Hilo

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 84 near the shore to around 67 at 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 71 near the shore to around 56 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers. Highs 75 to 84 near the shore to around 68 at 4000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Kona

Today: Mostly sunny with isolated showers in the morning, then cloudy with showers in the afternoon. Highs 83 to 89 near the shore to around 68 near 5000 feet. West winds up to 15 mph. Chance of rain 90 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to 49 to 54 near 5000 feet. Northwest winds up to 15 mph in the evening becoming light. Chance of rain 20 percent.

Monday: Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 82 to 88 near the shore to around 69 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Today: Partly sunny with scattered showers. Highs 64 to 82. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 71 near the shore to 55 to 62 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 80 near the shore to 68 to 79 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Today: Partly sunny with scattered showers. Highs 64 to 82. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 71 near the shore to 55 to 62 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 80 near the shore to 68 to 79 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Breezy. Mostly sunny with isolated showers in the morning, then cloudy with numerous showers in the afternoon. Highs around 85 near the shore to around 66 near 5000 feet. East winds up to 20 mph shifting to the southeast 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to around 52 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Monday: Mostly sunny in the morning then becoming mostly cloudy. Highs around 84 near the shore to around 66 near 5000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon.

Puna

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 84 near the shore to around 67 at 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 62 to 71 near the shore to around 56 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers. Highs 75 to 84 near the shore to around 68 at 4000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny with isolated showers in the morning, then cloudy with showers in the afternoon. Highs 83 to 88 near the shore to 66 to 73 above 4000 feet. Northwest winds up to 15 mph. Chance of rain 90 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 74 near the shore to 51 to 56 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Highs 82 to 88 near the shore to 66 to 75 above 4000 feet. Northeast winds up to 10 mph.

Detailed Forecast

Synopsis

Gentle to moderate trade winds will prevail with afternoon sea breezes along terrain sheltered western slopes of each island today. Trade winds will strengthen into the moderate to breezy range as sea breezes diminish from Monday onward. Clouds and passing showers will favor the windward and mountain areas, trending higher in the overnight to early morning hours. Isolated thunderstorms are possible today near Kauai. More stable conditions are forecast from Monday onward with brief passing showers mainly forming over windward and mountain areas.

Discussion

A subtropical high pressure ridge north of the Hawaiian Islands will keep trade winds in the forecast through this week. An upper level low roughly 200 miles north of Kauai will continue to drift west today, and then weaken as it moves northward on Monday away from the region. A weak low level trough under this upper low will keep trade winds in the gentle to moderate range for one more day. Upper level forcing from this passing low will enhance shower activity over the western islands, mainly affecting windward and mountain areas in the overnight to early morning hours. Sea breezes will also develop today over terrain sheltered western slopes of each island. Large scale trades and local scale sea breeze winds will converge, producing afternoon clouds and showers over these terrain sheltered leeward locations.
By Monday, the ridge will build into the islands as the upper low weakens and drifts northward away from the region. Trade winds will strengthen into the moderate to breezy range through much of next week. Stronger subsidence under this ridge will stabilize the atmosphere by lowering the trade wind thermal inversion heights and reducing cloud heights. Expect mostly brief passing showers from Monday onward as more stable conditions return to the Hawaii Region.

Aviation

Moderate trades expected through the rest of the weekend. SHRA and low cigs will return to windward and mauka areas. VFR should prevail, with brief periods of MVFR under heavier SHRA.
No AIRMETs are currently in effect.

Marine

High pressure north of the state will maintain moderate to fresh trade winds today. Monday through midweek, trades are expected to strengthen back to fresh and strong levels, and a Small Craft Advisory will likely be required for the typically windy waters around Maui and the Big Island.
No significant south swells are expected through this upcoming week. However, a series of small south-southwest and southeast swells will keep south facing shores from going flat.
Typical mostly flat summertime conditions will continue along north facing shores.
East shore surf will remain below normal on today, then trend up closer to seasonal levels early to mid this week as the trades strengthen over and upstream of the islands.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov