Monthly Archives: August 2017

August 29th

Hi All,

Just another short blog this week despite the fact that I’m now back at work after a lovely relaxing break in France and then renovating my back garden, interspersed with plenty of fly fishing :)

Unfortunately Unisys Weather have problems with their GFS – long range forecasting output, it hasn’t updated now for 6 days, so I have very little provision to provide an outlook. Add to that my inaccurate weather forecast for The Bank Holiday in the U.K which I called as rain across the north and west (accurate) but unsettled for the south and central U.K (totally inaccurate) when the reality was that we enjoyed perhaps one of our best Bank Holiday’s for a long time weather-wise. My house backs onto a recreation ground and with the brilliant weather it was full of people enjoying the sun and the warm evenings. All generations alike seemed to be out in force and it was a pleasure to see. I can’t think why anyone would want to try and fight their way along our congested roads or through our equally congested airports to get away to the sun when you have it for free on your doorstep, it beats me…..

The reason for the change in weather from forecasted to actual was a shift from a south westerly wind to a southerly one and that pushed a warm air peak up from The Mediterranean and gave use warm, even hot conditions yesterday with my weather station recording 29.1°C at 3.46 p.m. No wonder I was sweating buckets digging out beds full of roots and builders rubble !

The weather is quite odd this week because although we are pretty settled in terms of high and low pressures we will move from a warm air peak to a cooler trough and that’ll peg back the temperatures somewhat from their recent heady highs….You can see the contrast between yesterday’s weather and this coming Friday’s weather below ;

PeakTroughSept17

So one things we can summise from the above is that we will be cooler from today onwards and that’s because of a change in wind direction (correctly predicted last week) from southerly to northerly…

General Weather Situation

So Tuesday starts off with a band of rain across the north west of Scotland and some additional lighter rain across The Humber estuary area along the east coast of the U.K. This is projected to fizzle out through the morning to leave a largely dry day for all of us but with quite a temperature difference between the north and south of the U.K. The south will hold on to that warm air for one more day so I’d expect temperatures to be up to the mid-twenties across the south of England, maybe high teens for The Midlands, Wales and Ireland and low to mid-teens for Scotland under that thicker cloud base. Light winds but variable depending on location from westerly to north westerly.

Wednesday’s forecast is a tricky one because it includes that old cheshnut of continental rainfall and we know how unreliable that is in terms of forecasting :( So we have a risk of potentially heavy rain over night across the south east corner of the U.K and potentially some more showers affecting the south west and south coast through the day. Some of these may even push up towards The Midlands and South Wales. In addition we also have the risk of showers affecting the west coast of Ireland and moving across country during the course of Wednesday afternoon. Similarly we have a risk of showers across the north west and north east of Scotland. As we go through the afternoon there is a risk of that rain returning in heavier form to the far south east of England, but we’ll see. My advice is to keep your eyes pinned and whatever active rain radar system you utilise. Feeling cooler on Wednesday with that northerly airstream in place and this will push that warmer air away from the south coast so feeling a good bit cooler there as well. So mid to high teens will be the order of the day with the former across Ireland and Scotland and the latter across the south of the U.K.

Onto Thursday and a sunshine and showers type of day for the east of Ireland / south west / north west of England with some of those showers pushing across The Pennines and also into West Wales. Elsewhere it’ll be largely dry day with long spells of sunshine and some cloud cover as well, so pleasant I’d call it. Always a risk of a shower across the western coastline of the U.K though. Similar temperatures to Wednesday with mid to high teens the order of the day. Light winds again for Thursday.

Finishing off what will have been a short week for those recipients of the Bank Holiday (Ireland enjoyed theirs earlier in August) and Friday looks settled but potentially a duller day for the east of England as we pick up a change in wind direction to easterly at the end of the week. This always has the potential to bring Haar in from The North Sea so I think a cloudier day for most on Friday, but a dry one with that cloud thicker across eastern and central areas and consequently more chance of a break in the cloud and better temperatures across the west. So we see Ireland pick up some warmer air and that’ll push their temperature up to the high teens maybe breaking into the twenties you never know vs. mid to high teens for areas affected by that cloud cover.  Winds will be light and from the east / north east.

So how are we looking for the weekend ?

There’s a good deal of uncertainty about the weekend’s weather because we have the threat of a rain front pushing in from The Atlantic. Two models state this will reach Ireland on Saturday and push eastwards into Scotland, Wales and The South West / west of England on Sunday. Another model says it won’t come at all. Without my faithful Unisys output I am struggling on this one. My hunch is that we will see that rain front push across into Ireland on Saturday and then into the western half of the U.K on Sunday morning slowly transgressing across country through the day. The wind direction is also set to change through Saturday to a more south westerly orientation but wind strength looks to remain light to moderate.

Weather Outlook

I think next week will start off unsettled with that rain front from the weekend carrying on its eastwards movement through Monday. We have the threat of a low pressure trough system forming on Wednesday next week so that could mean further rain is likely (and perhaps welcome in some parts of the country ?) so potentially wet through from mid-week to the end of the week next week. If Unisys pops up and is running again, I will of course update you.

Agronomic Notes

With me being out of the loop for 2 weeks I can’t rely on end-user feedback and / or my own experiences for this part of the blog so it’ll be brief I’m afraid. Next week we have month end so I’ll be able to look at our accumulated GDD and G.P data to see whether we are continuing the trend for 2017 to be the warmest year ever.

As we approach this time of year I often think it is one of the harder months to gauge turfgrass requirements. For instance this weekend will have dried out rootzones significantly across the areas that received the heat and I noticed my own ryegrass wilting under foot yesterday and in need of irrigation. It’s 10 days here in The Midlands since we had good rain and that’s enough to put grass on the back foot moisture-wise, so that’s the first thing I’d be keeping an eye on.

Next we have the ever-present threat of disease but with humidity levels currently sitting in the 70’s, I don’t expect disease pressure to be high this week. Now if indeed we do run into a more unsettled vein of weather from the weekend (and remember the jury’s out on this) then we will pick up moisture and that’s likely to promote a fresh disease outbreak from the usual suspects of Dollar Spot, Red Thread and Microdochium nivale.

I’ll be interested once I’m back in the flow of things to see how active Anthracnose has been out and about because certainly the conditions in late May and late June favoured activity of this disease in late August. My advice on disease in general really from now on is to keep your disease population pinned down and managed because it is a fact that whatever we have in late August / early September, we will likely carry through to the cooler, muggier month of October, our biggest Microdochium nivale month for sure.

This autumn will be an interesting one from the perspective of disease control because we have some new actives coming onto the market and their performance over the next few months will draw a line in the sand on how effectively we will be able to manage Microdochium as a disease going forward. Certainly by the time I step up at Harrogate to speak to you all on Microdochium and Anthracnose management I will have some good data from my own research combined with end-user feedback on this aspect. I know it isn’t all about fungicides, they are only one piece of the puzzle that is effective disease management but they are currently an essential piece for most of us.

It’ll also be an interesting one from a worm and insect perspective because we will perhaps start to see the effects of successive generations of Leatherjacket and Chafer without the control of an insecticide. That said I see very little Crane Fly on the wing currently. It will also be our first autumn without Cardendazim, last winter I think we got off lightly from a worm perspective because October, December, January and February were drier than normal months.

If your weather forecast starts to pick up that unsettled weather from the weekend onwards and confirms this is how it is shaping up then I’d use some of this week to get prepped. Selective herbicide applications to weeds that have emerged during August will work well this week if we have the moisture to facilitate uptake and knock-down from the early part of next week.

Overseeding weak areas, renovating collars, approaches and weak fairway areas will also be worth a shout this week because the ground is warm and if you can provide moisture and / or Mother Nature obliges then this will put you in a good position to gain ground cover in the autumn rather than the areas become over-run with weeds and / or moss.

Short and sweet this week, (like me arf arf :) ) hopefully we will have Unisys back again next week.

All the best.

Mark Hunt

 

 

 

August 21st – Mini Blog

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Hi All,

Still on holiday (yes I know) so this week’s will be another mini-weather blog.

Last week I gave a synopsis for this week based on high pressure exerting it’s influence on our weather and returning us to a dry, settled and warm pattern. Sadly that’s not going to be the case for the whole week though it will be for the first part of the week but then it looks like low pressure will once again dictate our summer’s weather.

It kind of neatly illustrates the point that within a 7-10 day time frame our expertise at forecasting / predicting the behaviour of weather patterns is at the limit of current technology and algorithmns.

RaincloudsI took some pictures on the approach to Stansted airport as we came through the cloud base and you can see the energy in the clouds building from the top and then the resultant rain falling below somewhere over Essex I think…. Mega interesting I thought and it helped break up the monotony of yet another pleasurable Ryanair flight experience for me. That said, they were on time and if it weren’t for them, there’s alot of places we simply wouldn’t be able to get to for an affordable price…

When you look at the top image of rain clouds building and producing rain and then go on to imagine all the different factors impacting this process, one that is then described mathematically to produce a forecast scenario, it is hardly surprising that it isn’t 100% accurate. Summer rainfall is as I understand it from Meteoblue, one of the hardest weather events to predict accurately…So with that clever caveat underpinning the accuracy (or inaccuracy) of this week’s forecast, it is onto the weather :)

This week’s weather outlook

So last week I said that the bulk of any rain events would be north and west and that bit I got right because on Monday we have rain over Ireland in a line from Galway to Dublin extending into Wales pushing north and east through this morning. We also have some lighter rain still hanging on across the south east and this will move off into The Channel during the morning. The rain over Ireland is heavy and slow moving so expect some flooding where you get it. Eventually it will move off into the Irish Sea and across to hit the west of Scotland around tea time and then proceed to give significant rain for Scotland tonight as it moves eastwards slowly. South of this rain band (Ireland and U.K) it will be initially cloudy but the sun will break through eventually to give a pleasant warm day with temperatures in the high teens, low twenties. My only concern on this forecast is the rain over Wales which looks to be more on an easterly trajectory and so may affect The Midlands and north of England p.m. Winds will be light and from the south / south east.

Tuesday sees a similar picture with some rain over Ireland (Clare) developing through the morning along with the remnants of that overnight rain across Scotland clearing through the morning.  Away from this we see another dry and settled day with a mix of cloud and sunshine through the day. During Tuesday afternoon though we see that rain over Clare begin to consolidate and this will spread to cover most of Ireland late afternoon. At the same time we will also see some rain develop across The Pennines and eastern coast of Scotland for a time before clearing later on Tuesday night. That Irish rain front looks to consolidate and become heavier as we go through Tuesday afternoon / evening so quite a bit of rain here I’m afraid. Away from this rain it’ll be a warm day with temperatures pushing up into the low twenties I think with light south / south easterly winds in situ.

Onto Wednesday and overnight we see that heavy rain over Ireland clear into Scotland to bring further rainfall here and potentially further south across The Pennines. Through the morning this rain will clear the north of England but I think it will be slow to leave Scotland. By late afternoon we see another rain band push into the west of Ireland and this will push east and north through the course of Wednesday evening / night.  So another day of north / south / west divide because we have a dry and potentially warm day for the bulk of England and Wales on Wednesday with temperatures pushing up into the low twenties again, cooler if you have that cloud cover and rain further west and north. The wind will shift round on Wednesday from southerly to more westerly and that marks the notice of intent of a low pressure system coming in.

Thursday sees that low pressure begin to exert its influence and that means it’ll push rain further southwards to give a more unsettled end to the week with rain over Ireland pushing into Wales and then eventually across the south of the U.K later on Thursday. This low pressure will also spin rain into Scotland during Thursday in two bands, one affecting the far north and the other over The Borders. There’s also a risk of some rain just tipping along the south east coast of England during Thursday morning and pushing into Kent by late morning. You’ll notice the wind will now be south westerly and moderate to blustery so a marked change from the beginning of the week. It’ll feel a bit cooler as well with that change in wind direction and strength so high teens will be the order of the day.

Finishing off the week on Friday we see that low pressure continue to extert its influence though it should be a drier day save for some showers over the north of England and Midlands accompanied by a thick cloud base. These showers may sink south later in the morning. Otherwise it’ll be a drier and sunny day for Ireland, Scotland and Wales but staying on the cool side even though the winds will lighten and change round to the north during the day. That northerly wind change will knock another degree or two off the temperatures so probably mid-teens is likely, maybe a little higher down south.

So how do we look for The Bank Holiday weekend and just as importantly MotoGP at Silverstone ?

Well Saturday looks unsettled with plenty of sunshine and showers around, initially in the north and west but sinking south for the 2nd half of the day to bring rain to most areas. The wind is also likely to strengthen from the west again so that means similar temperatures to the end of the week, mid to high teens. Sunday looks the better day of the weekend with any rain confined to the north and west of Scotland. Onto Bank Holiday Monday and it looks potentially wet and windy in the north and west with a strong westerly wind in situ. Drier further south but with low pressure in charge we can expect sunshine and showers I think and mid to high teens temperatures.

Weather Outlook

So we know next week looks to start off unsettled but will it remain this way ?

Well currently the synposis is for high pressure to try and push in from mid-week, next week but it will butt up against the low pressure that we had over The Bank Holiday impeding its progress. We know what happens when a high and a low butt up against each other and principally this means the wind shifts to a more northerly orientation pulling cool air down from mid-week onwards next week. So we will have a west / east split for the latter part of next week with finer, warmer weather to the west and cooler, dull and potentially more unsettled weather across the east.

Agronomic Notes

Disease Pressure

Beginning to sound a bit like a scratched record this summer I’m afraid but it’s a fact that with high moisture levels, a wet plant leaf and high humidity, summer disease pressure has been pretty much the highest I’ve known it since the weather pattern shifted and introduced a change from hot, dry conditions back in July (remember them ?)

I’ve got a new weather station that I’m looking at as a cost-effective option to the more expensive units available on the market to supply temperature, humidity and rainfall data (more on this in the future when I’ve seen more of how it works accuracy and durability-wise)

So I decided to download some data over a 24 hour period for August 20th to see where and when during the day we are experiencing the highest disease pressure…

Aug20_2017

So what we have in the graph above is a trace of relative humidity shown as blue columns, the maximum air temperature as a red line and The dew point as a blue line. The dew point is the temperature at which point the atmosphere becomes saturated with water (in other words reaches 100% humidity) and if cooled further the water condenses out of the air to form droplets on the plant leaf. So as the red line and blue line become close then we are reaching saturation point in the atmosphere and this in my mind is when we face the highest disease pressure…i.e conditions are ideal for mycelium development…

Diary of a Day in August…

Starting on the left hand side, the graph above begins at midnight with humidity in the low 80’s and the air temperature and dew point seperated by about 2.5°C and this is pretty much how it stays through the morning. So I’d classify this as a lower disease pressure night.

You can see the point when the sun came out quite obviously as the air temperature increased markedly at around 8 a.m. and the humidity dropped off down into the 70’s as moisture was being evaporated from the atmosphere. Around 4 p.m, the air temperature begins to drop and consequently the humidity begins to increase as the moisture content of the air begins to build.

Around 9.30 p.m we had a light rain shower and the humidity point reaches 90% very quickly thereafter and the dew point / air temperature graphs almost touch so the atmosphere is becoming saturated with moisture and again conditions become conducive to disease development.

The humidity then stayed > 90% all through the night and I can tell you that as I type this it is still > 90% at 10.47 a.m.

So if we look at the potential for disease development on this particular day it started at 9.30 p.m. and has continued right through to the time I’m typing this, that’s a 13-hour period.

Now if you were in removing dew from your surfaces at say 6 a.m. this morning then the plant leaf would have been sitting wet for 8 1/2 hours prior to that.

DollarSpotmycelium

And that is the rub as to why diseases like Microdochium nivale, Dollar Spot, Leaf Spot and Red Thread really like this type of weather. Long periods of high humidity and a warm enough air temperature for their populations to reproduce quickly from spore germination, mycelium development and then onto spore formation / production.

Happy Days….

With the Bank Holiday Monday next week, I’ll be back to normal (whatever that is ?) on Tuesday..In the meantime, all the best.

Mark Hunt

 

 

 

August 14th

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MeyrueisGorge#

Hi All,

I am on my hols for the next fortnight down in The beautiful Cevenne in France where I can report the weather is very nice indeed. I’m sitting typing this blog and there are 9 Griffin Vultures circling above me, strange I didn’t think ICL worked this far south :)

Here like us they have had their heatwave and then their cold, very wet period and now it is pleasant. So this week’s blog will be mini one focussing on a general weather synopsis and most importantly a peak into next week to see what we have in store and if there’s any change in the position of the jet stream. It’s a good job I am on my hols because it looks like Meteoblue are also en vacances judging by their output :)

DGzDZtEWsAAGqa9Last week I presented at The Grass Court Seminar held at A.E.L.T.C, Wimbledon and I’d like to say thanks to Neil, Grant, my fellow speakers and of course the audience for listening to my chat. It was a great networking event and very interesting for me to listen to how the game of tennis has changed, how that effects the wear patterns on the grass and what the future holds. During the run up to this years championships and courtesy of  a peak pattern in the jet stream that pushed heat up from Spain, the temperature on the baseline on Centre Court exceeded 40°C on a number of days. Now that’s beyond the comfort zone of most cool season grasses including Lolium perene. I’ll talk a bit about this later but first a quick coffee and Croissant :)

General Weather Situation – Summary

As you can see from the animated GIF courtesy of Paul in our office, we have an active low pressure system in place this week and that’ll bring more rain for most areas however I have some good news as from Sunday it looks like high pressure will begin to exert its influence and that means warmer and crucially drier weather for us all for next week I think (sticking my neck out a bit)

So putting some detail into this forecast from a rainfall perspective ;

On Monday we have the first of those wet and windy shower bands moving north east across the U.K stretching from the south west of England all the way up to the north east. Scotland is sitting under some heavy rain today which will slowly move north and east so this part of Scotland in particular is set for a very wet Monday indeed. The same pattern of rain is present over Ireland with a band stretching north east from Kerry all the way up to Derry. Mid to late morning it’s likely The Midlands will pick up some of this rain as well but south and east of this I think you’ll be fine today. Overnight and we’ll see more rain pushing in across Ireland, the north west of England and Scotland on Tuesday, not as heavy this time and this will potentially push eastwards across The Midlands into south and eastern England early doors Tuesday. Once this rain clears through the morning, it looks drier. The wettest band of weather this week will push in over the second half of Wednesday across Ireland, Wales and then overnight into Thursday for the rest of the U.K giving a wet Thursday morning for many. Strangely a lot of the rain will fall overnight this week. We finish the week off with a showery picture on Friday with blustery showers pushing in across Ireland and quickly whisking over The Irish Sea to give an unsettled picture for both Friday and Saturday. The good news is from Sunday we will see that high pressure edge in and bring a settled and drier theme to most of the U.K and Ireland so happy days and long overdue. Wind-wise it’ll be a blustery week with strong to moderate south westerly winds turning more westerly as we approach the end of the week. Temperature-wise we will fluctuate from mid-high teens during the rain events to just touching twenty degrees during the drier interludes.

Weather Outlook

Next week looks fine and settled for most of the U.K as the jet stream takes a hike up north and allows warmer and settled weather to predominate, We will see a northerly low just glance the top of the U.K during the early part of the week and that’ll mean some unsettled weather still for Scotland on Monday and Tuesday before you join the dry and settled picture for the rest of the week.

Agronomic Notes

Meteoturf140817

A lot of clubs are doing renovation in August and this weeks (and last weeks) weather will make that a tricky process in terms of core harvesting and getting that sand dried out enough to fill in the core holes (or graden slits depending on your preference). Thankfully though the sunshine and showers and reasonable temperatures will mean a very good outlook for growth with near optimum conditions over the coming week for recovery.

hr0817

That good growth and moist plant leaf will unfortunately mean disease pressure remains high and that’ll particularly apply to foliar pathogens like Microdochium nivale, Red Thread, Dollar Spot and Leaf Spot.

High Humidity = High Disease Pressure

From the end of July to the present date and including the coming week we will have had 4 weeks of high relative humidity and a moist plant leaf and that has driven some of the worst Microdochium activity I have seen for this time of year. Disease pressure from Dollar Spot has also been particularly aggressive on some sites. Dollar Spot is significantly influenced by plant leaf wetness and this is why we’ve seen activity over the last 3-4 weeks.

As a disease it also prefers to grow in acidic conditions in terms of plant leaf surface pH so if you’re planning on applying sulphate of iron and sulphate of ammonia to this disease, think again because you’ll be playing right into its sweet spot. Once we get through the weekend I expect disease pressure to drop back significantly as drier conditions prevail.

High air temperatures are a great PGR and they’re free…..

On another subject and prior to going into another spell of warm, settled weather (though hopefully not as hot as late June’s) it’s worth taking the time to consider our use of PGR’s during the summer heat. We know some grass species like Poa annua are affected more by Trinexapac-ethyl than bentgrass sp. so if you’re managing a mixed Poa / Bent stand and applying TE, the effect will not be uniform it will be proportionate to the species content you have and this may vary from green to green on the course.

Bearing in mind that during some parts of the summer we hit temperatures > 26°C for sustained periods of time (I put this figure specifically because above it Poa annua doesn’t really like to grow much and goes under heat stress)  it is quite likely that the growth rate of Poa annua suffered because of high temperatures. In addition we then applied a PGR to our grass stand to hold back growth, effectively a double whammy on Poa annua already checked by high temperatures. So I got quite a lot of reports of Poa looking yellow and sickly during June and July and this is why I think, the collective result of high temperatures and TE applications. Now you could argue that if you were also overseeding bentgrass during this period then you would be tipping the balance in favour of this grass vs. Poa so the strategy may have an upside as well. (particularly if it is creeping bentgrass)

The same rationale would apply for those maintaining a mixed stand of Lolium perenne and Poa annua during the summer months (though I appreciate many of you do summer renovations on sportsfields), the high temperatures and a PGR application would hold back the Poa annua and because TE affects Lolium less, it would have a competitive advantage in terms of growth and establishment.

One last point here and that concerns the rebound effect when TE breaks down in the grass plant and the plant ‘rebounds’ from its suppressive effect. During this summer’s high temperatures we probably only got 10-12 days of suppression before this occurred on fine turf so if you were applying at longer intervals than this it is quite likely you saw a surge in clipping yield even though you had applied a PGR two weeks prior to this. So I guess what I am saying is if you’re committed to using PGR’s, keep your application intervals tight. I know you read those tweets concerning high rate applications on fine turf but in essence they are for me no more than bragging rights with little scientific basis.

The key to TE is frequency of application and not rate and there’s good, unbiased research to support this statement.

Ok that’s it for me, time to get the factor 30 and walking boots on, turn the phone off and forget low pressure systems for a few days. All the best to you all.

Mark Hunt

 

August 7th

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Hi All,

So our wet start to August continues with some significant rainfall over the U.K and Ireland over the last week. I got some interesting snippets emailed to me last week, the first stating that it is set to rain all through all of August (that one is from the Express and we know what they’re like accuracy-wise when it comes to weather :))

The second was that Shetland was sunnier than Cornwall in July and that’s due to the fact that the jet stream sunk a long way south and so did the low pressure systems bringing more rain further south. Lastly as a result of that trough pattern in the jet stream, Hampshire was one of the wettest places in July with 118% of its normal July rainfall. What’s the betting that the rain fell in 3-4 days rather than evenly across the month ?

This week we are set in that trough pattern and so we can expect some more rain, some of it may be very heavy. There is though just the merest hint of a change in the weather right at the 10-day mark with high pressure making an appearance next week but I don’t think it is set to last.

General Weather Situation

So we start the week on Monday with a rain front that has crossed the U.K and Ireland overnight just exiting across the east of the country. So currently we have some rain around across northern England and the north Midlands in a line drawn from the Severn Estuary up to The Wash. These showers will push up diagonally across northern England during Monday morning. We will also see further showers affecting The South West and the south coast of England. All of these shower fronts will move north east across the U.K during this morning. The same is true for Ireland with some showers over west Munster moving north east across the country during the morning with another band across Donegal. These shower bands will eventually stretch right up to the Scottish border however north of this looks mainly dry today. As these showers clear through the afternoon we should see some sunny intervals between them except for The South West where later in the afternoon we see the cloud build and more showers push in. This band of thicker cloud will push north and east across the southern half of the U.K later this evening. Quite a temperature difference today with Scotland and Ireland in the mid-teens and the south of England and Wales sitting in the high teens, perhaps just breaking into the twenties. Winds will be light to moderate and from the south west.

Onto Tuesday and last week I commented that we have a battle between an easterly low and an Atlantic high projected for the start of this week, well the easterly low wins. So it will be on Tuesday with wet weather pushing in from the east coming off The Wash and affecting East Anglia and The Midlands initially. This rain will consolidate and become heavier through the morning so not a nice day here. We will also see another rain front affecting Ireland that consolidates through the morning along with Wales and the north of Scotland as well. By early afternoon that low pressure is tilting and pushing rain across most of the southern half of the U.K and it extends into northern England as well pushing north into Scotland by mid-afternoon. So Tuesday looks like a pretty wet day for most of us and because the low pressure system is in a trough, it’ll be slow moving and therefore localised rainfall totals may be heavy. As we go through Tuesday afternoon, that rain over Ireland starts to fizzle out and you’ll have some sunny intervals here but across The Irish Sea that rain will sit stubbornly over the southern half of the U.K from northern England down to the south coast. Scotland looks to lose its showery rain pattern to finish the day dry. As predicted last week, a battle between a low and a high pressure yields a northerly wind direction and that’s what we will get on Tuesday so a much cooler feel to the weather for all of us with temperatures down in the low to mid-teens at best. Pretty crap for August.

Mid-week beckons and Wednesday starts off with that rain front over The South West and southern coast of England at dawn and it’s likely to add even more rain to Hampshire’s high total with some torrential rain likely in this area before it moves off into The Channel. This band of extremely heavy rain looks set to track very slowly eastwards along the south coast through the course of Wednesday so really affecting the area from the M25 / London southwards I’d say pushing into The South East later in the afternoon. Potentially very heavy rain here. The exact location of this rain band will I’m sure change as we progress through Monday and Tuesday so keep an eye on your forecast and rainfall totals, they may change significantly depending on the behaviour of this band of rain. North and west of this band of heavy rain it’ll be a dry day after that overnight rain clears so Ireland, Wales, Scotland and the remainder of England will have sunshine and broken cloud. Temperatures still low though for August with mid-teens the best we will do in that moderate to blustery northerly / north easterly wind. Ireland, Wales and Scotland though away from that cloud cover will be warmer with high teens likely.

Onto Thursday and a much better day for everyone as that rain finally exits into The Channel overnight. So a settled and much sunnier day on Thursday for all areas with some long spells of sunshine and lighter north easterly winds. High teens expected in that sunshine and may be we will just nudge into the twenties in some areas through the wind direction will keep temperatures down. Enjoy it while you can because overnight into Friday we see the next band of rain push into the west coast of Ireland.

So Friday starts with a change in the wind direction from northerly to westerly and that’ll push rain across Ireland from dawn. This rain will also push into the north west / west of Scotland in time for the morning rush hour. The rest of the U.K looks to start dry and indeed in some places most of the day will be dry with hazy sunshine and cloud. During the afternoon, that rain front begins to clear the west of Ireland but it’ll push across most of Scotland and into the north west of England reaching Wales by the evening rush hour. As it does so it’ll also push thicker cloud in front of it and this will finally introduce some showers to more central areas overnight on Friday. With a change in wind direction it’ll feel warmer with high teens / low twenties likely before that cloud pushes in later in the day. Cooler across Ireland and Scotland where you’ll see more of the cloud and rain during Friday so I’d expect mid to high teens here.

So how does the outlook for the weekend look ?

Well mixed is probably the best description with Saturday looking to be an unsettled day with rain pushing across Ireland during Saturday morning and this will move west into Wales and central England for the second part of the day. North of this rain band over The Borders and Scotland I think you’ll have a better day after showers and thicker clear in the morning. Sunday looks to be a much better day as high pressure nudges that rain away so plenty of dry weather around on Sunday I think.

Weather Outlook

So next week we have high and low pressure slugging it out once again over the U.K and Ireland and as you’d expect the outlook will be mixed depending on which one is in the ascendency. So I think we will see an unsettled start to the week, next week with rain pushing through on Monday and Tuesday coming in from the north west and heading southwards. All the time I think the rain bias is more north and west. By mid-week, high pressure pushes in and that looks to dry us out nicely with warmer temperatures and more settled conditions through Wednesday into Thursday. After that it’s tricky to call, but if I was a betting man (and I’m not aside from Paddy Power and White Christmas) I’d say that we’ll see a new Atlantic low pressure push in to bring wind and rain by the end of next week unfortunately.

Agronomic Notes

July GDD- Thame Location

Ok first off we look at July’s GDD information from our resident location at Thame, Oxfordshire.

GDDmonthlycomparisonJantoDec2010to2017image

So July racked up 374 growth-degree-days which puts it on a par with last year at this location and cooler than other July’s, notably 2014, 2013 and 2011. The total for the year though just keeps going buoyed by the heat earlier in the spring and during May and June.

GDDmonthlycumulativeJantoDec2010to2017image

So we are still looking at our warmest year to date, a full 25% warmer, as measured by GDD compared to 2016 and that is a significant increase that brings many consequences to turfgrass management.

GDD and Rainfall – July 2017 – U.K Locations

For this month’s UK summary, I thought I’d add a few more locations in to try and reflect more accurately where the rain fell during July and to pick out the southern and eastern bias that a low-situated, trough pattern can bring to the weather.

Here’s the U.K stats….

MonthlyRainfallGDDJuly2017

So some interesting variability here and firstly you can see quite wide differentiation in GDD with both Scottish locations , Fife and Irvine down at 263.5 and 280.7 respectively. Although they were cool, the rainfall totals are a good bit lower than some of the more southerly locations.

Coming down country, Portsmouth stands out with 445.9 GDD for the month of July, along with 83.1mm of rain, but you can see the variabilty in rainfall with Okehampton picking up 147mm of rain and Norwich, 141.5mm !

In july there were plenty of times when the rain tracked eastwards and so East Anglia picked up more than its fair share of the moisture, quite strange really for that to happen.

What is also clear is that heavy rainfall didn’t fall evenly across a month…Here’s the monthly rainfall pattern for the two highest rainfall locations we have looked at in the U.K during July..

RainfallOkeNorwichJuly2017

You can see that the first part of July was pretty dry except for some storm events when Norwich picked up 45mm in one day and a further 20mm for both locations on the 10th and 11th of July. The change from peak pattern to trough pattern in the jet stream is clear to see with cooler, wetter weather arriving from the 18th July onwards and prevailing for the rest of the month and into August as we know..

GDD and Rainfall – July 2017 – Irish Locations

Onto Ireland now and it’s a familar picture in terms of west / east divide with Valentia and Claremorris coming out highest compared to the eastern side of the country from a rainfall perspective…

MonthlyRainfallGDDJuly2017Ireland

GDD-wise again we see a west / east divide with the eastern locations of Dublin, Wexford and Cork highest and the most north west location (we monitor), Claremorris, Co. Mayo, the lowest.

I was on holiday once on Achill Island, Co. Mayo, and whilst I watched the wind and rain laying siege to the campsite in August, I commented to the campsite manager, (an unexpressive old chap),  “Nice Day” , he looked up and said…”You don’t come to Achill for the weather boy” and duly returned to his paper…I considered myself told….Still love Co. Mayo though :)

July from an agronomic perspective..

I know I’ve talked about this before but it doesn’t hurt to re-visit a theme (aside from the weather on Achill Island that is…).

When we get these peaks in rainfall during the summer of 20mm plus in a day, it can test the most free-draining rootzone. Especially when you consider the fact that more often than not at times the rainfall rate can get up to 200mm an hour, even if just for 5-10 minutes.

For this reason it is implicitly important that we have all the dots joined from a rootzone perspective..

Rootzone

I’ve talked before about the merits of summer vertidraining with small tines and no heave (to minimise disruption) and although the above model assumes a functional drainage layer (which I admit sometimes isn’t present :( ), it can only help shift water off the surface and down deep into the rootzone when we have high daily rainfall. This is key to maintaining good soil oxygen levels, for microbial activity and for plant health.

But you have to have all the dots joined…

The first significant barrier to water movement from the surface down is obviously the organic matter layer on the surface. Now this doesn’t have to be a deep layer to cause an issue. If the level of topdressing is insufficient and the organic matter layer is tight, then 8mm of tight, compact surface fibre is quite capable of perching water on the surface, no matter what the rootzone quality below it.

Assuming you have your surface matter layer well-integrated with topdressing, the next barrier to movement is the infiltration characteristics of layers L2 and ultimately L3. So if you’re moving the water from the surface efficiently and these layers aren’t conducive to water movement (because of poor sand quality maybe or high levels of silt / clay) then what you’ll see is that after a rainfall event the water will ‘back up’ to the surface.

Lastly we have our functional drainage layer which if present and effective (and that’s a big ‘if’) will move water away from the rootzone. So aeration in my mind is all about joining the dots, varying the depths and moving that water away from the surface wherever possible.

That’s why if you’re looking into how your rootzone is performing it is best to sample it in sections, I routinely use 50mm depths, so you sample the top 50mm, 50-100mm, 100-150mm and so on and get them analysed seperately from a physical analysis perspective. If you just take a sample from 0-150mm and send it away for analysis, the readings you’ll get back will be averaged over the depth of the sample and this may ‘hide’ the presence of a badly-performing layer…

Here is an actual example of this from a poorly-performing golf green where we took an initial analysis over 150mm depth and then when the results didn’t pick up anything obvious, we split the sample into 50mm sections..

rootzonesampling

In this case, the topdressing being utilised was too fine and this was capping the surface. Even though the Superintendent was aerating regularly from 0-100mm to move water from the surface, the green sat wet and stubbornly refused to dry down.  The answer was in the bottom 100-150mm of the roozone where there existed a layer of silt, fine and very fine sand and this was acting as a barrier to water movement down the profile. So aerating above and moving water through was just backing up water from the bottom and actually increasing the ability of the greens to sit wet.

Aside from playability and keeping greens / sportsfields open for play, there is of course a disease parameter here that has to be considered. Microdochium, Anthracnose, Dollar and Leaf Spot all like wet, humid conditions in order for their mycelium to develop across a plant leaf and to move from plant to plant. The dryer the surface, the harder it is for them to develop, it’s as simple as that.

That’s why as we continue our cool, wet summer we need to prioritise aeration wherever possible amongst all that your fixture list throws at you. I appreciate fully it is easy for me to sit in my office and put this blog together and it is much harder to make this argument to the powers-that-be and / or have the resource to enable you to do the work when you want to. (And that’s without the weather intervening and spoiling the day)

Looking ahead

I’m afraid with a mix of alternating high and low pressure systems in mid-summer, we will continue with our high humidity theme through August for the next 10 days and that means more disease pressure from the types of fungus that prefer these conditions, namely Superficial Fairy Ring, Microdochium, Dollar and Leaf and I believe Anthracnose.

Sorry to be the pervayer of bad news….

Meteoturf070817

The flipside is that our Growth Potential outlook for the next 7 days is very good because of the optimum night and day temperatures for cool season grasses (not too hot you see), so that means we should be able to grow out foliar pathogens like Microdochium nivale as quickly as they invade a green.

One last point though concerning these cooler conditions, it will pay to mix up your nitrogen sources and include some ammonium and nitrate N with your normal summer N source (along with iron) . This is because slow release N sources like methylene urea and to an extent, urea, rely on microbial conversion for their release and with cooler temperatures this will inevitiably slow down N availability…

Ok next week I’m off to do some serious walking in the beautiful Cevenne area of France but if my shakey hotel Wifi is working, I’ll put together a mini blog to keep you posted.

All the best…

Mark Hunt