Photo Credit: James Grenz

Hilo

Today: Scattered showers. Partly sunny, with a high near 81. Light and variable wind becoming east northeast 5 to 8 mph in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 67. Calm wind becoming west southwest around 6 mph after midnight. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 81. Calm wind becoming east 5 to 7 mph in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Isolated showers after noon. Mostly sunny, with a high near 79. Calm wind becoming northwest 5 to 9 mph in the morning. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Partly cloudy, with a low around 67. North wind 5 to 7 mph becoming calm after midnight. Chance of precipitation is 20%.

Monday: Scattered showers after noon. Mostly sunny, with a high near 80. Light and variable wind. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers, mainly after noon. Mostly sunny, with a high near 75. Breezy, with a northeast wind 9 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers, mainly before midnight. Partly cloudy, with a low around 57. East wind 7 to 9 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Monday: Scattered showers, mainly after noon. Partly sunny, with a high near 76. East wind 7 to 9 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Scattered showers. Partly sunny, with a high near 70. East wind around 14 mph, with gusts as high as 18 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 55. East wind around 14 mph, with gusts as high as 18 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Showers likely, mainly after noon. Partly sunny, with a high near 70. East wind 8 to 13 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Mostly sunny, with a high near 83. Breezy, with an east wind 17 to 20 mph, with gusts as high as 25 mph.

Tonight: Partly cloudy, with a low around 72. Breezy, with an east northeast wind 17 to 20 mph, with gusts as high as 24 mph.

Monday: Isolated showers after noon. Mostly sunny, with a high near 83. Breezy, with an east wind 17 to 21 mph, with gusts as high as 26 mph. Chance of precipitation is 20%.

Puna

Today: Scattered showers. Partly sunny, with a high near 77. North northwest wind 5 to 9 mph becoming east northeast in the morning. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 64. Light and variable wind becoming north northeast 5 to 7 mph after midnight. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 77. North northeast wind 7 to 10 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waikoloa

Today: Sunny, with a high near 82. North northwest wind 5 to 7 mph becoming light and variable in the afternoon.

Tonight: Partly cloudy, with a low around 66. Light and variable wind.

Monday: Isolated showers after noon. Sunny, with a high near 84. Northwest wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

Brief passing showers will continue today as a lingering upper level disturbance slowly moves away from the islands. Trade winds will weaken over the next several days allowing local scale sea breezes to develop over terrain sheltered leeward areas. Lighter winds and a more stable ridge aloft will keep drier trends in the forecast for most islands from Monday into Friday.

Discussion

The high pressure ridge far north of the islands will weaken as two cold fronts drift eastward into the Central Pacific. Trade winds will weaken as this high pressure ridge decreases in strength. An upper level low just north of the Hawaiian Islands will slowly drift northward over the next two days, and another weaker low near Kauai will drift westward away from the area on Monday.
In the short term forecast, some upper level instability will keep brief shower activity over all islands through Sunday. As the two upper lows drift further away from the islands a more stable ridge will build in over the region producing drying trends from Monday through Friday. Trade wind speeds will also decrease allowing on-shore local scale sea breezes to develop each day over terrain sheltered leeward areas of each island. Fairly stable conditions will keep rainfall amounts on the lighter side as clouds will struggle to produce rainfall in most areas. Kona slopes of the Big Island will continue to see scattered showers mainly after sunset each night.
In the extended forecast for next weekend, the high pressure ridge north of the islands strengthens allowing more moderate to breezy trade winds to return across the region. Early signs show yet another unstable upper low moving into the area from the east, potentially increasing shower activity for some islands. Global models are less certain on the location of this upper low, so our confidence in this wetter solution is only fair at this time.

Aviation

High pressure northeast of the state will keep light to moderate trade winds in place through tonight, with some localized land breezes and sea breezes possible in the more sheltered leeward areas. Scattered showers are expected to affect windward areas through the early morning hours. Another round of daytime heating driven showers will be possible again this afternoon, but the coverage and intensity of the showers should be less than what was seen yesterday. Predominantly VFR conditions should prevail during the next 24 hours, with some brief MVFR cigs and MVFR/IFR vsbys possible in showers.
No AIRMETs are currently in effect.

Marine

Trade winds are expected to persist well into the new week as a surface high remains far northeast of the islands. The associated surface ridge extending southwest from the high will be moving south during the first half of the week. The ridge is currently 550 nm north- northwest of Kauai. By Thursday, the ridge will be 240 nm north of Kauai, or at the northern limit of our offshore waters. So, our light to moderate trades will be trending down to mainly light by Thursday. The ridge is expected to shift north on Friday.
The current south swell is forecast to peak today before gradually subsiding through Monday. With the current buoy data, surf along south facing shores is slated to be just below the high surf advisory criteria of 8 feet for today, but we will be monitoring the situation closely. There will be other smaller swells reaching our south facing shores for the rest of the week that will keep surf from going flat. A small to moderate northwest swell will be coming in today, peak Monday. A slightly smaller pulse will arrive Tuesday, peak Tuesday night, and another swell of a similar size arriving Thursday night through Friday night. With the trade winds forecast to be trending lighter in the coming days, look for surf along east facing shores to be a foot or two less than it is now. Strengthening trades Friday through Saturday will be boosting the surf up along east facing shores.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov