March 18th, 2024

Hi All,

I was out on a long cycle over the weekend. I have this (foolish) notion in my mind to cycle from Market Harborough to Wells-next-the-Sea (on a mountain bike) at the age of 60, in time for Fish & Chips at French's on the Quayside. It's 107 miles, so I am kind of training and kind of mad maybe. 😊 This weekend I managed 45 miles, so some way to go, but the sun was shining, the first of our summer migrants, Chiffchaffs were announcing their arrival in the hedgerows and one could be forgiven for thinking that we had turned a weather corner. Last week, Anglian Water and Leicester and Rutland Wildlife Trust announced that the 1st of the Ospreys, Maya, had returned from her winter break in Gambia. A 3,000 mile journey nonetheless. I hope she can find some clear water to hunt fish in and do a spot of long-overdue calorie replacement !

Staying on a wildlife theme, my resident and visiting Hedgepigs appeared on the 8th March, 7-10 days earlier than they normally do and now I have 3 queueing up for food in the evening.

A day after this brief glimpse of spring and its Groundhog day, with another 12mm odd falling overnight. Back to square one with swollen rivers and water lying in the fields. My sympathies everyone.

The question we all want answered of course is when we get a break in this rainfall dynamic. The Met Office confirm a 3rd SSW event occurring in early March which normally (but not always) points to the development of a high pressure blocking event and cooler than 'normal' weather. Well, there is no consensus in the long range models currently.

Below is the projection for 10 days time according to the U.S - GFS (Global Forecasting System) and European - ECMWF (European Centre for Medium Range Forecasts), left and right respectively.

The two forecasting systems both predict a peak and trough development of the jet stream, essentially the same pattern. What is different is the longitudinal position of that peak and trough pattern. GFS predicts a trough pattern sitting over the U.K & Ireland and a southerly (very) position of the jet stream that allows cold air to push down across the U.K & Ireland. The ECMWF predict a peak pattern with a ridge of high pressure fending off cold, unsettled air over The Atlantic.

What is clear to me is the presence of cold air late in March, so I can't see it being a warm, mild Easter, more likely a cooler one with a northerly wind, but the pattern and nature of that weather is clearly up for debate when you look at the forecasting models. The position of the jet stream will of course be key, if it sits south of us then we can expect more low pressure systems from The Atlantic, if it sits north, then drier weather will prevail. Incidentally, the GFS prediction for the end of March is one hell of a low pressure system, let's hope they're wrong and it changes.

General Weather Pattern - 18th March, 2024

I have borrowed an image from meteoblue.com showing a map of the U.K & Ireland in order to depict a demarcation line for this week's weather. If you look at the rainfall pattern for March so far, the south and east are already running at higher than the average for the total month, whereas the north and west are showing less. Well this week will balance this picture out somewhat because the bulk of the wet weather will push across Ireland, the north west and north, leaving the south and east drier. Not totally dry mind, but drier.

Putting some detail on it, Monday sees the first of that rain push into Ireland around midday and track north and east crossing The Irish Sea into western Scotland by dusk. Wales, The South West and northern England will also see rain overnight with that rain front departing eastern England by the morning rush hour. That south west wind will stay with us till the end of the week reducing in strength as we pass mid-week. Temperatures will also stay up in the low teens, lower over Scotland, but 12-14°C elsewhere. Tuesday is a drier day, once that light rain has cleared, with mild air and a south westerly wind in situ, but later rain will arrive into Ireland around dusk. This will again track north east across the east of Ireland, North Wales and into northern England overnight into Wednesday morning. This rain band will largely exclude The Borders and the remainder of Scotland and the southern half of England, with The Midlands likely to cop some on Wednesday morning. Remaining mild.

Thursday starts to see a change as a ridge of high pressure pushes that rain band further north but it also introduces cooler air into the equation. Not immediately but by Friday you'll notice the difference and particularly over the weekend. Thursday will again see that split in the rainfall with rain arriving into the north west of Ireland and Scotland and then push down eventually reaching northern England and North Wales. South of this, we see another drier day with a strong to brisk south westerly wind and mild temperatures. Dare I say it, a nice drying day.

Closing the week out on Friday and we begin to lose those milder temperatures, Overnight we see a wind change to a more northerly direction and as a result it will usher that rain across the north, southwards into The Midlands and south of England, so a wet start here. This rain should clear by midday to leave a dry picture across Ireland and most of the U.K, save for showers bubbling up along western coasts. Feeling cooler with temperatures dropping to low double figures, cooler in Scotland.

The outlook for the weekend is mixed. Cooler again on Saturday as those temperatures are likely to remain in single figures in a chillier north west / west wind. Showers again on western coasts of Ireland and the U.K, some of these pushing inland later on Saturday before more rain arrives into Ireland on Saturday pm and crosses into the U.K in time for Sunday. This rain will mainly affect western areas on Sunday, so The South West, Wales, The North West and western Scotland. It'll take its time edging eastwards, so the south and east should stay mainly dry with some sunshine. 8-10°C is likely.

Weather Outlook - w/c 25th March, 2024

So, I have already mentioned the uncertainty surrounding the forecast leading up to the Easter weekend, so this one's is tricky to predict and liable to change.

My hunch is that next week will be a cold one starting off with on Monday with a north easterly wind. If this is the case, expect a return to night frosts and the risk of showers ushering off The North Sea, some of these may be wintry in nature. This sets the scene for the week with light winds, day temperatures I think in the 6-8°C range and showers more likely across eastern coasts. The further north you go, the more likely they will be wintry in nature. As we approach the end of the week, we could see a change to slightly milder conditions with a south westerly wind, if we do, it'll usher in more unsettled conditions for Easter. Like I said, lots of uncertainty here, to the point where I considered omitting this part of the blog, but if you take the SSW event into consideration, then to me, it's more likely to point to colder conditions than warmer.

Agronomic Notes

Cumulative GDD - Danish Sea Scurvy and Poa annua seeding and all that.....

If you look at the GDD chart above, you could be forgiven for thinking everything in the garden is rosy, given we are so far ahead of last year in quantifiable growth terms. Forgetting the amount of rain we have had for a moment if that is possible ?

Last week on the March 13th, we passed the cumulative 130 GDD point and sure enough as I was out walking, I noticed the 1st flowers of Danish Sea Scurvy along the salt splash area of my local verges. This tough halophyte (salt-tolerant) is my reliable 130 cumulative GDD marker for the commencement of annual Poa biotypes seeding, initially on higher-height-of-cut areas but on thin areas of greens collar / greens alike.

Now before you reach for the Poa Busters or equivalent, just remember what the weather outlook is. We do this most years from a GDD perspective you know, we march up towards 130 GDD (using a 6°C base temperature) and then at some point hit a GDD brick wall before the commencement of spring proper at a later date. The same tends to happen next month when we approach the cumulative 180GDD point that marks (in my mind) the commencement of the perennial Poa biotype seedhead flush. We waltz up to it, but seldom continue unhindered by the weather thereafter.

And so it will be this year, we are ahead of last year growth-wise (a month ahead if you work on GDD alone), but we are likely to stop piling on growth days when we get to the end of this week and I can't yet see when that growth will re-commence from a meteorological - agronomic perspective. It is interesting because looking back at my notes from last year, I noticed the Danish Sea Scurvy flowering two weeks later than this year, so maybe that's a more realistic yardstick ?

Now if you have maintenance week coming up and are indeed able to get out on site with machinery (and let's face it, a lot of people can't currently without causing more damage to their surfaces), I would think very carefully what type of maintenance you're going to undertake because the outlook for recovery currently is on the low side. Of course you could resort to applying one of those 'miracle' products that provides growth by virtue of applying 40 kg / N / hectare in one application, but aren't you just creating what you have been busy removing ?

If we look at the early season aeration exercise from the same location, commencing at the beginning of February, these chaps were home and dry recovery-wise by the middle of March courtesy of that super-mild February this year.

Now, I 100% appreciate, it isn't for everyone - resource, ground conditions, budget all come into the equation, I am just making the point there is an option to the 'we aerate in March' doctrine.

Food for thought.

All the best.

Mark Hunt