December 2nd, 2024

Hi All,

My 1st blog for awhile as I have been a busy chap (for me) with Saltex, The Scottish Greenkeeper Conference and finally, the Danish Greenkeeper Conference, in Svendborg, Denmark. The latter was particular special for me to return to my Motherland for the first time in 6 years and experience Denmark and Danish hospitality.

A big thank you to all attendees for listening and for the organisers for putting on a great conference. It was an brilliant experience.

I knew I had arrived in Denmark when I walked into the Gents and found this !!!!

I am sure if this was present in England, somebody would write in to complain how it portrayed the male physique, blah, blah, blardy blah, but thankfully the Danes have a great sense of humour and we evidently lost ours as a nation sometime at the end of the 20th century, replacing it with political correctness gone mad, ho hum.

The next morning there had been a light snowfall so I walked down town and found a lovely cafe with excellent coffee, a lit candle on every table and an array of proper Danish pastries (as opposed to the shoddy imitations you see in England), a definite 'hygge' experience. I didn't want to leave. So if you're ever travelling across Denmark, Svenborg is a lovely harbour town to drop in and visit with a cracking cafe, BRØD.

Looking back at November as a month, we have gone from some of the mildest (and most humid) conditions I can remember in November, to frost, snowfall and back again, finishing the month on a very mild note. At the end of the month we went from -4°C to +10°C in the blink of an eye, pushing onto 15°C for the last day of November. Uncanny. (see graph below)

So after a brief flirtation with winter, any sign of more on the horizon for the 1st part of December ? ......well maybe....

General Weather Situation - 02-12-24

As the animated GIF from tropicaltidbits.com shows, we are now on a bit of a rodeo ride courtesy of an active jet stream (dark green line between areas of cold and warm air). This means we will dip in and out of low and high pressure systems with neither dominating for the foreseeable. What you do notice more at this time of year though is the effect of wind direction on temperature.

As a low pressure system passes across the U.K and exits onto The North Sea and our Danish colleagues, the trailing edge of that low pressure pulls down cool, northerly winds. And that's why we go from mild, south westerly winds as the low approaches Ireland and the rest of the U.K changing to cold, northerly winds as it moves eastwards. We will see that pattern this week with mild and strong south westerly winds through Thursday and Friday, quickly changing to north westerly / northerly winds over the week, with a big temperature drop to boot.

So this week's forecast is for a cool start to the week, some rain around on Tuesday pushing across Ireland and into the north west of England and Scotland in particular. With cold air sitting across the north, some of this rain may change to snow over higher ground as it encounters that colder air later on Tuesday. Further south we should be mainly dry on Tuesday with some rain maybe overnight into Wednesday.

Mid-week looks mainly dry for the U.K, but Ireland will see the arrival of a deep low pressure with plenty of rain associated with it and strong winds. This is projected to arrive to the west of Ireland on Wednesday afternoon before pushing onto Scotland shortly afterwards on Tuesday early evening. Some of the rain will be heavy. Overnight into Thursday this rain will push into Wales and then across all of the U.K, lessening with intensity as it does so. Thursday will see more heavy rain for Scotland, The Borders and northern England before it pushes down into The North West, North Wales and then Central England later in the day. It will also be very windy on Thursday, dropping back a little for the end of the week. On Friday we have a mainly dry day save for some showers across western coasts before a new low pressure arrives on the Atlantic conveyor belt and deposits rain across the southern half of Ireland before moving briskly into The South West and southern coast of England. It is this low that will pull down northerly winds as it passes through on its way to the continent where it will become increasingly wintry in nature. The outlook for the weekend is mainly dry but noticeably colder with a brisk north westerly wind that will ramp up in intensity on Sunday providing a distinct wind chill.

Weather Outlook - w/c 09-12-24

So a very mixed week this week, what about the GFS projections for the week after ?

Well we start the week with a dramatic peak and trough, convoluted jet stream shape resulting in high pressure over Ireland and the west of the U.K vs. low pressure over the eastern half of the U.K and Scandinavia. I'd expect snow showers for Denmark incidentally. With high pressure and low pressure arranged as described, the wind is funnelled down between the two in a pronounced northerly direction, so it'll be a pretty cold start to the week, wind and with a pronounced wind chill. A northerly wind direction may end up being a theme for next week as high pressure and low pressure jostle against each other. They will scoop down showers, some of them wintry in nature from Monday onwards, with more rain and sleet over elevation pushing down on Tuesday and Wednesday across the U.K & Ireland. This continues through Thursday before the potential arrival of a super-intense low pressure at the end of next week. This could pull down very cold air, wintry showers and some very strong winds. Currently it is projected to vector towards Scandinavia for the middle of December, but this could change. So cold with frequent showers and a strong biting northerly wind sets the theme for next week, perhaps more frequent over eastern coasts but I'm not sure on the detail of this.

Agronomic Notes

It struck me at the Danish Greenkeeper Conference how many of the themes they were discussing were common to the rest of Scandinavia, Germany, Austria, Holland, France, Switzerland, Ireland and of course, the U.K.

Their biggest disease issue is Dollar Spot.

It's activity and severity is on the increase bigtime, as it is across all of Scandinavia. We have also seen the same increase as it has marched northwards (and westwards to Ireland) over recent years affecting fine turf areas as well as tees, approaches and surrounds. No respecter of grass species either as it is quite happy to munch on Fescue as it is Poa, Agrostis and Lolium. If you haven't experienced it as a disease, you are lucky, but you probably will soon enough especially as our dew events are on the rise given the increase in atmospheric humidity we have experienced of late.

Delving into the some Danish weather stats courtesy of the Davis weather station network and some agreeable data donors (thanks Jeppe !), you can see how some of the climate processes that I see over here are the same for Denmark.

Namely, warming sea temperatures, super-charging rainfall events and warmer, more humid air carrying on later into the apparent autumn / winter. Wetter, warmer summers as well which depart from the climate predictions for heatwaves and droughts.

Longer periods of plant leaf wetness due to an increase in dew events during the summer and early autumn were also common to there and here.

In Denmark, they do have one fungicide (Signum - Boscalid) which is approved for use on this disease but in some areas they are not allowed to use this or any other pesticide dependent on local regulations. That makes life interesting when you are faced with not a new disease but one that is new geographically in terms of its occurrence and severity. Without a doubt the fungus responsible is also more active at lower temperatures than were previously attributable to Clarireedia homeocarpa (Dollar Spot) as it now known. The bastion of all things turfgrass pathology, Kate Entwistle, remarked to me at Saltex 2024, that for a disease that's been around for well over 50 years, we know a remarkably small amount about its life cycle, pathology and its survival mechanism, year-on-year. The conference brought together some very useful experiences from Holland on this pathogen, again set against a background of a non-pesticidal framework.

Collaboration within our industry is going to be essential if we are to learn some quick lessons on this pathogen and apply them effectively.

Dew formation

With higher levels of humidity in the atmosphere this year, we have seen more dew events. More dew events means longer periods of leaf wetness and this combined with high overnight temperatures is the driver for many of our foliar pathogens be that Microdochium, Dollar Spot, Leaf Spot, Red Thread and / or Anthracnose.

The management and removal of dew can be carried out by either manual means or by applying a surfactant. The advantage of the latter is that it is working at night to reduce plant leaf wetness whereas your dew brush / swish is not. Recently I heard from a superintendent from Ireland who was using a back pack blower to remove dew from his greens and he thought it was more effective than using a brush / swish, interesting.

If we look further ahead, how long before we see automated mowers equipped with a dedicated dewbrush attachment doing the work during the night to keep the greens dew free ?

It isn't a new concept / idea of course as I know it's already been done within the football pitch world in specific situations. It is an investment for sure because of the cost of battery technology but this is one area where great advances are being made in terms of materials, efficiency and cost.

My point is we have to up our game and optimise our technology and work practices to meet the new challenges that climate change is throwing at us in the forms of weather extremes and new disease occurrence. I don't see this as a negative, more of a challenge to be met.

Ok, time to hop off the soapbox.

All the best.

Mark Hunt