Last week I signed off with the comment that I had a bitch of a week coming up. I guess it’s a measure of my forecasting prowess that a little more than 5 hours later I was heading over the bars of my mountain bike at 20 mph with a heavy and painful landing to follow. A bitch of a week then followed so in this respect I can say my forecast for last week was 100% accurate even though it may have had not a lot to do with the weather 🙂
With high pressure out in the Atlantic and low pressure sitting in a cold air trough over us, it’ll definitely feel like autumn this week. As commented on previously, this combination of weather systems drags cold air down from the north and that always takes the temperature downwards.
Out walking yesterday it was notable to me that the hue of the countryside has changed since my last walk with the gold of crop fields now changed to earth brown with lots of ploughed fields already sowed for next year. Skimming low over them were flocks of young House Martins and Swallows feeding up before they disembark to warmer climes for the winter, no doubt gorging themselves on the numerous Daddy Longlegs that I could see. So must we prepare ourselves for autumn and perhaps not the most favourite time of year for greenkeepers and groundsman alike as leaves, worms and Microdochium move up the things-to-sort list 🙁
So are we staying unsettled or do we have any hope of an Indian Summer ?
General Weather Situation
So kicking off Monday we have a raft of showers moving on a west to east trajectory with some heavy bands already present across south west Munster, Connacht and Donegal. For the U.K we have a particularly heavy belt moving along the M4 / M25 stretching from Bristol to Kent so this will be a feature of your day here I think. Further north we have heavy showers over mid and North Wales, The Pennines and The Lakes and a heavy rain front over central and eastern Scotland. As we go through the morning we will see further showers crop up and push eastwards across all areas of Ireland and the U.K and these will continue through the afternoon becoming more westerly-orientated as we move towards dusk. These showers will be pushed along by a strong to gale force westerly / north westerly wind and it’ll be a cool one for sure, so expect mid-teen temperatures today in that wind. Time to reach for the winter buff or snood I’d say (this one is my favourite :)….
Onto Tuesday and that low pressure system that has brought us unsettled conditions moves off north east and takes the majority of the rain with it, so a drier day is likely on Tuesday with most of the showers confined to the north west coastline of the U.K. We will still have that strong wind in place though so continuing to feel on the cool side if you’re out in the wind. Later on Tuesday as we approach the evening rush hour, we see another band of heavy rain push into the south and west of Ireland and this will quickly push north and eastwards so a wet end to the day here. Overnight this band of rain is likely to push into all areas so significant rainfall expected overnight into Wednesday.
So for Wednesday we still have the remainder of that heavy overnight rain affecting our weather with the heaviest rain reserved for the north of England up to The Borders of Scotland as we kick off mid-week. That doesn’t mean that everywhere else will stay dry though because we can expect rain across the north of Ireland and Scotland with another band pushing into The South West. Some of that northern rain may also push down into The Midlands. Later on in the day we will see another rain band push into Kerry unfortunately. Still with those strong westerly winds but they’ll lighten as we approach the evening and turn round to the north west. Staying cool then.
Onto Thursday and that wind change to north westerly / northerly means a cool day for all and continuing unsettled. There will be more in the way of sunshine around on Thursday between the showers that will rattle across the U.K and Ireland so a better drying day I suppose you could say (trying to be positive that is..). I don’t think we will see the same intensity or frequency of showers so for many Thursday could be a drier day. Staying cool mind with mid-teens the best you can hope for considering the direction of the air flow.
Closing out what will have seemed more like an October / November week, Friday sees high pressure nudge in from The Atlantic (See Mr Collins it will arrive but may be not to give an Indian Summer 🙁 ) and that means a drier day is in prospect for all areas but that high will continue to hold the winds in a northerly orientation so it’ll remain cool, maybe even cooler for Friday with that wind direction but it should stay largely dry. I say largely dry because there’s a risk of a new rain front pushing into Donegal / Connacht later on Friday afternoon and if that comes to pass it’ll signal a wet end to the week for Ireland.
The forecast for the weekend will be a tricky one because this wet weather over Ireland has the potential to move eastwards on Saturday morning but exactly where that line will be drawn is difficult to say. So for Saturday we may see a very wet day for the west of the U.K and east of Ireland depending on where that line ends up being drawn. On this one I’d suggest you keep an eye on your forecasts for the end of the week but expect the Saturday rainfall prediction to change a lot. Sunday looks drier with lighter winds and all in all, a slightly nicer feel to the weather with a change to a more southerly / south westerly airflow and hopefully slightly better temperatures. It should remain dry with just the risk of rain across the north east and east I think..
So I knid of promised high pressure for next week didn’t I or at the very least hinted at it in last week’s blog well that’s what we’ll get, certainly for the start of the week anyway. So Monday should see us start largely dry and settled next week with a much warmer feel to the temperatures as that warm air pushes in from the west. Light winds so all in all a nice start to the week. It should be largely dry but there is a risk of some rain across the east of the U.K as the high / low battle line will be just off us in The North Sea. I think the west and south will be dry and warm and this should extend into Tuesday and Wednesday at the very least. The slight buggeration factor will be a northerly low pressure system that might introduce some rain across the north and west during the week but I don’t expect it to be heavy. So not exactly an Indian Summer but better weather next week, warmer and drier, still with the threat of some rain though but I think it won’t be a patch on this week and the winds should be lighter. As we progress to the end of the week we see Scotland and the north come under the influence of that low pressure so cooler and more unsettled here. The south and west should hang onto that warm high pressure though so a bit of a north / south divide on that front.
Disease Pressure – What else ?
Yep it’s that scratched record again but on a serious note we had another extremely aggressive week of disease pressure last week especially across the south of the U.K so I thought I’d first have a look at some data to see why. Then I thought I’ll have a look at some other locations around the U.K and Ireland to see if everyone was in the same boat ?
Now before you say there’s no location near you, I have to say I simply don’t have the time to download, transpose and graph out multiple locations…well not yet anyway….but I try my best..
So starting off with a south of England location, Epsom in Surrey (these are chosen randomly)
So above is a chart of rainfall, temperature and humidity over the last week and what I’ve done is to highlight in a red dotted line the period of time when the humidity was > 90% and the air temperature greater than 15°C.
Now it doesn’t mean that outside of this you won’t be seeing disease, it means these conditions represent maximum disease activity / pressure and that’s for me the most important thing to look at particularly when we go on to discuss fungicide efficacy.
So we can see last week that there was a period starting on 6.18 a.m. on the 4th Sept through to 10.41 p.m. on the 5th Sept, when the humidity and temperature were conducive to high disease pressure, a total of 39 continuous hours. We then had a shorter period between 8.46 a.m. on the 8th Sept through to 7.41 p.m. on the 8th Sept, when again disease pressure was high, another 11 hours in total.
So last week we had 50 hours of high disease pressure, that’s over two days worth and that’s why we saw very aggressive Microdochium.
Aggressive to the extent that most fungicides were unable to limit the reproductive growth of the pathogen because we are dealing with the see saw of fungicide holding back pathogen population growth vs. climatical conditions promoting pathogen population growth.
Last week during these red dotted periods, the latter won.
Now probably the only fungicide that would work in these conditions is a local penetrant like Iprodione because not only is the A.I loading high (the amount you’re applying per hectare) but it also gets into the plant fast. (and you need both to control disease…)
Dovetail that in with the potential presence of contributory turf conditions in terms of surface organic matter levels holding water and promoting pathogen growth, susceptible plant species that most of us are dealing with, Poa annua, and the problem is a hard one to deal with and will become harder once we lose Iprodione.
So if you had aggressive disease activity on your turf last week, firstly you weren’t alone and secondly, you’re probably going to have to get used to it to a certain extent.
Let’s look at some other locations and a quick trip across The Irish Sea to Cork…
Not quite so bad here in terms of the longevity of continuous disease pressure but it was still present for 24hours at the start of the week and then another short but nasty blip for 4 hours on Sept 8th. So we have a total of 27 hours of disease pressure here last week.
Half that of the Southern England location though mind…
Up to a not-so-sunny Manchester and you can see again we have some aggressive disease activity, not to mention a lot of rainfall (no wonder you guys are fed up of it 🙁 )
So for Manchester we see a period of 24 hours between the 4th and 5th Sept when disease pressure was extremely high and just to make matters worse no chance to apply a fungicide, turf hardener, etc because of the near continuous, heavy rainfall on the 5th, 8th, 9th and 10th… In other words tricky conditions from a greenkeeping and indeed groundsman’s perspective because not only will this combination of temperature and humidity drive on Microdochium nivale, it will also promote Red Thread, Dollar Spot and Leaf Spot to name but 3 others…
Not to leave Scotland out, we head up country to South Glasgow…
A shorter period of high disease pressure here simply because this location was cooler so 12 hours of disease pressure here.
So hopefully you can see how variable the disease pressure picture is and in this case how severe the conditions were for The Midlands south to The South West and southern part of England.
Now this week though unsettled will I think produce less disease pressure simply because we are cooler and we have a brisk wind which will reduce the humidity between the rain showers.
I’d love to hear your feedback on this at the end of the week maybe to see if this synposis is accurate.
That’s all for this week and hopefully a less bitchy one for us all 🙂
All the best…