Met Eireann has taken the step to extend its current Status Red warning for Storm Emma.
A Status Red came into force at 11pm on Wednesday night and was initially valid until 12pm on Friday. That was later extended to 3pm but now the red warning is valid in Leinster and Munster until 6pm on Friday evening.
The warning states that blizzard like conditions are likely on Thursday night and much of Friday. The worst weather will hit late on Thursday night into Friday morning.
Huge snowfall levels are expected with snow drifts bringing accumulations to around one metre in certain areas of the east in particular.
People are told to stay indoors during a red alert and to avoid road journeys unless it is an emergency.