December 7th

 

Hi All,

Less than two weeks to the longest day and we currently sit in a cold trough pattern in the jet stream (shown above) that reminds us we are actually in winter with some freezing fog, overnight frosts and occasionally a bit of sunshine as well. We got down to -2.6°C here overnight and after a little warming during the night as the fog rolled in, the temperature is now on it’s way down again as heat is being lost from the ground and not yet countered by sufficient solar radiation from the sun. (hence why dawn is normally the coldest part of the day)

I see the Met Office is saying that by the middle part of this century these type of days will be a thing of the past as frosts become less severe and the chance of lying snow on the ground likewise. Last week saw the first significant snowfalls over parts of the U.K and particularly down the eastern side of the country as wet air encountered cold air over the continent and fell as snow rather than rain.

As predicted that slow-moving low pressure brought very high rainfall totals for some areas and particularly the east, west and north of the U.K with 35 – 50mm of rain, sleet, snow common over a 24-hour period.

Looking a long way ahead I’ve been watching the weather patterns for later into this month and what’s been very noticeable is the lack of any cold air over Russia / Siberia that could influence our weather to give us a cold Christmas. Today for the first time though I can see some. Now at this stage it means nothing as we are 18 days out from Christmas but it’ll be one to keep an eye on as we get nearer to that date. What we could do without is another mild, muggy, high humidity and no wind sort of Christmas period. We have endured 3 on the trot over the U.K so it’s time that cycle was broken and we can have a more peaceful rest over the Christmas period with much nail-biting from a Microdochium perspective.

So will the cold spell continue or are we in for milder and wetter weather ?

General Weather Situation

So currently we have low pressure sitting to the south west of us and this will throw up some rain across the south west of Ireland and England early doors. This rain will remain a threat all day running along the south coast of England from west to east and it may also threaten West Wales and the east coast of Ireland. Away from this rain risk, the rest of the U.K and Ireland is waking up to a hard frost and foggy conditions with some cold overnight temperatures. The fog may be stubborn to clear in places with a dull day on the cards for many of us but happily a mainly dry prospect on Monday after the very wet end to the week, last week. Later in the day we may see some brightness across the eastern side of the country, but a mainly dull, cold day for many areas of the U.K & Ireland. Temperature-wise, 2-4°C would be typical with very light winds.

Onto Tuesday and overnight low pressure across The North Sea moves east to west (and so contrary to the normal west – east airflow courtesy of the trough pattern) bringing rain and wintry showers to Scotland and The Borders. Through the morning we will also see some showers across North Wales and The South East move slowly across those areas before fizzling out. That rain over Scotland and the far north of England will push south into northern England and Northern Ireland, clearing Scotland through the morning and aided by a strengthening north westerly wind, but it’ll take until dusk to push into The North West and North Wales. So along the eastern coast of England, South Wales and really south of The Humber I’d say, we look to have another dry day after a frosty start. With a strengthening wind this should move any early morning fog / mist away quite sharply, unlike Monday. Ireland looks to have a mainly dry day as well save for some rain across the north west and western coasts during the first part of the day. Temperature-wise, we look to be 4-6°C on the whole with a much fresher north westerly wind in situ across the north and Ireland.

Mid-week beckons and overnight that northern rain has moved south, so some areas will start the day wet, notably across The Mersey estuary / North Wales, Cheshire (Hi Mikey!) and across eastern counties of England. Through the morning we will see more in the way of showers across the north western / south western coast of Scotland and East Anglia , whilst a much more consolidated rain front looks to push in from The Atlantic making landfall across the west of Ireland just in time for the Fanore rush hour 🙂 This rain across the west of Ireland will quickly push eastwards across all of Ireland making landfall across The Irish Sea into Wales and The South West of England by dusk. So away from the western and northern rain we look to be largely dry again across central and eastern areas once any rain has moved off into The North Sea. Later in the day we may even see some weak winter sunshine. The wind will be from the west, swinging round from the south later but it won’t really change the temperature much with 4-6°C again the norm.

Thursday sees that rain move over Wales and England overnight but by the morning it’ll be butting up against that cold air across the east and so we may see some wintry showers across Lincolnshire and the north east of England extending north. They’ll also be some wintry showers across the west of Scotland and some further rainfall across The South West and south east of England. Ireland looks to start dry and in fact as we move through the day on Thursday most of that wintry shower / rain mix tends to fade away to give a dry second half of the day. Across the north east and east of Scotland we should see some sunny intervals as that cloud breaks for a time. The same over East Anglia. As we approach dusk we see more rain push in from The Atlantic into the west / south west of Ireland and this will quickly move eastwards overnight. Winds will be light to moderate on Thursday and swing round to the south east temporarily.

So by dawn on Friday that rain is across the western half of the U.K and also across the west coast of Ireland. Some of this rain will again be heavy. The rain will move quickly west to east, so if you start dry on Friday, you probably won’t stay dry for long. Friday will feature bands of rain crossing Ireland and moving east through the day with the heaviest, most concentrated band across central and eastern U.K areas by lunchtime on Friday. During the afternoon, these bands of rain will break down into showers across Ireland and the U.K, so a really wet day for some areas on Friday if you’re sat under one. Winds will be swinging round to the south / south east during Friday but temperatures will be stubborn to improve across the U.K with 5-7°C likely. Across The Irish Sea, you’ll pick up a milder airstream so temperatures could just push into double figures 🙂

The outlook for the weekend looks mixed. Saturday will likely be the driest day of the weekend with showers across Scotland and the north west of England from the off. Some of these showers will push south into The Midlands through the course of the day. Ireland will see some showers across the north west through the morning but these will clear to leave a dull and reasonable day with a strong westerly wind in situ. Across The Irish Sea we look to mainly dull and dry on Saturday across most of England and Wales with a greater risk of showers the further north and north west you go. As we approach dusk, Ireland will see rain push into the west and this rain will rapidly move across the country. So Sunday looks wet for Ireland and the western half of the U.K as this rain slowly moves west to east. It may not reach the eastern half of the U.K till late in the afternoon on Sunday aided by a strengthening south westerly wind, so much windier on Sunday. Across Scotland this band of rain will fall as sleet and snow over elevation and possibly at lower altitudes as well. A milder day on Sunday with that change in the wind direction and strength with temperatures up around 8-10°C, with the higher temperatures across the west.

So a bit of a mixed bag of a weekend I’d say with the eastern / south eastern side of the U.K staying driest, longest.

Weather Outlook

Well, a very different GFS output for next Monday vs. today’s with a strong south westerly airflow in situ and that means milder and obviously some rain around as well.

Next week’s GFS outlook is really strange because when you see the above, you naturally expect a wet, mild and windy week, but whilst this may be the case on Monday and into Tuesday with strong winds and rain, high pressure looks to push up from the south and move this moisture more northwards through Tuesday into Wednesday. Just when you think it’s going to settle into a southern high (which incidentally from a disease perspective we definitely don’t want), we see a succession of Bay of Biscay low pressure systems feed moisture into a southerly airflow so whilst Wednesday might be on the drier side, rain builds from the south and affects the southern half of the U.K and Ireland for the second half of the week with some pretty heavy rainfall totals I’d say by the time we reach the weekend.

It is a really strange weather dynamic and not one I can remember seeing before so I’ll caveat this forecast with caution as should you 🙂

Agronomic Notes

As this is my first blog of December I’ll take a look back at November as per normal.

GDD – November 2020 – The Oxfordshire

So straight away you see the issue with November from a disease perspective as denoted by a GDD total of 84.5.  It was mild. Not the mildest by any stretch of the imagination, years like 2015 still hold the record for that but November 2015 was wet and mild and that doesn’t mean high disease pressure. November 2020 was a different animal entirely, wet and mild in some parts of the month, muggy and mild in others.

So unless something remarkable happens in December we are on our way to another > 2000 GDD year which will mean 3 out of the last 4 years have recorded a total GDD figure exceeding 2,000. If you look at the fact that when I started this blog back in 2010, we recorded a total of 1671 for the year, it means we are >20% warmer from a GDD perspective. This tallies well with The Met Office’s findings that the 3 out of the last 4 winters have been the mildest (and wettest) on record since the late 1800’s.

Call it what you will but we are warming up, no doubt about it.

Now I know some will point to the possibility that this is just part of a longer cycle and we will return to a period of colder winters at some point in the future but there’s scant evidence to support this.

GDD & Rainfall Summary – U.K Locations

Some very interesting stats in the above summary for November from some different locations across the U.K.

Firstly, The South West again picked up the worst of the rainfall with amounts decreasing as we head north and east.

North Wales and Fife came in as the highest GDD for the month and that is because we had a cooler high pressure system affecting the southern half of the U.K and a milder airflow affecting the north. This milder air across the U.K caused some issues in terms of carrying over higher soil temperatures than normal from October and together with wet soils caused worm activity to be much higher than last year, more on that later.

Glancing back at November 2019 and picking out a few GDD totals back then we see Okehampton ’19 = 38.1, Thame ’19 = 37.5 and Fife ’19 = 34.4.

Compare those ’19 totals with this year and you can see how much milder we were this year than last !

GDD & Rainfall Summary – Irish Locations

Ireland shows a very different picture from the U.K, particularly when it comes to rainfall. As mentioned above, the south west of England picked up some really high rainfall totals and these are reflected in the Irish situation. Again we see the west and southern part of Ireland was directly in line for the bulk of the rainfall but as we go up the east coast to Dublin, the rainfall totals drop markedly with 50% of the rainfall of Wexford and only 36.6% of Cork’s rainfall. Now I know there’s a lot of rivalry between those two cities, so I’ll just leave it there for the time-being 🙂

GDD-wise, temperatures and therefore GDD were much more similar across the country with 60-70GDD typical for the month, not that dissimilar to U.K locations.

Looking back though at November 2019, we see how much milder Ireland was in November 2020 with total GDD figures for Cork ’19 = 35.8, Dublin ’19 = 28 and Claremorris ’19 = 32.2.

So Ireland packed on 2-3 times as much GDD in November 2020 as it did in the same month in 2019, and that temperature increase caused an increase in disease and worm activity.

Soil temperature, rainfall and worm casting…..

I mentioned earlier the unseasonably warm GDD stats for November which primarily concern air temperature in terms of the GDD calculation, but for this section I am going to look at the autumn trend for an increased soil temperature.

Lots of golf clubs have posted on Twitter and Facebook that this autumn / winter they are seeing extremely bad issues with casting worms, much worse than in previous years and definitely the worst since we lost Carbendazim. So first off if you are seeing more worm casts than you can remember, you are not alone, many clubs are in the same boat. I know this has been particularly difficult for courses in England which have just returned back from lockdown to fairways with a high degree of worm casting. I am not saying it’s only affecting England, it’s a problem U.K & Ireland-wide, but the timing of the return to golf in England has created problems.

So why are we seeing it ?

Well this autumn / winter, not only have we had a wet autumn period which unusually started in September, (normally a dry month with stable high pressure systems in place) but it’s also been much milder than previous years. We saw earlier in this blog some really high GDD figures for U.K & Ireland and although they reflect air temperature, they will also have a bearing on soil temperature. The reason is that if we have rain falling through mild air then the rain itself will very quickly increase the soil temperature. On higher sand content rootzones we are talking over the course of a couple of hours.

Let’s look at some stats to justify my claim that this autumn has been both wet and mild in terms of soil temperatures ;

 

So you can see from the top graph that we carried double figure soil temperature right up to the end of November, normally we see this dip and stay down at the beginning of November. So a warmer soil means more activity from worms, especially those in the surface which cause issues with casting. Secondly, we can see that the rainfall we have received has been in some very significant daily rainfall totals but also with very few dry-down days in-between. So we have wet soils with a very slow dry down time due to light winds that remain wet but also warm. In other words perfect conditions for worm casting.

So what’s to be done ?

Well there’s unlikely to be a chemical replacement for Carbendazim, not unless something very different happens to the slant of legislation in the U.K and / or Ireland (as they are now different)

Yes I know we have a raft of oil-based materials used to discourage worms and whilst they may be considered cost-effective on fine turf areas, there aren’t many clubs that could afford to use these on fairways. And of course we have the legality issue to chew on….not to mention the sight of thousands of worms on the surface that require picking up and disposal. Food for thought.

On the other side of the coin we have the issues related to cutting fairways with heavy worm casting, rollers full of mud that need cleaning repeatedly, smothered grass, increased weed populations as the casts bring weed seeds to the surface and a poor surface to both present and play off. It is one of those problems that has no immediate answer, it’s no easy one, there is no black and white solution. I don’t normally shuffle my feet and shrug my shoulders when it comes to an agronomic turfgrass problem, but on this one, I do.

So clubs look to brushing, to sand topdressing fairways but these all come with a cost and a reliance on budget and increased resource just when budget and resource are heading the other way. A perfect storm, I’m afraid so.

If the Met Office is right about the trend towards milder and wetter winters and let’s face it it is something we have seen in our life time, then we can expect this to be a consistent problem and one therefore worthy of research to solve it.

Sorry to park the blog on a negative but we have to face up to a situation where there is currently no easy solution. If though you have one, (and its legal of course !) why not share it with your colleagues 🙂

All the best…

Mark Hunt