Today: Partly sunny with scattered showers. Highs around 79 near the shore to 62 to 67 at 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.
Tonight: Mostly cloudy with scattered showers. Lows 61 to 68 near the shore to around 56 at 4000 feet. East winds 10 to 15 mph shifting to the southeast after midnight. Chance of rain 50 percent.
Saturday: Partly sunny with scattered showers. Highs around 79 near the shore to 62 to 67 at 4000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 50 percent.
Kona
Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 78 to 86 near the shore to around 67 near 5000 feet. North winds around 10 mph shifting to the west in the afternoon. Chance of rain 40 percent.
Tonight: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 68 to 73 near the shore to 50 to 55 near 5000 feet. Northwest winds around 10 mph in the evening becoming light. Chance of rain 40 percent.
ARTICLE CONTINUES BELOW AD
ARTICLE CONTINUES BELOW AD
Saturday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 78 to 84 near the shore to around 66 near 5000 feet. Northwest winds around 10 mph. Chance of rain 40 percent.
Waimea
Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 78 near the shore to 69 to 77 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.
Tonight: Partly cloudy with isolated showers. Lows 62 to 70 near the shore to 54 to 61 near 3000 feet. East winds 10 to 15 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 78 near the shore to 68 to 75 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.
Kohala
Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 78 near the shore to 69 to 77 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.
ARTICLE CONTINUES BELOW AD
Tonight: Partly cloudy with isolated showers. Lows 62 to 70 near the shore to 54 to 61 near 3000 feet. East winds 10 to 15 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 78 near the shore to 68 to 75 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.
South Big Island
Today: Breezy. Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 79 near the shore to around 66 near 5000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.
Tonight: Partly cloudy. Breezy. Lows around 70 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph.
Saturday: Mostly sunny. Breezy. Highs around 79 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph.
Puna
ARTICLE CONTINUES BELOW AD
Today: Partly sunny with scattered showers. Highs around 79 near the shore to 62 to 67 at 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.
Tonight: Mostly cloudy with scattered showers. Lows 61 to 68 near the shore to around 56 at 4000 feet. East winds 10 to 15 mph shifting to the southeast after midnight. Chance of rain 50 percent.
Saturday: Partly sunny with scattered showers. Highs around 79 near the shore to 62 to 67 at 4000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 50 percent.
Waikoloa
Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 79 to 84 near the shore to around 67 above 4000 feet. East winds around 10 mph shifting to the northwest in the afternoon. Gusts up to 30 mph. Chance of rain 40 percent.
Tonight: Partly cloudy. Lows around 71 near the shore to 51 to 56 above 4000 feet. North winds around 10 mph shifting to the east after midnight. Gusts up to 30 mph.
Saturday: Mostly sunny. Isolated showers in the afternoon. Highs 78 to 83 near the shore to around 65 above 4000 feet. West winds around 10 mph. Chance of rain 20 percent.
Detailed Forecast
Synopsis
Enhanced showers and possible thunderstorms remain in the forecast for the western islands into the weekend, thanks to a surface trough lingering to our west and an upper trough expected to develop this weekend. Rainfall will favor southeast facing slopes and coasts. Winds will remain southeasterly through the weekend, then return to a more easterly direction early next week.
Discussion
Our weather pattern has changed little since last evening and forecast philosophy remains unchanged. A stationary surface trough lies just northwest of Kauai this morning. A ragged 200 mile wide band of overcast layered clouds with embedded deep convection marks this trough and lies over and west of Kauai. Surface wind flow east of the trough is predominantly from the southeast, causing showers embedded within this flow to favor southeast-facing shores and slopes. Isolated thunderstorms within the cloud band remain across coastal waters north, west and southwest of Kauai but have yet to reach that island. Overnight soundings show our airmass is rather moist and unstable across the western half of the state, with weak capping inversions at 5300 feet and 10700 feet. Instability increases toward the west.
A surface ridge over the islands will keep light to moderate southeasterly surface flow in place through the weekend. Warm, muggy conditions will continue, but with less instability across the central and eastern islands, only isolated to scattered light showers are expected there. Kauai will see the greatest potential for rainfall and thunderstorms, being closest to the trough and furthest from the ridge axis. Models show an upper trough forming over the islands Saturday night into early next week. This would trigger an increase in showers and increase potential for thunderstorms once again across the state by late Sunday into Monday. Trade winds will set up again late Sunday into next week as the surface trough to our west moves away.
Aviation
A low pressure system with an associated trough far northwest of Kauai will bring enhanced showers and isolated thunderstorms to areas west of Oahu today. Periods of MVFR ceilings and visibility my accompany some of the more robust showers and storms.
Light southeasterly flow will lead to late morning/early afternoon sea breeze development. Thus, isolated to scattered afternoon showers will likely develop over the interior and higher terrain of the islands.
There are no AIRMETs in effect at this time.
Marine
A trough of low pressure will linger west of the state during the next couple days, then shift slowly westward Sunday through early next week. This will lead to a slow and gradual return of trade winds from east to west across the marine area, with the strongest winds remaining over the eastern end of the state. A Small Craft Advisory (SCA) is now in effect for all waters surrounding the Big Island through 6 PM Saturday.
The current small northwest (320 degrees) swell will slowly decline today and Saturday. A small northeast swell is expected to fill in today, peak Saturday, then decline on Sunday. Otherwise, very little energy is expected from the North Pacific through late next week.
Fresh trades upstream of the state will continue to produce near to slightly below normal surf along east facing shores during the next 7 days. Small background energy from the southwest, south and southeast will continue to produce small surf along south facing shores through late next week.
HFO Watches/Warnings/Advisories
Small Craft Advisory until 6 PM HST Saturday for Alenuihaha Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.
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