Category Archives: Mark Hunt’s Weatherblog

April 16th

Hi All,

For some of us this week we have some warm, dry and sunny weather and be jaysus it has been a long, long time coming.

Soils are still saturated mind from weeks of incessant rain so it won’t be an instant turnaround but it is heading in the right direction and accompanying those temperatures is significant evapotranspiration. 22mm of E.T is forecast for my location here in Market Harborough, Leicestershire. So effectively we will expect to see nearly an inch of rainfall evaporated from a grass sward this week (sorry for the mixed measurements) and that’s good news for sure in terms of drying up turf.

We have to be patient though and let Mother Nature do her job before we can take over.

I was out walking on Saturday and to have warm sun on my face was a true pleasure even if it was matched by wet boots and mud splattered trousers. I watched Buzzards climbing in the thermals and then fold their wings and plummet like a stone before pulling up just before the ground, only to do it all again 10 minutes later :). They seemed to be having a blast…

The air was full of Skylarks as well on some parts of my walk and the chatter of Swallows and Martins, newly arrived from Africa and gorging themselves on the huge Midge hatches taking place. Simple things please simple minds for sure and definitely the case this weekend that bigger fools on….(politically)

So onto this week’s weather and the crucial question, is this just a welcome blip for most places or something longer term remembering that April isn’t traditionally the greenkeeper / groundsmans friend when it comes to growing grass.

General Weather Situation

With a deep Atlantic low west of Ireland and high pressure over the U.K it isn’t going to be sunshine and warm winds for everyone for sure..

So Monday sees the last vestiges of Sunday’s rain push up north across North Wales, north-west England and western Scotland during the morning and fizzle away to leave a dry day just about everywhere. I say just about because that Atlantic low will make landfall across south-west Munster and Connacht early afternoon and will push rain across Ireland through the 2nd part of the day. Some of that rain will be heavy in coastal areas of Kerry, Sligo and Mayo. Away from this low pressure, the U.K looks to have a dry and dull day according to the forecast but looking out of the window right now, it is blue sky and so your temperatures will depend on cloud cover. I’d expect 11-13°C over Ireland and Scotland and something approaching 13-17°C across England and Wales if you see breaks in the cloud cover. A strong to moderate south-westerly wind will be in situ and that will only help in the drying game.

Onto Tuesday and that heavy rain over Ireland continues overnight and then edges west into Scotland by dawn bringing heavy rain to the west and south-west of Scotland. This same rain front pushes into Mid and North Wales and the north of England in time for the morning rush hour, edging slowly eastwards through the morning pushing cloud cover ahead of it. By mid-morning that rain will be into The South West, across Wales, the north of England and most of Scotland leaving behind a pale of thicker cloud over Ireland which will break slowly through the 2nd part of the day. Further south and east looks to start dry with clear skies across the south-east of England and bright sunshine greeting the day. As that rain front pushes eastwards through Tuesday it’ll push thick cloud ahead of it so you might start bright but it’s likely to cloud over from the north-west through the morning. At this stage that rain looks to halt over the western side of the country, so south and east of this you should stay dry. I also think The Midlands should miss most of that rain. Temperature-wise, a real split as you can imagine, 11°C for Ireland, Scotland and Wales, 14-16°C for central and southern regions, maybe higher.

Mid-week beckons and Wednesday promises a better day for those areas that picked up rain on Tuesday with thick cloud and light showers starting the day off for Ireland and the west coast of the U.K. Just in time for the morning rush hour, another rain front pushes into Kerry and south Munster but the majority of this rain will track northwards and quickly clear so by lunchtime it’ll be away out into The Atlantic. Closer to home and after some thicker cloud and light showers across the west coast of the U.K, the cloud will thin and break by lunchtime with the sun pushing through and temperatures really ramping up. For most areas, Wednesday will be the warmest day of the year so far. Scotland will see some thicker cloud and rain for the 2nd part of the day but this will clear through the evening to finish dry and sunny. With a strong to moderate south / south-easterly wind in situ, Wednesday will also be a significant drying day to boot with 13-16°C for Ireland and Scotland and I’d say 19-21°C for England and Wales.

Thursday sees the last vestiges of that rain clear the north west of Scotland and then for the rest of the day we will see cloud clear (where it is present) and the sun pushing through. I’d expect the south-east of England to start be clear from the onset and that means here you’ll likely to get the highest temperatures. With cloud clearing Ireland and Wales quickly as well, Thursday promises to be a cracker of a day with long spells of sunshine and rising temperatures. The wind will be very light and swing round to the north by close of play, not that it’ll be very noticeable though. So I’d say 16°C for Ireland and Scotland, rising to 23°C or even a smidge higher for the south-east of England. What a turnaround, factor 30 here we come.

Closing out the week on Friday and we see more in the way of cloud around for Scotland and the north of Ireland. Some of this cloud may be thick enough to give some light rain in coastal areas. Ireland looks to start cloudy with that cloud breaking through the morning whereas England and Wales will start with pretty clear skies and so another warm, dry and sunny day beckons. Similar temperatures to Thursday, maybe a degree or two down but I’d expect to hit the twenties again in the south of England, high teens for The Midlands and north of England and mid-teens for Ireland, with Scotland only low teens because of that thicker cloud cover. The wind will be north-westerly / westerly and light to moderate.

So how does the weekend look, are we hanging onto that high pressure ?

Well the weekend will be mixed as we still have rain fronts trying to push in from The Atlantic so expect to see more in the way of cloud and showers of rain across Ireland and the west of the U.K, probably more so for the 1st part of Sunday I’d say than Saturday. Lot’s of sunshine as well so temperatures will stay up in the high teens I think, maybe touching 20°C down south. With moist air fronts pushing into a column of warmer air, there may be an increasing risk of some thunder and lightning as well. With thicker cloud over Scotland I think the temperatures will remain cooler here so just breaking into the teens possibly.

Weather Outlook

The above image is the prediction for the jet stream position come this time next week and hopefully you can see that it is sitting in a more traditional position with a westerly air flow, an Azores high pressure below it and an Icelandic low pressure above it. This is where it should be and so I think next week we are set for a sunshine and showers, April scenario. So initially on Monday we will start a little unsettled with rain across the west and as we progress to Tuesday we see low pressure push in westerly, mild winds and more showers. I think the tendency will be for more cloud cover and rain across the north of Ireland with some heavier rain on Tuesday and Wednesday for these areas. Unlike past rain though, this will whistle through on a westerly wind so that’s the key difference between last month and this month, no dwelling low pressures sitting in a big deep trough next week 🙂 Further south I think it’ll be sunshine and showers with good growing conditions, high teen temperatures and mild nights, all in all good I’d say. Maybe a little cooler at the end of the week as the wind swings a bit more north-westerly.

Agronomic Notes

Growth Spike

Ok it doesn’t need me to tell you this week that we have a significant growth spike coming for the areas that are set to receive the highest temperatures. You can see how it relates to the rest of the year in the graph below using data from my Netatmo Weather Station, I’ve added in the rest of April from temperature projections.

So on the 12th April, 2018 we were ticking along with scarcely any growth here and a G.P of 0.1 and 7 days later the projected G.P is 0.94, that’s some growth spike and traditionally the type of growth we have seen in the first week of May over the last 2-3 years and not the middle of April.

We know that the Sudden Stratospheric Warming event that took place in mid-February has brought us a very cold (and wet) start to the year but it is uncanny when you compare it with 2013 that the effect of this SSW ceased practically on the same date. In 2013 we started to get strong growth on the 13th of April and in 2018, it was the 14th April, weird.

So this growth spike brings with it both welcome and unwelcome consequences.

Firstly, we must remember that there are lots of sites which are still sitting saturated and so trying to keep on top of this will be very tricky without causing more mess than just a lot of clippings. Patience is the key here on all sides. We will obviously get a reduction in greens speed regardless of nutrition because the plant is growing 8-9 times faster than it was a week ago. On the flip side, newly seeded areas, areas that have received high levels of winter wear, scars from Microdochium nivale last autumn and of course, aerated surfaces will heal up so much quicker now and that’s a welcome bonus.

Remember I said in one of my recent blogs I put some Fescue / Rye seed down in mid-February hoping for an early spring and had seen nothing. The transformation in 3 days has been incredible, bare areas are filling in and newly-germinated seed is popping. So that means divot recovery or if you are able to undertake the work, overseeding thin areas will pay its way from now onwards.

For some areas in the north I would temper the description of a growth spike to just growth because up there it has been practically non-existent up until the middle of April. Happily despite your projected lower temperatures this week, you are still going to see some good growth and some drying days.

Poa annua

A week ago as we were just starting to see some growth I remarked that it wouldn’t be long before we started to see the annual biotype of Poa annua pop up its head. Now I know the annual biotype will produce seed in any calendar month of the year but traditionally for me it starts to really push along when the cumulative GDD hits the 100 mark, with the perennial biotype following on behind some 80-100 GDD days later. So for my location here we hit 100GDD tomorrow and sure enough I can see plenty of annual biotype Poa seedheads.

The question is when will the seedhead flush start for the perennial Poa annua biotype ?

What never ceases to amaze me is the fact that whatever type of winter we have we end up reaching a very similar time for the perennial biotype seedhead flush, typically the first week of May.

For my location I have projected forward the potential GDD count for the rest of April. Now there’s going to be siginficant variation with actual because of the inaccuracy of weather forecasting past 7 days temperature-wise.

So by the end of April we will be hitting a projected cumulative GDD of 170 in Market Harborough and just as importantly stacking on 30GDD a week. So ‘if’, and it’s a big ‘if’ at this stage, we carry on like this we will see the start of the perennial biotype seedhead flush at the end of this month / first week of May.

Looking back at data from our Northampton location makes interesting reading (Ta Rob) when we take into account SSW events vs. the date we hit a cumulative GDD total of 180….

So I’d say the smart money on the first week of May for the main Poa annua seedhead flush 🙂

Disease Activity

Last week’s climbing day and night-time temperatures coupled with high humidity resulted in a good amount of disease appearing and not just on existing scars carried over from last autumn / winter. Last week saw significant new disease ingression and so we can deduce from this that the infection cycle has gone full circle and that last week represented high enough temperatures to initiate new infection activity from new disease populations rather than existing disease populations. A fortunate consequence of the growth spike though will be that this and any existing disease should be happily grown out without having to apply a fungicide.

Ok that’s it for this week, enjoy the sun if it is heading your way and don’t forget the sun cream…

All the best….

Mark Hunt

April 11th – Mini Update

April 9th

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Hi All,

I think the map below explains the weather story for March very well.

Image courtesy of The Met Office (https://www.metoffice.gov.uk/climate/uk/summaries/anomacts)

Access it from The Met Office website here

The negative North Atlantic Oscillation (NAO) which caused (and continues to do so) the jet stream to sit lower than normal allowed low pressure after low pressure to affect the U.K, hence the heavy rainfall. Coupled with the predominantly easterly wind aspect, we can see the result in terms of rainfall distribution, it has a pronounced eastern bias.

The bad news for us is that the jet stream is still sitting low and the NAO is still the wrong side of where we need it to be. The indications up to the middle of April point towards another strong negative dip so in my books it looks like more of the same I am afraid in terms of rainfall.

On the flip side we have seen much better temperatures over the last week and that has at least allowed some growth. In fact there’s been more GDD across the U.K over the last week than we had in 3 weeks during March and that rise in temperature will help a little in terms of faster drying of the turf surface. Yes I know I’m trying to put a positive spin on it when a lot of surfaces remain saturated but that’s just me 🙂

General Weather Situation

So we start the week with a dull and pretty dry picture on Monday save for a raft of showers that is working along the Dorset coast. With an easterly wind in situ these showers will move west across Wiltshire and into The South West through the course of the day. Elsewhere we have plenty of cloud cover that will eventually break across the east coast, north-west England and Leinster to reveal some patchy sunshine. As we close out the morning, that rain across The South West will push north and eastwards into South and mid-Wales and later The Midlands. At the same time we see another strong rain front push into the south-west of Ireland. Through the course of Monday night that rain will edge eastwards to cover most of the south and central regions of the U.K, pushing up into northern England by dawn on Tuesday. A north-east / easterly wind will keep temperatures down to low double figures, so maybe 11-12°C for the U.K and Ireland.

So a very wet start to Tuesday beckons for England and Wales and also for the east and west of Ireland as a band of rain is set to lie horizontally over the country. South of this band you’ll be dry and dull though. As we go through the morning rush hour, the band of rain over England and Wales tracks northwards clearing the south and south-east of England as it does so. The reason I haven’t mentioned Scotland yet is because you’ll be dry and dull through Tuesday but expect that southerly band of rain from northern England to push into north and east Scotland during Tuesday afternoon. As we go through the afternoon the rain over Ireland, Wales and England begins to dissipate and we may even see some spells of sunshine break through as it does so. Still plenty of rain showers around though it has to be said. Where that sun breaks through it may just lift the temperature up from 11°C to 13°C in places as we close out Tuesday, cooler in Scotland mind.

Onto Wednesday and a much better day with a pretty dry picture, save for the risk of showers over Northern England. Plenty of cloud initially but this will clear from the south and south-east to give long spells of sunshine and rising temperatures pushing up into the mid-teens during the day. More in the way of thicker cloud for the north of England and Scotland in particular means that temperatures will sit a good bit lower and struggle to break out of single figures. Ireland should almost mirror England, with a dull start and the cloud cover breaking across the south-east during the morning and clearing northwards. A lighter easterly wind will allow a much milder feel to temperatures.

Thursday sees the effect of the east wind come into play as a bank of thick cloud is pushed in off The North Sea. This will bring rain to the east / north east from first off pushing north and westwards during the morning into The Borders and North East Scotland. South of this band of thick could we will see a dull, dry start with cloud breaking across The South West and east of Ireland to reveal hazy sunshine. Through the late morning there’s a risk of a narrow band of rain running along the south coast westwards, some of this may be heavy across The Isle of Wight and Hampshire, rain shadow or no rain shadow 🙂 During the course of Thursday evening this rain pushes into The South West from the east and may be heavy in places. Further north we see that rain peter out and be replaced by a bank of thick cloud so nothing great about the temperatures here. 9-10°C under that cloud and 13-14°C further south, so a real north-south divide. Winds will be easterly swinging round to the south east at close of play.

Closing out the week on Friday and overnight we see that band of heavy rain over The South West and Wales extend into Leinster and Connacht bringing the risk of heavy rain here. Likewise we see thicker cloud over the south and central parts of England on Friday and so a dull and potentially damp start here too. This time the north of England and Scotland gets the better start with sunny intervals breaking through a clearing cloud base but it won’t last long as more cloud pushes in from The North Sea on a south-easterly wind bringing rain to the north of England and Scotland for the second part of the day. This will clear from the south mind. For the south and central regions which had that thicker cloud and early rain you’ll see it clear during the afternoon to finish pretty nice really with hazy sunshine and warming temperatures.

So how does the weekend look ?

Saturday looks potentially pretty good at this stage with a warm, sunny day for most of England and Scotland at least. There’s a threat of some rain for The South West and South Wales possibly but plenty of time for this to change yet. Ireland looks to have a dry Saturday morning but there’s a threat of rain for the east for the 2nd part of the day I’m afraid 🙁 With those rising temperatures we could see some snap showers associated with thunder across the U.K later on Saturday afternoon. Mid to high teens for England on Saturday, cooler across the west with that cloud cover and for Scotland, but low teens here and dry crucially. Sunday looks similar, more cloud cover about though and heavier showers running up from The South West up the west coast. There’s also a rain risk for the east coast of Ireland as well. Some of these showers may extend into The Midlands during Sunday afternoon. Winds will swing round from the south east to more westerly on Sunday and I’d expect temperatures to stay in the mid-teens for Central England and low teens elsewhere. So a bit more unsettled on Sunday but remaining mild.

Weather Outlook

Images courtesy of Unisys Weather

So the outlook for next week is I’m afraid a continuation of unsettled conditions with a deep Atlantic low pressure developing from mid-week onwards and set to give us some heavy rain for the 2nd part of the week and extending into next weekend possibly. As you can see from the Unisys graphics above, the orientation of the low is more south-westerly so perhaps reversing the easterly trends of late. If I try to pick some crumbs of positivity, I’d say it will remain mild with a south-westerly / southerly airstream but we really don’t need any more rain as we all know.

Agronomic Notes

Until I see a change in the weather I will keep churning out comparisons with prior years because I think they’re helpful in understanding exactly where we are.

Now I got this idea from Rob Hay at Northampton County who kindly forwards his weather data to me. (Thanks Rob)

His contention is that 2018 is closely following 2016 in terms of growth and rainfall patterns and we know that in both years we had late SSW events so there’s some logic there. I happen to think he is right.

I plotted out his data and expressed it as Cumulative Growth Potential comparing 2013, 2016 and 2018, when we had SSW events, with 2017 when we didn’t.

Here’s how it looks….

So you can see from the data that all SSW-affected springs show lower (and slower) growth levels compared to 2017, when we had a decent spring with no SSW.

Broadly-speaking, 2018 is tracking mid-way between 2016 and 2013 in terms of cumulative growth and roughly 25 days behind 2017 (as of 08/04/18). The gap has closed a bit because we have had some growth over the last week or so.

The other interesting parameter that Rob documented was rainfall, so here’s the same graph as above but looking at cumulative rainfall.

So you can see from the above that a SSW event doesn’t necessarily mean we will pick up high levels of rainfall as a result because in 2013 we had lower rainfall than 2018, beset by a pattern of cold, dry easterlies. If you look at 2018 and 2016 though, the rainfall total to date is very similar though the pattern is different.

So we continue to track behind 2017 in terms of growth and a long way ahead in terms of rainfall. That trend will I am afraid continue through the next 10-14 days by the look of it with further high rainfall predicted. As a reminder, April 2016 finished off cold and dry in the last week with night frosts but come the end of the 1st week of May we had a massive growth flush.

Warming air means higher E.T rates and quicker drying

I am determined to keep positive despite how the weather looks and one point I’d like to emphasise is the effect of that warmer air coming into play. As we progress through April and pick up warmer day temperatures it means we also get higher evapotranspiration and that means surfaces dry down quicker.

If I look at the stats over the last week from The Oxfordshire, they received 17.4mm of rainfall but crucially 13mm of E.T so some of that rainfall effect was negated by evaporation. Now the further north you go, the lower the E.T and I accept it isn’t the case for everyone, but warmer air dries surfaces quicker so I’d like to think we will dry down quicker as we go through April.

Where is Poa annua in all of this in terms of seedheads ?

Well usually what we see in the spring is that the annual biotype of Poa annua begins to seed at around 100 cumulative GDD from Jan 1st. If I pick the data from Northampton, they’re up at 82 come yesterday so a little way off. That said they were only at 62 at the end of March so have packed on 20GDD in the last week. That means if we continue this trend we will see the annual Poa biotype seeding in greens in a week or so for The Midlands and given the fact it’s been warmer down south, you’ll already be seeing it.

The perennial biotype seeds later in the spring and typically anywhere from 180 cumulative GDD so we are a long way off that at present.

I haven’t had the opportunity to strip down any Poa plants of late and have a look (a great way to pass time if you are exceptionally sad like me) but I wouldn’t expect to see much at current GDD levels.

Just as an aside, if the perennial Poa annua at Augusta (perish the thought) seeded at a similar GDD point, the seedhead flush there would have been around mid-February !

Following Rob’s line of thought that we are tracking similar to 2016 in terms of GDD and rainfall, the Poa annua seedhead flush started on 7th May, 2016 looking back at my records. It was the week when we went from a G.P of 0.25 to 1.0 in a matter of two days, with Poa seeding profusely and clippings around our ankles !

Disease Activity

With the milder weather and high humidity of last week comes Microdochium nivale with plenty of reports of disease activity out there last week. Looking back at the data from my little Netatmo Weather Station, I recorded a period of 34 hours between the 2nd and 3rd of April when the humidity and air temperature were above the threshold for Microdochium activity, so it is not surprising that we are seeing disease activity. Thankfully though with those same temperatures comes growth and that means we are at least able to grow the effects of the disease out of the sward.

Linking your Netatmo Weather Station with Weather Underground

Now I know quite a lot of people have gone out and purchased one of the above weather stations after reading my blog. I should point out there is no commercial connection between myself and Netatmo and therefore you won’t see me retiring to a life of fly fishing and mountain biking just yet….:)

I have though found it a cracking piece of kit so far in terms of weather monitoring but to the contrary I have also found The Netatmo dashboard quite limiting in terms of the ability to look back at historical data.

I thought I’d got round this when I found out you could link your Netatmo Weather Station to the Weather Underground (WU) – Personal Weather Station Network (PWS).

When you do so you can spot your weather station on their map, click on it and look at your data. My weather station is 1of 5 in Market Harborough as you can see on the Weather Underground (WU) map below.

Now I am not going to go into how you link your Netatmo with WU because I don’t think the software marriage between the two of them is very robust. I encountered a number of instances when the WU map said my Netatmo wasn’t reporting data to WU when it was working fine, but the link between them wasn’t so I ended up with missing data, sometimes for days.

I then happened upon another solution using software from a company called Meteoware Plus. They offer the ability to look at your weather data from your Netatmo in a fancy dashboard set up which is nice but their ace card is that they also offer the ability to link your Netatmo PWS with WU, if you click here

It’s really simple to do once you enter your Netatmo login details and within an hour or so you’ll see your data featuring on the WU map. It transmits your PWS data every 15-20 mins or so and you can click on a log (shown above) to check that your weather station is uploading data.

So what’s the advantage of sending your weather data to the WU site ?

Well if you click on your weather station you can put in custom historical dates and it will pull up your data in either graphical or table form. Here’s my March summary…

So you can easily take this data and fill in your GDD / G.P spreadsheet, rainfall and the like. What’s more WU have a map of PWS’s all over the world so you could say hypothetically click on a weather station next to Augusta and look at their weather or anywhere really where there’s a PWS indicated.

Now the idea of a PWS Network is pretty recent so don’t expect to find years worth of data, also sometimes there are gaps in the data if the weather station wasn’t maintained, battery went flat, WiFi broke down or the software between the two didn’t work for while.

Now I don’t claim to be an expert on this so please don’t email me asking ‘x’, ‘y’ and ‘z’ because I probably won’t have the answer, I’m simply relating my experience so far with my own PWS and data usage / availability.

Ok that’s it for this week, it must be a record for me to finish this blog it on the day I actually started it 🙂

All the best for the coming week.

Mark Hunt

4th April

2 Replies

Hi All,

Well as forecast we endured a pretty torrid Easter with incessant torrential rain in the south, west and east and snow further north. Truly I can’t remember a time when I’ve seen so much water lying on the landscape locally with rivers bursting their banks, reservoirs being pumped out to reduce dam pressure and the like. Image right is the usually tranquil River Welland that flows through Market Harborough. The reason for this weather as we know dates back to mid-February and that Sudden Stratospheric Warming (SSW) event which has pushed the position of the jet stream south and allowed low pressure to dominate proceeedings, bringing cold, snow or rain. The rub is when is our weather going to get back to normal because the economic and agronomic impact of this latest SSW is significant and goes way further than a low GDD calculation.

Looking at the jet stream position, the questions on everyone’s lips are when are we going to get some warmth and now more significantly, when is it going to stop raining ?

Image courtesy of NetWeather

As you can see from the graphic above which shows the current position of the jet stream (yellow / orange pattern), it is still lying well below the U.K and Ireland and while it does so we can still expect more rain and an unsettled outlook, particularly for the south of the U.K because the low pressure systems are sitting south rather than west of us. There is some positive news however and that concerns temperatures because this southerly air stream is projected to give us some decent day and night temperatures over the next week or so. So that will start some growth plus warmer days will also initiate some surface drying by raising E.T, however if it keeps raining, the latter’s effect will be minimal.

The problem for our industry is that it is saturated soils and not a tardy GDD figure that closes venues and restricts income and that’s what we are facing at present.

Sorry not to be the bearer of positive news with an anticipated end to our current run of crap weather but the truth is we aren’t out of the woods yet and although we will pick up some welcome warmth, it may well be transitory.

Image courtesy of Unisys Weather

General Weather Situation

Wednesday sees a raft of moisture over Ireland falling as wintry showers, sleet and rain and extending across Scotland. A belt of heavier rain is also projected to extend across North Wales into northern England first thing and this will drift south and east into The Midlands, central and southern regions through the course of tomorrow morning. By late morning Ireland should have lost that colder moisture and it’ll be replaced by sunny intervals but much cooler on Wednesday due to a northerly wind across Ireland. At this stage it looks like the heaviest rain will be across northern England, North Wales and the south coast of England as well falling as wintry showers at elevation but there will be rain for pretty much everyone through the day. As we go through the evening that rain will clear most areas but any remaining will turn to more of a wintry shower mix as the wind takes on a north-westerly slant. A little cooler feeling on Wednesday with still mid-single figures for Scotland due to a northerly wind aspect and low double figures for Ireland, Wales and England.

Thursday looks to be a much better day from a lack of rainfall perspective with a cool, bright start to the day for most areas save for a block of wintry showers across the north-west of Scotland. So a bright, but cool day on Thursday with a north-west wind keeping the lid on temperatures across the U.K (southerly across Ireland). A bit of cloud cover moves into Ireland in the afternoon, pushed ahead of another rain front coming in off The Atlantic but that’s about it. A little milder feeling for Scotland with 6-7°C likely here in a north-west wind and 9-10°C further south and across Ireland and Wales.

Friday sees a new band of rain push in off The Irish Sea into Kerry and Connacht and here it may be heavy I’m afraid. This band of moisture may fall as snow for the north-west of Scotland as it meets the cold air pushing south and east through the morning. Elsewhere a dull and cloudy start to the day but with a south-easterly / southerly wind in situ it’ll feel much milder with temperatures pushing up into the teens through the course of the day despite the lack of sunshine. Through the afternoon that rain will cross over Ireland and push into The South West, Wales and the west coast of the U.K and through the course of Friday night become heavy over Scotland. Different ends of a low pressure means Scotland’s temperatures look to remain on the cool side between 6-8°C, whereas a southerly wind aspect for England, Wales and Ireland will mean milder temperatures pushing up to 11-13°C depending on rainfall / cloud cover.

So how does the weekend look ?

Well tricky to forecast for one with more in the way of wintry showers turning to rain for Scotland starting off Saturday but with a southerly wind in situ this should clear off into The North Sea through the morning to leave a dull mild Saturday for you with much-improved temperatures. Ireland and Wales look to have a dull, mild day with a low threat of some light showers but it’s the south of England that’s the tricky one to call. There’s a risk of a band of showers pushing into the south coast and extending northwards across to The Wash through the day. My call on Saturday for The Midlands and south of England is mild, dull and unsettled with a risk of rain through the mid-part of the day and a mild south-westerly wind. All change on Sunday with the wind doing a 180° and swinging round from to the north-east to bring a more unsettled feel back to the weather and for Scotland a drop in temperatures compared to Saturday. Still mild though for Ireland, Wales and England with temperatures peaking at mid-teens for the south of England, a couple of degrees down on that for Ireland, Wales and The Midlands and then only high single figures for Scotland with the risk of some snow showers still remaining for the north east of England. Again I don’t think it’ll be entirely dry across England with a risk of rain across East Anglia and The South East through the day. Dull again for most but maybe Scotland seeing the Lion’s share of the sunshine once those wintry showers depart.

Weather Outlook

Well taking into account that the greatest issue currently is saturated ground conditions then the fact that we may have a continental high pressure system building next week could be the kind of breather we need to help things dry out. It looks like we will still remain unsettled through Monday with a small low pressure bringing rain but after that it looks like high pressure is going to build over Scandinavia from the early part of next week and that will work to block Atlantic low pressure systems. So I reckon we will be drier next week but not necessarily warm because a continental high pressure is likely to funnel over easterly winds through the week and probably cloud cover coming off The North Sea. So I’d say 8-10°C would be my guess during the day and hopefully with cloud cover, frost-free. So a cool, dry and largely settled week, probably on the dull side as well with fog / mist and if I really Mystic Meg it, I reckon we may see the wind change back to south-westerlies at the end of the week / weekend to push in more milder air, but more unsettled as well.

Agronomic Notes

Crumbs, where do I start to write this weeks notes when I know the state we are in presently and would like to put some positive spin on it ?

Well first up let’s do a thorough review on March and I’m going to burn some midnight oil on this one to give as wide a perspective as possible geographically.

We will start with our default, Thame location.

GDD Review March 2018 – The Oxfordshire, Thame, England

Well I guessed that March would finish off with a total GDD of 15 ish halfway through the month and I wasn’t that far off with a GDD total of 21 at this location. That’s the second lowest on record since 2010, with 2013 the lowest at 12.5. Now we know both 2013 and 2018 have in common, a late SSW event so it’s interesting that their effects on air temperature and therefore grass growth have been broadly similar.

If we compare with last year, we have had only 17.7% of the GDD of March 2017, so it cannot be a surprise to anyone (but of course it will be) that we are behind growth-wise.

Now that’s only one part of the equation that is making life difficult at present, the other and more significant one is rainfall and saturated ground conditions, but of course a lack of heat means less evapotranspiration and therefore less drying so there’s a link between the two.

From a cumulative perspective, a GDD total of 57 by the end of March is again second only to 2010 though it has to be said that other SSW-event years have similarly low cumulative GDD figures.

Comparing this site with 2017, we hit a total cumulative GDD of 57 on the 23rd of February so we are 36 days behind last year in terms of reaching the same growth point.The graph below illustrates how 2013, 2017 and 2018 pan out from a cumulative GDD perspective, you can download it here.

If I look back at 2013 we are 4 days ahead of that year so in other words we are tracking pretty much bang on 2013 when we had a late SSW event.. uncanny eh ? It is worth remembering that in 2013 we carried that cooler theme for the spring till the mid-part of April and so that’s why I’m not convinced we are totally out of the woods yet.

Data usage from this blog

Just a quick note on data from this blog in terms of usage – It’s come to my attention that my various competitors are using information from this blog for their own commercial ends so please be advised that all the information in this blog is protected by personal copyright, it is not permissible to download, duplicate, tweet or share this information without the express wish of the author and that’s me. This blog is designed to provide information to greenkeepers, superintendents, course managers, groundsman, lawncare operators and the like working in the turf maintenance industry and not to further the ends of a commercial business and especially one that competes with the one I work for. Go off and do your own hard work.

Ok that’s the rubbish out-of-the-way, let’s get down to business.

GDD Comparison – U.K

So I wanted to split this up into GDD and rainfall comparisons vs. last year and include as many geographical locations as I could. The problem is I don’t get GDD / Rainfall data from a lot of locations so I’ve burned the midnight oil on Weather Underground, accessing weather stations data from around the U.K and calculating GDD and rainfall totals. If I tell you it took me 8 hours to put together the chart below, you may understand why the blog is late this week 🙁

This data is available for end-users to download as a pdf here

So the above chart shows the cumulative GDD figure at the end of March 2018 vs. the end of March 2017. The next column shows the variance between the two, so if for example the figure from Uppingham shows a variance of -70%, it means the figure from 2018 is 70% less than the figure from 2017. The next column shows how many days in front or behind 2017 we are at the end of March.

So if I look at the data from Norwich I have a figure at the end of March 2018 of 59.8 cumulative GDD. In 2017 we hit this same GDD total 34 days before so that would be something like the 26th of February. This gives a good indication of how far behind we are this spring vs. last spring in terms of growth.

The chart shows that the variance vs. 2017 ranges from -55% in Kent to -93% up in The Highlands of Scotland at Charlestown of Aberlour or Aberlour as it’s commonly known.It serves to illustrate just what a hard winter Scotland has had and is still enduring.

If you’re wondering where Aberlour is, it’s a simply beautiful spot on the River Spey where I used to deal with a rough and ready Farmer many years ago, who shall remain nameless, it’s also the home of Walkers Shortbread. After the usual tense and terse negotiations contracting Spring Barley seed acreage (not helped by my nationality I might add) , I would sit on the bridge and watch the Salmon jump and munch on a packet of said Shortbread biscuits by way of compensation for having to call on a miserable chappy, 8 hours drive from home in my 4-speed Volvo 340DL that I eventually wrote off out of sympathy.

A slow spring isn’t all bad news…

I digress, so rather than just look at figures let’s talk through the implications practically of being behind in the spring season and note that it isn’t all bad news.

Firstly, of course if we are looking for recovery from disease scarring or aeration then for sure having a spring where we have only had 30% of the growth of the previous year will present an issue, the process will be slower. If however you have come through the winter with a good sward cover on say greens than that’s great, they’ll be just ticking along nicely with no growth flushes.

Now when we come to outfield turf and look at areas receiving wear day in / day out so that means winter season pitches, wear pathways from green to tee and the like, then these areas will have received wear but not had the recovery growth and so will be looking pretty tired and thin. Trying to get new grass cover, a result from overseeding and / or divot recovery on tees (and fairways if you do it) will be slower because until recently we haven’t had the soil temperature to promote germination and establishment.

As an example, I put some Fescue / Rye seed out in the middle of February (before the SSW event I hasten to add), hoping to catch some early mild weather and get ahead and to this date it hasn’t germinated, so that’s going on 7 weeks now.

The lack of growth is in some cases an advantage though because it means less cutting and no growth flushes over the Bank Holiday so no piles of clippings lying around. On the flip side it does make it difficult to get presentation between fairways, semi-rough and rough if growth rates have been slow but you can always use iron for this purpose. Similarly converting from winter sports to cricket requires consistent growth to take down the cutting height on cricket squares and outfield, again until recently this hasn’t been forthcoming.

I think one of the major benefits (which isn’t readily apparent) is root development, specifically because the plant won’t have been putting its efforts into top growth. When I’ve been out and about, taking cores, I’ve been encouraged to see really good root development and that should stand us in good stead if we get our usual dry, cold period towards the end of April.

Rainfall Comparison – U.K

This data is downloadable as a pdf here

The above is more straight-forward I think and reflects a comparison of rainfall totals for the period January 1st to 31st March, 2018 vs. the same period in 2017. Now there’s several caveats to these type of figures that should be made clear from the outset.

Rainfall is extremely localised, so for example Uppingham has had 15mm more rain than the same period last year but I happen to know a golf club barely 8 miles up the road that had another 30mm in March alone. Secondly it’s often not the total amount of rain that has fallen but how it fell and in particular, the number of dry days that allow turf surfaces to dry out that matters to us.

Lack of dry days

March 2018 has been one of those months where we have had more rain than previous years yes, but it has fell consistently so we have had very few drying days in-between that allows turf to recover and surfaces to dry down. Trawling through the data I would say on average we have had only 20% of the month with dry days and no rainfall for a typical U.K location.

Now I know for some places that figure is lower, but there’s not many that are higher. The last caveat relates to snowfall in that snow doesn’t contain the same amount of moisture as rain, typically it’s 10%, sometimes 15% for dry powder snow. I think that’s why some weather stations and particularly those in the north and Scotland are showing less rain vs. 2017 because it fell as snow and contained less moisture. It’s still disruptive though.

GDD & Rainfall Comparison – Ireland

Thanks to Aine for her consistent data summaries, the Irish comparison was considerably less work 🙂

This data is downloadable as a pdf here

Looking at the Irish GDD data we see a similar pattern in terms of variation vs. 2017 with a range of -51% from Valentia Co. Kerry to -77% from Ballyhaise, Co. Cavan. As we would expect there’s a north – south and east-west bias here in terms of growth and that is reflected in the GDD totals. All things considered we vary from 37 – 65 days behind 2017 in terms of GDD across the 7 Irish locations.

The rainfall stats also show an east-west bias with Dublin, the driest location, and Valentia not surprisingly, the wettest. Aside from those two locations, there’s some significant year-on-year variation when it comes to rainfall with the location in Co. Wexford receiving 58% more rain in the first 3 months vs. 2017, just short of 5″ and similar for Co. Cavan with 74% and 136mm extra rainfall.

So for both U.K and Irish locations we see that the trend is for significantly less growth and more rainfall in the first 3 months of 2018 vs. 2017 and that’s a fact.

GDD Spreadsheet

Just a quick note that the GDD spreadsheet is available here to download if you fancy filling in your max and min temperatures and rainfall. I’m working on an upgrade for 2019, which will provide you with a lot more features and information from the GDD spreadsheet, more on that when it’s finished :). You can download the current spreadsheet here

Pathogen Activity

I expect with some milder nights (for some) this week, you’ll see some Microdochium activity out there but hopefully with milder nights comes growth so we should be back to the balancing act between generating growth and growing out disease.

I’d also expect to see more in the way of grub activity as the soil temperature warms up including Bibionids which will be set to hatch into adults over the next 3-4 weeks. Also keep an eye out on any core holes for that familiar countersunk appearance as larvae like Leatherjackets emerge at night to graze around the edge of a tine or vertidrain hole. This can seriously slow down recover from aeration.

Augusta Comparison

So this week marks that lovely tournament that sends predictable ripples through our industry every year and raises many a collective hackle.

I’ve updated the comparison with our default UK, location and here’s how it looks…

So at the end of March, Augusta were running 62 days ahead of our U.K location, that’s a whole 2 months and highlights the somewhat ludicrous nature of the comparison.

Now looking at their GP figure of 45.2 (yes I know I swop around between GDD and G.P), last year in what was a good spring, The Oxfordshire didn’t hit that cumulative figure till May 26th.

So what we are saying is that the air temperature / Growth Potential that Augusta receives by the end of March this year was equivalent to what The Oxfordshire receives by the end of May, so there’s the two months difference again.

If you want to know where Augusta were from a GDD perspective at the end of March, the figure was 570.35 !

Compare that with the charts above for the Irish and U.K locations…

Ok that’s it for this week, my head is swimming with numbers, sorry it’s taken longer than normal but there was a lot of data to collate.

All the best…

Mark Hunt

March 26th

2 Replies

Hi All,

Sometimes I sit at this desk on a Monday morning and through the thin veil of sleep I have to remind myself of the date. Early signs of a cognitive disorder or a topsy-turvy year when it comes to the weather I’m not sure but as we embark on the 2nd day of British Summertime we still aren’t done with winter yet. As a customer said to me last week, my blogs make depressing reading this spring (or maybe always?) for that I can only apologise.

So my call of last Monday for a cool, unsettled Easter looks to be correct I’m afraid, don’t think it will be the Beast from the East MKIII, but it will be turning cooler again as we fail to move from the trough pattern in the jet stream that beset us back in the middle of February, that’s 6 weeks and counting. It may not seem like it this Easter but I have a suspicion that the jet stream is beginning to pull back into line slowly, beginning the week after Easter, time will tell. Yesterday though marked the start of British Summertime and what a lovely day it was, exactly a week before I could hardly bear the windchill from the east wind on my face whilst out walking, yesterday I was sweating…

For now let’s get on with the general weather situation…

General Weather Situation

So Monday starts off dry, cool and settled after what was for us here in The Midlands (and hopefully for the rest of you) a lovely spring day yesterday. A light frost as well in places. Ireland will have a duller start as cloud cover from an approaching Atlantic frontal system pushes ahead of it. The U.K should be bright, sunny and dry, not a bad way to start the week mind. As we go through to the afternoon we see that rain front push into the west of Ireland and move across the country for the rest of the day making landfall across The South West of England around about midnight. So not a bad Monday for the U.K and a wet second half for Ireland sums it up. In light north-westerly winds, temperatures will rise into double figures, especially where you see plenty of sunshine, a couple of degrees down on that for Ireland and Scotland.

Tuesday sees that rain front clearing Ireland by the time the M50 turns into a car park. it’s now the turn of the U.K to get the rain and by the morning rush hour it’ll be ensconced over the western half of the U.K and moving eastwards. This rain may fall as wintry showers over the mountains of Scotland and The Lakes and they’ll be some very heavy bursts amongst it for the former as well, so expect some local flooding. By late morning Ireland is left dull and damp with some showers remaining, the worst of the rain will have cleared the west and now situated over the eastern side of the country clearing most areas by dusk. I say most areas because it looks to stay entrenched over Scotland well into the evening and with temperatures dropping it will turn to snow more readily over higher ground. So for a lot of areas of the U.K on Tuesday, you’ll start wet but then the rain will clear eastwards and then temperatures will pick up nicely in the sunshine up into the low teens across the south of England, what a pity it isn’t set to last as it is good growing weather. For Scotland, a pretty wet day I’m afraid and high single figures at best with Ireland similar, maybe just nicking up into double figures. Winds will be moderate and from the south turning westerly across most areas except Scotland where they start off south-easterly and then turn south-westerly.

Mid-week and Wednesday sees a band of wintry showers sitting across the west coast of Scotland and northern England. A much cooler feel to the day as the cooler air that will dominate Easter begins to make its presence felt. This means that any moisture will have a more wintry feel to it so during late morning we will see some showers of sleet, rain and snow push into western Ireland and also Wales moving eastwards across Scotland, the north of England and The Midlands of England by lunchtime. As we go through the afternoon these should clear southern England and become isolated to the east coastline of the U.K, still though those wintry showers affecting the west coast of Ireland mind. In-between the showers we will see plenty of sunshine but a more raw feel to the day for sure compared to the milder air of Monday and Tuesday despite a westerly wind direction. Expect 6-8°C as a typical temperature.

Thursday is significant because the wind changes round to a more easterly aspect and that’ll pull in some wintry showers across north-east Scotland through the morning. Elsewhere a bright, cold start to the day with plenty of winter sunshine after a light ground frost. Through the morning we may just see some wintry showers skirt the southern coast of England and South Wales in-between the sunshine. Those same showers may just spoil what will be a bright, cold day for Ireland by pushing into the south-east of Leinster / Munster on Thursday night. Feeling cold with that easterly wind over Scotland and mid-single figures likely here. Further south the wind will be more southerly orientated and that’ll push up temperatures a little into the high single figures.

Closing out the week with Good Friday and quite a complicated picture in terms of where may get wintry showers and where may stay dry. So complicated is it I’m not even going to try. Ok I will, at this stage it looks like the wintry showers will be confined to the south-east of Ireland, The South West and South Wales first off before moving away and dissipating. Scotland looks to keep those wintry showers across the north-east of the country and as we go through the morning they’ll move westwards pushed along by an easterly wind. We do have a low pressure sitting right over us and so for England, Wales and Ireland, I expect it’ll be a day of sunshine and then wintry showers moving through on a light to moderate south-east / southerly wind which turns increasingly easterly. I expect this to change as we go through the week rainfall vs. location-wise so plan for a cool, sunny and unsettled Good Friday and you won’t be disappointed.

So how does the rest of Easter look ?

Well I think Easter Saturday will be similar to Good Friday, bright and cool with some rain, sleet and snow showers (over elevation) to spoil the show. An easterly wind in situ so that means any moisture will come off The North Sea and English Channel / Irish Sea. Best to keep an eye on your local forecast for more up-to-date info on where the showers will affect but usually they come in off The Wash / Thames Estuary and the like. The second part of Easter Sunday sees the wind turn round to the south-west across Ireland and push in some heavy rain and strong winds. These looks set to affect most of the U.K on Easter Monday but with a south-west air stream it’ll feel milder in that wind and rain. (always looking for a positive spin like :))

Weather Outlook

Well it looks pretty straight-forward next week kicking off with the arrival of that Atlantic low pressure over Ireland on Sunday afternoon. At this stage it looks like next week will be windy, potentially very windy at times and wet with unsettled weather sitting with us most of the week. Initially cooler and unsettled but crucially with a south-west airstream they’ll be no risk of snow or night frostsand it’ll feel milder from Monday I reckon possibly. From Thursday next week I think we will pick up a much milder airstream and therefore see a hike in temperatures to normal for the beginning of April. I think the worst rain of the week will be on Easter Monday which is just bloody typical.

Agronomic Notes

So last week I produced a graph from The Oxfordshire showing we were currently sitting 11 days behind 2017 from a cumulative Growth Potential perspective. I’ve picked data from another location today, Northampton (thanks Rob) to do the comparison. Of course next week will be the end of the month so I should have lots of data to compare with 2017, it’s my intention to do as many representative locations as possible and certainly Scotland, Ireland, England and if possible Wales, but presently I have no data from that region.

So last week at The Oxfordshire location, we were tracking -11 days behind 2017 from a growth perspective and this week at a close-by location, we are now 19 days behind so the gap is stretching. I think it will continue to do so through the rest of this month looking at the projected forecast, maybe finishing -23 days behind 2017 at the end of March. So over 3 weeks behind at the end of March in other words.

I thought it would also be interesting to see how the daily and total Growth Potential per month shaped up for this location ;

So you can see currently we haven’t had as much growth in March as we had in January this year, in fact I think we will be lucky to exceed January’s growth.

The last time this happened was 2013, another year when we had a late event, Sudden Stratospheric Warming.

A final perspective on growth, we have had just 2 days when the G.P was 0.4 or above, denoting good spring growth and both of them were in January.

Definitive proof then that we are behind and that any growth we have had this year was earlier.

Consequences of a late spring..

I have already talked about the fact that recovery from aeration will take a lot longer this year because of the slow start, easily a month if you aerated at the beginning of March and possibly longer. So punters, management and the like will just have to be patient I’m afraid.

If I was looking for some light at the end of the tunnel, then I’d hope that with next week’s unsettled forecast comes some milder day and night temperatures and that’ll move things on a bundle. Even today when the sun is out and temperatures are on the up, we started with a hard frost just short of -1°C, so we won’t hit a good growth day today.

The same goes for the conversion of winter season pitch to outfield on school pitches, it will take a bit longer this year but I’m hoping next week’s forecast will help the job along.

Looking at Meteoblue, they are projecting from 11-13°C next week with 3-5°C night temperatures and that’ll be good enough for some consistent growth, ok it won’t be jumping out of the ground, but if the forecast is right, it’ll be enough growth to move surfaces along 🙂

Selective herbicide timing

When I was out walking yesterday I saw some really small yellow flowers at the edge of a copse and thought they were Celandines but on closer inspection they were actually Dandelions ! They were really small, but in full flower with a shortened stem, almost dwarf-like and it got me thinking. At this stage of the spring we are normally on the cusp of spraying a selective herbicide but of course weed growth will be behind this year, just like grass growth so if you intend to spray early, make sure your target weed is visible. If not you are likely to spray and then have to spray again later in the spring when other weed species are fully emerged.

A good week for granulars…

With an unsettled forecast this week and a most-likely windy and unsettled next week then this coming week should prove ideal for granular fertiliser applications, especially if next week’s milder low pressure comes to fruition.

Nowadays more than ever this job is about spotting windows and taking advantage of them regardless of what the calendar may say sometimes.

Using GDD and G.P Data

You don’t have to be a rocket scientist to know from my blog and talks, that I’m a big fan of promoting the use of GDD / G.P data in communication with customers and management alike. People have very short memories when it comes to the weather conditions and precious little acknowledgement about their effects on grass growth and related management issues but this is changing. One of the reasons (I like to think) is the use of this type of information when addressing committees and the like, it really does put things into perspective in my humble opinion. Similarly golf clubs can use this data to explain to golfers why conditions are as they are….Over the weekend I could see from my twitter feed that a number of you were using GDD / G.P / Weather stats to present to members at your clubs and I can only applaud your efforts. (Matt, Kevan, Rob et al 🙂 )

Ok that’s it for this week, short and sweet (like me)

Make the best of Easter, I don’t think it’ll be as bad as the tabloids are saying and for sure I intend to get out regardless. Fishing is one of those hobbies / past times/ obsessions that is unaffected by rain, now mountain biking is another matter 🙂

All the best.

Mark Hunt