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Hi All,

Thornton010417Frit

Well April certainly started off with sunshine and showers. I was fly fishing on Saturday with warm sunshine interspersed with some angry showers as you can see from the image above. The air was full of midges, House Martins, Sand Martins and some Swallows, all intent on putting on some insect-based calories after their mammoth flight up from Africa to the U.K. It’s a great time of year isn’t it if you’re out and about seeing everything bursting out of its winter drabness. And you get some real gems as well with these beautiful Snakes Head Fritillaries poking up to say hello. The pattern on their flowers is so intricate…

Last week I predicted that this week would be dominated by high pressure and I’m delighted to say that has come to pass so a much drier week in prospect but with high pressure comes cool nights and they as we all know are the hand brake to grass growth…So let’s look at this week’s weather in detail and a sneak preview on the run up to Easter which you may wish I hadn’t done when you see what’s on the horizon next week…

General Weather Situation

So a pretty straight-forward week to forecast on my side as high pressure is calling the shots but there will be a bit of rain about at the start of the week.

So Monday sees a cool bright start for most of the U.K and Ireland but already we have a band of rain just tipping into the west coast of Ireland. This will move eastwards across Ireland through the morning and early afternoon, decreasing in intensity as it does so. For the U.K we look to stay dry all Monday morning but by the early afternoon that band of light rain is into north west Scotland. By late afternoon it pushes south and east into central and south west Scotland so a wet end to the day here. Further south across England and Wales a pretty nice day actually, dry with long extended periods of sunshine. Temperature-wise I think we will see 15-17°C for central and southern parts, Wales as well, 12-14°C for Ireland and Scotland under that thicker cloud and rain. The wind will be predominantly from the south for most places and light to moderate away from that rain and moderate to strong under it.

Moving onto Tuesday and the remnants of that rain will be present as thicker cloud and some mizzly drizzle over England and Wales as we start the day. So a cool start here with that cloud cover pegging back temperatures but the areas that suffered the cloud cover on Monday (Ireland and Scotland) will see more in the way of sunshine on Tuesday. That thick cloud moves eastwards through the day so a cool, dull day for central and eastern England, warmer in the north, west, across Scotland and Ireland where you’ll see more of the sun. That thick cloud may be thick enough to bring some light rain and heavy drizzle to England on Tuesday. Temperature-wise, cooler for sure under that cloud so maybe 13-15°C across the south of the U.K and despite the sun for Ireland and Scotland it’ll feel cooler here as well, 11-13°C and that’s because of the wind direction. During Tuesday the wind will swing round from the west to a more northerly direction and that’s because the leading edge of the high is pushing in. It’s this wind that will peg back temperatures along with thicker cloud in places.

Mid-week and we are into Wednesday and we start with a near ground frost I think across the south and east of England where the skies are likely to be be clear overnight. For Ireland, Wales, the north of England and Scotland you should be spared this with more in the way of overnight cloud cover but it’ll feel cool on Wednesday make no mistake. That cloud cover for Ireland looks to stay in situ most of the day so a cool, dry day on the cards here. For the east of Scotland and England, more in the way of sunshine here and that’ll lift the temperatures a little, but further west and south across Wales and central England, Scotland, you’ll see more cloud. So dry but cool on Wednesday with a north westerly wind in situ and that’ll peg back temperatures to 11-14°C for most places, maybe higher where you see the sun.

Thursday sees another cool start for the U.K as you’re likely to have had clear skies overnight. Further west across Ireland though you’ll keep that thicker cloud cover to start the day I’m afraid. Through Thursday morning that cloud cover will sit over Ireland and Scotland (maybe the east will miss the worst), thick enough for some light rain in places it’ll be a cool, dull day here I’m afraid. England and Wales look to steal the show from a sunshine perspective and so we see a clear split in temperatures, 9-12°C across Ireland and Scotland under that cloud and 12-14°C across England and Wales. Through the day that cloud will if anything thicken over Scotland to bring drizzle and light rain across most areas as we go through the afternoon / evening. Most areas will still have a north westerly wind in place but it will be much lighter on Thursday and during the day it’ll begin to move round to the west.

Closing out the week on Friday we see a real change in temperature particularly for the west where you’ll now pick up the south and westerly winds from the high pressure as it moves eastwards so here we’ll see some nice increases in temperature to the high teens I think over Ireland and Wales. For Scotland and England it’ll feel milder as we enjoy more westerly winds but they’ll be more thicker cloud for Scotland and that’ll push in some showers into the north west of Scotland and central regions through the day. Further south over England you’ll enjoy more of the sunshine and so a warmer day to finish off the week so I think 12-14°C under that cloud in the north and 14-18°C in the sunshine. (probably highest across eastern Ireland and Wales)

Looking ahead to the weekend I think I got the last two weekends pretty spot on so here goes for a three in the row accumulator. (Obviously introducing a horse racing theme as we have The Grand National on Saturday 8th April 🙂 ). So how will we be looking for that great sporting event ? Well after a cloudy start for many I think Saturday is likely to be a beautiful day for most areas with Ireland, Wales and England enjoying bright sunshine and warming temperatures pushing up into the mid to high teens in places. Scotland and possibly the west of Ireland though may stay blanketed under that stubborn-to-go low cloud base and here it’ll be a duller, cooler affair. With a south westerly wind pushing up the temperatures I think 15-17°C in the sunshine and unfortunately 10-13°C under the cloud on Saturday. Sunday looks the slightly lesser partner of the weekend at this stage with thicker cloud cover pushing into most areas but temperatures are looking likely to hold up.  That cloud cover is signalling the arrival of an Atlantic low pressure that is set to dominate next week’s weather so all change I think from the dry theme.

Weather Outlook

So this week we sit under a nice peak in the jet stream and next week it’s trough time…As hinted at the start of this blog, next week couldn’t be more different with a much more unsettled theme to the weather starting off on Monday with rain already into Ireland courtesy of that Atlantic low pressure system and this will push eastwards to most areas through the latter part of Monday . Thereafter we look to be staying unsettled with a south westerly wind and frequent rain I’m afraid. Mid-week we look to have another low pressure slinking into the trough pattern and that means it is projected to sit right over the U.K and Ireland, so at this stage I foresee a wet and cool start to the Easter Bank Holiday.

Agronomic Notes

Ok so it’s the start of the month and as usual we’ll have a look back at the GDD and G.P data for March. I’m missing some of my usual contributors data so you’ll have to bear with me but I understand everyone is busy, so not a problem. For the vast majority of you, the spring is really early and we are significantly ahead of 2016 in terms of cumulative GDD, but let’s look at some U.K and Irish data to summarise March 2017..

GDDRainfallUKMarch2017

Four locations only this month but they tell a real story in terms of growth and also rainfall.

The highest growth levels have been experienced in the south of England with a total GDD of 126.5 recorded for Guildford and Thame not much behind either at 115.1.

Our Devon location (cheers Pete) was a bit on the cooler side and you can see why when we look at rainfall totals, 146mm for the Devon location and so the extra cloud cover has reduced the potential for growth, particularly at the start of the month. That shows that the rain was mainly Atlantic low pressure-based because it always hits the south west of England first when it is in this weather pattern. The same is true for Ireland as you’ll see shortly.

Fife, normally a temperate region of Scotland, highlights the north / south divide when it comes to the weather with a GDD figure of 48.6, so that’s approximately 38% of the growth in this location compared to Guildford.

IrelandGDDRainfallMar2017

For Ireland the situation in terms of GDD and rainfall is much more consistent with very little in the way of variation between Dublin, Cork and the west of Ireland. Valentia as usual shows more GDD. Look though at the rainfall pattern with the south and west of Ireland receiving a very high total rainfall for March 2017, but Dublin missed the vast majority of it with half of Valentia and Claremorris’s total.

Pattern of growth – March 2017

GuildfordMar2017GP

So we can see that in the south of England we enjoyed some very good periods of spring growth especially towards the end of the month. Interestingly we didn’t have 1 day in March 2016 when we exceeded a growth potential of 0.4 which highlights just what a poor month it was growth wise…

The pattern in Fife is very different…

FifeMar2017GP

Here we can see a cool start to March in Scotland, a reasonable mid-month period but strong spring growth didn’t really get going until the last two days of the month. Below is the same graph for Dublin (bearing in mind, Dublin, Cork and Claremorris were all very similar in terms of growth during March 2017)

DublinMar2017GP

A cross really between Fife and Guildford with some better growth mid-month and then strong growth at the end of March.

So how far ahead of 2016 are we ?

I’ve picked two locations to do a comparison, Guildford and Dublin.

I’d like to do more but it take simply ages to collate the data and put the graphs together.

It is worth it though when you look at the results (well I think so anyway :))

So first off Guildford, where do we stack up vs. 2016 ?

GDDCompMar20172016Guildford

So you can see the big difference in 2017 was the steady incremental rise in GDD from around the 7th of March, whereas in 2016 the graph is shallower and that means slower growth. You can actually see if you follow the 2016 graph through March and April that it flattens out at the end of April 2016 and that’s because we were still getting frosts right up to the start of May last year 🙁

So in the south of England, typically we are 3 weeks ahead of last year growth-wise.

Onto Ireland and using Dublin as an example the results are even more marked when you compare 2017 with 2016…

GDDCompMar20172016dUBLIN

Same exercise, different result and you can see how brutally slow a spring it was last year compared to 2017. If you follow the blue graph through April and into May you can see strong growth didn’t really start in 2016 until the end of April whereas growth started in 2017 way back in mid-February. Following the 2017 cumulative GDD from the end of March (148.9) it took me until the 8th of May, 2016 before I reached the same total, that’s a clear 5 weeks difference !

The coming week…

So this week we are dry but cooler, especially if you have either cloud cover or clear skies and a cool start to the day. That north westerly wind will also peg back temperatures mid-week as well…

My advice is to work hard to get any ongoing projects finished off this week, any outstanding renovations you’re thinking of getting done because by next week it’s going to be much harder to achieve the same result because of the rain and ever-present south westerly wind I think.

I don’t often pick South Wales as an area but let’s look at how Meteoturf projects growth and E.T here for the coming week ……

SouthWalesMeteoturf030417

We can see consistent growth through the week, not at the same level as last week mind but consistent nonetheless.

That surface is drying out….

You can also see that we have 12mm of E.T projected for this week in South Wales and coupled with a warm, windy Sunday it means the surface of the rootzone is going to dry out quickly.

I could already see some areas of green showing moisture stress on Friday last week so have the usual spring dilemna…to water or not to water. Now a lot of areas have had plenty of rainfall of late so this isn’t relevant to you, but some areas are dry and with a windy, drying week coming up, those rootzone moisture levels will drop markedly, especially at the surface.

For me it makes sense to do a short irrigation cycle ideally in the morning (depending on play levels / numbers) to just wet up the surface of the rootzone and ensure moisture continuity with adequate moisture deeper down the profile. You can achieve the same result by hand-watering the hotspots and leave the main irrigation alone for the time-being.

The argument about not wanting to apply cool water is largely redundant this year as we are warmer and also like most years we will enter a period of the spring when growth is limited not by temperature but by moisture availability. Even though you may have a moisture meter, remember that unless you have a shorter, custom probe (20mm) you’ll probably be measuring deeper than the issue with the standard 55-60mm probes.

Ok that’s it for this week, a lot of data to collate, thanks to everyone for their contributions and I’m glad we only do a GDD summary once a month !

All the best..

Mark Hunt