Hilo

Today: Sunny. Isolated showers in the afternoon. Highs around 78 near the shore to around 69 at 4000 feet. Northwest winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 67 near the shore to around 52 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Saturday: Partly sunny. Scattered showers in the morning, then showers likely in the afternoon. Highs around 78 near the shore to around 68 at 4000 feet. Northeast winds around 10 mph. Chance of rain 70 percent.

Kona

Today: Sunny. Isolated showers in the afternoon. Highs around 83 near the shore to 65 to 72 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 71 near the shore to around 52 near 5000 feet. Light winds. Chance of rain 20 percent.

Saturday: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to 64 to 70 near 5000 feet. Northwest winds around 10 mph. Chance of rain 50 percent.

Waimea

Today: Sunny. Isolated showers in the afternoon. Highs around 79 near the shore to around 72 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 68 near the shore to around 56 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 79 near the shore to around 71 near 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Today: Sunny. Isolated showers in the afternoon. Highs around 79 near the shore to around 72 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 68 near the shore to around 56 near 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 79 near the shore to around 71 near 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Sunny. Highs around 81 near the shore to around 65 near 5000 feet. East winds up to 10 mph.

Tonight: Mostly clear. Lows around 70 near the shore to around 51 near 5000 feet. North winds up to 10 mph.

Saturday: Mostly sunny. Isolated showers in the afternoon. Highs around 81 near the shore to around 64 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Puna

Today: Sunny. Isolated showers in the afternoon. Highs around 78 near the shore to around 69 at 4000 feet. Northwest winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 67 near the shore to around 52 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Saturday: Partly sunny. Scattered showers in the morning, then showers likely in the afternoon. Highs around 78 near the shore to around 68 at 4000 feet. Northeast winds around 10 mph. Chance of rain 70 percent.

Waikoloa

Today: Sunny. Isolated showers in the afternoon. Highs 78 to 83 near the shore to 65 to 74 above 4000 feet. North winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 69 near the shore to around 52 above 4000 feet. Southeast winds up to 10 mph.

Saturday: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 80 near the shore to 65 to 72 above 4000 feet. North winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Trade winds will return over the weekend as high pressure builds well north of the state. Periods of enhanced windward rainfall will accompany the trades as an upper trough passes over the state, decreasing stability.

Discussion

Winds remain light this morning as a surface ridge lingers across the western islands. Land and sea breezes will dominate through today, with stable conditions expected for the next few days as weak ridging continues aloft. Satellite loop shows very little cloud cover across the islands, thanks to overnight land breezes. Surrounding waters have scattered low clouds to clear skies. Little or no shower activity is noted on radar. Overnight soundings show a dry and stable airmass, with less than an inch of PW along with positive lifted index values and a strong capping subsidence inversion.
Upper ridging will begin to erode this evening as a front weakens and dissipates north of the islands. Building surface high pressure will replace the front, heralding a return to trade flow across the state Saturday. A weak upper trough will swing through the islands tonight into Saturday morning. This will erode the inversion and allow windward showers to develop. The upper trough will deepen and become a cutoff upper low northeast of the state by Sunday before drifting southward toward the Big Island into early next week. Expect enhanced trade showers through the first part of next week as this happens, especially over the eastern end of the island chain. Models weaken the upper low as it lingers over the area through mid-week, which could keep enhanced trade showers around. Surface high pressure will strengthen far northeast of the state, boosting trade winds back into the moderate to fresh range for the latter half of the week.

Aviation

Winds will remain light across the state through today, with nighttime land breezes giving way to daytime sea breezes in many locales, as a surface ridge remains nearby. Clouds have been clearing out during the overnight hours and will develop again over interior and mountain sections beginning in the late morning. Showers will tend to be light and spotty in the afternoon and evening hours under this type of regime. Northeast trades in the light to moderate range will return by Saturday.
No AIRMETs are in effect, and none are expected through the day.

Marine

A surface ridge axis lies across the northwest and north offshore Hawaiian waters. This has maintained gentle easterly trades across most waters…locally moderate trades around Big Island. A very slow eastern-advancing cold front approximately 250 nm northwest of Kauai will skim the far northern offshore waters through the day and veer winds around to the north. Trades will strengthen over the weekend as high pressure passes off north of the area. Gentle to moderate early week trades will occur from a relatively tight pressure gradient created by this high as it strengthens and moves further off to the northeast.
The west northwest swell that peaked Wednesday has flattened out through the day. It is still undergoing a very slow decline, so this swell will remain slightly elevated through tonight before fading out over the weekend. The next moderate size west northwest swell will arrive and fill in next Tuesday. This swell will peak Tuesday and Wednesday and may push north and west facing shore surf back up to High Surf Advisory levels. A reinforcing west northwest swell will build in around next Friday. Small, mainly background south swell energy will move through during the next few days. A slightly larger, long period south swell is scheduled to arrive late Monday into Tuesday that will bump up south facing shore surf another foot or two. East facing shore wind wave chop will remain small in response to more gentle trades but then increase to around seasonal averages late Saturday into Monday as a result of strengthened trades.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov