Mark Hunt weather corner
Welcome to my regular weather column, where I take a look at all things weather-related and how they impact on turfgrass management. Weather dynamics have always fascinated me and especially how they impact on turfgrass growth, nutrition and disease management. No two years are the same.
What chance a nice spring?
As February 2023 heads to a conclusion, it has for many areas been an unusually dry and at times very mild month. Here in Leicestershire, my local weather station is showing a mere 6.1 mm rainfall for the month. Single-digit rainfall totals in February are a meteorological rarity with The Met Office listing 1932 as the driest February on record, recording an average of 8.8mm across the U.K.
Normally, the U.K & Ireland experiences a strong westerly jet stream flow from November to February which pushes Atlantic storms across our shores and provides seasonally high rainfall totals for many areas, especially in the west, northwest and north.
2023 has been different though, with a near shut down of rainfall since the 16th of January, particularly across the southern half of the U.K. This has been caused by a premature weakening of the jet stream which has allowed blocking patterns to form and high pressure to dominate our weather.1
I think this weakening of the jet stream has occurred much earlier in the year than normal, typically we see it in late March / early April with a high pressure, blocking pattern developing. It is this phenomenon that has led to the absence of our once-traditional April showers and the now more typical cold / dry - warm / dry April weather that makes turf management in April such a challenge.
As we now head towards the first day of meteorological spring (March 1st as opposed to the spring Equinox on March 20th), we have a further meteorological phenomenon that could potentially muddy the turf management waters for us.
As we now head towards the first day of meteorological spring (March 1st as opposed to the spring Equinox on March 20th), we have a further meteorological phenomenon that could potentially muddy the turf management waters for us.
A Sudden Stratospheric Warming (SSW) event has occurred over the North Pole in the middle of February. This has the potential to reverse the normal west-east flow of the jet stream and allow much colder weather to dominate. It is often the process behind the so called 'Beast from the East' that our tabloids are so fond of dusting down as a news story every winter!2
One thing to state here and now is that a SSW event doesn't always result in a return to winter, but it was behind the cold spring weather in 2009, 2010, 2013 and 2018. By the time you read this we will know if the SSW event of 2023 has caused a return to winter for the first half of March. Hopefully it will be short-lived and spring will be just around the corner.
1 Read all about the different types of blocking
patterns and how they affect our weather:
www.metoffice.gov.uk/weather/learn-about/weather/how-weather-works/high-and-low-pressure/blocks
2 Read about why a SSW affects our weather @
www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/wind/sudden-stratospheric-warming