. So another sunshine and showers day consolidating into more widespread rain for the 2nd half of the day with temperatures staying firmly down in the mid to high teens across England and Wales and mid-teens for Ireland and Scotland. The wind will remain fresh from the north west across the U.K and Ireland, easing a little on Sunday across England and swinging round to the west.

Weather Outlook

So the big question is…After a cooler and wetter (for some) interlude at the end of this week, are we going back to square one next week ????

It is interesting, this weather projection story because we have two competing organisations, GFS in the the U.S and ECMWF supported by 34 states across Europe and based in the U.K. I can access GFS projections for weather patterns and rainfall easily but ECMWF restrict their content and only open it up fully to paying customers, which is fair enough.

Now I’d say looking at the projections for this week made by both organisations a week ago, GFS got the nod there and ECMWF were a bit wide of the mark whereas the consensus is normally the other way round in terms of accuracy.

The change in the weather that is taking place later this week will introduce a trough pattern into the jet stream as I predicted a week ago and at present it looks like another low pressure will sit in this trough through till about Wednesday / Thursday next week before being pushed out of the way. It’s important to note that next week’s low pressure will be pushed south so that means we may pick up a nice bit of rain further south than this weeks / weekend low pressure interloper.

Now in my experience once a trough pattern has formed at this time of year it can be quite stubborn to budge, it almost seems to set a permanent change in the pattern of the jet stream.

So next week looks like starting off cool and unsettled with rain across the north initially before more showers push further south later on Monday. Tuesday seems a bit of a hiatus with a drier interlude as the winds drop and things settle down but later on Tuesday, a new low pressure system arrives and this will push further south as already intimated bringing wet weather for Wednesday / Thursday. You can see this in the GFS projection below. If this occurs on plan, the bulk of the rainfall will be from The Midlands south.

Now GFS suggests that high pressure will nudge this low aside at the end of next week so we have a return to warmer, drier conditions but ECMWF suggests the opposite with the trough pattern continuing.

It’ll be interesting to see who wins this one in terms of accuracy 🙂

Agronomic Notes

I’ll do a proper round up of May’s weather next week but for now let’s look at the stats from The Oxfordshire from a GDD perspective.

So May 2020 came out as one of the warmest (highest from a GDD perspective) May’s with a total GDD of 215. Now in the grand scheme of things that isn’t a record breaker with both 2018 and 2017 higher. If I were planning my PGR apps on greens and working on a re-application period of every 130GDD using a 6°C base figure (as opposed to every 200GDD in the U.S using a base figure of 0°C), that would mean applying every 14 days or so through May, which is normal I’d say.

From a year-to-date perspective we are at a total GDD of 493 since Jan 1st at this location. That puts us as the 2nd highest year working on total GDD since Jan 1 with only 2017 higher. You can’t help thinking that our climate is indeed hotting up.

The real story of May 2020…

As I talked about last week, the real story of May 2020 and indeed the weather since March 19th, is of high E.T, low rainfall and a growing moisture deficit.

The worry for us all is that we have already reached a significant moisture deficit and it is only just June whereas in other years, it wasn’t until July and August that we felt the true effects of drought. Many facilities have also used more water in the early part of the year because the dry spell started earlier and due to the effects of Covid-19. I have spoken to a number of end-users who have told me that the loss of staff due to furloughing has meant a temporary halt to hand-watering simply because of this lack of available labour which means more mains watering and ultimately more water usage. (less efficient)

As mentioned earlier the issue before us is that the dry conditions this spring started much earlier than they did in 2018 and so we are already experiencing drought in 2020 when in 2018 we weren’t.

So to get a clear picture of this I have charted out the two respective springs starting from March 1st and looked at rainfall, E.T and the resultant soil moisture deficit / surplus.

I’ve used the data from The Oxfordshire because that’s the only location where I have historical E.T data but it’s fairly representative of a number of locations. It is an open site so the E.T readings are higher than most and it is also a pretty dry site. Typically rainfall is 500 – 600 mm per year which is similar to a lot of locations in the U.K anyway.

So first off I looked at rainfall, E.T and the resulting soil moisture deficit / surplus for spring 2018 commencing on March 1st. Here’s how the data looks…

Looking at spring 2018 we can see we had continual rainfall through March and although April was drier we didn’t go into a soil moisture deficit scenario until early May. At the end of May 2018 though we had significant rainfall which redressed the balance somewhat and by the end of May 2018 we stood at a moisture deficit of -20 mm.

You’ll notice the difference in spring 2020 !

As stated before we are enduring a taps on – taps off type of year and in spring 2020 the taps were turned off on the 19th of March, pretty much universally. Since then we have had precious little rainfall so the soil moisture deficit curve has grown incrementally with very little rainfall to redress matters. At The Oxfordshire location, the last meaningful rainfall was at the end of April and so by the end of May the soil moisture deficit was / is sitting at -190 mm.

So -20 mm in spring 2018 and -190 mm in spring 2020, some difference !!!!

Here’s how the 2 moisture surplus / deficit curves look plotted against each other….

So if you have delightful members who are wondering why it is so brown and crispy out there, maybe you can send them this data !!!

The chart for 2018 is available to download here ,2020 here and the comparison graph between the two, here

Going forward….

Now of course the worry is we are only at June 1st and we still have the summer before us.

Now we know we typically have two types of summer, hot and dry ones and cool and wet ones.

2018 was the former and 2019 was the latter, so I thought I’d chart out the soil moisture deficit / surplus for both years from June 1st onwards to mid-August.

You can see in a wet summer (2019) we only incurred a moisture deficit of -130mm compared to uncannily twice that amount in the scorcher of 2018. The worry is then that we even if we have a wet summer from now onwards, we are sitting at -190mm at the end of May and so a likely position by mid August could be -320mm, which is actually worse than 2018. It doesn’t bear thinking about if we had a summer 2018 scenario on top of our current moisture deficit….

Food for thought I’d say…Talking about food….

Image kindly reproduced with the express permission of Iain Richardson Photography Ltd 🙂

Leatherjackets

This cracking photo of the much-maligned Starling was taken by our much maligned (by me) resident photographer extraordinaire, Iain Richardson, and it highlights a problem for many turf areas at the moment, that of Leatherjackets.

I’m getting a lot of people commenting on slow to heal areas from spring aeration or weaker areas on greens, tees, fairways and outfield that aren’t responding to fertiliser / irrigation applications. Unfortunately the mild and very wet winter seems to have resulted in a high residual level of Leatherjackets, which are busy chomping away at an already stressed grass plant leading to damage. The fact that this has been going on since mid-February on some courses makes it even worse. With adult Cranefly visible for the last 4 weeks now I guess we have overlapping generations out there as well ? (Glenn / Dan feel free to comment and I’ll publish next week if you like)

Not much to say about this one other than it is a feature of the world we live in currently and that milder winters are increasing pest numbers faster than control products are getting registered 🙁

Anthracnose

Now it is clear to many that we have a very stressed Poa annua plant out there after the dry spring of 2020. We have also had some pretty high temperatures and certainly high enough for Anthracnose spore germination but we have also had pretty low humidity as witnessed by the high number of dry cuts you guys have been able to get in with very little dew formation.

Now as you know with me data is everything so I’ve pulled together some maximum air temperature vs. maximum humidity data at a Sevenoaks location (ish) for your perusual.

Looking at the data we have had some high temperatures towards the end of May and the occasional high humidity spike as well. Dew formation has been limited though to very short periods of the night, typically from 2 a.m to 4 a.m. Now Anthracnose is a slow-growing fungus by all accounts and a fragile one to boot, so you’d surmise that up until later this week there has been insufficient moisture / humidity / plant leaf wetness for it to develop. That said if we do get the rainfall at the end of the week, then we could conceivably mark down the end of May 2020 as the first potential Anthracnose trigger of the year. Now normally I’d say we should be alert for symptoms in 4-6 weeks time but I’d be on my guard anytime from mid-June onwards looking at this data. If I was maintaining a site with a high level of Anthracnose, I’d be implementing my Anthracnose preventative program that we have discussed many times in the past. Here’s a link to some of the best management practices documenting by Bruce Clarke at Rutgers University – BMPAnthracnose

This advice would definitely include Scotland because they have also had a dry spring and some very warm weather and are more likely to get the rainfall that’s forecast. Ireland’s maximum temperatures look down on the U.K during May but this week they are similar until we lose that high pressure so you never know, one top watch I’d say.

OK, that’s it for me today, bit of a mega blog.

I hope you get some rain this week / next week and that the weather stays kind to all of us.

All the best.

Mark Hunt