Pinch and a punch, first blog of the month and all that. So we meander into July from what was a cool and wet at times June. Not complaining because as we discussed at the end of May, if we have 3 months of high temperatures and E.T across June, July and August, we will be in a critical situation from a water perspective and the grass plant will be on its backside.
Now we know it is only a matter of time before we pick up some heat again, after all it is the summer, but every week closer to the end of August is a week saved from this perspective.
General Weather Situation
Crumbs it’s been windy but surprisingly it hasn’t generated sky high E.T levels every day, I’ll talk about that later. So the reason for the strength in the wind is clear to see from the GFS image above. High pressure sits to the south west of the U.K, low pressure to the north east and so the winds are funneled between the two competing weather systems. They will relent this week a tad.
So Monday starts off with sunshine and still breezy. The winds in the north west so that means we are likely to see a sunshine and showers day and sure enough we have some heavy showers moving over central Scotland, the north west of England and across The Black Mountains of Wales. I once mountain biked over the Black Mountains in October, it seemed like a good idea at the time 🙂
As we progress through the morning we will see these showers move into the north Midlands and then during the afternoon they’ll affect the eastern side of the U.K. Dry for Ireland it looks like with only the occasional interloper of a shower. That strong, blustery wind will stay with us from the north west today so that’ll keep temperatures down to the mid to high teens, with the lower figures further north and west.
With further ado we are hop skip and a jumping onto Tuesday and overnight a new Atlantic low has slipped into the picture just off the coast of Ireland. During Tuesday morning this will bring rain to the north west of Ireland and western Scotland before it sinks south and east across Ireland and into north west England. South and east of this expect a dry, bright start, still breezy but now the wind is swinging westwards and maybe decreasing just a tad. During the afternoon the rain consolidates over Ireland and moves south into northern England and the north Midlands, north east of England. As it does it begins to fragment and dissipate so as usual with a north west low pressure, not that much gets to the south of England. By dusk it has cleared Ireland and most of Scotland to leave showery picture across The Midlands, Wales and southern England. Under that rain and heavy cloud expect 13-15°C, further south temperatures will rise into the low twenties in the absence of cloud.
Wednesday beckons and that rain now lies straddled across the Mid-Wales and the north Midlands. Overnight it has been joined by more rain in off The Atlantic which will affect the southern half of Ireland from dawn. Through the morning that rain will fizzle out across the south of England so for the north and Scotland, Wednesday looks reasonably dry, if a little dull, with the odd shower across The Highlands. That low pressure of Tuesday sort of punched a hole across the U.K and pushed the high pressure further south and this will allow a new Atlantic low to come in and dominate. So on Wednesday we see that low feed in showers across the south of Ireland and the southern half of the U.K, though at this stage it looks like the band of showers will stretch across Wales into The Midlands and East Anglia and reach up towards north Yorkshire. As that low pressure edges closer to the west coast of Ireland, those showers will consolidate to longer spells of rain for Ireland, Wales and England. Very much a south of the U.K-orientated low pressure system so that means Scotland will miss most of this and only pick up a few showers. Temperature-wise, we will see a significant variation depending on whether we pick up cloud cover and rain, with 16-17°C likely over Ireland, Wales and northern England, Midlands and Scotland. Further south away from the bulk of that rain and again you’ll nudge into the low twenties. The winds will freshen from the south west through the day, first over Ireland, then the west of the U.K and overnight it’ll become windier everywhere.
Thursday sees that low pressure track north overnight so by dawn it’ll be sitting off The Western Isles. This means the wind and rain will follow it north, so first thing on Thursday expect showers pretty much everywhere from the off, with the heaviest rain across the north west of England and Scotland. Through the morning this heavy rain will track eastwards across Scotland and leave behind a trail of showers in its wake across Ireland, Wales and the north of England predominantly. These will fizzle out for a time as the low pressure moves off to Scandinavia, but by mid-afternoon we will see a resumption of rain across The South West, Wales and most of the north of England / Scotland. Ireland will be mainly dry save for some showers tracking up the east coast from Cork to Dublin. During the late afternoon, the low pressure will push these showers further south and east across England. As you might expect with low pressure doing the rounds, a breezy day with the wind mainly from the south and west, though as usual, the trailing edge of the low pressure will pull in north westerly winds behind it. So Ireland will be the recipient of those cooler, fresher winds as we close out Thursday. Similar temperatures to mid-week with the rain -affected areas in the mid to high teens and nudging 20°C across the south.
Closing out the week on Friday, that low pressure is well and truly out of the picture but it will drag a trailing edge of showers across the east of Scotland first thing. These showers will consolidate into longer spells of rain across all of Scotland through the course of Friday so a bit of a ‘pish poor’ end to the week here I am afraid. Further south and west, we see a much drier picture than of late, still the chance of the odd shower over the north / north east of England but south of that dry, if a little on the dull side. So sunshine and cloud for Ireland, Wales and England on Friday with temperatures on the fresh side because of that trailing edge of the low pulling winds down from the north west. So on the cool side for everyone at the end of the week, mid to high teens the order of the day.
So how does the weekend look, after a hat trick of Saturday morning soakings in the boat whilst fly fishing, will I see a repeat of another soggy Saturday ?
Well the answer is no, it’s unlikely because for the coming weekend we have high pressure nudging into Ireland and then the U.K over the course of Saturday, so we look settled, dry with light winds and some sunshine and cloud. It won’t be a heat wave because they’ll still be plenty of cloud about but it should be dry for everyone with temperatures in the high teens to low twenties (down souff Mr)
So above is the GFS projected output for w/c 13th of July and as you can see we have high pressure sitting over the U.K, so that means calm winds, warm and settled. If you look at the different shades of orange, light orange equates to around the twenties temperature-wise, mid orange, low-mid twenties and dark orange, high twenties to low thirties. So you’ll get the gist that this high is pleasant rather than excessively high temperatures thankfully. As we move through next week we look to continue with warm, pleasantly light winds and settled through to around Wednesday when a Bay of Biscay low will funnel in some potentially heavy rain and no doubt thunder storms across the south coast of England. Now at this stage it looks to only affect the south coast but in my experience this can and will change as we get closer to the day. So the 2nd half of next week could see rain for the south of England, drying up momentarily through Thursday / Friday before a new Atlantic pressure snuggles down into the trough created by the previous low and brings windier and wetter weather for the weekend. So no one weather system dominating and therefore we are set to continue the pattern of alternating low pressure-high pressure-low pressure. Not complaining me.
GDD Comparison – June 2020 – The Oxfordshire
I didn’t get a chance to do this last month, too busy and probably wasn’t in the right place to be honest so I’ll look at both May and June’s stats at The Oxfordshire from a GDD perspective.
May 2020 came in amongst the highest GDD’s we have recorded for this month but as we also know, May 2020 was an extremely dry month so although the temperature was there, the growth wasn’t because of a lack of rainfall and high E.T, particularly at the end of the month. The weather chart flipped from peak to trough on the 2nd of June and we picked up a sunshine and showers month with a mini-heatwave from the 23rd to the 26th of June with temperatures in the low thirties and really high E.T levels, typically averaging 5 mm+ moisture loss per day, up to 6.6 mm on the final day. There was rain though to offset the high temperatures with the mid part of the month nice and wet.
Cumulative for the year we are tracking towards the top end of our y-t-d totals with only 2017 coming in higher. Time will tell how July pans out but to me I can’t see it breaking any temperature records just yet. (famous last words eh?)
Rainfall and GDD comparison – U.K Locations
Looking across the U.K we can see reasonable consistency among the GDD totals with a pronounced north-south divide in temperature. York came in 13% lower than our Thame location and Fife, 21% lower. This is pretty typical in that the north of the country shows a consistently lower GDD as you’d expect, with Scotland 25-30% lower over the year. Having worked across all of Scotland as a seed contractor in agriculture I also know that Fife isn’t representative of the west or the north though it’ll be similar to The Black Isle for example. Rainfall-wise, we saw the highest totals in the south west, down in Devon and across Avon as that’s where the low pressure systems made landfall, across the south west of the country. The totals for the rest of the U.K where there or thereabouts and reflect the stormy nature of the weather mid month with some epic thunderstorms. Here we got one more storm than either Northampton or Thame and that’s where the extra rainfall for Market Harborough came from. I am consistently intrigued as to the higher rainfall levels for Central Birmingham and I think this is likely to be explained by heat emanating from concrete (roads and buildings) causing warm air updrafts and storm seeding. We have seen the same thing along motorways where the storms track along the road systems as the heat from traffic and the road vectors upwards. After the no show of rain during May (we had 0.5 mm here in total for May), June’s rainfall was welcome although high localised. Unfortunately rainfall of this type is usually pretty inefficient at wetting up the soil profile, tending to run off instead.
Rainfall and GDD comparison – Irish Locations
Ireland’s June stats show the effect of most of the country coming under the influence of cooler and at times wetter weather. The GDD is remarkably consistent from Cavan to Cork and from Dublin to Co. Mayo. Rainfall-wise a real hit and miss month, bit like the U.K with some significant variability, typical of summer rain patterns and incidentally, the hardest to forecast accurately.
GDD y.t.d totals – U.K & Ireland
I thought it’d be interesting to just compare how the U.K and Ireland shape up when we look at the y.t.d figures, especially the temperate south west of Ireland locations (weather speak for it rains a lot)
Location Total GDD y.t.d end of June 2020
Quite interesting I’d say with significant variability north – south as you’d expect.
Soil moisture deficit update – 2020 vs. 2018….
Continuing my theme of lots of stats this week, I have updated the E.T comparisons from 2020 vs. 2018 to see how we shape at the end of the first week of July…
So you can see how June’s weather in the respective years was quite different. In 2018, it was hot day after hot day, high E.T day after high E.T day. In 2020, the cumulative graph flattened out in June as we got welcome rainfall, accelerated again during that mini-heatwave but has since shallowed out again as the E.T levels have dropped back this last week despite the wind and the location picked up a bit of rainfall.
I did want to do a comparison between a high E.T day and a low E.T day to show you the factors driving the evaporation of water from the soil surface and the grass plant but the graphs are pretty complicated and so that’ll have to wait till next week.
The week ahead….
This blowy wind will keep life interesting this week and will dry out surfaces but as that low pressure brings rainfall and with it higher humidity values, the E.T levels will drop away again. Currently we are looking at a projected E.T loss of 22 mm over the next 7 days, so roughly 3 mm a day roughly in the south of England. Further north and west across Ireland, Wales and England, that figures drops to 16-18 mm, with Scotland just behind at 15 mm for a Central Scottish location. So yes we are drying out with this wind but nothing compared to the end of June and with some rainfall hopefully mid-week that should compensate.
Keeping the grass plant ticking is very much the name of the game at this time of year, adequately supplied with nutrient so it isn’t running lean and therefore at elevated risk of Anthracnose and / or Dollar Spot, two diseases that will quickly take advantage of a weak, under-nourished plant. Minimising plant stress with use of biostimulants and keeping some air in the profile with non-invasive aeration work (micro tines) is also key. Disease risk from Microdochium will be reasonably low with the high wind speed and then settled conditions at the weekend, so all in all, not bad folks.
OK, that’s it for me, next week I’ll delve more into the E.T side of things and put some stats up about Dollar Spot for those interested in this ‘lovely’ disease 🙂
All the best.