Weatherblog - March 2nd, 2022

All GFS images contained in this blog are published with the kind permission of www.tropicaltidbits.com.

Hi All,

Well if you have got this far then fair play to you :)

So this is the new home of my weather blog and if you've found it by accident, you'll need to sign up on the home page just like you did with the last one. It's not being hosted on LinkedIn but I will publish this blog on that platform initially to help people make the transition. If you go to www.weatherblog.co.uk you'll see a sign up button that takes you to a form that looks like the one on the right. Fill it in and 'jobs a good one', you'll get notified every time I publish a new blog. I promise you won't get bombarded by emails trying to sell you things but its necessary for GDPR. Now my first caveat, this is a new blog editor for me to adapt to so there's bound to be some err 'snagging points'....😊

Now if you can't manage to find your way to the right place, or you're just plain lazy 😂 then drop me an email on ; markh@weatherstations.co.uk or send me a message in LinkedIn.

Just to reiterate something, the aim of this blog is the same as it always was, to inform in a non-commercial manner on all things weather and turf and the views expressed are entirely my own.

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So we made it into March and the start of meteorological spring but nature is one step ahead of us I think. Spring bulbs are well into flower and they seem earlier to me again this year. Wildlife is also reacting to the change in climate.

Traditionally I've noted Hedgehogs to hibernate in the 3rd week of November and emerge in the 3rd week of March, but with the milder autumns, Hedgehogs are having a litter as late as October so often the parents hibernate and the young are left to fend for themselves. Sometimes they haven't been weaned and need special care from a Wildlife hospital or in the case of these two, they needed to put on weight to survive. So I've been feeding mine every night and they haven't hibernated at all. There's a debate here in that if you keep feeding they won't hibernate but the flipside to that coin is if you stop feeding and they are underweight, they die. Normally I'd have whisked these two off to the local Wildlife hospital but they are inundated and they don't give me them back in the spring so that isn't an option for me. These two are obviously from the same litter because they tolerate each other and feed together with no aggressive snuffling. You can spin it any way you want but my take is they've made it through to the spring with my help and that's two more than I had last year 👍

Weather Outlook

Something of an abridged commentary this week because I am typing this on a Wednesday so I'll look at the rest of this week and what we may get next week.

The first thing I'd say is that I don't think we are set for an early spring because there's still a lot of cool / cold air about to the east and west. (Just look at the animated GIF at the top of the blog and especially towards the end of the output). The jet stream also seems to have the potential to drop south towards Portugal and Spain which often means cooler air follows it southwards. Now as we know things may change but it's my hunch as I sit here now and observe the weather that we won't be pilling on GDD just yet !!

For the rest of this week we have a bit of a 'pick and mix' really with successive rain fronts moving north and east. Today we have rain over the southern half of the U.K pushing northwards slowly with the heaviest rain looking to be across West and North Wales. Ireland and Scotland look to be pretty dry after a cold start in the latter but both countries will see rain pushing in later today. For Ireland it arrives in the south west around mid-afternoon and for Scotland around dusk. On the cool side everywhere really with temperatures in the 7-9°C range, which is nothing to shout about, especially with a cool south easterly wind.

Overnight into Thursday and that vertical band of rain that crossed Ireland late on Wednesday is now off the west coast of the U.K and due to make landfall around dawn. So a brighter, cool day for Ireland but a wet day for the west initially on Thursday and then through the day this band of rain will push east into central and eastern areas. Ireland will see a weaker rain front push into the west The front looks to stall across the middle of the U.K later in the afternoon so that may mean a good bit of rain and the east missing the worst through the day. That cold air across Scotland could see some of this moisture fall as sleet and snow over elevation. A milder day though further south with temperatures pushing up into low double figures in that south easterly wind. Cooler and windier across Ireland and Scotland with a north westerly wind here pegging temperatures back into the high single figures.

Closing out the week on Friday and overnight that rain band across the middle of the U.K is set to edge into the east side of the country leaving a dull cloud base immediately behind it. Further north and west across Ireland and the western coastline of the U.K, Friday should be a brighter day and a drier one as well. So definitely an east-west split at the end of the week. Dull and wet for central and eastern areas clearing from the west and brighter / colder across the west and north. Temperature-wise 7-9°C wherever you are and a real 'pick and mix' of wind direction dependent on your location.

So how is the weekend shaping up as I know some of you guys and girls are running the Cambridge Marathon / Half Marathon ?

Well not great really especially if you're on the eastern side of the country between The Wash and The Humber where Saturday will see a rain front spin round off the North Sea coast and move inland into northern England through the day bringing rain and wintry showers. Away from this if you track further west to Wales and Ireland, it should be a bright but cold Saturday, the same for Scotland. I don't expect temperatures to change much from the 7-9°C range, Sunday still sees that weak rain front across The Wash and pushing some drizzling rain down into East Anglia so I think a bit of a drab, dull and cold event in Cambridge is on the cards with the odd bright spell. The best weather again is to be found west and north of this with a cool and bright dry again for Ireland, Wales and Scotland.

Weather Outlook

Looking at the GFS image above for Monday 7th March we see high pressure centred across Europe and the U.K / Ireland and cooler, more unsettled air out to the west. During the first part of next week that cooler, wetter air pushes eastwards and butts up against the high pressure squeezing the isobars in-between. We have seen this pattern before and we know it means a resulting northerly airstream is created. So I think Monday and Tuesday are likely to be dull, cool and dry affairs but the weather will become increasingly unsettled from the west with rain and wintry showers arriving into Ireland later on Tuesday. Ireland and possibly the south west of England / West Wales look to pick up the worst of it. A succession of low pressure systems is set to push in from Tuesday to Friday and butt up against the ridge of high pressure over the U.K, so here it looks cool and wet but milder with a southerly airstream. Across the Irish Sea into Wales, England and Scotland, I think it will be dry and cold for the first half of next week with a pronounced northerly wind and associated wind chill. As we get towards the end of next week, that protective ridge of high pressure relents and low pressure pushes in across Ireland and the U.K, so that means and wet and milder end to the week with a change to a more southerly / south westerly air stream. Things may grow 👍

The image above shows the GFS projection for the end of next week. Now we all know this comes with a caveat but you can see what I mean about a cold start to March if it does transpire.

Agronomic Notes

Ok, so this is my first blog and as such I'll be finding my way a bit as explained earlier.

Next week, I'll do my monthly comparison looking back at February but as a quick look see I have created and updated the Growth-degree-day (GDD) data from my default location, The Oxfordshire, courtesy of Sean (cheers chap)

For the uninitiated, GDD is a blunt measurement tool for the potential of plant growth according to temperature only. It takes the average daily temperature (in °C) and subtracts a base temperature, in my case I've always used 6°Cm because that's when cool season grass species begin to put on leaf growth.

So if the average temperature is say 8°C and we subtract the base temperature of 6, we get a figure of 2 growth degree days.

What does that mean ?

Well it is a scalar measurement, so a figure of 2GDD would indicate a low potential for the grass plant to grow. A figure of 4-6 GDD at this time of year would suggest a nice amount of growth and a figure of > 12 GDD would suggest a flush of growth.

The table above adds up all the daily GDD into a monthly total so indirectly it gives a measurement of how warm or cold the month was. Commercial growers use GDD to predict flowering and turf managers use it to gauge where they are growth-wise one year, month to the next and also to track product timings and longevity.

Now I had to take a second look at the stats above because rarely have I see two months from one year match the same two months in the preceding year from a GDD perspective.

At the end of February 2021, we were looking at a total GDD of 54 and the same time period in 2022 gives us a total of 54.7. Amazingly similar.

So if we are looking at the potential of the grass plant to grow purely from a temperature perspective, we are in exactly the same place (near as dammit) as we were last year at the same time...Now as we will see next week, that isn't the case for the whole of the U.K and Ireland, that would be both bizarre and highly unlikely, but for this location, that's where we are....

If we look at the daily growth as denoted by growth potential (another growth measurement and denoted by G.P), we see that there were very few opportunities for the grass plant to grow (on greens that is). The first 3 days of January and 4-5 days in February were the only times the daily G.P figure has approached the 0.3 - 0.4 region we know that matches up with a bit of spring clip in the grass box.

No great shakes, we have only just emerged from the winter after all but when I look at the stats above and see that March 2021 only came in at a total GDD of 52 for the month, it does make me wonder about the prospects for this March.

One exercise I did recently was to look at the total GDD but from a seasonal perspective , grouping the months. Here's how the stats look, again for this location...

See any trends ? 🤷‍♂️ (can you tell I have a new emoji button !!!)

Just the one for me.....

I had it in my mind I might see some long-term trends indicating a marked change in our climate from a temperature perspective but looking at this data, the only trend I see is pronounced variability.

Maybe that is the new norm, the lack of consistency in our seasons and the ability of the weather to change from one extreme to another seemingly overnight.

Take April as a month from a GDD perspective...

Last April was cold, dry, dull and bitter, it was quite frankly an a**e of a month. Nothing moved from a grass perspective (above ground anyway), whilst expectations raised as lockdowns ended. At the end of April we came in with a total GDD of 26, lower than both February and March of that same year.

Cast your minds back to April 2020, the first lockdown and the weather was glorious. We came in with a total GDD figure of 151, > 5 times higher than the following year.

That for me is the new norm for the U.K & Ireland and as I've discussed before it is all to do with our friend, the jet stream. If we understand the behaviour of this parameter, we will do much better at understanding the real climate change issue that faces us. Truth is we don't, there's work to do.

No one predicted the really strong jet stream current that pushed through in February and brought Atlantic storm after Atlantic storm to our shores and millions of £'s worth of damage but it was due to the position and strength of the jet stream. A lot of the outliers in the GDD stats above, have a jet stream theme behind them.

So that's how we have to kit our stall out for the future in my mind. We have to be ready to change our turf management practices at the drop of a hat and not just blindly carry on because 'we have always done it this way at this time of year'.

The world in many ways is a far more uncertain and volatile place than it used to be and that extends from normal everyday living, to conflicts, to turf management. On the latter we have to embrace the new normal.

All the best for the coming week and my thoughts are with everyone in Ukraine. Their reality is so hard to understand and so difficult to accept in this day and age.

Mark Hunt