June 10th

Hi All,

Just back from my week off in The Cevenne and what a lovely area of France it is. Steep canyons, beautiful rivers and a massive limestone plateau absolutely full of nature in terms of birds, butterflies and flowers. I managed to get a photo of this indigenous Blue Green Lizard as well, they aren’t rare but they are hard to photograph as all you normally see is their tail disappearing into the undergrowth at a rate of knots !

I’d like to say it was a relaxing break, but I don’t really do relaxing so I walked and even ran (scrambled) up this canyon and another mountain just for the sheer joy of it…(ahem)

The lack of people and traffic contrasted markedly with over here, an observation rammed home to me as I negotiated the traffic and roadwork-strewn M11 / A14 back home.

The night before I’d watched a Hobby hunting bats down the main street of Meyrueis treating me to an aerobatical display I won’t forget for a while. Incidentally, their winter and spring weather mirrored ours, not too cold in the winter, a late spring, but definitely very dry.

‘Very dry’ was the theme for most of us during May as we know but June is already making up for that with 70% of May’s rain total already falling in the first week and if the forecasters are right, this week will see some massive rainfall totals for some areas of the U.K.

Image courtesy of meteocentre.com

The wet start to June is down to a trough pattern forming in the jet stream allowing cool wet air to push down and pick up humidity from the warm air over central and southern Europe. This type of pattern is notorious for being slow-moving and so any weather systems can sit in the trough and rotate slowly dumping large amounts of rainfall. Looking at Weathercheck for Market Harborough, we are forecast 62mm this week, probably one of the highest rainfall totals I’ve seen in a single week for this location and it’ll be interesting to see if we do indeed get anywhere close to that…

General Weather Situation

So kicking off Monday morning, well if you are in the south-east or east of the country, the word is wet. As you can see from the graphic above, a large amount of rain is moving slowly north-west and pushing in from the continent. We can also see some pretty sharp showers across Munster and Connacht. Through the morning this rain over the south-east / east of the U.K is projected to move north-west and cover all of the south of England, The Midlands before pushing into the north of England, North Wales during the afternoon. Now we will see but currently it looks to me like it is tracking more northwards than north-westerly. Away from this rain we are looking at not a bad day at all for Scotland and Ireland with some mid – high teen temperatures and plenty of sunshine for the first half of the day anyway. During the afternoon, Ireland will see some of this rain push into Leinster and move westwards so the driest weather will be in the west of Ireland and you don’t say that very often…We have very little wind across the U.K and Ireland a.m. today so that’s why the weather system you can see above is so slow-moving and so by dusk we can expect the entire south of England, most of Wales and The South West to be under a blanket of slow-moving, heavy rain with significant rainfall totals. Temperature-wise, low teens if you’re under that rain and mid-high teens for the likes of Ireland and Scotland. Later into Monday evening the wind will ramp up in strength and drop the temperatures significantly.

Onto Tuesday and that low pressure sitting across mid-France will pull in more rain across the southern half of the U.K. At this stage it looks likely to affect the southern half of the U.K from The Humber estuary down with some significant rainfall totals again expected. Much windier for everyone on Tuesday with closely packed isobars and as you can see from the graphic above, the wind will be north-easterly and a cool one. So a pretty cool June day with temperatures struggling to get into double figures / low teens across the south of England and Wales. Further north into Scotland and west into Ireland we have a duller day than Monday with plenty of cloud cover about. Windier as well but not as windy as further south so here temperatures will be up into the mid-teens, maybe a tad higher if the sun pops out. That rain over the south of England is expected to stay through to dusk though it may clear the south coast through the evening. With the wind turning more northerly as we go through the day, expect a cool night with temperatures dipping down into single figures.

Onto Wednesday and really a re-run of Tuesday with that low pressure system again swinging in a mass of rain, some of it very heavy across the south of England. Some of that rain is projected to push westwards across The Irish Sea into Leinster during the morning and it may also move more north on Wednesday bringing more rain, some of it heavy, into the north of England. At this stage (and let’s face it, things may change when we talk about rainfall), that rain won’t ingress further west away from east Leinster but it will push north through the 2nd half of the day into northern England and eventually north-east Scotland late on Wednesday evening. A little milder across the west with Ireland and Wales nudging into mid-teen figures and Scotland again coming out top with a warm, largely dry and pleasantly sunny day until that rain arrives into the north-east later in the evening. So probably down at 11-13°C across the southern half of the U.K and pushing up to 18°C for Scotland. Notably the wind will swing from north-east to south-west later on Wednesday evening.

Thursday sees low pressure firmly centred across the U.K so that means a very unsettled day with plenty of rain around. The two main areas of rain are projected to be across the southern half of the U.K (again) and across Scotland as well during the morning but as we progress into the afternoon, that rainfall spreads across all areas of the U.K and again in places it’ll be heavy. With some areas receiving 4 days of successive heavy rain, expect flooding in places. Ireland again looks to miss all but some showers across East Leinster through the course of Thursday and so enjoys a dry if dull day. Temperature-wise, again a little milder across Wales and Ireland with temperatures in the low to mid-teens for most areas courtesy of that milder southerly / south-westerly wind. As we progress through Thursday evening that rain moves away and we have a dry picture for pretty much the first time this week.

Closing out the week on Friday and a more familiar rainfall pattern with low pressure still pulling the punches when it comes to wind and rain. A much drier day though it has to be said with showers limited to north-western and western coasts through the day and just the odd one making an appearance inland. Some of those showers will merge into longer spells of rain across Central Scotland and South Wales and they’ll also be some showers bubbling up along the south-west and west coast of Ireland. A dull day with low pressure increasing cloud cover for most of the U.K and Ireland but at least the first pretty dry one for the southern half of England.Through the course of Friday evening that low pressure is at it again as it pushes more rain into the south and west of England pushing north into The Midlands later in the night. Probably the mildest day of the week for the south of England with temperatures hitting a heady 16-18°C, but cooler across Ireland and Scotland.

The weekend looks well….unsettled for Saturday with plenty of rain around across Ireland and the south-west of the U.K with showers across The Midlands but as we go into Sunday, high pressure from the continent nudges that low pressure northwards so we see a much better picture as temperatures pick up and we have a drier day. Not to say there won’t be any rain around though as the south-west of Ireland and Scotland and the north-west of England will see plenty of showers around. Some of these will push into The Midlands and along the east coast later in the morning / afternoon. Scotland will see that rain across the west move into central regions through the course of the day and Ireland will also see rain push north and east from the south-west to most areas. Pleasant temperatures in the mid to high teens with 17°C typical despite the unsettled outlook.

Weather Outlook

So how are we looking next week ?

Well there’s a bit of uncertainty looking at next week’s weather with GFS outputs pointing towards another unsettled week but differing on the position of the low pressure system responsible. This is key because if the low pressure sinks towards the south of the U.K we get a week like this one, if it sits west of the U.K, then primarily it is more unsettled in the west and north.

My feeling is we will start the week relatively dry across central and southern parts of the U.K with rain spreading first into western Ireland on Monday and moving north and west into the north-west of England / Scotland later in the day. A sunshine and showers-type scenario for Tuesday with a strong south-westerly air stream before a new low pressure slips south to bring more in the way of rain for the southern half of the U.K / Ireland / Wales with this trend continuing into the end of the week.

So continuing unsettled but with a south-westerly air stream I think next week will be milder with temperatures up in the high teens, in other words, a good growing week.

Agronomic Notes

As I was elsewhere last week, this week’s blog takes a look back at May 2019 using data from the usual contributors to whom I am extremely grateful.

May 2019 – GDD Summary – Location – The Oxfordshire, Thame

May 2019 won’t actually sign off as a particularly warm one with a total GDD figure at this location of 174 for the month. That is some 26% down on the previous year and I wonder if it marks a trend for summer 2019 vs. 2018 ?

May 2019 was definitely cooler and particularly night temperatures stayed low so that held back growth through the month. We also know of course that the other growth-limiting factor was moisture, more on that later…

If we look at the year-to-date cumulative GDD total we can see that 2019 has actually slipped behind 2018 now and that’s a surprise when you consider how cold a start we had to the year last year. In 2018 from the middle of April we picked up warm temperatures and these changed to hot temperatures from the end of May, not so in 2019….

GDD & Rainfall Totals – UK & Irish Locations

Looking at the data above we can see that the main story of May 2019 for both the U.K and Ireland is the lack of rain with 20-30mm for the month pretty common for the locations that submitted data. As usual the GDD data for the U.K tracked around 25-30% higher than the Irish locations and we saw some significant variability in both data sets.

Looking at the south-west location of Okehampton, Devon, it came in at 119 total GDD for the month which is lower than all of the other locations and highlights a trend for some really chilly nights during May for the south west of England and Wales. This undoubtedly held back growth and if temperatures were good enough for growth, then it was too dry.

May 2019 – Too cold or too dry for good consistent growth……

So looking just at GDD you’d say May 2019 wasn’t a great growing month and you’d be right, throw in rainfall or more precisely, a lack of it and the job got harder. I haven’t got E.T readings for the location above but I know at Thame we had a total monthly E.T loss of 96.3mm vs. a total monthly rainfall of 21mm. That is a deficit of 75.3mm and an average daily E.T loss of 3.1mm of moisture.

As the graph above shows, on the few days when we had moisture, it was cool so growth was slow and when we had high temperatures we also had high E.T and very little rainfall.

So areas that were already struggling coming out of the dry spring such as outfield, fairways, (ridge and furrow particularly) had a hard time in May because without a very efficient irrigation system and ample supply of irrigation it was hard enough on its own to keep up with this type of daily E.T loss. Consider then newly germinated or seedling stage grass with an inefficient root system and just keeping the plant alive was tricky.

If in doubt use a bowser…(err not)

I had one contributor who was asked why weren’t they using a 400 gallon bowser to help the grass through this process ?

Apart (and it is a big ‘apart’ ) from the cost of labour, the inconvenience, the health and safety angle and the purchasing the water, let us just consider the practicalities of this suggestion using the E.T and rainfall data above for the 2nd half of May.

So the above example shows a net E.T moisture loss of 70.7mm vs. a contribution from rainfall of 3.6mm, pretty typical for a lot of locations in the U.K and Ireland in May (though the E.T loss is lower across the water for sure).

So that puts us at a moisture deficit of 67.1mm. Now of course we don’t need to irrigate at 100% E.T to keep a grass plant alive, typically 50% is a number I use and come across readily, so that means in this example we need to replace 31.75mm (50% of monthly E.T – rainfall).

So what does 31.75mm represent in litres per hectare, well my calculation is about 317,500 litres ?

A 400 gallon bowser holds 1812 litres, so to put out enough water per ha over that period you’d need 175 bowsers of water. If we assume 10 ha of fairway, that would be 1,750 bowsers in total or 92 bowsers per day !!!

I don’t suppose they’d be much chance of playing golf in-between of course and I’m not so sure there would be a budget tucked away for that amount of mains water either 🙂

Ignorance is bliss as they say….

I’m sure there is likely to be an equally ‘bright’ suggestion regarding drainage waiting in the wings…

Ok that’s me for this week, I hope you stay dry and that a ‘months worth of rain in a day’ for 4 days in a row isn’t too problematic…Maybe you could use an empty bowser….I better stop now…

All the best for the coming week,

Mark Hunt

 

 

 

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