Flash Flood Watch

The National Weather Service in Honolulu has issued a Flash Flood Watch for Maui and Hawaii Island in effect through Friday afternoon (April 12).

A broad upper level low nearing Hawaii Island from the east will remain in the area through Friday. Cold air aloft and instability associated with this upper feature combined with plenty of moisture will lead to periods of heavy showers and thunderstorms. Showers will become heavy at times, potentially leading to flash flooding. Although most of the activity will focus over windward areas with the strong trades in place, heavy showers and thunderstorms will also remain possible across leeward areas.

Campers and hikers should avoid low lying flood prone areas. People should stay away from streams, drainage ditches and low lying areas prone to flooding. The rainfall and runoff will cause hazardous driving conditions due to ponding, reduced visibility, and poor braking action. Excessive runoff may cause rockslides and mudslides in steep terrain. Remember, if lightning does threaten your area, the safest place to be is indoors.

Debris in streams and gulches may clog bridges and culverts resulting in flooding outside normal water channels causing damage.

Do not cross fast flowing or rising water in your vehicle or on foot. Turn around, don’t drown.

Winter Weather Advisory

The National Weather Service in Honolulu has issued a Winter Weather Advisory for Hawaii Island summits above 11,000 feet until 6 a.m. Saturday (April 13).

Snow is forecast for the summits with a total snow accumilation of 1-3 inches, and localized amounts up to 6 inches.

Be prepared for reduced visibility and slipery road conditions on summit roadways.

A Winter Weather Advisory for snow means periods of snow will cause travel difficulties. Be prepared for snow covered roads and limited visibilities, and use extreme caution while driving.

High Surf Advisory

A High Surf Advisory is in effect for east facing shores of Kauai, Oahu, Molokai, Maui and Hawaii Island until 6 p.m. Sunday (April 14).

Surf is forecast to be in the 6-9 foot range along east facing shores on Thursday rising to 8-12 feet Friday and Saturday.

Coastal areas can expect strong breaking waves, shore breaks and strong longshore and rip currents making swimming difficult and dangerous.

Beachgoers, swimmers and surfers should heed the advice given by ocean safety officials and be careful. Know your limits and when in doubt, don’t go out.

Boaters should expect recreational surfers and bodyboarders using harbor channels to access surfing areas.

Small Craft Advisory

A Small Craft Advisry is in effect until 6 p.m. Sunday (April 14) for Kauai, Oahu, Maui and specifically Hawaii Island waters of the Alenuihaha Channel, windward, leeward and southeast waters.

Offshore winds are forecast to be in the 20-30 knot range with seas 8-12 feet.

A Small Craft Advisory means that wind speeds of 25 to 33 knots and/or seas 10 feet or greater are expected to produce conditions hazardous to small craft. Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in these conditions.

Wind Advisory

A Wind Advisory remain in effect 6 a.m. Friday (April 12) for Lanai, Kahoolawe, Maui and Kohala.

Winds are forecast to be from the northeast at 20-30 mph with localized gusts to 50 mph across Lanai, Kahoolawe, the central valley and west end of Maui and the South Kohala district of the Hawaii Island. Winds will be strongest over and immediately downwind of mountains.

The strong winds can send trees, branches, and other objects into roadways, power lines and/or equipment. Winds this strong can damage roofs and cause flying debris if outdoor items are not properly tied down. These winds can make driving difficult especially for high profile vehicles. The winds can also forcefully swing doors open or shut so use caution when opening or closing vehicle doors.

Hawaii Electric Light Company (HELCO) reminds people that if you see a downed power line you should stay as far away as possible and report any damage or outages to their dispatch center at (808) 969-6666.

For links to the latest weather forecasts, reports, radar and satellite imagery visit our Weather Page at hawaii247.com/weather