Hi All,

Well after another exceptionally mild October week / weekend, when I walked the Rutland peninsular in a T-Shirt yesterday, the news this week is in the forecast…

Pretty wet mid-week and pretty bloody cold thereafter as northerly winds pull cold air down from The Arctic and they’ll have us all reaching for those winter coats and a decent buff.

After the warm October, it’ll come as a bit of a thermal shock, but our bodies will adapt. I remember back in 2013, when we had that really cold start to the year with day after day of easterlies and close to zero temperatures. One day the temperature went up to 6°C and it felt tropical, this time it’ll be the other way round. !

I don’t think this is an early step down into winter just yet, it’s a bit early for that….

GFS output 18-10-21

General Weather Situation

So as predicted last week. the first part of this week is all about low pressure, mild, south westerly winds, gale force at times and rain, lots of it.

Already today we have a band of rain having crossed Ireland overnight and now it’s into the western coastline of the U.K, crossing Wales, The North West and edging its way into western Scotland. This band of rain will track north and east across the U.K, but it’ll fizzle out as it reaches central and eastern parts. So here a mild, dull day with a moderate south westerly wind and temperatures in the mid to high teens. For Ireland, a reasonably dry and mild day after overnight rain but for Scotland, it’ll be a wet one as that band of rain crosses central areas and moves eastwards through the day.

Onto Tuesday and overnight we see another pulse of heavy rain push into Ireland with some showers along the south east coast as well. By dawn most of Ireland will be under heavy rain accompanied by strong winds and this will also be pushing into the west of the U.K, with some additional rain across The South East. Through the morning this rain pushes into The South West,Wales, The North West and Scotland and then tracks north and east probably missing the south and south east as it does so. A second front of rain pushes into Wales and the west later in the day and this one heads south and east so overnight into Tuesday that’ll catch central areas as well. Wales will get a clattering, as will Scotland with Ireland seeing strong winds and rain throughout the day. It seems strange typing this now with scarcely a breeze to trouble the treetops. Not cold though because that wind is south westerly and vectoring warm air in, so 16-19°C across Ireland, Wales and England, with Scotland in the mid-teens. Mild, wet and windy then is the forecast for Tuesday with the south and east of England missing the first rain front but catching the second 🙂

Mid-week beckons and after some heavy overnight rain for the southern half of the U.K, Wednesday still finds us with rain across Ireland, particularly for Munster and Connacht but also across The Irish Sea for Wales and southern England / Midlands. During the morning that rain will again move north and east across the U.K, so another day of strong south westerly winds, not as mild as the start of the week as those temperatures commence a gradual nose dive. The rain looks to be concentrated across the north west of Ireland and England pushing up into The Borders but I think Scotland should miss most of it. Ireland sees the north of the country wet but drier across central and southern parts until the evening when more rain pushes into Kerry.

Overnight into Thursday and the temperatures continue their sharp drop into single figures but this time they don’t recover, so by dawn on Thursday it’ll feel noticeably chilly especially across Scotland and Ireland where skies have cleared overnight. It won’t be clear everywhere because they’ll be a band of rain stretching across from mid / North Wales to The Humber at dawn and this will slowly sink southwards during the morning before fizzling out across the south coast of England in the afternoon. So for Scotland and Ireland, a sunny but noticeably chillier day on Thursday as those winds whip round to the north. Plenty of sunshine but chilly like. Further south as that low pressure departs, the wind will still be making its mind up quite which way it wants to go, so light to moderate winds. Temperature-wise, just struggling into double figures in most areas.

Closing out the week on Friday we have a pretty dry picture across the U.K & Ireland save for a risk of showers across the far north west of Ireland and along The Mersey estuary. Elsewhere it’ll be dry, cold with some sunshine but also plenty of cloud about as well. The feature of the day will be strong north / north westerly wind that’ll keep things on the chilly side and continue Thursday’s theme in that respect. So across all of the U.K & Ireland, save maybe for the Mersey estuary / North Wales where there’s always a chance of a shower streaming in off The Irish Sea, a cold day with temperatures hovering around double figures but no higher.

So how do we look for the weekend ?

Well hmmm….delicately balanced I’d say…Saturday sees probably the best day of the weekend for the U.K, but it’s a downward spiral for Ireland as a front of rain, some of it heavy pushes into the west early doors and moves eastwards across the country through the course of the day. That means that Sunday is the better day for Ireland, but not for the west of the U.K, which will see rain from dawn on Sunday and this will in turn move eastwards through the day. So the best place to be this weekend is kind of east if you want to avoid the rain one way or another. Temperature-wise, Saturday remains on the cool side but Sunday is milder as that wind swings round to the south west. You’ll notice this first across Ireland where it’ll be mid-teens on Saturday and slightly milder still on Sunday. There will still be some showers across the west of Ireland on Sunday but these should be confined to the coast. Scotland will see a wet start before that rain clears on Sunday and another tranche moves into the west later in the day. Here it’ll remain on the cool side with double digit temperatures only as opposed to England and Wales where it’ll push up into the teens on Sunday despite the rain.

GFS output 25-10-21

Weather Outlook

So we start next week with another unsettled sort of outlook beckoning from the GFS but actually it doesn’t look like being a re-run of this week. First up at the start of the week we will be unsettled with rain crossing Ireland into the U.K during Monday and overnight into Tuesday with a band of rain across the U.K accompanied by strong, south westerly winds. Temperatures pick up through the week as we see more rain on Wednesday but this time it’ll be with a northern-bias. From mid-week, next week we have a ridge of high pressure pushing up warm air through Wednesday to the end of the week so I think high teens is entirely likely in conjunction with moderate to strong westerly winds. As we go through to the end of next week, the winds tip more north westerly and that’ll cool things down a little and introduce a more showery nature to the weather before high pressure nudges in again in time for the weekend with lighter winds and cooler temperatures.

Agronomic Notes

Well it’s been a real up and down October so far with some really humid and mild air, perfect for disease development, especially over the last 10 days….

Yeah well you might say, that’s what we get in October Mark…..OK, then ever seen Red Thread that looks like this ?

It’s Red Thread….but not as we know it…

Nope, me nether…..I’ve never seen such aggressive Red Thread formation in a patch like this, never in 31 odd years (geez I am old :))

Temperature / Humidity profile – October ’21 to date – Northampton

When you look at the humidity profile for this month so far and consistently see it topping 90%+, you get the picture that it’s been a really humid month.

October has also shared another recurring feature of the last few months, a real lack of consistent wind. So the air has stayed settled and muggy and that’s perfect for disease development.

For that reason we see fungal growth in overdrive as in the image above of Red Thread.

The good news is we saw this peak coming and I know many of you reacted to it preventatively, whether that be dew control, non-pesticidal or pesticidal (or indeed a combination of the afore-mentioned). Maybe you didn’t, maybe you just let the disease ride in and do its bit, confident that at some point the weather will change and knock it on its head. Personally that isn’t the smart play anymore (or maybe never was) because we know from experience that as soon as we let disease establish in the autumn, we are on the back foot and resigned to a drawn out period of resurgence and yet more resurgence after the high inoculum level is established.

The good news is that this weeks weather will serve to decrease markedly the level of disease pressure though those high temperatures on Tuesday could be challenging if we lose the wind speed.

A bunch of rain followed by cold and windier weather will do a nice job of putting Microdochium and other foliar pathogens back in their place.

You can see this clearly in the disease model prediction for this week from a location in South Wales with a drop off in disease pressure from mid-week.

Predicted Microdochium nivale pressure – w/c 18-10-21 – Newport, S.Wales

The next hurdle from a disease pressure perspective could potentially be the back end of next week when that high pressure is predicted to nudge in some mild temperatures just in time for Halloween. Well that happens a lot, except last year from memory when we had an unseasonably cool end of October.

You can see from the MeteoTurf output what a topsy-turvy ride we are going to have temperature, rainfall and growth-wise when you look at the Growth Potential figures for the same location. This Tuesday we will hit nearly optimum G.P (in the third week of October !) but 2 days later and we will be down at 20% odd of optimum before recovering again at the end of the weekend / early part of next week as that wind shifts round to usher in milder air.

It should knock grass growth on the head though as soil temperatures will drop back from their current high of 13-14°C !

If I was planning a foliar I’d leave it in the locker till this weather event has passed because with heavy rain forecast, then cold, then mild, I’d wait till next week and apply on an upward G.P curve when the grass has had time to re-orientate itself somewhat !

Could do with a bit of that myself currently.

All the best.

Mark Hunt