The Met Office has also issued an amber weather warning for rain.
The warning runs from 6am on Wednesday to 6am on Thursday.
It reads: "Rain will turn persistent across much of the north of Scotland through Wednesday and overnight into Thursday with some heavy outbreaks.
"This will lead to large accumulations building, most likely across the eastern part of the Great Glen and around Inverness where accumulations of 80mm to 100mm are possible in 24 hours with 60mm more widely across this area.
"Given the rainfall of recent days this is expected to lead to some surface water flooding and disruption.
"The rain eases and moves south through Thursday."