(BVIN) – The National Weather Service in Honolulu has issued a Winter Storm Warning for Hawaiʻi island summits, and a Flood Watch for the entire island, to be in effect later today through late Monday night.

“A low level trough moving into the Big Island from the east will be enhanced by a deepening upper level system producing moderate to heavy rainfall mainly over the eastern slopes of the Big Island starting this evening,” forecasters wrote on Sunday. “The heaviest rainfall amounts are forecast to fall along the eastern slopes of the Big Island from North Kohala, down the Hāmākua Coast, into the Hilo and Puna Districts.”

The Flood Watch will be in effect from this evening through late Monday night.

The Hawaiʻi County Civil Defense issued a radio message, advising:

• Residents in flood prone areas, take this time to prepare for possible heavy rains and potential flooding.
• Be aware that road closures may occur without notice.
• Do not attempt to cross flowing water in a vehicle or on foot; turn around don’t drown.
• Remember, if lightning threatens your area, the safest place to be is indoors.

From the National Weather Service discussion on Sunday morning:

Ensemble weather model forecasts from the National Blended Model, the European and American (GFS) ensembles are continuing to show the highest rainfall totals falling along the eastern slopes of the Big Island from the North Kohala area, down along the Hamakua Coast, into the Hilo and Puna Districts. Rainfall activity will continue to trend higher for the Big Island through the day today with more consistently heavier showers expected by this evening. Using the 90 percent ensemble threshold we see storm total amounts in the 4 to 8 inch range for these eastern Big Island slopes over a 36 hour time period. A Flood Watch for the Big Island was issued this morning to cover this increasing flood threat.

Meanwhile, a Winter Storm Warning for the summits of Maunakea and Mauna Loa will be in effect from 2 p.m. this afternoon to 6 p.m. Monday.

Forecasters say total snow accumulations of 5 to 8 inches, with freezing rain that could produce ice accumulations around two tenths of an inch, are possible.