A yellow weather warning for heavy rain has been issued by the Met Office for Northern Ireland on Saturday.
The weather warning will remain in place between 12am and 3pm on Saturday.
It is expected that the rain could cause some disruption, with flooding of a few homes and businesses likely.
Spray and flooding on roads could make journey times longer and and bus and train services may be affected.
The Republic of Ireland is bracing itself to feel the brunt of Storm Hannah.
"A band of rain will move west to east across Northern Ireland from the early hours of Saturday, turning heavier and more persistent in places through the morning," a Met Office spokesperson said.
"Many areas will see 20mm of rain in total, though a few spots could see 30 to 40 mm within around 6 hours. The rain will clear the northeast coast by mid-afternoon."