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Hi All,

Firstly an apology for being a day late, sorry about that but work and other matters conspired to make it impossible to post a blog yesterday.

As one of my customers stated though I’m only posting on Tuesday so I can get Monday’s forecast spot on ! which I thought was unfair but entertaining nonetheless (thanks Mr Porter :))

So the last blog of 2016 for me and before I embark on a weather resume and why it now looks like I’ll lose some or all of my Paddy Power White Christmas bets for a third year running (maybe only by a day up north bah bloody humbug 🙁 ), I’d like to wish you a Happy Christmas and all the best for 2017.

I’d also like to take this opportunity to thank those who have diligently sent in their weather data for my usage during the year, it’s so appreciated and without it I couldn’t make this blog as relevant as I hope it is to you all.

So thanks lads and lasses, you all know who you are, cracking service and much appreciated by me.

sunseeker201216

We are a day away from the Winter Solstice and as you can see from the Sunseeker image above, the yellow line that marks the path of the sun today is on top of the blue line that marks the path of the sun on the shortest day. After tomorrow the days gradually start to get longer again. Yipee….:)

jetstream211216

Not that some of us are going to be seeing much of the sun over Christmas unfortunately because we have an ‘L-pattern’ formation in the jet stream which means that it’ll push frontal low pressure systems across the Atlantic and straight to us, so in a couple of words, wet and windy will describe what’s on the Christmas menu. Now it only needs for that ‘L’ to take a little nudge down south and it’ll also bring in cold weather with it, hence my Paddy Power comment.

General Weather Situation

Ok Monday looks like being…..ahahaha thought I’d try that to see how awake you all are…

Tuesday looks like starting off quiet for us all with some hazy sunshine over the east of Ireland and central areas of the U.K but it won’t last I am afraid for the former. As mentioned above we have a succession of low pressure systems heading our way courtesy of a strong ‘L’ signal in the jet stream and the first of these rain fronts will push into the west of Ireland mid-morning. By early afternoon this will moisture band will also reach north west Scotland but because it’s colder up there it will fall as a wintry shower mix so maybe good for skiing in the Cairngorms over Crickey ?. By Tuesday evening that rain will be into the south west, Wales and the north west of England but amounts should initially be light. For the rest of the country away from this rain you can expect a settled cool, dry and sunny day with a slowly strengthening southerly wind. Temperature-wise I’d only be looking at mid to high single figures in the wind.

Wednesday sees that scuddy rain by and large clearing the central and southern U.K overnight with maybe a vestige hanging on across the east. Ireland will start largely dry with only Connacht likely to see rain from early doors but the north west of Scotland will see a mix of rain, sleet and snow (for higher ground) right from the off I’m afraid in what will mark for you a concentrated spell of wet weather over the Christmas period. By lunchtime we should see that cloud break over Ireland and the U.K from the north of England down to give long spells of winter sunshine marking the Solstice. Scotland will hang onto its wintry showers / rain mix and some of this may drift south into north west England and West Wales through the course of Wednesday afternoon. With clearing skies we may see a ground frost in areas of the U.K and Ireland for Wednesday night, Thursday morning.  Cool again in strengthening westerly winds.

So onto Thursday and more or less a dead ringer of Wednesday with that rain embedded over central Scotland right from the off I’m afraid and some of that murky rain may be lingering over north west England during Thursday morning. South and east of this for the rest of the U.K and Ireland you should enjoy a bright, dry and sunny day so don’t ring me because I’ll either be on a bike or in a boat 🙂 By the afternoon on Thursday we may indeed see some rain drift into West Wales and then fizzle out. Cool again with a strong drying wind in the south and west but wet again over Scotland so expect high single figures temperature-wise.

Closing off the week (I like these 4-day weeks) Friday sees the first of those low pressure systems really start to wind up so that means tight isobars and a strong westerly wind reaching gale force up north I’m sure. By dawn that system will be pushing rain into Ireland and Scotland and this will move quickly eastwards aided by that wind. That rain will increase in intensity by lunchtime on western coasts and it’ll move down into northern England by early Friday afternoon pushing down into The Midlands by close of play and then onto southern England, clearing Ireland as it does so. Similar temperatures for most except Ireland where it’ll feel noticeably milder.

This is when it gets interesting for me as I have some spread bets on Paddy Power and they are orientated to the north not surprisingly. So for Christmas Eve (one flake, just one flake…) we kick off Saturday with that rain band still in evidence over north west Ireland, Scotland and England but elsewhere it’ll be a bright start for most. That rain will be falling as wintry showers over elevated ground in Scotland and over The Pennines first off. By lunchtime that rain / wintry shower mix will still be in evidence across Scotland and the north of England but south and west of this it’ll be a nice, sunny and very windy day (good for drying things out though) with a very strong westerly wind in situ. By mid-afternoon that wind will be introducing fresh rain fronts into the west of Ireland and these will move rapidly eastwards to reach the west coast of the U.K late on Christmas Eve providing a strong headwind to Santa’s efforts so expect delays in present deliveries. (that’s what I’m going to tell all of my relatives anyway to explain the lack of presents :)) Cool across the U.K but remaining mild across Ireland with double figure temperatures likely.

Christmas Day looks at this stage like being a story of two halves of the U.K and Ireland with Scotland and the north of England cool with a lot of rain around, some of it heavy and very, very windy. Down south we will have a very stong wind early on Christmas Day but gradually it’ll ease through the day. That mild air from Ireland is predicted to reach central and southerly parts of the U.K by then so you may see people in shorts enjoying low teen temperatures.It won’t be dry though initially because that rain from Christmas Eve will be in situ across most of the U.K for Christmas Day morning but by the afternoon we should see the sun breaking through away from western coasts and across Ireland just in time for you to walk off Christmas lunch with attending methane clouds quickly dispersed in that strong wind pnar pnar blaming the sprouts and parsnips I’m sure 🙂

Weather Outlook

A short outlook for Christmas week starting with Boxing Day…

I think Boxing Day will take on a much cooler feel as the wind tips round to the north west so maybe, just maybe a late Christmas Day flake, come on Santa, make my day. There’s likely to be some more rain over the north of Scotland but this may be the last of it.

So potentially glad tidings I bear particularly for Scotland which will have had a hammering with the rain and wind over Christmas. At this stage the projection is for high pressure to build south of the U.K from the Tuesday of Christmas week so that should push any unsettled weather over us and relieve saturated areas in the north with a spell of settled, dry weather for the rest of the week. So that means a return to cold nights, frosts and settled conditions. These should last until the run up to New Years Eve when I think new low pressure systems will push in to introduce windier, wetter and milder air for start of the New Year.

Agronomic Notes

mycelium

This year I think the ‘m’ in December stands for MYCELIUM !!!!

I cannot remember a time when I have seen so much mycelium from Microdochium nivale but also Red Thread on outfield areas be they tees, approaches, fairways and some winter sports pitches. It’s interesting because when you look at the past week it hasn’t been especially mild but two factors alone have contributed to this huge flush of disease.

The first is humidity, that is atmospheric moisture levels. We have been running on pretty much moisture-saturated air for the last 5-7 days with little wind to dry out the grass leaf. So now we know that if we have humidity levels over 95% during December we will have disease ?

Well not quite, because if we have rain we will also have high humidity levels but when we have cool, wet and windy weather we don’t see anything like the disease pressure so it’s not just having a wet atmosphere, it’s the ‘type of moisture’ that contributes to disease pressure . (I’ll explain later)

The second factor is overnight temperatures and last week what we saw was some nights when the night air temperature was identical to the day air temperature at 7.5°C. So we had a comparatively mild night, little air flow and fine, misty moisture in the air.

Dew

Now I’ll come back to the ‘type of moisture’ that contributes to disease and mycelium formation. When we have misty, foggy conditions what we are seeing is very fine droplets of moisture in the air and these are very effective at coating a surface with droplets including a grass leaf. With little wind / air flow there is precious little E.T to move these droplets off by evaporation and so we have a saturated leaf surface for the majority of a 24 hour period. Even if you are physically removing the dew by swishing, brushing, cutting, it will only be a short-term solution because moisture from the air will settle onto the leaf afterwards.

Fungal mycelium grow favourably in just such an environment and utilise the moisture to move up a grass leaf and to cross between one leaf and another. So that’s why we are seeing such disease pressure at present on higher-height-of-cut areas, air temperature and an atmosphere saturated with fine moisture droplets.

As we pick up a stronger wind this week we will see this disease pressure drop even though the humidity will remain high but the type of moisture and the presence of a strong wind / air flow will prevent droplets of moisture remaining on the grass leaf and this will make it harder for the mycelium to form and move IMHO.

What to do on affected areas ?

If the disease pressure were to remain high you wouldn’t actually achieve anything by trying to fertilise out the damage and that’s because when the plant is being attacked by a pathogen it is being damaged physiologically so even though you may have applied a fertiliser you won’t necessarily see a response.

I remember a few years ago I had an aggressive attack of Red Thread on my front lawn even though I’d recently applied a granular fertiliser. So to test the hypothesis that the disease was holding back the grass plant from taking up nutrient I sprayed half of the lawn with a fungicide. (cue twitching curtains)

In the picture below you can see the two halves, the area on the left of the augur has been treated with a fertiliser and a fungicide, the area on the right just a fertiliser. Hopefully you can see how healthy the area on the left looks because with the disease controlled, the grass is able to grow normally but on the right, it isn’t…

RedThreadThrottle2

So looking at the weather this week I think we will see a lowering of disease pressure (even though we may see a spike on Christmas Day) because of the change to windier weather and so if you did get out and apply a light foliar with iron then you should see a benefit and some recovery. (Obviously this won’t be possible across areas affected by the high wind and rainfall such as Western Scotland)

I’ve been asked if brushing areas whilst they are full of mycelium would spread the disease and I guess it probably would but I’m not aware of any specific research on Microdochium nivale. Once the disease pressure has reduced then I think brushing out the dead and decaying leaves is the correct thing to do to allow more air flow into the grass canopy.

One last point to make about this kind of outfield disease, it isn’t fussy about grass species and so far I have seen (or had reports) of Poa annua, Ryegrass and Fescue equally affected. Here’s a picture from some Fescue turf (with I think some rye in it) with classical Microdochium nivale mycelium in full flight…(Bet you like that one Kate :))

mcelium3

Ok that’s me done, thanks to everyone for their contributions in 2016 and may I wish you all the best for 2017.

Mark Hunt