December 9th

Hi All,

As predicted our unsettled weather made an unwelcome re-appearance after a short period of an intervening high pressure and dry weather. The picture below sort of sums the weather up at the moment, an angry sky and a little bit of sunshine. It doesn’t highlight the saturated fields, full ditches and the mud-spattered trousers that go hand in hand with winter walking in Leicestershire and Rutland.

Still love it though….

The west of Ireland took a battering yesterday as the first storm of the winter moved north and east across the country. This one was called Atiyah and you’ll be glad to know our respective Met Office’s (and The Dutch Met Office) have worked together to produce a list of names for this years winter storms !

Courtesy of The Met Office

I could not help but notice there’s no Storm Mark which is disappointing. The Irish influence is clear though, none more so than Storm Brendan which after his name sake in Cropcare, I predict to be a stealthy one with a strong and feisty demeanour :).

I could have hours of fun with the above but I’m not too sure about blog publishing and libel cases so I’ll desist. (for the time being anyway)

So any more storms for the coming week ?

General Weather Situation

So Monday kicks off with a cooler feel to the weather after the mild (ish) weekend as the wind shifts round to the north / north-west. Today looks mostly dry for the U.K and Ireland but there will be some blustery showers around, pushing down the north-east coast into East Anglia and other the other side of the country, extending from North Wales down to the south coast in a line. They’ll be plenty of sunshine in-between these showers and many places will stay dry all day with a strong north-west wind in attendance. Temperature-wise it’ll be 7-8°C, but feel cooler in the wind.

Overnight into Tuesday ,a low pressure system will push rain fronts into the west of Ireland and these are set to cover Ireland and arrive on the western coastline of the U.K around dawn on Tuesday. This rain will push eastwards through Tuesday morning with some of it pretty heavy across the west and north-west of Scotland. It will feel a good bit milder than Monday as the wind swings round to the south-west. They’ll be a brief hiatus during the afternoon before a second, heavier rain front will push into the west of the U.K and bring heavy rain to Wales, the north-west and south-west of England. This rain will push eastwards across all areas on Tuesday night leaving Ireland dry after a wet day. Much milder as mentioned above with temperatures up to 11°C. Winds will be very strong and from the south-west.

Onto Wednesday and with another rain front stacking up on the west Irish coast it is going to be unsettled again with that rain pushing across south Munster and Leinster. This rain will be much more westerly focussed with Wales and the west coast of the U.K likely to see most of the rain during Wednesday morning. Despite the fact that the wind is still westerly, it’ll feel much cooler than Tuesday with temperatures back to the 6-8°C. During the 2nd part of the day the rain will push eastwards across the U.K, falling as wintry showers across Central Scotland. As the rain pushes eastwards in the afternoon it should clear Ireland from the west leaving behind some isolated rain showers along western coasts.

Thursday sees yet another Atlantic low pressure push in from the west bringing rain to the west of Ireland from the off I am afraid. By the time the morning rush hour starts in Magor Services, it’ll be into West and South Wales and extend all the way up from The South West through Wales, the North West up to Scotland. During Thursday morning this rain will push eastwards on very strong south-westerly winds, still with the heaviest rain affecting the western side of the U.K. As we approach sunset practically all of the U.K and Ireland will be affected by rain and strong winds I am afraid with that rain falling as sleet and snow across Scotland. Temperature-wise, a little milder on Thursday with 8-10°C likely.

Friday sees that wind swing round to the north and that’ll pin those temperatures back down. Again we will see showers from the off but these will mainly affect the north and north-east with some of them wintry in nature. Elsewhere a much drier day after the rainfall of Tuesday and Thursday and with a strong wind, a chance to dry out a tad. The distinctive feature will be the temperature and the wind direction though, it’ll feel proper Baltic in a strong north-westerly / northerly wind.

So what is the outlook for one of the last shopping weekends of the Christmas period. You know the one that started in September, featured Black Friday, Cyber Monday and all that crap as retailers generally increased prices and then discounted them back down to where they were before. The term ‘Pavlov’s dogs’ springs to mind.

Anyway what’s the weather likely to be for the shopping weekend ?

Well, it is an East-West divide with the bulk of the rain across Ireland and the west-facing coastline of the U.K. Saturday sees plenty of showers across Ireland, some of them wintry on the tops. These showers will also affect Wales, The South West, The North West and western Scotland through Saturday morning and with the cold temperatures don’t be surprised to see some of the white stuff at elevation. Most of the showers will be confined to the west on Saturday with central and eastern parts enjoying a cold, breezy but largely dry day. Sunday sees a more general band of rain and wintry showers cross the southern half of the U.K and Ireland overnight. A drier day for the U.K with the showers confined to The Lakes and western Scotland. Ireland should be reasonably dry until lunchtime when more rain and wintry showers pitch up at the south-west coast and push eastwards. Cool though with 5-7°C the top temperature and feeling colder in the strong wind.

Weather Outlook

Well this is how the GFS (Global Forecasting System) projection looks for next Monday and you may notice two or three things. First we are in the cold bit, second we have some low pressure systems close to us and thirdly (and perhaps the most unwelcome bit), the jet stream has returned to a position below the U.K & Ireland. This means that we are back to a weather pattern where low pressures can rattle in from The Atlantic but unlike September, October and November, they will pass through quickly so we will have drying days in-between. Happily though the jet stream is predicted to take a nudge upstairs later next week 🙂

So next week looks like starting off unsettled again as low pressure rattles in some south-westerly mild winds and showers. These showers will mainly affect the north and west of the U.K and Ireland and as we go through the first part of next week, we will see this trend continue as most of the rain showers will affect the north and north-west. Thursday looks a wet day for Ireland and Scotland as we see some heavy rain push through. It is also likely to affect the west side of the U.K as well but the east and south-east could stay dry. Nothing to shout about temperature-wise, probably 7-9°C will be the norm. At the end of next week we begin to dry out as the jet stream is pushed high above the U.K confining any rain to the far north. So possibly a dry run into Christmas ?

Want to see the first GFS prediction for Christmas Day ?

You will, you will, you will (Father Ted style) ……

Well if this turns out to be true I won’t be a happy bunny over Christmas, not that much will change there really as I’m a bit of a Bah Humbug type of chap when it comes to all the festivities. Truly, I’d rather be running, cycling or fishing than sitting down to days of calorific excess. I do like the rest though so I won’t begrudge it all and if its dry I can exercise it all off 😛

Agronomic Notes

So why is the above image potentially not good news ??

Well, firstly it means I will lose my Paddy Power bets for a White Christmas for the 5th year in a row 🙁

Secondly, if any of you have been to my talks recently where I summarised last Christmas and why we had high disease pressure through to The New Year, you’ll recognise the weather pattern above. Here’s what our weather pattern looked like last Christmas ;

So you can see some similarities with last Christmas and the first GFS prediction for this Christmas. Now I cannot stress enough this is 16 days out and as we know a lot can change in that time weather-wise, so let’s not jump to too many conclusions, too quickly. The high pressure is in a different location as well, it isn’t as far north and west as the one last year.

That said if this does turn out to be right it could suggest high disease pressure for the central and southern part of the U.K. The north and west will be in the main wind flow of the jet stream so they’ll be milder, windy and unsettled. The threat as it stands now is for the south.  It’s an early warning to make sure that you’re covered for the Christmas period and if the weather does pan out as predicted, you should have some spray days to do this (unlike last year).

As I didn’t have the time to cover this last week, I thought I’d do a speedy recap of November 2019, although most people will want to forget it as a month due to the excessive rainfall.

GDD Comparison – UK – Thame Location

So November 2019 came in at 37.5 total GDD, which if you look at the graph above for the previous years, ranks it as a cool one. Actually the 2nd coolest since 2010. Significantly it also meant that this run of cool weather had a negative (positive) effect on Microdochium activity, with much lower disease pressure compared to 2018.

You can see how much warmer November 2018 was as it came in nearly three times higher from a GDD perspective ! The other benefit was that grass growth was much lower which meant that you weren’t having to get out and cut wet fairways / outfield because it was growing so fast. On the flip side if you needed recovery from winter wear, you simply didn’t get it in November.

As mentioned last month I don’t think 2019 is going to go down as a record breaker in terms of temperature (though it might do in terms of rainfall). At the end of November 2019, the total y.t.d GDD was running at 1828, which puts it as a so-so year really and 10% behind 2018.

GDD / Rainfall Comparison – U.K Locations

As you hopefully see November was universally cool across the U.K with barely any difference between the GDD in Fife and Bracknell (34.4 vs. 38.5). It was also universally wet with poor Okehampton coming out tops for rainfall at 172mm, that’s nearly 7″ in old money.

GDD / Rainfall Comparison – Irish Locations

Ireland pretty much fared the same with a low GDD / high rainfall month representing November 2019. Valentia came in as the mildest, but not the wettest, with Killiney measuring a whopping 187.5mm, now that’s proper wet !

A quick 5 minutes on climate change…

You know it doesn’t seem a day goes by without another piece of climate change information making the news and in some respects that’s good, but in others it is confusing.

I’ve seen output from the Met Office and other national weather organisations saying the trend for the future is for hotter, drier summers and warmer, wetter winters. Well I’m sorry but I don’t think it is that clear cut for us in the U.K and Ireland simply because of a geographical location.

Recently, I did a couple of talks at Sportsturf Ireland (thanks Damian and Finbarr for the opportunity and hospitality) and in one of those talks, I looked back at 55 years of climate data for 2 locations in Ireland for the months of October, November and December.

Why those ?

Well in my humble opinion it is because they represent the most changed months of the calendar year. That is to say it is our autumn / winter season that has changed the most in my lifetime.

Now, firstly hats off to Met Éireann, the Irish Weather Organisation. A couple of clicks of a button and I could download 55 years of minimum and maximum daily temperature data along with daily rainfall. Try to do that here with The Met Office 🙁

Now I have these ideas you know and almost instantly I regret them because my is that one hell of a lot of data to analyse. So anyway 6 hours later and with a scrambled brain, I graphed out the monthly Growth Potential and rainfall for the last 55 years from 2 Irish locations.

What did I expect to see ?

I suppose you’d expect to see evidence of a general warming trend denoted by increasing G.P over the last 55 years. After all Growth Potential is calculated from maximum and minimum temperature vs. an optimum temperature for cool season or warm season grass species. The graph doesn’t show a clear trend from a G.P perspective.

Here’s the same chart for rainfall ;

Now maybe here there’s more of a case for saying the wettest October’s have occurred more  often in recent years, I’d accept that.

I also looked at the warmest and wettest single day of the autumn winter as defined by the period  October, November and December. This would help pick out extremes of warm and / or wet weather that may have been hidden by a monthly total.

So here’s the years when the top 10 warmest single days of the period October – December for Dublin since 1964 were recorded ;

Oct 1985 / Oct 1970 / Oct 1984 / Oct 1969 / Oct 1969 / Oct 1971 / Oct 1977 / Oct 2013 / Oct 1969 / Oct 2002

So what I’m saying is that October 1985 recorded the warmest day on record since 1964  at 21.3°C on the 1st of the month. In that top 10 there are only 2 years since the turn of the century. Surely we’d expect to see more recent years in the top 10 if the climate was warming consistently ?

If we do the exercise for rainfall the results are different. So here’s the years when the top 10 wettest single days of the period October – December for Dublin since 1964 were recorded ;

Oct 2011 / Nov 1996 / Nov 2000 / Nov 2002 / Oct 2003 / Nov 1965 / Oct 1990 / Oct 2002 / Nov 2017 / Oct 2004

So here I’m saying that October 2011 recorded the wettest day on record since 1964 at 82.2mm falling on the 24th of that month. Now in this top 10, 7 of the years are since the turn of the century and interestingly all of them are either October or November, no December’s made the list.

I performed a regression analysis to see if there was a relationship between the warmest and wettest months. There wasn’t.

So for this admittedly very small sample set, the data didn’t confirm that winters were trending to be warmer for either Shannon or Dublin. It did however suggest they were getting wetter and that’s the take home I think.

So what am I saying about our climate ?

Well, I can’t speak for the U.K as I haven’t crunched any data (yet) but if you look at Ireland to me it isn’t clear that we are on an upward temperature trend for October, November and December since 1964 anyway. There is a suggestion that we are on an upward rainfall trend though for those months.

This shouldn’t be a surprise to us because we are situated on the path of the jet stream and how this behaves really dominates our weather patterns. We know it forms ‘peaks’ and ‘troughs’ and that these can give us excesses of temperature and rainfall. (either way)

From this little cropped study it would suggest that the trend (if there is one) appears to be resulting in more rainfall, more often than it results in more (higher) temperature.

Chatting this through briefly with Trygve S. Aamlid from NIBIO, Norway (Norsk institutt for bioøkonomi) at a conference where we both spoke, he made a very good point to me. That is that the further north you go latitude-wise, the greater the change in temperature over the winter months. So if we did this same exercise for Copenhagen, Oslo and Helsinki, we may say a much clearer pattern evolving. (See Trygve I do remember some things 🙂 )

OK, back to the day job and before I get a knock at the door from Greta Thunberg (you need to get out more) for doubting climate change (which I am not doing incidentally, I’m merely saying that for Ireland and the U.K, it isn’t as clear-cut as for other countries / regions), let’s look at Microdochium pressure (sigh)

Microdochium nivale pressure

Well for this week the prevailing high winds and in the latter part of the week, cool / cold temperatures will drop disease activity back to a low point after some locations experienced a peak last week. Good news and this continues the trend for a lower than normal disease pressure autumn. Before we relax though let’s remember last Christmas (not the Wham song thankfully) when we were all caught on the hop. I’ll be keeping an eye on the GFS output for Christmas and not just from a Paddy Power perspective to see if that high is going to make an appearance.

OK, all the best for the coming week, I need a coffee and a lie down 🙂

Mark Hunt

 

 

 

 

 

 

 

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