As my significant other reminded me yesterday, today is St Swithin’s Day, which we can think of as an early attempt at weather forecasting.
The ryhme goes “St. Swithin’s day if thou dost rain For forty days it will remain St. Swithin’s day if thou be fair For forty days ’twill rain nae mair“
Well according to that we will have 40 days of fair, dry, warm and sometimes dull weather and no rain. Sadly or fortunately depending on your water situation, the rhyme will prove inaccurate this week / year as we have rain on the horizon at the end of this week and possibly next. We also picked up two nightly rainfall events here last week, each came out of nowhere and each gave us around 6mm. Marvelous.
Speaking of marvelous, I enjoyed a beautiful morning’s fly fishing the other day, notable for some feisty Trout that made me work hard with my left arm casting, (don’t ask) four low passes over the reservoir by a Spitfire that was obviously on a testing circuit, a low pass by another fantastic aviator, a Hobby, (Falcon) intent on catching an unsuspecting Swift, Swallow or House Martin and capped off by seeing an Osprey take a Trout right in front of me. Cracking. There’s something about the sound of a Merlin engine on full chat that gives me goose pimples. Never forgotten.
Being slightly patriotic (when it suits), I should mention what a great day it was for England yesterday in both the F1 and Cricket World Cup, both had their fair share of fortune for sure but just for once we won and that was brill. I don’t know what it is about the Kiwi’s but they represent their country brilliantly at all sports I watch and their team yesterday were a credit to their country. Fair play to everyone involved and to the game of cricket.
OK, without further ado, onto the weather as I have to see a man about a dog later…
General Weather Situation
Well the story for Monday is dry but a little dull to start off with as there’s no rain on the radar anywhere in the U.K and Ireland as I sit at this well-worn desk. So dry and dull for many and quite cool as well with temperatures in single figures last night. Through the morning the cloud will break and we will see some pleasantly warm sunshine. The east coast may hang onto that cloud all day as could some parts of North Wales and The North-West but other than that it should be a nice day. Light winds swinging round from the north to the south through the day and temperatures evenly distributed across the low twenties projected for the U.K and Ireland. Later in the day we may see cloud push in and bring the odd bit of mizzly, drizzle to the west coast of Ireland.
Overnight into Tuesday and that thickening cloud across Ireland may bring some light showers through the course of Tuesday morning. These will push eastwards. For the U.K, a similar start to Monday with plenty of cloud cover but this will soon burn off to give long spells of unbroken sunshine during which temperatures will quickly push up to surpass Monday’s, with low to mid-twenties very likely across the south of England, The Midlands and Wales. Scotland and Ireland will see more in the way of cloud and this will keep temperatures down into the high teens, low twenties. We will also see that rain pushing east across Ireland during the afternoon and consolidating into heavier showers across the east of Ireland and west of Scotland. These showers across Scotland will push inland through the afternoon and again consolidate over the north-east of Scotland.
Wednesday sees the beginning of the change to the weather this week as a transitional high pressure peak is punted politely out of the way by an incoming north-westerly, Atlantic high pressure system. (see image above) This low pressure system will push rain into the north-west of Ireland just in time for the Co. Sligo rush hour and through the course of Wednesday morning this rain will move south and east across Ireland. Further east across The Irish Sea we will get another day out of the high pressure peak so a repeat really of Tuesday for England and Wales at least with early cloud burning off to give us long spells of warm sunshine. Warm again with temperatures pushing up into the low to mid-twenties across England and Wales. Scotland will see that rain make landfall across the north-west around midday and this rain will then move slowly into central areas later in the day, pushing showers ahead of it. So a cooler day for Ireland and Scotland under that cloud and rain, expect high teen temperatures and a strengthening south-westerly / westerly wind veering north-west overnight.
Thursday sees that rain clear Ireland overnight, push into the western side of the U.K and stretch all the way from The South West up to Scotland. By dawn this rain front will have broken up into a belt of slow-moving showers arranged from The South West up through Wales across The Pennines and into The North East. Scotland should start dry on the west and in central areas but they’ll be rain across the east. Through the morning the belt of showers will move slowly eastwards clearing Scotland and pushing thick cloud ahead of them so a much duller start to the day for England and Wales. So a risk of showers for England and Wales through the morning on Thursday but these will disperse as we go through Thursday afternoon. After a drier morning, Ireland, Northern Ireland and Scotland will see rain push into the north-east for the 2nd half of the day as that low swings in more unsettled weather. At this stage that rain looks to stay mainly confined to the north-west of Ireland, Northern Ireland and Scotland. England and Wales will see a day of sunshine and showers, cooler than of late with temperatures just nudging into the twenties. Ireland and Scotland with that thicker cloud will be more like mid to high teens so a little cool for this time of year. One of the reasons for that dip in temperatures will be a north-westerly wind which will blow fresh to moderate through the course of the day.
Closing out the week on Friday we see that first Atlantic low held in situ off the coast of Scotland but a new developing low will push in from the south-west and this will bring more southerly focused rain. From dawn this will already be across the south-west of Ireland, England and Scotland and through the morning it will push in to all western areas consolidating as it does. By Friday lunchtime that rain will straddle Ireland, Wales, the north west and north of England and Scotland but East Anglia, The South East and East Midlands may stay dry for a good bit longer with spells of sunshine for the east coast. By late afternoon Friday that low is centred over Ireland and so will push rain more eastwards across the southern half of the U.K, clearing Ireland as it does so. So a wet night for Wales, Scotland and England on Friday going into Saturday but Ireland should stay dry, though dull and cool. High teens likely for Friday for just about everyone, maybe nudging into the low twenties before the rain arrives for the east and south-east of England.
No surprise then that the outlook for the weekend starts unsettled with Saturday looking to start showery across central and eastern half of the U.K, with heavier rain for northern Scotland. Ireland should see the best of the weather as the thick cloud begins to lift giving some nice spells of sunshine. Through the course of Saturday those showers may linger across England, Scotland and Wales right through to early evening before the cloud breaks and we see some decent sunshine. Sunday looks a much nicer day for England, Scotland and Wales with early cloud breaking to give long spells of pleasant sunshine. Ireland on the other hand picks up the leading edge of another Atlantic low which will bring cloud and rain to the western half through Sunday. This rain will push eastwards through the course of Sunday. So dull cool and potentially wet for Ireland, but pleasant for the U.K with temperatures picking up into the low twenties on Sunday.
Hmmm, a tricky one to call because usually with low pressure pushing in from the west on Sunday that would make for an unsettled week, next week but I’m not so sure. So currently Monday does indeed look unsettled especially for the north and west with some wind and rain pushing showers through from early doors. Further south we could indeed see some of these showers push inland but as we go through Monday a continental high pressure is set to build and that may bring significant heat into the weather picture for next week.
The image above shows the projected hot air plume extending up from Africa for Wed 24th July potentially resulting in high temperatures for the U.K and Scandinavia next week.
So heat building from Monday through to Thursday but it isn’t going to be just dry and hot, I think we might be in for a humid one as well as there’s moisture lurking south of the U.K next week. At this stage it looks like Tuesday to Thursday will be warm / hot and dry before we start to see a cooling off later next week and rain push into the picture from Friday onwards, initially into Ireland but England and Wales later. With the threat of rain coming from the continent we can be certain of uncertainty about who and where will get it and also that Scotland and the north will see less of it. It wouldn’t surprise me if we don’t see this weather forecast change around a bit next week.
Soil Moisture Status
I thought it would be interesting now we are theoretically half way through summer (June to August in my books) to see how 2019 and 2018 compare from a soil moisture status perspective. Now I appreciate this isn’t for everyone, especially where you’ve had plenty of rain but as we saw with last months stats, we have been dry in some locations and in July for places like The Oxfordshire, they’ve had no rain at all.
It is slightly unrealistic as it takes no account of what happened soil moisture-wise in May or before that but for me it gives an indication of how much plant stress we are facing and your likely water usage so far…
So how is summer 2019 shaping up vs. 2018 ?
The graphs above highlight the two very different patterns of soil moisture deficit and how crucial that wet week in June this year was in terms of recharging the soil on unirrigated areas.
In 2018 you can see how we basically flat-lined E.T and therefore moisture deficit right from the 1st of June with no rainfall at this location through the 6-week period. In 2019 we began the same pattern in early June but the week of rain pushed us into a soil moisture surplus that prevented us going into a deficit until the end of June, it effectively brought us a month less plant stress and water usage. From the 1st of July though we have followed a similar pattern in 2019 vs. 2018 with consistently high E.T and no rainfall.
Comparing the first 14 days of July, our E.T loss this year has been 47.4mm vs. 63mm in 2018, so still pretty significant and that’s why we are seeing unirrigated areas going under stress. Hopefully the projected rainfall at the end of this week will help matters a little.
That said however you dress it up we are in a better situation than last year.
Watching the cricket yesterday it was impossible not to notice the large amount of Fairy Rings on the pitch. This isn’t a criticism it’s more an indication of the type of summer we are having in 2019 vs. previous one’s. The wet spell in June brought us humidity and that’s something that didn’t feature highly last summer, hence the higher disease activity associated with June 2019 and to a slightly lesser degree, July 2019.
I charted out my Netatmo weather station stats from June 2019 vs. 2018 to see how the two months compared from a humidity perspective ;
OK, now my weather station is in a sheltered location so tends to run higher humidities than a more open location but the difference between this June and last June is clear to see. In June 2018 we never once topped 90% average daily humidity, whereas in June 2019 we have topped out at 100% daily humidity for an extended period, particularly when we got that rain between the 8th and 16th of June.
So that’s why we have seen plenty of Fairy Ring, Waitea Patch and Red Thread activity as these diseases just love humidity. Now it’s worth bearing in mind that although Fairy Rings are more aesthetic than disruptive they do have a dark side to them in that they can turn the soil profile hydrophobic and stress the grass plant. There’s also a suggestion that they can in certain instances release ammonia gas (which is toxic to plant root systems) and thereby kill off the grass plant.
It very much depends on the type of Fairy Ring you have as these moisture level samples show below….
Bearing that in mind and the potential prospect of some high temperatures this week and next, it’s worth keeping an eye on them from a hydrophobicity perspective.
On another disease-related note, I saw my first Anthracnose last week, a little bit of basal rot on a wear pathway at the edge of a green, nothing more than that but I am wondering if this week’s high temperatures followed by rainfall will be a trigger event. The same could easily be said for next week with likely even higher temperatures for a period if the hot plume weather pattern takes place.
2019 must surely be the longest seedhead flush I can remember at 10 weeks and counting. I think the wet period in June almost reset the Poa and so we saw a big flush of seedheads after the rain event. If that’s correct, the level of seedheads should begin to decline over the next 7-10 days naturally without cultural assistance 🙂
OK that’s it for me this week, enjoy the heat and hope for the rain afterwards 🙂
All the best.