As Storm ‘Posh Totty’ or rather Imogen joins what seems to be a long list of Atlantic storms that have battered our shores since the back end of last year, you could be forgiven for wondering if there is any end in sight to this weather phenomenon ? Well I think we will have a temporary reprieve in some parts of the U.K and Ireland this week.
As we know the path and strength of Atlantic storms has a lot to do with the jet stream and I managed to pull a lovely graphic off Netweather Extra that highlights why they keep on heading our way. The white circle in the middle of the map is the North Pole and the red / yellow / orange band is the Northern Hemisphere Jet Stream.
When the jet stream dips below us then the storms tend to affect the south of the U.K, when it goes straight across us, the storms tend to affect the west, north west and Scotland. This week it’s likely to be the former so the north gets a reprieve from the wind and rain. Another feature of a dipping jet stream is that it tends to drag down cold air into a trough and this is the case for the coming week so a much colder (but drier for some) outlook.
Traditionally this week and next week are the coldest two weeks of the year with February 17th down as the coldest day. Certainly this week will enhance those statistics.
General Weather Situation
We start Monday suffering the after-effects of what for many in the south was a wet weekend, particularly Saturday and Sunday p.m. So we have that familiar pattern of rain affecting Ireland and the western coastline of the U.K from Devon / Cornwall all the way up to south west Scotland. As we move through the morning this band of rain and wintry showers sinks south into Northern England and south Munster / Leinster and by lunchtime it is into The Midlands. This moisture is accompanied by some pretty strong south west / westerly winds and these will peg that temperature back to mid-high single figures. Through the afternoon this band of rain / wintry showers sinks further south and east to affect all areas of the south into the evening.
For Tuesday we see three separate bands of rain in place over the U.K and Ireland and these are positioned horizontally. The first is over Northern Scotland and through the morning it’ll push into the north east of Scotland. The second stretches from Connacht / Donegal across Ireland and into Northern England. This will be wintry in nature so expect to see some snow at elevation. The last is skimming the south west / south coast of England. If you’re located between these bands you’ll get to see some sunny intervals. By Tuesday afternoon these bands tend to push south into The Borders, Leinster, South Wales, Northern England and the south west of England bringing a mix of rain, sleet and some snow at higher elevations. Again it’ll be breezy, but less so than Monday. This will do nothing for the temperature though because I don’t expect it to struggle much above mid-single figures even where there’s no moisture.
For Wednesday we have a much drier day in prospect for large parts of the U.K and Ireland after the last of those bands of moisture has cleared the south east of England. Some areas will wake up to a ground frost as well, particularly across the west. So dry and bright for most of us until lunchtime anyway when a band of wintry showers pushes into Donegal, The Highlands of Scotland and the south west of Scotland as well. Through the afternoon these push east into north east Scotland and The Lakes, with some rain also just tipping a hat to south west Kerry. The wind on Wednesday will tip round to the north west so that’ll bring a colder edge to it and again I wouldn’t expect temperatures to rise much above 5-6°C. For many Wednesday will be a nice, cold, bright winter’s day.
Moving onto Thursday we still have that north west wind in situ so that means it remains cold. It will be a largely dry day with plenty of winter sunshine but right from the off you’ll notice that shift in the wind and that means it’ll drag in some even colder air. That colder air arrived overnight so many places will see a ground frost to start the day. As we progress through the morning there’s a risk of wintry showers moving along the south coast of England and more substantial snowfall along the north east coastline of the U.K. These wintry showers will move south through the afternoon but hopefully they’ll just miss the east coast of England. For Ireland we look to have some moisture moving into Connacht pretty much from ‘first knockings’ and this will stay in place most of the day pushing north into Donegal during the afternoon / evening. As hinted above temperatures will be pretty parky Mrs in that north westerly wind so although it may reach 4-5°C, the windchill will keep things only just above freezing.
Closing off the week Friday looks to go one step further with a pretty hard ground frost to start the day for most areas. I say most areas because for the west and south west of Ireland it’ll be milder as heavy rain pushes in overnight. By the morning rush hour this rain will be into the south west of England as well and it’ll slowly move north east through the course of the morning. Away from this rain / wintry shower mix it’ll be bright initially with a hard ground frost, but as the rain pushes north east it’ll bring more cloud into the equation. By lunchtime this band of heavy rain and wintry showers will have edged into Leinster, but across the Irish Sea it doesn’t looked to have moved that from the south west of England and West Wales. The reason why this band of moisture makes slow progress is because of a change in the wind direction to the east and it’ll be a bitter one for sure with temperatures barely above freezing all day, with a negative windchill.
Looking to the weekend I think Saturday looks to be a re-run of Friday with heavy rain / wintry showers pushing into south west Munster overnight and moving north east into Leinster and Connacht. Again across the Irish Sea, this moisture will make landfall across the south west of England and South Wales and these showers could fall as sleet and snow depending on your elevation. Again away from this moisture and cloud cover you can expect another penetrating frost overnight into Saturday and a cold, bright day initially. Again this moisture stays pinned in place across Ireland, Wales and the south west of England by a very cold easterly / north-easterly wind. During the afternoon / evening though there is a risk of that south west moisture pushing along the south coast into the south east of England and the South Midlands. As it meets the cold air I predict a snow event. Sunday looks to be the drier day of the weekend but with north east winds in place it’ll feel bitter and of course that brings with it the risk of snow showers coming in from The North Sea. So don’t be surprised to see some white stuff on Sunday at some point and another ground frost depending on your level of cloud cover.
So how are we looking next week ?
We look to start next week with that cold trough still in place. I say in place because that cold air is extending all the way down to Southern Spain and The Med. So a continued cold start to next week with northerly winds in place and that means a risk of snow, particularly for eastern coasts. As we move onto Tuesday, the west (Ireland) picks up some milder air, but the U.K looks to stay cold but with lighter winds so I think Monday and Tuesday will see continued ground frosts. By the second part of Tuesday those strong westerly winds are in place as a very deep low passes close to the north of Scotland so I expect high winds and plenty of rain / wintry showers for the north and west I’m afraid by late Tuesday / mid-week, next week. This rain may extend down into Northern England and The Midlands for the 2nd part of Tuesday. Further south it’ll be windy, but milder with strong westerly winds. For Thursday and Friday those winds shift round to the north west so a cooler theme to the weather and that will push showers of rain into all parts for the end of next week accompanied by a strong north westerly wind.
That Drying Wind 🙂
Last week I quoted some stats from The Oxfordshire for the last 10 days of January when they had consistent rainfall but also some good drying winds. The stats showed that most of the rainfall they received was evaporated off by E.T (Evapotranspiration).
Of course one size hat doesn’t fit all as I was reminded by a comment sent in by Lee at Woburn Golf Club who presented some very different stats for the same period of time. (Thanks Lee)
Although both of these golf courses are quite close to each other (25 miles apart as the crow flies) they feature very different locations and design and this has a massive impact on their weather stats as we can see below ; (a.s.l = above sea level by the way)
So being at a higher elevation and tree-lined made Woburn the recipient of more rainfall and less E.T (because the trees block out the wind). Of course there is a flip-side to this as I will demonstrate this summer (if I remember) when we will hopefully be running very high E.T’s and you’ll then see the benefit in terms of lowering E.T that having a wood-lined situation brings.
It does highlight how location and design have such a great impact on how a sports facility performs and brought to mind those football and rugby stadiums you see with all-enclosing stands, how do you dry the leaf off there when there is no wind ?
I will however risk the continuing wrath of Lee (:)) though by continuing in the same vein 🙂
If you look at the top of Meteoturf, you can see a temperature dynamic for the week ahead and the declining temperature that is projected to occur as we progress through the week. You can also see a thin blue line that oscillates between day and night and this represents relative humidity. (Highlighted by red arrows)
At the beginning of the week it sits around 80-85% during the day and goes up to 90-95% at night, hardly surprising when we have plenty of rain around so the atmosphere is saturated. Watch what happens to that line during the day as we get colder, the relative humidity drops in the day down to 60% and that means the air is a lot drier. It therefore presents the opportunity for more moisture from the ground to be evaporated. (that’s why you can get desiccation even in the middle of winter)
Diagram contrasting a wet day with high relative humidity with a cold day with lower relative humidity…
Not a lot happening this week plant-wise….But…
You can also see from the same Meteoturf image above that the projected GDD total for the coming week is all of 0 and for Growth Potential, it is only 0.2 for the whole week. This means the plant will be dormant for I think the next 7-8 days depending on your location of course and so little or no leaf shoot production will be taking place.
It won’t have totally stopped growing though because if the soil temperature is above freezing then it will still be making roots, particularly if no energy is being diverted into top growth. So if ground conditions allow you to, this week is a good time to aerate and make things easier for the grass plant to physically develop roots, whether that’s pushing out of a compacted surface fibre layer or developing deeper roots into a less-compacted rootzone courtesy of a vertidrain.
I know, (I know) if your facility is at filled-capacity, it’s a no no, but not everyone is in the same boat and this blog casts a wide net…
I’ve already had reports of some golf courses taking the opportunity to hollow core and top dress last week because their site conditions allowed it. Above is an image of one such course taken last Thursday, 4th February. I’m going to follow this one on my blog on a regular basis to monitor recovery and report back.
Ok, I think I’ve reached my own saturation limit today, dig out those winter buffs (God knows how I managed without one before) and for all you guys in San Diego, firstly I’m so so jealous, secondly you’re going to have quite a temperature change to cope with when you return this week so I hope you enjoy some warm sun before freezing your nads off 😛
All the best..