Updated at 9pm. Additional reporting by PA.
A red weather warning for the southwest of the country has been extended to Clare and Waterford.
Met Éireann have warned Storm Eunice will "track quickly over Ireland tonight and Friday morning, bringing severe and damaging winds".
The two counties have been added to an earlier red warning issued for Cork and Kerry.
The warnings for Clare, Cork and Kerry will begin at 3am on Friday, lasting until 8am. Meanwhile, Waterford's alert will begin at 7am on Friday, lasting until 11am.
Minister for Education Norma Foley has confirmed Clare and Waterford have been added to the list of counties where schools should remain closed on Friday due to the storm. Earlier seven counties were instructed to close, namely; Cork, Kerry, Donegal, Mayo, Sligo, Leitrim and Roscommon.
🚨 Storm Eunice update: Met Éireann has now advised that counties Clare and Waterford have been issued with Status Red wind warnings. The Department is advising that schools in both counties should not open tomorrow 18 February along with the seven counties previously announced.
— Norma Foley T.D (@NormaFoleyTD1) February 17, 2022
On RTÉ News at One, Met Éireann's Bonnie Diamond warned there would be strong winds which could lead to fallen trees, danger to buildings and power lines. High tides could also lead to coastal flooding.
Ms Diamond explained red alerts are "relatively rare", reserved for the most dangerous, severe and impactful weather conditions.
She advised people in red counties should not go outside, cancel trips, stay away from coastal areas and remain indoors until the storm passes.
Orange weather warnings
A status orange warning has also been issued for 16 other counties.
Donegal, Leitrim, Sligo, Mayo and Roscommon will be under an orange snow warning from 3am on Friday until 3pm.
Meanwhile, a status orange wind warning will take effect at the same time, lasting until 11am, for Carlow, Dublin, Kildare, Kilkenny, Laois, Offaly, Wexford, Wicklow, Galway, Tipperary and Limerick.
“Storm Eunice will bring heavy sleet and snow, leading to blizzard-like conditions in parts, with treacherous driving conditions,” Met Éireann warned.
#StormEunice will bring challenging and disruptive conditions on Friday due to very strong winds, heavy rain and snow.
⚠️Weather Warnings for #rain, #wind and #snow are in place.
⚠️Keep an eye on the latest warnings and updates over the coming days 👉🏾 https://t.co/BoUueCIxKa pic.twitter.com/0od83XSror
— Met Éireann (@MetEireann) February 17, 2022
Yellow weather warnings
Finally, all remaining counties will be placed under a yellow wind, rain and snow warning at 1am on Friday, lasting until 3pm.
The UK Met Office has issued similar warnings for the North. From 3am on Friday, all six counties will be placed under a yellow warning for snow, which will remain in place until 6pm, while a yellow wind alert will commence at 7am for Antrim, Derry and Down, lifting at 6pm.
“Storm Eunice may cause disruption due to heavy snow and some strong winds on Friday,” the UK forecaster said.
Due to the storm, a number of Government departments, emergency services and businesses have issued updates for Friday.
The Irish Coast Guard urged all mariners and coastal communities to be mindful of the severe weather warnings, adding open water recreation should be avoided, "as it may result in arousing public concerns and causing rescue services to be alerted". Walkers are also urged to avoid exposed areas, including seafront and cliff walkways, "as they may be hit by sudden gusts, exposing themselves to unnecessary danger".
The Department of Transport said the storm will make travel conditions particularly difficult, asking people to pay close attention to updates from key transport agencies, including the National Transport Authority, Road Safety Ireland, Bus Éireann and Transport Infrastructure Ireland. Those hoping to travel by air or ferry are also advised to check directly with their flight/ferry operator in case of any service disruption.
The HSE, meanwhile, has established a dedicated webpage to provide information on the availability of local services during the storm. The HSE added the National Ambulance Service will always prioritise emergency calls during severe weather events, asking members of the public to think carefully before calling the service.
AIB Group has also confirmed it will temporarily close its AIB and EBS branches in areas impacted by the red and orange warnings. However, the branches will reopen from 1pm on Friday.