The news is full of weather events at the moment, Hurricane Florence, Typhoon Mangkhut and last week, Hurricane Helene. My oldest Stepson is currently teaching in Shenzhen, China and this weekend they got the full force of Mangkhut to such an extent it was pushing water through the window frame into the house !
In our little world sometimes we seem a million miles away from these storms but their influence stretches far and wide and already our weather is being affected by Helene. We are due to get the downgraded Tropical Storm Helene in the early part of this week so expect a very windy start to the week for some areas and a very windy end as well courtesy of another storm system.
Now I mentioned that Helene is already affecting our weather and that comment related to temperature and humidity and not wind because what we are already seeing is very warm air pushing up from Helene across the U.K.
You’ll have noticed how warm it was last night maybe ?
Here we didn’t drop below 16.8°C overnight and we saw the humidity rise to 97% as warm, humid air associated with Helene pushed into the southern half of the U.K and Ireland. Later this week we will see another low pressure come into effect bringing very windy and potentially very wet weather for the end of the week / weekend, so the autumn storm season has started in the U.K.
General Weather Situation
As we start the week we already have a pulse of heavy rain pushing across the west of Ireland affecting Galway, Mayo, Sligo and Donegal on Monday. This band of heavy rain stretches across into north-west Scotland as well and through the morning it’ll move east across Ireland lessening as it does so and into the west coast of the U.K. Away from this active rain band it’ll be a cloudy, humid and dull start to the day with warm overnight temperatures carrying over. As we progress through the afternoon, this rain band will clear all but the far north-west of Ireland and sunshine will break through over central and southern areas of the U.K pushing up the temperature. Scotland will see that rain push into central areas from the west, light at first but becoming heavier into the evening / night. Warm temperatures of up to 24°C across the south and central areas of the U.K, 20°C across Ireland (courtesy of Helene) and cooler across Scotland. The wind will strengthen across all areas as we progress through the afternoon, blowing mainly from the south and becoming very strong over Scotland later. It’ll be another very warm night.
Tuesday sees that a heavy rain front push across the south-west of Ireland overnight but by dawn it’ll have cleared most of the country and is due to affect The South West, Wales and the west coast of England and Scotland. It is projected to be pretty heavy over south-west Scotland. By the morning rush hour it’ll have moved east pushing cloud ahead of it with the rain now into northern England and South Wales. Through the afternoon the rain front sort of fizzles out though may persist across northern England. Ireland after that wet overnight rain will see a new rain front push into Kerry late morning but it’ll clear north and east quickly with warm sunshine following. By late afternoon we have a mix of sunshine and showers (mainly in the west) and again some pretty warm temperatures in the low twenties across the south of England, mid to high teens across Ireland, Scotland and Wales. The wind will be very strong across all areas and from the south-west, a courtesy call from Helene 🙂 The strongest of the winds may not reach Scotland till later on Tuesday night.
With Helene now upon us it’s no surprise we see a heavy rain front start off Wednesday for Ireland pushing across in time for the Sligo morning rush hour and heading across Ireland during the morning. This rain front will also affect the west coast of Scotland with some heavy bursts late morning for The Western Isles. The main rain front from Helene is projected to move across the west of Ireland and into Scotland so that means south of this it’ll be clear, warm and dry with plenty of sunshine for England and Wales. Later in the afternoon we will see thicker cloud and rain push down into North Wales and northern England. This rain front will lessen but push further south bringing a cloudy end to the day down south. The clear feature of Wednesday will be the very strong winds associated with the storm system with the west of Ireland and Scotland in line for the worst I think. Temperature-wise I think similar to Tuesday with mid-teens across the windier and rain-affected areas and high teens to low twenties across the south of England. Another very mild and humid night.
Thursday sees one storm centre pass but another one appear out in The Atlantic. Overnight this will push rain, some of it heavy, across the south of Ireland and into Wales and the north-west of England. By the morning rush hour this rain band will extend across from Ireland through Wales and up to The North East. North and south of this will see a cloudy and dull start for Scotland and central England. As we progress through till the afternoon the rain will become potentially heavier across Ireland, the very tip of North Wales and northern England and it’ll slowly edge north as it does so. By the evening the rain is projected to be across The South West, Wales, Ireland and Scotland intensifying as we progress through the night.
Weather forecasting caveat – Now I expect the direction of that rain to change over the coming few days so it may move south or north depending on path of the storm centre, be warned your rainfall totals will I’m sure change for Thursday.
The rain will also move eastwards overnight to affect all areas pushed along by some very strong winds to boot. With a low moving across the U.K and another huge depression above Scotland, expect much cooler weather moving down from the north from Thursday, you’ll see why from the Unisys graphic below ;
I just had to double take then because that low will drop temperatures so significantly through Thursday into Friday that across the high ground of Scotland you may just see some wintry showers. What a crazy, crazy (expletive deleted for the sake of decency) weather week this is to forecast !
So Friday starts off very windy, pretty cool and very wet across Scotland with the rain extending down into northern England. South of this rain front it’ll be bright and sunny across Ireland, Wales and England though it’ll be much cooler as that cold front sinks south. During the morning they’ll be a rain front pushing across The South West / Wales and this may skirt the south coast of England but elsewhere aside from persistent rain across the north-west of England, it looks a better 2nd half of the day with that heavy rain clearing Scotland. It’ll feel a good bit cooler everywhere now with low to mid-teens more the norm and thankfully the night temperatures will follow this trend (more on this later). A pretty windy day again, especially at the start of the day with strong westerlies likely throughout the day.
Nothing is normal this week and that forecast extends into the weekend with more heavy rain for the south west of Ireland on Saturday and this will push across Ireland through the day and into the west of the U.K through the 2nd half of the day. I then expect this rain to push eastwards overnight to all areas for the start of Sunday though again the exact path of that rain may change. After a quieter wind day on Saturday (not for Scotland but for Wales and England) I expect the wind to gain strength through the day and swing round from the west to the north during the day to bring a cooler feel to the weather as we close out Sunday. So windy and unsettled is the forecast for the weekend with the west and north getting it first and on Sunday I think the heaviest rain will be for Scotland and the north currently.
After such a turbulent week this week with low pressure systems assaulting the shores of the U.K and Ireland can we expect better for next week ?
Well the answer looks like a resounding yes to me at this stage with an Atlantic blocking high pressure system due to establish from Monday onwards, bringing dry and mild, warm conditions with light winds. So a bit of an Indian Summer next week and at this stage it looks to last the whole week and possibly into next weekend 🙂
Ok, it’s going to be a short agronomic blog this week because I am under pressure work and time-wise. Looking at my emails and texts that pressure is coming because of the current weather trait that I referred to earlier, high overnight temperature and high overnight humidity.
I downloaded the data from my Netatmo weather station this morning and here’s how it looks for the last two days…
So for my location here at the centre of the universe that is Market Harborough, you can clearly see the effect of Helene pushing in humid and warm air overnight. Dove-tail that humidity in with an overnight temperature that didn’t drop below 16.8°C and that means in my books high Microdochium nivale pressure.
So I’d expect a lot of you to come into work today and notice copper blotches on the sward suggesting high disease pressure from this pathogen. Now life is anything if not interesting this week because not only does that combination cause high disease pressure, it also causes strong grass growth.
You’ll see this from the Meteoturf output for the same location and note the pattern as we progress from this warmer to cooler air later in the week…
So the suggestion is that grass growth will be optimum at the point where disease activity is also at optimum. How this pans out across your surfaces will depend largely on where you are nutritionally because if nutrient is available then it is quite possible that we will see Microdochium nivale grow out as fast as it occurs through this week before the cooler temperatures of later in the week lower the disease pressure. To further complicate the dynamic, any fungicide applied prior to this event will also have a much shorter longevity because it’ll be removed during this growth flush.
As more than one person commented to me recently, fungicide longevity is probably around the 14-day mark currently with a cumulative Growth Potential of around 10 for that period.
Now it’ll be longer in Ireland, but not by much because the projected G.P for this week for say a Shannon location is 4.4 (compared to 5.3 for Market Harborough). Other values to throw into the mix would be 4.0 for Central Scotland, 5.8 for South Wales and 6.0 for Southern England.
So all in all we have a pretty tricky dynamic this week, high disease pressure for Monday, Tuesday and Wednesday in particular vs. high growth rates.
So how do we proceed with that type of outlook ?
Well in the past we maybe would have applied Iprodione to knock populations back and clean up the sward particularly in the knowledge that this disease pressure is short-term and will decline by the end of the week and drop away fully next week with the arrival of high pressure.
Trouble is we can’t do that because Iprodione is no longer available is it 🙁
So this is our first taste of life without that active and it’ll be an interesting lesson for all of us and one we should learn from. Now I can’t make a call for all of your locations, with all of your variables sitting here typing this blog but here’s my thinking for what it is worth….
Firstly, use this period of weather to observe how your surfaces react and record this data somewhere because it’ll be useful in the future. I can’t see the point of applying a systemic fungicide right now because the disease pressure is already upon us and more likely with the growth flush, remove some of the A.I by cutting pretty much instantly. With the wind strength and rainfall for some areas as well it’s going to make getting anything on tricky by the by.
If I could get a spray on, it would just be a hardening one to try and keep the plant healthy through this period and hopefully decrease the activity of the pathogen. I would hope that with the enhanced growth rate any scarring of the sward would be avoided because you’ll grow it out before it becomes an issue.
Now that’s just my opinion and you know what they say about opinions ;P
This week I’ll be up at the S.T.R.I Research Event (details above) along with some other rabble (:P) to chat through our latest research into Microdochium control and it’ll certainly be very relevant looking at the current weather conditions. I’ll look forward to hopefully seeing some of you up there but if not I’d really like to understand how your surfaces come through this week with the challenges I have outlined above.
All the best for the coming week.