September 30th

Hi All,

It seems Mother Nature flicked the autumn switch pretty instantaneously this year. Only last weekend we were in the 20’s temperature-wise and enjoying an Indian Summer. Barely a week later and more than a ‘months worth of rain’ has fallen and temperatures are heading downwards, no bad thing for the latter though.

 Out walking yesterday, ditches had turned to rivers and brooks to torrents, some areas were totally impassable and truly I’ve never seen so much water at this time of year.  I also look at it as a wasted resource, all that energy going to waste.

And we aren’t done yet as more storms are lining up in The Atlantic to lash our shores with only a brief, cool / cold respite mid-week. Yesterday, my erstwhile colleague Dave Howells informed me of the latest Daily Express rant as Hurricane Lorenzo is set to track its way towards our shores at the end of this week and is billed as the ‘worst storm to ever reach the U.K’. (and Ireland of course)

Now if you read the graphic below it states that the probability of a 1 minute gust averaging >=39mph (62kmh for our European friends) is between 10-20%. Rather than show a path of destruction this graphic shows a decreasing chance of hurricane force winds. Now without wishing to do a Michael Fish (thanks Dave) it will be generate an Atlantic storm but it won’t be the same intensity as it stands today out in the South Atlantic unless something different from this happens between now and Thursday night. Currently the projection is for Lorenzo to actually miss the U.K and track north-west of us, a detail The Daily Express seems to have overlooked 🙂

Image courtesy of https://www.nhc.noaa.gov

One thing is true though in that we are seeing more violent storms and more intense rainfall events and these are and will have a profound effect on modern-day life. Let’s hope Lorenzo gathers force, steams easterly along the Thames and takes out The Houses of Parliament, no loss there in my mind.

Looking ahead we have a succession of Atlantic low pressure systems gathering after this one courtesy of a jet stream that dipped south last weekend and opened the floodgates quite literally to a westerly airflow. So let’s put some detail on this.

General Weather Situation

OK, so we start the week on Monday with a brief hiatus from the autumn storm season, note the word ‘brief’. Brief because we are already seeing a new rain front push into the south-west of Ireland on Monday morning. This is set to bring heavy rain to Munster and Leinster and by lunchtime this rain will be into The South West and most of Wales before briefly halting. So away from this rain front across the south-west of the U.K, expect a quiet cool start to the day with light winds, a heavy dew and lower temperatures than of late. By mid-afternoon, this rain front gathers momentum and pushes eastwards across the southern half of the U.K to give a pretty wet 2nd half of the day for most. That said it may not reach eastern counties till after dusk. Since this low pressure is southerly orientated, the north and Scotland will see a pleasant, autumnal day with light winds, mid-teen temperatures and hazy sunshine. By mid-afternoon, the rain will start to clear Ireland from the south-west as it moves eastwards. So mid-teens and windy away from the south / south-east for Ireland with temperatures down in the low teens under that thick cloud and rain.

Onto Tuesday and overnight that rain will have brought some heavy totals to Wales, The Midlands and East Anglia / Lincolnshire as it moves across the centre of the country. By dawn it should be drier over these areas but the rain front will then be pushing north into northern England and a second front will now be across Ireland so a wet start to the day here. As we move through Tuesday morning, these two fronts consolidate as the centre of the low passes across Central England bringing further rain to Wales and the southern half of the U.K, from The Pennines south. Scotland again misses the worst and Ireland should clear from the west through the morning to leave a drier 2nd half of the day.  The centre of the low will slowly move across the southern half of England through the 2nd part of the day, so a very wet end to the day here. Pretty pointless forecasting wind direction because it’ll depend on your proximity to the low pressure. It may be north-westerly, north-easterly or south-easterly 🙂 Similar temperatures, low to mid-teens for Tuesday and pretty average for the time of year. As skies clear temperatures will drop sharply on Tuesday night.

Wednesday brings  a cold respite, at least I hope it does because I won’t be able to get my trials out if it doesn’t 🙁 It may also bring a touch of ground frost in places as skies clear overnight and temperatures drop significantly. So Wednesday looks like a dry, cold and sunny day with a brisk to strong, north-westerly wind which will certainly remind you that we are now in autumn. As we progress through the day we will see cloud build from the west across Ireland and later, the west of the U.K as Hurricane Lorenzo looms, well what’s left of it anyway. So temperatures down in the low double figures on Wednesday across all of the U.K and Ireland with Scotland and the north of England / Ireland, cool in that northerly wind. A good drying day mind.

Thursday sees the next Atlantic storm in the form of Hurricane Lorenzo push into Ireland in time for the Kerry rush-hour maybe. By midday, the rain from that storm front is across Ireland and further east we will start to see cloud and the wind build. That said for most of the U.K, Thursday morning will be another cold, bright and possibly frosty in places start to the day before that low pressure moves in. So a wet morning for Ireland, drier further east. Now currently the worst of Lorenzo is expected to stay out in the Atlantic .

Here is a schematic of its current tracking as of Monday morning…

Images courtesy of Meteoblue, graphical arrangement courtesy of me…

Now storm paths and intensities can change so best to keep an eye on the local weather advice as we move closer to Thursday. Currently then as you can see we will see rain and strong winds move into the west of Ireland from dawn and this will push eastwards across The Irish Sea into the west of England, Wales and Scotland during the course of Thursday afternoon accompanied by strong but as currently projected, not hurricane force winds. If the storm path changes and it crosses the U.K, that’s a different matter. There Dave, a Michael Fish banana skin avoided…….So after a cold start for the U.K, cloud will swiftly move in and push rain across the country. Staying cool with temperatures across Ireland only in the low double figures maybe just nudging the teens further south.

Closing out the week on Friday and we see that rain band cross the U.K overnight bringing heavy rain in places, possible to The North East leaving us with a showery and breezy picture to finish the week. So Friday will see a showery picture across Wales and the west of England (particularly) interspersed with some sunny intervals with more of these further east. It will feel milder than of late with temperatures nicely up into the mid to high teens across the southern half of the U.K. So a good drying day between the showers on Friday but always we have the risk of a new rain front lurking out in The Atlantic. This is currently projected to make landfall into West Ireland around midnight on Friday and will bring heavy rain across Ireland for Saturday I’m afraid.

So how are we looking for the weekend ?

Well I think it is very much a west-east divide with Ireland, Wales, The South West and western coastline of the U.K stretching all the way up to north-west Scotland in line for some pretty heavy rain on Saturday. This rain front is projected to move eastwards leaving behind a showery picture over Ireland and the west and bringing further rain to central and eastern areas of the U.K for the 2nd half of Saturday. The wind will be fresh to strong and from the south-west and so it’ll continue the mild feel to the weather. Sunday looks like a sunshine and showers day with lighter winds and a slightly cooler feel to the weather.

Weather Outlook

So how is the outlook for next week shaping up ?

Well next week looks to start as this week is projected to finish, that is wet and pretty windy with rain moving through on Monday. Tuesday and Wednesday look milder and a ‘sunshine and showers’ type scenario, particularly in the west with a strong westerly wind before a deep low looks to affect the north / Scotland on Thursday with very strong winds and heavy rain. Further south we pick up some much milder weather so it looks drier and warm with a strong wind for the latter part of next week, still with some showers feeding into the west, but most of them northerly biased. The weekend of the 12th October sees Saturday continue the sunshine and showers theme before it turns cooler with the wind switching round to the north. This heralds the arrival of an Atlantic high pressure to bring a northerly theme to our weather so that’ll be much cooler with night frosts and a cold wind. Plenty of time for this to change yet though.

Agronomic Notes

Well quite a lot to talk about since I haven’t been able to publish my blog for a few weeks. Most of it is unfortunately disease-related 🙁

Microdochium nivale activity

For some the Microdochium nivale season has started early with the end of the dry spell signalling an increase in humidity and dew levels and hence disease. Initially the north and west of the U.K and Ireland picked up the rain whilst the south and eastern counties stayed dry. So this meant that for Ireland, Wales, the north-west and Scotland we saw increased Microdochium activity from the 3rd week of August onwards. For the south of England, Wales and eastern areas we had a couple of weeks of grace before the same set of conditions transpired to promote quite aggressive disease activity particularly towards the middle of September.

Warm, humid overnight air with very little wind (and hence dry down of a wet plant leaf) are the optimum conditions for autumn Microdochium nivale and so we often see more aggressive attacks at the start of the season on sheltered turf surfaces with less air flow. This is quite different from later in the season when the exact opposite can be the case.

As some of you will know I’m working hard with my colleague, Paul Vipond, on a disease prediction model for Microdochium nivale and it’s definitely a case of the more you know, the less you understand 🙂 That said we are making progress and it allows me to put up some graphical information showing how disease severity has panned out during September in a number of locations. It also shows the difference in disease pressure between a sheltered and open site scenario.

Here’s a taster from a few locations, sorry the bottom scale is small but it can’t be avoided ;

So you can see a much higher level of predicted disease on the sheltered sites within a location as opposed to more open sites. This has proved to be the case in practice but of course other variables come into play like surface organic matter content which cannot be forecast in a disease model.

Here’s a great proof of the pudding shot taken at the end of last week…

The majority of the Microdochium on this green was in the shaded environment which was likely to have had dew forming on it for longer. Throw in some nights when the air temperatures stayed up above 15°C and there you have Microdochium.

That said I did see some shaded greens last week with much lower level of M.nivale compared to more open, higher surface organic matter examples on the same site. This level of disease is I think typical of a badly hit golf green currently ;

Now ordinarily you might be reaching for the fungicide when you see such a level of active disease but even that has been a bit of a quandary hasn’t it ?

This cropped image from Weathercheck highlights the 3 main issues with combatting disease during September, 2019.

They are of course ;

  1. Very high growth rates that limit the longevity of a fungicide and any other liquid application.
  2. Very high daily rainfall totals that risk washing product straight through the profile soon after application.
  3. Windy, unsettled conditions that make finding a spray window tricky.

Now of course there’s two sides to every coin and that high level of daily growth that limits product longevity will also mean that the scars from these early Microdochium outbreaks will be grown out quite quickly. The more your surface organic matter is where it needs to be % wise, the quicker that process will take place. Wet and windy weather also doesn’t tend to encourage high levels of disease activity because that weather dynamic is very different from dew formation in terms of plant leaf wetness and possibly other parameters.

It isn’t just Microdochium nivale that has been evident, we have also seen some very aggressive Red Thread and Leaf Spot out there on high Fescue / Ryegrass swards because of the combination of humidity and temperature.

Looking ahead…..

Now some of you out there may not have applied a fungicide and may not have needed to either because of the climatic conditions on your site and other variables I’ve already eluded to.

We do know that October normally represents the highest incidence of Microdochium nivale inoculation that we will experience across a season but not the only incidence as last year proved with aggressive new Microdochium outbreaks in late November and December.

For this reason one of my concerns going forward is getting a spray window to apply any liquid application be it fungicidal, non-fungicidal or nutritional. Looking at this week, Wednesday seems to be the only day when the outlook is pretty dry and wind speed reasonable. Thereafter it becomes much harder to spot a window at all for the next 7 days particularly in the north and west.

Crane Flies…

A lot of these guys around at the moment and there have been for the last 10-14 days in my neck of the woods. Syngenta’s Turf Pest Tracker provides a good update on regional variations and intensity of hatch (you can find it here)

My hobby of fly fishing also helps in this respect because Trout really turn onto Daddies as we call them when they are in abundance.  Out on the beautiful Eyebrook reservoir recently one of the old lads pointed to a tractor working the fields close to the reservoir. “He’ll be stirring up all the Daddies, that lad will, worth a try I think” he remarked. As usual he was right, there’s a lot to be said for experience 🙂

It got me thinking about the timing of late season aeration and the fact that many areas are seeing Crane Fly laying eggs at the moment and if you have greens with open hollow / sold tine patterns , that presents a perfect incubation site for the Crane Fly. We are all familiar with the chamfered tine hole edge indicative of the nocturnal chomping of a Crane Fly larvae and if your greens have open tine patterns, it is a perfect opportunity for them.

A good argument for late summer rather than late autumn aeration maybe, pushing recovery and getting things put to bed before the end of September ?

Ok that’s me for now, apologies for the hit and miss nature of the blog of late, it is I can assure you unavoidable.

All the best.

Mark Hunt

 

 

 

3 thoughts on “September 30th

  1. Mark Jones

    Cheers Mark,
    Great information as always.
    On this seasons form Lorenzo will be a bit of a disappointment and the storm could be a non event too!
    Keep up the good work and look forward to seeing more of the disease model.
    Cheers, Mark

    Reply
    1. mark.hunt Post author

      Hi Mark,

      I did very much want to make a Lorenzo MotoGP-inspired comment along those lines but reflected on the fact that most of my subscribers wouldn’t get it. Agreed on this seasons form, Lorenzo will turn up sometime next week and be barely a wisp of wind…

      Reply

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