Mark Hunt weather corner; 123 - Preparing for winter stress
If I was writing this article when I first stepped foot into this industry (1989!!!), I would probably approach it with a view to preparing turf for the effects of winter frosts and cold air desiccation.
Back to the present day, we know our climate has changed since then and that autumn and winter have shown perhaps some of the biggest changes, with less frost days and higher air temperatures.
Consulting The Met Office Climate Information Centre, there is a database of climatic values that has been running since 1884, an invaluable reference resource. Meteorologically-speaking, winter is defined as the period running from December through to February and if we consult the Met Office database, the last 10 warmest winters since 1884 are as follows:
We can see that 4 out of the top 5 warmest winters have occurred since 2007, and if I consult maximum number of frost days, we see only 3 winters (2009, 2010, 2011) that appear in the top 30. So, the trend is for warmer winters with less frost days.
One of the driving forces behind this change is the propensity of the jet stream to form Omega blocking events where warm, humid air is drawn up underneath a dominant, high pressure system in the middle of winter (shown above).
In my view, if I am thinking as a turf manager and preparing for winter, this is the event I should be preparing for.
Warm, humid air introduces two factors that drive winter disease development. They are warm overnight temperatures and long durations of plant leaf wetness in the form of dew.
The first part of the preparation process is to recognise the development of this type of weather system. This is easy, you don’t have to rely on weather apps or be a meteorologist. Simply go onto www.tropicaltidbits.com (donating as a Patreon is worthwhile to support the resource), select > Europe > Upper Dynamics > 500mb Height & MSLP. And press play. Look for the type of weather pattern shown above, one that shows warm air (orange) and a wind direction conducive to pulling this across the U.K, remembering that the wind rotates clockwise around a high pressure system.
From an agronomic perspective, your tools should be set:
- Dew control
- Turf Hardener package
- Fungicide (if appropriate)
Finally, one factor that works in our favour here is that high pressure systems and their development ‘tend’ to be more predictably forecast by weather models, so we often have enough prior warning to react as a turf manager. Not always, but most times, happy clicking.
visit: www.weatherstations.co.uk
Send your questions for Mark to: editor@pitchcare.com