August 7th, 2023

Hi All,

Well after the 4th weekend in a row that has been characterised by low pressure, I think we all deserve a bit of warmth and dry weather. This week we will pick up a warm, high pressure ridge and some high temperatures and although we still have low pressure systems in the outlook, it looks warmer and drier in-between these Atlantic incursions going forward thankfully.

Last week, I mentioned that I saw my 1st Hummingbird Hawk Moth of the year whilst sitting in a coffee shop in Oakham, Rutland.

A week later, I was sitting in the delightful clubhouse at Flempton Golf Club having a (short) discussion on the merits of Fescue with Kim, the course manager, when I noticed another one buzzing around the hanging baskets dotted around the building.

They are definitely attracted by hanging baskets so they're on my shopping list for next year. Still on the subject of nature, I was working around the back of my house that borders the local rec (groan) and there on the floor was a pile of sticks, a dead Pigeon chick and sitting on top of some willow sticks stacked there, a very alive and indignant Pigeon chick, who I have nicknamed 'Donald'.

Now I am not a fan of Pigeons, but I my better nature prevailed so I picked up an old Blackbirds nest from elsewhere, fashioned the pile of sticks into it and dumped him (or her) in.

Now if you don't know, Pigeons chicks are ugly, very aggressive and between pecks and impertinent clicks from its beak, I managed feed it with a long syringe and get it to drink some water. A couple of hours later, its mother visited and probably wondered quite how the nest appeared where it did but hopefully she is now feeding it. It is extremely ungrateful for my efforts and whenever I approach, it rears up, pecks and clicks with its bill. Ho Hum.

Onto the weather....

General Weather Situation

So starting the week we have a reasonably dry day aside from a rain front that will briefly skim the south west of Ireland and push showers into The South West later. Some more rain over the north and east of Scotland as well during the day. That strong to blustery north west wind will remain with us, so we will also see some showers pushing south and east off The Mersey estuary. Staying on the cool side for August, but nothing like the 10°C we had on Saturday though. So mid to high teens across the U.K & Ireland on Monday. Onto Tuesday and we have some showers across the southern half of Ireland and the U.K through the morning and continuing into the afternoon. Presently they don't look too heavy in nature, but there will be more cloud around on Tuesday, however with lighter winds, temperatures will be up a degree or two and nudging towards 20°C.

Now as we head towards Wednesday, a ridge of high pressure will nudge in and this will create two key benefits. Firstly, it will push any rainfall away to the north and secondly we will see a temperature hike into the mid-twenties by mid-week for all areas with Ireland picking up the first wave of this warmth. So a much brighter and warmer day on Wednesday with light winds and plenty of sunshine. Temperatures will be in the low to mid-twenties, coolest for Scotland. Haven't written that for awhile !

Thursday sees warmth build under that high pressure ridge with the wind swinging round to the south overnight. Temperatures will push up into the mid-high twenties with mid-twenties for Ireland and Scotland and the highest temperatures across Wales and England. Later in the afternoon, this rise in temperature may trigger some localised thunderstorms, especially across The South West and south coast. Later on Thursday evening, a band of rain will push into the south west of Ireland. This rain will move north and east overnight into The North West and Scotland.

Closing out the week on Friday that rain will be sitting over Scotland and will give some heavy localised rainfall totals. That rain over Scotland will push north and east and should clear through the afternoon. Further south we look to be dry and windy with the nearby low pressure pushing the wind round to the south west. Ireland, with that low close by, will see a cooler day with sunshine and showers.

For the weekend, we look unsettled and wet across the west and north west of Ireland as that low vectors rain fronts across Connacht, the north of Ireland into The North West of England and the south west of Scotland. Sunday sees heavier rain for most of Ireland from the off and some of this rain will tip into The South West during the morning. This rain will stall as it crossed The Irish Sea so although we will see some showers across the south west of England and West Wales, these shouldn't progress further inland. Some showers for the north of Scotland as well. Weekend temperatures back down to high teens for Ireland and Scotland, lower for the former because of that thick cloud base and rain. For Wales and England, high teens into the low twenties, with a strong south westerly wind on Saturday and lighter winds on Sunday.

Weather Outlook

As the GFS output from tropicaltidbits.com shows above for next Monday, we have low pressure projected to sit west of us and heat and warmth below. So the beginning of the week looks unsettled with a strong south westerly wind and rain showers crossing the U.K & Ireland. Tuesday looks drier for all however a sneaky Bay of Biscay low pressure is projected to develop and this will pull rain across the U.K and Ireland overnight into Wednesday and for the first part of the day, clearing from the south and west first. As we go into Thursday and Friday, we see a ridge of high pressure build and this will settle down the weather picture nicely with warmer and drier weather for all areas leading into the weekend. There is a low pressure out to the west of Ireland so we could still see some unsettled weather over Ireland.

So not totally dry but definitely some warmer and drier interludes between the low pressure systems.(From a glass half full perspective)

Agronomic Notes

So as is usual at the beginning of the month, we will take a look back at July, 2023, using GDD and rainfall data from locations around the U.K & Ireland beginning with The Oxfordshire, located just outside of Thame.

GDD Y.T.D 2023 - The Oxfordshire, Thame

So July 2023 came in at 319 GDD for the month, which is the lowest GDD for July since 2012. When you consider that June 2023 came in with 340 GDD, July was both cooler and as we will see, wetter. Looking back a year, July 2022 came in at 393 and featured a high pressure peak formation with record temperatures. In comparison, July 2023 featured a low pressure trough formation, two sides of the weather coin.

Growth Potential & Rainfall Monthly Totals - July 2023 - U.K Locations

High GP and rainfall means cutting wet areas was a challenge in July 2023

Although July was a cooler, wetter month, the Growth Potential data shows that growth was near optimum varying from 25.73 in Dumbarton to 29.08 in Brands Hatch, Kent. The average for the month was 28.15 out of a potential total of 31 (31 days x 1.0). So in other words we may have been very wet, but temperatures were high enough for very good growth. This high level of monthly G.P made keeping on top of growth on fairways, semi rough and rough a challenge or a pain depending on your level of resources.

When it comes to rainfall, we can see July 2023 was an extremely wet month for mid-summer, particularly for The South West, Bristol, The Midlands, North of England and Scotland. 225mm in a month for Dumbarton is 9 inches of rainfall, that's 2,286,000L per hectare !!!! The average July rainfall was I think between 75-100mm of rain, more typical of the winter than the summer. If you look at the yearly totals, you can see a clear pattern with The South West coming in consistently as the wettest area of England and Central Scotland, the wettest overall.

Growth Potential & Rainfall Monthly Totals - July 2023 - Irish Locations

Looking at the monthly Growth Potential figures for Ireland, we can see that that the south west of Ireland were as expected, slightly higher than the average for the month. (26.3). So a very similar problem to the U.K locations, high monthly G.P which would translate into high levels of growth dovetailed in with what we will see below, very high monthly rainfall. In fact I was quite staggered when I opened the spreadsheet to see the level of rainfall, aside from the magical rain shadow effect of Killiney Hill on Killiney Golf Club (You are going to have to move that hill Mick, you know that don't you 🙄)

To say that July 2023 was a wet month for Ireland would be one very large understatement, geez. Even across the east of the country which is typically, the driest, we saw > 100mm of rain and as for the west, a figure between 150-175mm was typical. That's 6-7 " in old money. Just to give you a sense of perspective, in July 2022, the average rainfall across the same locations was between 20-40mm. I would imagine there were plenty of clubs who were unable to cut their roughs, semi-rough and fairways just because you couldn't move a machine around the course easily. The same for the north, south west / north west of England, Wales and for Scotland.

The only saving grace for Ireland and the U.K, is that being July, we saw much higher monthly E.T than in the winter, so areas did dry down quicker.

July 2023 - A wet month but E.T exceeded rainfall in some locations....

Now although July 2023 was a wet month, it doesn't mean that everywhere was in a moisture surplus scenario. Certainly for any location receiving > 100mm of rain this was the case but across Wales and the southern half of the U.K, the average monthly loss of moisture by E.T during July 2023 was around 100mm.

So as you can see from the chart above, locations that received less than 100mm of rainfall were actually in a moisture deficit situation. That surprised me and shows why measuring E.T is such an important part of the turf management equation when it comes to irrigation but also grass plant stress.

I will conclude on that final point.

This week we will hit some high temperatures and with the wind associated with them, some high E.T values as well. We also have a grass plant that is used to getting plenty of moisture and so this will be shock to the system, both for the plant and for irrigation management (areas will dry down a lot quicker than you have been used to lately). That said, it'll be a very welcome change for those that have endured such a poor July.

Next week I am off in the campervan to sample the delights of St Davids in furthest, westerly Wales, so no blog next Monday. All being well I will be reporting back 21st August.

All the best.

Mark Hunt