With a mild, positively spring-like week coming up with double figure temperatures, one could almost think that we are on the upwards path out of winter 🙂
This week sees the re-emergence of the Atlantic high pressure that popped up during December and January and true to form it’ll funnel up warm air from southern Europe. The tricky part is whether it will also push on more disease pressure as it did in the months before. Still looking on the bright side (as one has to me thinks) this weather pattern will see us into the third week of February and every week that passes without a return to the tabloid’s favourite, ‘Beast from the East’, is another week when the chances of it re-appearing diminish 🙂
General Weather Situation
So Monday doesn’t start off half bad really with a dry picture over most of the U.K and Ireland. There’s a few showers showing on the radar across the north-east of Scotland, The far south-west of England and Ireland, and a few pushing in off the Mersey estuary. Apart from that we are set fair for a dry but cool day due to a strong northerly / north-westerly wind which will nip down the temperatures a tad, but at least it’ll keep the humidity low. Plenty of sunshine around across The Midlands and south of England early doors. Temperature-wise expect 7°C across Scotland and a double figure 10°C across Ireland, Wales and England. Once the sun is down, temperatures will drop off markedly, a feature of this week so expect low single digits and the chance of a ground frost in places.
Tuesday sees some rain push into the south-west of Ireland and move north and east into the south-west and west of Scotland through the course of the morning bringing wind and rain here. During the afternoon this will spread south into north-west and northern England reaching north Wales by the evening. Further south and east of this rain you can expect another nice, dry day and with the wind swinging round to the south-west, it’ll feel a little milder as well. So a dry, dull day for most away from the rain showers with possibly only East Anglia seeing the sun for any length of time. A strong to moderate south-westerly wind will persist through the day. Mild though for mid-February with 9-10°C for Scotland, but pushing up to 11-12°C for Ireland, Wales and England. I’ll take that for mid-Feb any day of the week.
Onto mid-week and my how time flies when you’re writing a blog against a publishing deadline of 1 p.m 🙂 Wednesday sees that high pressure begin to exert itself pushing any rain further north across Scotland during the morning, but even this is set to fizzle out through the afternoon. A milder night on Tuesday means a milder start to the day and although we have cloud to kick off, this will thin through the morning to bring long spells of hazy sunshine to England and Wales, with cloud over remaining over Ireland and Scotland. A strong to moderate south-westerly wind will remain in situ and you’ll feel the temperature drop away as soon as the sun sets. Similar temperatures to Tuesday for all areas.
Thursday sees that high pressure in a dominant position so a dull start but soon the sun will push through and it’ll be a lovely day with plenty of sunshine once the cloud breaks. That sunshine will extend across northern England into Scotland so a dry and warm day for most areas with a warm southerly wind pushing temperatures again up into double figures for Ireland, England, Wales and Scotland. More in the way of cloud cover for Ireland and that southerly wind will increase to strong to gale force in places here. A cracking day for mid-February really and again we will see temperatures drop away as the sun sets and with clear skies they’ll tumble to low single digits, cold enough for a grass frost in places.
Rounding out what can only be termed a half-decent week, Friday sees England and Wales continue the dry and sunny theme, but across The Irish Sea we see a rain front push into the south and west of Ireland and move eastwards from early doors, clearing from the west as it does so. This rain front will push into the west of Scotland by mid-morning and move eastwards into Central Scotland by late morning. Further south over England and Wales, we will see cloud cover build from the west ahead of that rain front which will sink south into north-west England and Wales on Friday evening. Cooler across Ireland and Scotland with that thicker cloud and rain, with temperatures around 9-10°C, but further south it’ll feel very nice thank you with 12°C likely across Wales and England. Remaining dry here as well but clouding over from the west later.
So after a nice week for most, we will see this settled, dry and mild theme extend into the weekend ?
Yes and no…
The outlook at the moment is for the high pressure to move slowly eastwards in response to a building Atlantic low pressure which will introduce more unsettled and windy weather into Ireland and Scotland through Saturday on the back of a freshening south-westerly wind. England and Wales I think will stay largely dry on Saturday despite more cloud cover so the mild, dry theme will maintain its momentum through Saturday here. Come Sunday I think another unsettled day for Ireland and Scotland and that rain could easily push in to Wales and the west through the course of the day though models don’t agree on this at present. I think we will see heavy rain for Ireland on Sunday and this rain front will push into Wales, Scotland and the west coast through the 2nd half of Sunday, that’s my take.
Looking back at last week’s prognosis for this week I’m pretty happy with the consistency of Meteocentre’s GFS output so here we go for next week’s outlook..
The rain front that pushed across Ireland, Scotland and Wales on Sunday looks to continue eastwards overnight into Monday. So I think a wet and unsettled start to the week beckons for the U.K and Ireland as low pressure is in charge. So a wet Monday extending into Tuesday with windy and unsettled conditions for many. As one low pressure moves away, another is projected to push in and bring more heavy rain for all areas mid-week, next week. The prognosis is for the unsettled conditions to remain throughout next week with a mild (ish) south-westerly air flow and plenty of rain. After that there is a great deal of uncertainty so we will see.
Does that mean that winter is over and done with ?
Well it would be one of the earliest starts to spring if that were the case but I’m still cautious on this one. For the moment it’s a case of ‘Carpe diem quam minimum credula postero’ which roughly translates to ‘seize the day and put very little trust in tomorrow !’
Microdochium Pressure – Not again ?
So I guess the first thing that came into my mind at the weekend (apart from how the fek do I fit an upgraded horn to my BMW R9T in the titchy little gap BMW have left me ?) when I saw the developing high pressure and mild temperatures this week was, oh no, here we go again from a Microdochium perspective.
On examination of the temperature and humidity data projected for this week I don’t think it’ll be as bad as the last time an Atlantic high pressure paid us a visit, i.e December 26th – Jan 1st.
You know how I love my graphs, well I charted out both periods of weather, the Christmas to New Year period and the projected data for this week to see how they looked and to help me get my head around both scenarios.
Here’s the first period…
What we had between Christmas and New Year was very consistent temperature with minimal drop off between night and day, sometimes less than 2°C. The humidity as well pretty much stayed over 87% at this location and peaked consistently close to 95% during the night. So we had an extended period of plant leaf wetness and temperatures high enough to facilitate strong Microdochium nivale growth both on existing scars and on new infection sites. Although the temperatures weren’t super mild, they were mild enough to promote fungal growth of this pathogen and the extended periods of plant leaf wetness did the rest.
So let us look at the prognosis for the coming week using hourly data. I make the point about hourly data because we know we only need a small period of time for Microdochium nivale to grow and so averaging out temperature and humidity data can often ‘hide’ these periods. It’s a bit like looking at a monthly rainfall total and saying we only had 50mm, it was a dry month, but if that 50mm fell in just two days, you might not agree.
Now looking at the graph above for the same parameters I hope you can see that the pattern is quite different ?
I’ve standardised the scales so the data is comparable and you can see that the drop off between day and night temperature is more marked for this coming week compared to the period above. So where the temperature differential between day and night was only 2°C for the period between Christmas and New Year, it’s more like 9 – 10°C this week. The only day where you see less of a drop off is overnight Tuesday into Wednesday so this period may be more conducive to Microdochium.
You can also see the lowest temperature point during the night is much lower as well with temperatures around 2°C, so that will mean a slower growth rate for the Microdochium fungus.
The other very important feature of this coming week is the wind and the fact that during the day it’ll be a drying wind and not only will that lower the humidity, it will obviously dry the plant leaf off quickly once the sun is up. So this means we won’t have the extended period of plant leaf wetness that we had over Christmas / New Year, another key difference.
Again the drop off between humidity at night and during the day should be much higher this week. Between Christmas and New Year the humidity hardly changed from night to day varying by only 2-3%, whereas the prognosis for this week is a 15-20% drop in humidity during the day, another important difference.
So for this location I would expect to see some activity around existing scars mid-week but no new infection. Now the above is the case scenario for one location, it may be different elsewhere but I think the comparison is pretty similar in other locations.
A nice weather window….
Central U.K Location
West of Ireland Location
Central Scotland Location
South Wales Location
So there you have 4 different locations from 4 different countries and Meteoturf highlights a nice steady growth window this week extending I think into next week as well though the weather will be different. The South Wales location above shows the dynamic really clearly with significant drops between day and night temperature through this week as high pressure is in charge and then a change to less variability between day and night as milder, south-westerly air pushes in to give unsettled conditions at the weekend.
So with dry conditions this week (once we dry out from Sunday’s rainfall that is) it’s a good time to get out and get any areas that you feel would benefit from an early push fertilised prior to more unsettled conditions next week.
With wet weather leading up to this week, moss and the like is fully-wetted up so iron treatments approved for mosskilling will work well, especially as we have more unsettled weather following on from this.
A lot of sites have carried out drought-damaged areas from last summer so here’s an opportunity to overseed and fertilise to gain some recovery whilst both moisture and temperature are available.
Too early ?
Well looking at the calendar you might be forgiven for thinking so but I just think we take the opportunity, we are only two and a half weeks away from March, so getting seed in the ground prior to the arrival of warmer air can only be a good thing. Yes, there’s always a chance that the weather will take a turn for the worse and winter will come back for one last hurrah, but the longer we progress through February without this occurring, the less likely that any return to winter will be prolonged. Now of course I have said that we will trip into a SSW and BFTE 🙂
If site conditions allow it, aeration will also be beneficial because with low rates of top growth, the plant can put its efforts into root growth and that’s the insurance policy for the spring and summer. The better roots we have, the more stable a grass plant is, the more resilient to summer stress. It all starts here.
Tempus fugit ! my friends, tempus fugit ! (Time flies)
Sorry about the use of latin (and bad punctuation) but I happen to like it on occasion, though neither were taught at Welland Park Comprehensive and yes I know it shows 🙂
All the best