Hawaii bracing for 'catastrophic' rainfall with flash flooding, landslides

Portions of Hawaii are bracing for potentially catastrophic rainfall this week, just days after some islands were hit with an early winter snowstorm.

Major flash flooding, river flooding and landslides are all possible on multiple islands, with a flood watch in effect across the state through Tuesday, according to the National Weather Service.

The city of Honolulu, which typically only sees about 2 inches of rain for the entire month of December, could get over a half foot of rain by Tuesday. Approximately 3 to 5 inches of rain has been forecast across low elevations, with 10 inches to 15 inches of rain possible in mountainous regions.

Heavy rain and flash flooding began affecting some areas Sunday afternoon and is now making its way westward toward the rest of the island chain on Monday and into Tuesday. Widespread gusty winds could cause issues as well.

Numerous landslides are also expected in areas with steep terrain.

Maui County Mayor Michael Victorino asked residents to avoid visiting flood-prone areas. Hawaiian Electric advised residents to clear their yards of any debris and secure items to avoid outages.

The storm system prompted several schools to close Monday. Weather conditions are expected to improve late Tuesday.

The heavy precipitation comes days after warnings for snow and wind were issued at the Big Island summits with snowfall nearing a foot in some places. However, blizzard warnings are issued at the mountain peaks about every other year, on average.

ABC News' Daniel Peck contributed to this report.