WE’RE IN FOR at least a week of unsettled weather, with no sign that it’s about to let up. But it’s not just Ireland falling foul to changeable weather again… it’s due to a meteorological event.

Meteorologists tell us that there’s a special reason for why it’s been so unsettled lately – with a mix of warm, sunny days and weather like today’s, where the rain is “down for the day”.

The UK’s Met Office calls it an “omega block”, named based on the shape created by the weather pressures, where a high pressure system is “sandwiched” between two low pressure systems. It gets its name as the shape looks similar to the Greek letter omega.

These pressure systems normally move, but are “blocking high”, or pressures stuck in place for a prolonged period (that could be days, or even weeks).

“The UK [and most of Ireland] is stuck with low pressure, which will continue to feed weather fronts in with pulses of heavy rain throughout this week.”

Met Office Met Office

Met Éireann explained the meteorological effect further:

“It’s a standing blocking pattern, where a high pressure system is caught between two lows,” which means that what was swirling around Ireland and the UK at the weekend is now swirling through France, Benelux and the rest of Belgium, swirling back around Ireland later in the week.

This doesn’t mean that the continent is getting the same temperatures as we are – they’re experiencing higher temperatures, which means their weather is a lot less unsettled.

Because these pressure systems are stuck in place, rain can fall or the sun can shine in the same place for days, instead of areas experiencing passing showers or sunny spells.

And it’s not going to go away for the foreseeable.

The low pressure system is close to Ireland’s northwest coast, and will bring heavy showers to the west and northwest this weekend. On Sunday, the low pressure system will track towards Ireland, bringing scattered showers with it.
“The cold pool is trapped because of that block set-up, so it doesn’t look like there there’s anything to break that up in the next 10 days,” according to Met Éireann.