Met Eireann has taken the step to upgrade and bring forward their weather warning to STATUS RED from 11pm on Wednesday night.
A Status Red was originally due to come into force on Thursday at 4pm but is now in force.
The warning states that blizzard like conditions are likely in Wednesday, Thursday and much of Friday.
The warning is valid from 11pm on Wednesday until 3pm on Friday.
Huge snowfall levels are expected with snow drifts bringing accumulations to around 50cm in certain areas.
Snow levels will be around 40cm in Offaly by Friday afternoon.
People are told to stay indoors during a red alert and to avoid road journeys unless it is an emergency.