May 3rd, 2021 - April Showers ? Not any more...

Hi All,

Well another Bank Holiday despatched and depending on where you were located it was either reasonably nice or a bit of a damp squib. We have been sitting in a bit of a back eddy weather-wise of late with no one system dominating. Throw in a slow-speed jet stream and you have a propensity for stalemate in the upper atmosphere. That said, more cloud cover of late has kept night temperatures up and that's helped growth no end despite the lack of rain in places. We finished with 17.4 mm in total for April here in Leicestershire and as I commented in an earlier blog when I looked back at recent April weather patterns, the trend is dry and cool / cold. Dry it certainly was....

General Weather Situation

So as we stand today, we are sandwiched between warmer air out in The Atlantic and cooler, moist air over the continent. This means the west and particularly Ireland will be pleasingly warm for the first half of this week whilst further east and nearer the cooler air mass, it will be a tad unsettled. So for Tuesday we will see some showers feed in today across the north and central regions of U.K, but these will move slowly as there's very little wind around today and what there is will be changing direction. Yesterday I fished Rutland Water and within the space of a 6 hour session, it blew from all 4 directions at one point or another ! Confusing for me and the fish (well that's my excuse any way !). A cloudy day for most with only fleeting glimpses of the sun but it will be pleasant enough at sort of mid-teen temperatures for the U.K and a few degrees higher for Ireland with more chance of seeing the sun as well :). Light winds today, primarily south easterly. Later in the day we will see some showers more down the east coast of Ireland and drift across Wales.

Overnight into Wednesday and that cloud cover will hold up night temperatures (good for growth as we will discuss later) nicely this side of double figures. They'll be a rain front that will push into the north west of Scotland and north of Ireland and this will move south in the wee hours to affect Scotland, northern England and the east coast of Ireland by dawn. Through the morning this will push showers southwards into The North West, Wales, The Midlands and East Anglia but as usual, some will see them, some won't. Ireland will see those showers clear before dawn and it'll leave behind plenty of cloud cover though later the sun will break through and temperatures will rise into the high teens here. For Scotland, England and Wales, the 2nd half of the day will see less showers, still plenty of cloud and temperatures will push up to 16-18°C, so not bad. Winds will pick up a little and push from the west / north west.

Thursday sees another front of rain push in from the north west of Scotland and move south overnight. By dawn it'll be gracing The Western Isles and west of Scotland and separately another front will push showers down across Ireland with heavier rain pushing into Connacht mid-morning. That rain or at least the heaviest of it will stay pinned across the north west of Ireland and Scotland through the course of the day with just the odd shower pushing south into England and Wales. Sunnier than of late for England and Wales and some better temperatures as well as a westerly wind brings over some of that Irish warmth with temperatures in the high teens and maybe nudging 20°C down south like.

Friday looks a complicated old day in terms of forecasting rain with showers again affecting the north west of Scotland, England and Wales, with some across the west coast of Ireland as well. During the morning these showers will consolidate into a heavier band of rain for the southern half of Ireland and this band of rain will stretch eastwards into northern England. Through the course of Friday afternoon, this rain will push southwards into Cork, Wales, The Midlands and possibly East Anglia. By late afternoon it'll spread itself across the southern half of England leaving behind showers for Scotland, the north of England and east of Ireland.

So what's the outlook for the weekend ?

Well Saturday looks good, mainly dry, little cooler temperature-wise, courtesy of a north easterly wind whipping up. So varying amounts of sunshine and cloud on Saturday, a little cool but dry nonetheless. Sunday sees the wind change 180° and switch round to a southerly and that'll mean a little warmer on Sunday and staying dry with a sunshine and clouds sort of forecast with temperatures nudging up to 16°C I'd say. Both Saturday and Sunday will start cooler than of late with single-figure night temperatures.

Weather Outlook

Without wishing to blow my own trumpet here, I think I picked out the 9th / 10th May as a change date for our weather and this does indeed look to be how it will play out.

The GFS output above shows something we haven't seen for awhile, an Atlantic low pressure system, a south west air stream and some heat into the southern half of the U.K. So next week will be a lot wetter for some because as we know, a south west wind tends to push in rain across Ireland, the north west of England and Scotland and that's what we will see for the first half of next week with rain on Monday, Tuesday and Wednesday for those areas. Further south it'll be notably warmer with temperatures breaking into the low twenties I think. The second part of next week sees the boot on the other foot as the rain looks to have a more southerly orientation so Thursday looks wet for all areas other than Scotland. Friday sees that unsettled picture continue for the north and west before high pressure pushes the rain north of us and settles things down for the weekend. With continuing cloud cover next week that means night temperatures will hold up and give us good growing weather with day time temperatures in the mid to high teens.

Agronomic Notes

GDD Monthly Total - April 2022 - The Oxfordshire

Looking at the stats above we see that April 2022 on first sight came out as a pretty reasonable month from a GDD perspective with a total of 102.1 GDD. If you compare with previous April's that's about average. Looking at the data above, the average GDD for April going back to 2005 to 2021 is 94.8, so yep about on the money.

What made April 2022 a tricky month for growth was two main factors, cold night time temperatures with frosts even at the end of the month and it was very dry, another feature of April.

At this location we picked up 19.6 mm of rain for the month, which I think is pretty similar to a lot of locations. Even one of our usually wettest locations (sorry Pete) down at Okehampton, Devon came in at 42 mm. At the other end of the country, Fife was similar at 40 mm (thanks Jon) . Most of the rainfall fell in the first part of the month so actually the number of dry days in April was high, again, this is par for the course.

Here's a selection of April rainfall totals from around the UK & Ireland for this April.

So one aspect that made April tricky was that it was dry and that means the balance tips in favour of bentgrass growth over Poa annua as I covered last week in my blog. Now depending on your sward composition, that was either a blessing or a curse.

Continuing my theme from last week and using the same Sevenoaks location, but now for the completed month, we can see the soil moisture deficit continued right up to the end of month and the soil moisture (from a heavy soil fairway area at 100mm depth) fell to just over 16 % vmc by month end after starting it nearer 40% vmc. (volumetric moisture content)

So you can see quite a mixed bag growth-wise even factoring out the E.T - moisture deficit and the lack of rainfall. Can you pick out the days of the month when the night time temperature held up ?

The highest night time temperature all month was on the 23rd when it held at 9.3°C with a corresponding growth potential value of 0.62, which represents good growth. 4 days later we had a run of ground frosts and daily growth potential figures barely above 0.1, in other words, very little growth. Night time temperatures are the handbrake to good spring growth no matter how warm it gets in the day and thankfully with more cloud cover since Saturday and projected for the next week or two, that should mean some growth consistency should occur on fine turf.

Strategies for managing growth during this type of weather

So there are some basic agronomic practices to try and manage these type of conditions, not least an effective irrigation system. I know opinions are divided on early irrigation but since only the surface is drying down, we aren't talking huge amounts of irrigation and also if we are overseeding early, we need to maximise the potential for new seedling germination though realistically with the typically cold soil temperatures that come with April, it's really from next month onwards that this becomes critical.

Wetting agents should always go on before April, look at the stats above, April is normally a change month from winter to summer, the jet stream runs out of puff and typically high pressure comes to play. April showers ? not any more me thinks. May is normally more typical of a sunshine and showers type of weather pattern. So having a surfactant and biostimulant down early makes really good sense to me because no matter how good your applied product is, it doesn't work very well without water :)

Early biostimulant use to take the stress off the grass plant is also a given and I have always found applying with a wetter is a great synergistic combination.

We talked about PGR's last week and thanks for some of you for feeding back on early PGR usage. The consensus so far was that it definitely helps with seedhead expression but it can delay winter recovery on Poa-dominated greens and that in a sentence is what you have to balance up. You can't expect Poa to grow well during these conditions and especially if you have applied a specific PGR. The flipside of that coin is winter recovery not withstanding, it can help manage Poa during this tricky part of the year. Horses for courses folks.

Nutritionally-speaking, when you have low growth potential, it follows that you'll see slow / low response from applied fertiliser and given the price of product nowadays, it doesn't pay to chuck it on and hope. Well-timed foliar applications tend to come into their own I think at this time of year and picking out the days when night and day time temperatures look favourable is all part of successful management. Working with the weather rather than against it is key. Chucking 40kg of fast start nitrogen on in granular form when it's cool and above all dry isn't likely to produce consistent growth or happy campers. Just saying...

Ok, that's me for another week but before I depart, I just want to wish Angus, Jamie and crew all the best with their tournament, The British Masters. I only hope they have a good interpreter and subtitles for any on course interviews with the wee man as he has one of the trickiest to comprehend Scottish accents out there 😂😂😂

Long ago when I started in this industry, an early May day was considered bloody hard work for hosting a tournament in the UK & Ireland. Nowadays we have more tools in the tool box but we still have the weather to contend with.....good luck chap.

All the best

Mark Hunt