If I said there was a 15°C temperature difference last Thursday between Scotland and the south of England, many of you wouldn’t have batted an eyelid. After all it isn’t unusual for Scotland to be cold and the south of England to be mild in January.
What was unusual was that it was actually the other way round with some parts of Scotland recording 13°C whilst in Kent it didn’t get any warmer than -2°C. Factor in the windchill and it was a Baltic -6°C during the day.
The unusual weather situation was caused by mild air pushing into the north and west of the U.K and Ireland butting up against cold continental air. In effect we were right on the edge of a peak and trough situation with the jet stream. The situation is back to normal (whatever that is :)) this week with Scotland sitting cold and frosty and the south of England mild and wet. So onto the weather.
General Weather Situation
So as we kick off Monday morning the key word is dull. Lots of cloud cover over all of the U.K and Ireland with maybe just a few breaks across The Lakes and the north east coast of Scotland. A dry if mizzly start but it’ll be short-lived because rain is into south west Kerry and the south west of England just after the morning rush hour and this will push north and east across Ireland and England during the morning reaching Wales by lunchtime. Further north and east of this rain we will see some breaks in the cloud cover along the north west coast of England, west coast of Scotland and across The North East. Here it’ll stay dry. By the evening rush hour that slow-moving band of rain is into The Midlands and south of England and it’ll cover Ireland in its entirety. Continuing mild in the west with double figure temperatures, slightly cooler inland with mid to high single figures the order of the day. The wind will be light to moderate and changeable ending up as an easterly me thinks.
Onto Tuesday and overnight that rain should have cleared Ireland but it’ll be firmly entrenched over most of the U.K with only the far south east likely to miss it initially. As we progress through the morning it will move unusually from east to west so back into Leinster, Wales and the west coast of the U.K clearing the east as it does so. So by the evening rush hour it lies across Ireland, Scotland, most of Wales and the west coast of the U.K. Not much chance of seeing the sun today with only the south west tip of Kerry odds on to do so. Slightly milder across England into double figures with Scotland and Ireland a couple of degrees cooler. Milder across the west again furthest away from that moderate south easterly wind.
For Wednesday we have two active rain fronts. The first is a vestige of Tuesday’s rain and this will still be sitting over the south east coast of England but clearing east into the North Sea through the morning. The second is across the west of Ireland and this will push north and eastwards possibly missing the south east of Munster as it does so. By lunchtime the bulk of the U.K is clear and they’ll be some breaks in the cloud cover pushing up temperatures. That rain across Ireland will still be affecting the north and west of Ireland but also the south west of Scotland where it’ll be falling as a mix of wintry showers and rain depending on elevation. A windier day on Wednesday, especially across Ireland with a strong south to south west wind present. Lighter winds across the U.K and southerly now in nature. Similar temperatures to Tuesday with high single figures possibly nudging double figures in the south of England and Ireland.
Moving onto Thursday and more rain for Ireland at the start of the day, some of it heavy across the south coast of Munster. That rain will swiftly move into the south west of England and Wales during the first part of Thursday morning and at the same time it’ll make landfall across the north west coast of England and Scotland. By lunchtime the projections are that the rain wil be moving eastwards, straddling Ireland and now across all of Wales and perhaps 100 miles or so inland. As we approach the evening rush hour it begins to fizzle out to leave a showery picture across the U.K and Ireland so you may catch one across the east, you may not Mild just about everywhere with temperatures just nudging into double figures for Ireland, Scotland, Wales and England with a moderate southerly wind in situ.
Closing out what has been a wet week, we have a deep low pressure system sitting over the U.K so that means a wet and windy conclusion to the week on Friday with a strong south westerly wind in place and frequent showers rattling across the U.K and Ireland. At this stage it looks like these will clear quickly through the afternoon to give a bright end to the day especially across Ireland. Similar temperatures everywhere with 10°C, a typical maximum daytime temperature and some very strong, south westerly winds in place especially for the west and north of the country.
With a deep low pressure system pushing across the country it’s perhaps no surprise that we have an unsettled outlook for the weekend. The centre of that low will be over the south east of England so I expect the worst of the rain here on Saturday but that said they’ll be plenty of rain for Ireland and the rest of the U.K as well as it sweeps up from the south west overnight. Scotland will see a mix of rain and wintry showers across higher elevations on Saturday. With the low sitting over the south of England it means that locations in the west and south will have a strong to gale force westerly wind but the north of England and Scotland will pick up an strong to gale force easterly wind so much cooler here and in fact cooler everywhere on Saturday with temperatures just above mid-single figures. Sunday sees a continuation of that unsettled theme with a mixture of sunshine and longer spells of rain over most of Ireland, Wales, England and Scotland. We will still see that split in wind direction with easterlies up north and westerlies down south so a little cooler up north I’d say and the wind strength will remain strong to gale force in places.
With an ‘L’ pattern in the jet stream, next week looks like being a bit of a continuation of this week with another deep, intense low pressure lining up in The Atlantic to whistle in and bring us windy and wet weather during next week. So Monday next week looks like starting off the week dry but cool with a chilly north west wind in situ but this is just the calm before the storm with that Atlantic low destined to hit the west of Ireland during Monday / Tuesday. So a very wet Tuesday in store I think accompanied by strong to gale force south westerly winds, but milder in that Atlantic air flow. That wet and windy theme continues into Wednesday morning I think but quietens down in the second part of the day so some respite here and possibly some sunshine. For Thursday we have a quiet start but I think more wet and windy weather will push in from the west affecting all areas by the second part of Thursday and continuing the same theme on Friday to give a wet, windy and mild end to the week and hopefully a good tailwind for my flight home
As I mentioned at the start of this blog we had an extreme temperature contrast from north to south this past week with mild temperatures across most of Scotland and extremely cold temperatures from The Midlands south I’d say with many rootzones frozen solid for the best part of two weeks. This can create a number of issues.
The first one occurred this weekend when milder air and rain arrived over the south of the U.K and fell onto deeply frozen ground. This then led to a situation where the surface underwent rapid thawing but the rootzone below it was still frozen hard.
The surface of the rootzone becomes ‘plastic’ in nature meaning it is mobile and when subjected to force will shear at the point that the thawed rootzone meets the frozen rootzone.
I have tried to express this diagramatically below ;
The effect is most severe when just the top 10-20mm has thawed out and as the thaw penetrates deeper the rootzone regains stability. I was down the south east of England last week and I envisage that some of you had a tricky Saturday and Sunday morning in terms of golfing pressure to get out and play and delaying this whilst the rootzone thawed sufficiently deep to have surface stability.
There is always a debate about playing on frost, there has been since I came into the industry in 1989 (cripes ) but I believe the above scenario is one of the most-damaging frost / thaw events that golf course managers and groundsman have to manage. I take my hat off to your powers of communication and persuasion. Of course many of you are reading this in the west and north and are probably wondering what I’m on about because you’ve been milder but in some areas the above was a problem I can assure you.
Cold Temperature Desiccation
Continuing on that vein (Scottish and Irish readers please bare with me :)) I also saw cold-temperature desiccation last week for the first time since 2013. In this situation the frozen soil is so dry there is no moisture available for the grass plant and it wilts, particularly under foot pressure just like you see in the middle of summer during drought stress. I got some weather data through from York today (Cheers Adrian) and you can see the period of January when this occurred. In actual fact the temperatures and lack of rainfall were actually worse in the south of England because the skies cleared from the south during the 3rd week of January so the temperatures dropped faster and earlier in the south of England than they did in the north.
It’s not all bad news…
It’s worth remembering that this time last year we were on the flipside of our third successive month of high rainfall and mild temperatures with winter projects not even started on plenty of courses because the ground conditions were so saturated. This winter so far we have had much drier conditions because of the stablising high pressure situated in the Atlantic (until recently) and that has made life easier I reckon. Even in the west which typically receives the highest amount of winter rainfall I know totals are much lower than the norm so we must be grateful for these small mercies
The weekend ahead
Looking at the Meteoturf outputs across the U.K and Ireland in terms of GDD and G.P, I expect you to see a pick up of growth this week as we return to milder temperatures and rainfall.
See below ;
The lowest growth prospects are up in Scotland as they return to cooler temperatures and the best across Ireland, the west of England and Wales. With moisture as well this makes it a good time to put down a gentle granular fertiliser on areas that require recovery from winter play and scarring and / or where you want to hit moss with a high iron treatment.
As mentioned last week it’s often the case that we get better growth in January and sometimes February than we do in March. Looking at your GDD / GP spreadsheets for 2016, the worst growth month of the year for some of you was March 2016 !!
Blog Disruption Predicted
As I’m off to the GCSAA show on Friday it’s going to be tricky for me to publish a blog next week as you’ll be 5 hours or so ahead of me and I have seminars booked for the entirety of Monday and Tuesday. The week after I have a P.I.T.A (you can work that one out) of a meeting on Monday, 10TH Feb, so I don’t expect to publish my normal blog till Tuesday 11th February. Sorry for the disruption but hopefully I’ll have lots of interesting work to share with you courtesy of the GCSAA Seminars and your month end data for January 2017.
All the best.