December 20th, 2021

Hi All,

Well the last blog of 2021, a day before the Winter Solstice when the sun sits at its furthest point south on the horizon and as such provides us with the shortest day and longest night. Thereafter it begins to climb, slowly at first before we really start to see the days extend out at the end of January. It always seems strange to me that this marks the point we begin to head to spring daylight-wise when meteorologically December, January and February are classified as winter.

Looking ahead to Christmas it’s been all over the place from a forecasting perspective, ranging from high pressure and settled to the ‘Beast from the East’ and everything in-between. Well it’s likely they’ll be a ‘w’ before Christmas but it’s going to stand for ‘wet’ as opposed to ‘white’ for most but maybe not all with some degree of uncertainty still lingering me thinks…

Onto the general weather situation because tempus fugit as always on a Monday for me….

General Weather Situation

So we start the Christmas week with high pressure still calling the shots but it’s drifting north and slowly losing its grip on the weather. To my mind that’s good because although it’s largely dry, it’s been a dull, dull set of affairs and so miserable with it….

I’m going to group Monday and Tuesday together because they’re very similar days in terms of weather if not temperature. Monday starts the dull, dull and reasonably mild with the thick cloud layer over the U.K & Ireland responsible for a grey start to the day pretty much everywhere. That thick cloud layer has kept temperatures up overnight but it means pretty much a re-run of Sunday. Cool, dull and with light winds and clouds thick enough to form into drizzle in places. I did a dusk 10 mile run yesterday and it was like it was raining, such was the moisture level in the atmosphere, grim man, grim. Light south easterly winds for most and temperatures in the 6-8°C region. Through the afternoon, you may just get the odd sunny interval, treasure it, for it is rare…:)

Overnight into Tuesday and we see pretty much a re-run of Monday though skies may have cleared marginally overnight so that means a colder start with some ground frost likely in places. Light winds and maybe more in the way of sunshine in the morning but otherwise another dull (ish) day and colder than Monday with temperatures in the 4-6°C region. Breezier across the west as low pressure begins to push in towards Ireland.

Mid-week already and this is the change day really as low pressure begins to make its presence subtly felt. Cold, bright and frosty for most areas of the U.K with a lovely sunny, winters morning. For Ireland though and particularly the south west, you’ll be seeing strengthening winds and rain from dawn I’m afraid. This chunk of rain will push up country but maybe Leinster will avoid the rain until later on in the morning when it looks like covering most of the country. A hop, skip and a jump across The Irish Sea to the west of Scotland where the rain over Ireland is set to make landfall during the afternoon and push eastwards. Now this rain will encounter a cold air mass over Scotland and readily turn to snow over elevation. The bottom end of this rain front will also push into The South West, West Wales and The North West later on Wednesday night. Central and eastern areas will have a cold, dry and sunnier day on Wednesday.

As we start Thursday the deep low pressure system that is set to bring us a wet interlude over Christmas is poised out in The Atlantic. Overnight it has pushed more rain into the south west of Ireland and it’ll continue to feed in to the west of Scotland as well bringing a wintry shower mix to the west and central areas of Scotland. By dawn on Thursday, the rain front is already clearing Ireland and pushing into the west of the U.K and this front will move eastwards but perhaps fizzling out as it does so across the south of the U.K. With the rain comes stronger and milder south westerly winds for the U.K & Ireland, pushing temperatures up towards 8-10°C, so milder than earlier in the week. As the rain fizzles out in the south, it’ll stay concentrated across North Wales, The North West and Scotland, again falling as a wintry shower mix over elevation. Finishing off the day and this band of rain will cross to the eastern side of the country so The North East and eastern Scotland will pick up what they missed earlier.

Closing out Christmas week and it’s Christmas Eve.

I’ll be busy rustling up some Masala Chai and also vegan Coconut Panna Cotta’s together with Orange and Almond Tuiles don’t you know. (Getting arty farty in my old age). They are my contribution to our traditional Danish Christmas Eve celebration together with copious amounts of Tuborg I hope as well 🙂

It’s all about the wobble with a Panna Cotta…..I have a funny story about that which I may trot out for my last blog 🙂

So Christmas Eve sees that Atlantic low pressure approaching and in the wee small hours it’ll push rain into the south west of Ireland. By dawn this rain is projected to be across Ireland stretching from Cork to Galway. It’ll also be tip-toeing into The South West of England during the first part of the morning. This rain front is set to move really slowly across Ireland so that means some high rainfall totals in places. By the afternoon it’ll be across The South West, Wales, The North West and moving slowly inland clearing the south west of Ireland as it does so. Before this rain event we will also see some showers across the north and north east of England through Friday morning. So a wet day for Ireland, a wetter 2nd part of the day for the west but a dry one for Christmas Eve for central and eastern areas until that heavy rain arrives into Friday night. Some of that rain may turn to snow across The Pennines giving a White Christmas for some up there.

Christmas Day looks a wet affair for some parts of Ireland and the southern half of the U.K, with again some wintry showers across the north. Scotland looks to miss this rain event and so for you it’ll be dry, cold and sunny with a night frost. So a wet one for most but dry, bright and sunny further north and a few wintry showers in-between. Boxing Day looks similar but perhaps not so wet with rain across the southern half of Ireland and the U.K, maybe some gaps in-between to get out for a brisk walk in between the showers which may turn wintry in places. Scotland looks to be dry, cold and sunny with night frosts and lovely and wintry.

Windier than of late over Christmas as that departing low pulls in colder, fresher air from the continent on a south easterly / easterly wind. That colder air may just turn some of the Atlantic low’s moisture to snow at lower levels for the last part of Christmas Day and the first part of the 26th. That’s the delicate balance that will play out this week. whatever, cooler as we get past Christmas with a chilly wind chill in place.

Weather Outlook

The GFS output for next Monday, 27th December, shows the low pressure pulling in that colder continental air for the start of next week. This colder theme is likely to continue through Tuesday as the wind turns more northerly but by Wednesday that wind is swinging round to the north west and pulling in milder air for Ireland and the west. The eastern side of the country looks to remain on the cold side as high pressure is now projected to push up. Unsettled then I think for the first part of next week with some wintry showers around, especially along eastern coasts and a keen wind chill. As we progress through next week, things dry up and settle down so it looks like a cold, dry and settled run up to the start of 2022. Ideal to get in some runs, cycles and long winter walks to work off the calorific Armageddon that Christmas represents for many.

Agronomic Notes

Disease pressure – w/c 20-12-21

Well last week we saw some moderate to just touching high disease pressure which I predicted to result in mainly re-activity around existing scars as opposed to new infection and that’s pretty much the feedback I got. Looking ahead for this week we have the same sort of pressure whilst our current high pressure is lingering and then as the wet and windy weather kicks in closer to Christmas that will drop things back accordingly. The colder airstream from after Christmas onwards will also keep pressure on the low side so I’d hope most of you can have a relaxing Christmas without fretting about this area of turf management. Golfers, course opening, frost delays, wet greens and the like, now that’s another matter 🙂

All in all I don’t think we can complain the hand we have been dealt with this autumn in terms of Microdochium. For many the highest pressure was in August and October with plenty of chance to get re-growth before temperatures began to slide at the beginning of November. I am convinced the lower than usual pressure was due in part to the heavy rainfall we experienced in October which would have significantly reduced spore viability leading up to now. Either way, I am not complaining…

It’s been a dull autumn / winter so far

So this data comes via a really cute looking sensor called an Apogee SQ212.

It measures PAR light, that is the spectrum of light that the plant can absorb and utilise for photosynthetis. I’ve mentioned it before. If you add up all the PAR light over a 24 hour period, you get a figure called the Daily Light Interval or DLI for short. There are some data points for what different grass species require and for the benefit of this graph I’ve put the threshold level for Ryegrass on because that way it encompasses both golf and winter season facilities.

This data is from the Milton Keynes area…

You can see how the autumn was split into two halves and very much the turning point for light coincided with the turning point for temperature, i.e. the end of October when the clocks went back. Prior to this you can see some nice bright days with DLI levels good for most cool season grasses including creeping bentgrass.

As the days shorten and we pick up duller weather to boot, you can see how low daily DLI levels have become…

Now we would expect DLI levels to drop going into the winter because of shorter daylength and without historical data it is difficult to compare this autumn with last autumn for example from a PAR perspective. What you can say regardless of this is that levels of PAR-available light are low for all of our grass species and this is likely to limit the potential of the plant to photosynthesise, make energy and develop new root and shoot tissue. The only plant species that is likely to benefit is Poa annua, which has the ability to continue to grow at low DLI levels, hence its innate ability to out-compete every other grass species in a shade environment. Now as I said, we have no data to compare against, but I’m guessing if and when we do, late autumn 2021 will come in as poor from a sunlight and PAR perspective.

So if your turf is looking a bit sad and unresponsive, it’s probably due to the lack of light we have been getting recently….

OK, that’s a wrap for 2021, it’s been an interesting meteorological ride as usual, a cool spring, a perishingly dull, dry and cold April, a cool and wet May, a so-so summer where thankfully we missed the heat plume that collected southern Europe and a lovely autumn until the clocks went back and then it’s been a tad, dull and dreary….I won’t complain as the afore-mentioned weather made for a cracking dry fly fishing season for me….

It would be nice to finish it off with a bit of snow, see Paddy Power catch a cropper and bring a smile to my face on Christmas Day (bit of a bah bah humbug type chap me)

I wish you all and your families and friends, a relaxing and above all safe Christmas…Good luck in whatever you decide to do whilst Boris fumbles and the world is restless in its sleep 🙂

Mark Hunt