NI Police have urged people not to make unnecessary journeys on Monday amid severe weather alerts across Ireland.
Storm Debi is forecast to bring intense rain and high winds, and authorities north and south have warned of danger to life.
Met Éireann has extended a red wind alert - the most severe warning level - to 14 counties. Schools have been asked to delay opening in affected areas.
An amber wind warning has been issued for parts of counties Down and Armagh.
"Please stay at home where possible and do not make unnecessary journeys. If you must travel, please bear the prevailing conditions in mind," the Police Service of Northern Ireland said in a statement on Sunday night.
"Consider the potential risks before you leave. Do not place yourself or others in unnecessary danger."
The Met Office said a spell of very strong winds is expected to develop during the morning across counties Down and Armagh, with inland gusts of 60-65mph likely in places and coastal gusts of up to 75mph.
Th amber warning will be in place in these areas from 06:00 GMT until 12:00, as Storm Debi moves north.
A yellow alert for rain and wind has been issued for all Northern Ireland counties from 03:00 GMT to 14:00.
Some places could get up to 40mm of rainfall within a six-hour period.
The warnings come as many towns and cities still recovering from recent flooding face the potential impact of this latest weather event.
The Met Office warns that Northern Ireland homes and businesses could be further affected by Monday's rain.
Drivers are urged to anticipate difficult conditions before a transition to drier weather from the south later in the afternoon.
Flying debris and damage to buildings could also occur because of the strong winds.
Large waves around the coast could cause injuries and pose a danger to life.
'Severe weather event'
In the Republic of Ireland, the government's National Emergency Co-ordination Group (NECG) met on Sunday to discuss Storm Debi.
The head forecaster at Irish meteorological agency Met Éireann has described the storm as a "severe weather event".
— Met Office - Northern Ireland (@metofficeNI) November 11, 2023
"We can expect some disruption with travel, some infrastructural issues such as power cables coming down," Eoin Sherlock told reporters after the meeting.
The red alert for wind means people should take action to protect themselves and their property.
The rare most severe weather warning is in place for counties Clare, Kerry, Limerick, Tipperary, Galway and Roscommon from 02:00 local time until 05:00 on Monday.
A red warning is also in place for counties Dublin, Kildare, Laois, Louth, Meath, Wicklow, Offaly and Westmeath from 05:00 until 08:00.
Mr Sherlock said those living in affected areas can expect winds of up to 130km (80 miles) per hour.
He has described the weather system as "very chaotic" and difficult to predict.
Dangerous features, extensive outages
The national director for fire and emergency management, Keith Leonard, said Storm Debi is a "serious winter storm with some dangerous features".
He has advised people to stay away from coastal areas as conditions will be "extremely hazardous" and has warned of "very hazardous and difficult conditions" on roads with a substantial number of downed trees.
"A very important message in relation to keeping your phone charged. There's going to be extensive electricity outages tomorrow and your mobile phone is your link to the emergency services," Mr Leonard added.
⚠️Red Wind Warning⚠️
Dublin, Kildare, Laois, Louth, Meath, Offaly, Westmeath, and Wicklow, Clare, Galway, Kerry, Limerick, Roscommon, & Tipperary
Cork upgraded from Yellow to Orange
Details on impacts & times for your area⬇️https://t.co/1P0YPQeYTB pic.twitter.com/DBmOgD4LVJ
— Met Éireann (@MetEireann) November 12, 2023
A status orange wind alert - the second highest level - has been issued for County Cork, from 01:00 until 04:00, with warnings of dangerous travelling conditions, damage to power lines and exposed structures, and disruption to services.
An orange alert for 19 other counties is in place from 02:00 until 10:00.
Disruption is also expected at Ireland's airports and ports. Irish Rail has warned passengers to expect delays as speed restrictions will apply across the Republic's entire rail network for safety reasons due to the storm.
The NECG has advised schools and pre-schools in all counties affected to remain closed until 10.00 and for those that can work from home to do so.
Yellow warnings have also been issued for rest of the Republic.
Storm Debi is the fourth named storm of the season which began on 1 September.