140728_gfs_pres_500p_loop_eur

Hi All,

Firstly, apologies for last week’s blog, we had to publish it twice so many of you will have got more than one notification, hopefully this week it’ll go more smoothly 🙂 Rainpattern2014Another very warm week for most last week with temperatures hitting 30ºC at the end of the week and over the weekend. This week will be cooler, but still very pleasant until the weekend that is…

We also had some very heavy thunderstorms in the south and south-east of England on Friday, prompting the veritable Kate Entwistle to complain on Facebook that I didn’t forecast it !!!!! I mean Kate using social media against me, just not fair…!! Now if you do insist on living closer to the equator down that neck of the woods, you should expect the unexpected when it comes to rainfall 😛

On a serious note, we’ve had two patterns of rainfall of late, (see image right) one from the north-west, one from the continent affecting the south-east and south of England, but that gap in the middle is extremely dry and has seen nothing of the rain, so I expect when we get to tally up this year’s rainfall, it’ll be the central and eastern belt of the U.K that’s the driest. (again)

General Weather Situation

Well it’ll be a cooler week this week than last, still pleasant though and with more tolerable night temperatures to boot. By the end of the week, we may even see some rain for most areas and certainly for the start of next week there’s a significant change on the horizon.

Monday is starting off fine and dry for most of us, except those affected by that continent rain front, so that’s the south-east of England, south coast along to the south-west of England. Elsewhere it’s dry, warm and pleasant with hazy high cloud.

* Stop Press * – Nathan at Sutton Green Golf Club, near Guildford has just reported 52mm of rain so far today with 35mm in 45 minutes, so they’re getting clattered, plenty of bunker pumping and raking for tomorrow I guess 🙁

That’s the way it’s set to stay with rain on and off in those areas during the day and later on this afternoon, a new rain front pushes into Connacht to bring a wet conclusion to the day. Out of the rain, winds will be light and from the south-east with temperatures in their low to mid-twenties.

Tuesday looks a much better day for the south of the U.K, but that rain front over Ireland looks to push south and east across most of the country through the day, weakening as it does so. Tuesday morning also sees rain into the north-west of Scotland pushing south into The Lakes and north-western England probably reaching as far south as Manchester before dissipating. Elsewhere it’ll be fine and dry, with temperatures in the low twenties and light to moderate north-westerly winds.

Mid-week sees more rain affecting the north-west of Scotland pushing south over most of Scotland through the day. Elsewhere it’s another fine, bright, sunny day with temperatures in the low to mid twenties.

Thursday sees more rain for the north-west of Scotland, but there’s also the strong possibility of some of this rain coming into Connacht / Donegal and pushing south eastwards across Ireland through the day. Again south of this line and very much like the pattern I showed at the beginning of this blog, it’ll be fine, dry and warm with similar temperatures to Wednesday. Winds will be light and from the north-west.

Friday sees a much more unsettled picture as a low pressure system starts to spread it’s influence further south. So more risk of rain for most of Friday, again it’ll be concentrated in the north-west of the U.K initially, but it’ll soon spread across Ireland, Wales and the south-west of England through the morning and it may just creep into The Midlands, but we’ll see. As the low pressure rotates around, it’ll move this rain northwards later on Friday night into the north of England and Scotland, with some potentially heavy bursts amongst it. Temperatures will be a little cooler under that cloud, high teens / low twenties the order of the day.

The weekend is looking pretty unsettled, certainly from the M4 up to the north of England inlcuding The Midlands where there’s risk of heavy rain during the day on Saturday and also with rain over Scotland courtesy of that low pressure. Between the two it should be fine and dandy, cooler though with more cloud cover, but pleasant all the same. Sunday looks much the better day of the weekend with that rain clearing the north and Scotland and leaving a dry, warm, pleasant day for many.

Weather Outlook

So lads who’ve had lot’s of rain lately will be asking if it’s going to continue and lads who have had note will be asking if they’ve going to get any ? Well I think next week will see a very rare (for this summer) Atlantic low pressure system coming into play, just in time for my annual pilgrimage to Denmark for our family reunion, so that means a wet and windy Jylland is on the cards. So after a nice Sunday, I think Monday will be quiet before rain arrives into Ireland and then the west of England pushing across the U.K on Tuesday and Wednesday. It also looks like we may have a very heavy bout of rain following it later in the week so potentially Thursday and Friday may be very wet indeed. Temperatures will be high teens, cooler and fresher with the wind from the south-west.

Agronomic Notes

Seriously High E.T and why I think the Growth Potential Model Base Temperature is wrong for Poa annua

Got some E.T data from Sean (cheers) at The Oxfordshire and as you can see we’ve shifted alot of water out of the soil over the last two weeks, despite the fact that some of you may have got it topped up again in a pretty significant fashion!

ETLossJuly2014

As you can see from the above, we’ve lost 65.7mm of moisture from the turf canopy over the last 14 days, I think that’s the highest I can ever remember seeing. Based on the fact that you need to replace 50% by irrigation and / or rainfall that makes a 32.85mm requirement. It means a lot of plant stress and that’s where I come on to the Growth Potential calculation.

As some of you may remember (or already know) the model is set with an optimum growth temperature of 20ºC and therefore if we have an average temperature of 20ºC across the day and night that means we’ll have a GP figure of 1.0, which is optimum. Looking at the chart above, the GP has been close to 1.0 all the way through the last week, except for Saturday when the maximum air temperature went to 32ºC at The Oxfordshire, so the GP dropped. For me I think Poa has been under stress for the last two weeks and so the GP model should be showing this with a lowered daily figure, but it’s not and therefore I think the optimum temperature is set too high at 20ºC, it should be more like 18ºC, so that’s what I’m going to change to in 2015.

 Nitrogen in the rain

Last week I mentioned about the fact that rain during lightning often carries with it extra nitrogen because of oxidation in the atmosphere. lightning1Well I took two samples last week, one in a morning storm that showed about 0.25kg / N / Ha per inch of rainfall and the other later in the evening recorded 1.25kg / N / Ha per inch of rainfall, which is quite a whack really and the highest I’ve measured in the U.K. So Kate if you’re getting a lot of thunderstorms down your way, take a chill pill, because at least you won’t have to go out and fertilise the lawn for a while! Interestingly the pH of both storms was the same at 6.4.

Disease Outlook

Bipolaris

As you’d expect with the combination of temperature, humidity and rainfall, this summer’s list of diseases continues to increase….

A first for me was this Bipolaris Leaf Spot recorded on a course in The Midlands last week. Appearances are deceptive because I thought it might be Pearlwort die-back (though we’re a little early for that) or Spiral nematodes, but it turned out to be Bipolaris. Reading up it needs consistent high temperature and humidity to become pathogenic and that’s just what we’ve had over the last fortnight…

Other than that we have plenty of Fairy Ring, Thatch Collapse and Superficials doing the rounds and I think ‘if and when’ the moisture arrives, Microdochium nivale (Fusarium to you and me) will become very aggressive, more so next week when it’s cooler and wetter.

Ok that’s it for now…time to dash, Mazz put the kettle on for 1.35 please 🙂

Mark Hunt