Met Éireann has extended its Status Yellow rain warning to more counties, with heavy thundery rain forecast from 4:00am until 11:00am on Sunday, September 27.

The warning covers Munster, Leinster, Cavan and Monaghan. Farmers in those counties should plan for blustery conditions alongside the rain, and the forecast carries implications for livestock handling, machinery work and any harvesting still underway on Sunday morning.

What does the warning mean in practice?

Met Éireann lists three main impacts from the confirmed forecast:

• Localised flooding;
• Poor visibility;
• Difficult travelling conditions.

The advisory adds a further coastal risk. The combination of spring tides, surge and strong onshore winds may result in wave overtopping along southern and south-eastern coastlines. Farmers with land or infrastructure near the coast in those areas should check boundaries, gates and any stock close to the shoreline before Sunday morning.

For field operations, the timing matters. The seven-hour warning window ends at 11:00am, and Met Éireann expects a clearance to sunny spells and isolated showers to develop in the south-west in the early morning, extending to the north-east by mid-afternoon. That means the second half of Sunday could still offer workable conditions in many areas, provided ground conditions hold after the rain.

How does the weekend build up?

Saturday brings sunny spells and well scattered showers in the morning. Cloud will increase during the afternoon and evening, and the showers will become more frequent.

Highest temperatures on Saturday will reach 15° to 20°, mildest in the east. Moderate to fresh and occasionally gusty south to south-west winds will develop, strong in western and north-western coastal areas.

Anyone planning spraying, topping or hauling across the weekend faces a narrowing window. Saturday morning looks the driest part of the weekend, before cloud and showers build.

What happens Saturday night?

It will be largely dry early on Saturday night with a mix of cloud, clear spells and isolated showers. Cloud will then build from the south-west, with rain following for the latter half of the night and reaching all but north-eastern areas by morning.

Met Éireann warns the rain will be heavy or thundery in places, especially in southern areas, with localised flooding possible.

Sunday starts wet, with outbreaks of rain, heavy or thundery in places. The clearance from the south-west then pushes through to the north-east by mid-afternoon.

What should farmers watch?

The key risks are concentrated into a short period: heavy, thundery rain from the pre-dawn hours to late morning on Sunday, followed by a steadier afternoon. Low-lying fields, river margins and coastal land in the south and south-east face the greatest exposure to localised flooding and wave overtopping.

Watch for further updates from Met Éireann on Saturday evening and Sunday morning, as extensions or escalations to the warning remain possible if the system tracks differently.