Hilo

Tonight: Mostly cloudy with numerous showers early in the evening, then mostly cloudy with scattered showers in the late evening and overnight. Lows 62 to 68 near the shore to 49 to 55 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 77 to 83 near the shore to around 66 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday Night: Partly cloudy. Scattered showers early in the evening. Isolated showers late in the evening, then scattered showers after midnight. Lows 62 to 68 near the shore to 48 to 55 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Kona

Tonight: Mostly cloudy with numerous showers early in the evening, then partly cloudy in the late evening and overnight. Haze through the night. Lows around 72 near the shore to 46 to 52 near 5000 feet. Northwest winds up to 10 mph in the evening becoming light. Chance of rain 70 percent.

Monday: Sunny in the morning, then mostly cloudy with numerous showers in the afternoon. Haze through the day. Highs 82 to 88 near the shore to around 65 near 5000 feet. Light winds. Chance of rain 70 percent.

Monday Night: Mostly cloudy with numerous showers in the evening, then partly cloudy with isolated showers after midnight. Haze through the night. Lows around 72 near the shore to 46 to 51 near 5000 feet. Light winds. Chance of rain 70 percent.

Waimea

Tonight: Partly cloudy. Scattered showers early in the evening. Lows 61 to 70 near the shore to 52 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Sunny and breezy. Isolated showers in the afternoon. Highs around 79 near the shore to 70 to 78 near 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Monday Night: Mostly clear. Breezy. Isolated showers early in the evening. Lows 61 to 70 near the shore to 52 to 60 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Kohala

Tonight: Partly cloudy. Scattered showers early in the evening. Lows 61 to 70 near the shore to 52 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Sunny and breezy. Isolated showers in the afternoon. Highs around 79 near the shore to 70 to 78 near 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Monday Night: Mostly clear. Breezy. Isolated showers early in the evening. Lows 61 to 70 near the shore to 52 to 60 near 3000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

South Big Island

Tonight: Partly cloudy. Breezy. Isolated showers early in the evening. Haze through the night. Lows around 72 near the shore to around 50 near 5000 feet. East winds up to 25 mph. Chance of rain 20 percent.

Monday: Breezy. Sunny in the morning, then partly sunny with scattered showers in the afternoon. Haze through the day. Highs around 86 near the shore to around 65 near 5000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Monday Night: Partly cloudy. Breezy. Scattered showers in the evening. Haze through the night. Lows around 72 near the shore to around 50 near 5000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Puna

Tonight: Mostly cloudy with numerous showers early in the evening, then mostly cloudy with scattered showers in the late evening and overnight. Lows 62 to 68 near the shore to 49 to 55 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 77 to 83 near the shore to around 66 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday Night: Partly cloudy. Scattered showers early in the evening. Isolated showers late in the evening, then scattered showers after midnight. Lows 62 to 68 near the shore to 48 to 55 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Partly cloudy. Numerous showers early in the evening. Haze through the night. Lows around 72 near the shore to 49 to 54 above 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Monday: Mostly sunny. Breezy. Haze through the day. Scattered showers in the afternoon. Highs 82 to 89 near the shore to 63 to 71 above 4000 feet. North winds up to 20 mph. Chance of rain 50 percent.

Monday Night: Mostly clear. Breezy. Scattered showers early in the evening, then isolated showers late in the evening. Haze through the night. Lows 69 to 74 near the shore to 49 to 54 above 4000 feet. North winds up to 20 mph shifting to the east after midnight. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to breezy trades deliver clouds and showers to windward and mauka areas through next week. Localized areas of heavy rainfall may develop in the afternoon early this week and again toward the end of the week.

Discussion

Relatively low stability environment prevails this afternoon, a consequence of the weak upper low that has stagnated over the state during the last few days. This low has allowed pockets of heavy rain to develop over portions of leeward Big Island and Oahu during the last couple of days as transient bands of trade wind moisture have capitalized on the softened inversion. At press time, the islands reside between shower bands leaving little in the way of moisture to work with as the last vestiges of cyclonic flow aloft depart to the northeast. Residing on the southwest periphery of said cyclonic flow, Leeward Big Island may see another healthy convective response on Monday as another band of enhanced moisture transits the forecast area. This potentially amounts to nuisance type flooding, mainly limited to more flood prone areas.
Height rises then commence on Tuesday as shortwave ridging builds during mid-week. This period of mid/upper subsidence will be brief and unlikely to make a considerable difference in the existing thermodynamic profile, but a temporary decrease in shower intensity is still likely as increasing stability puts a firmer lid on convective depths.
During the latter half of next week, guidance indicates another closed low developing over, or in the vicinity of, the islands. Of mid-latitude origin, this low will feature a notably colder mid- level cold pool and has the potential to bring more meaningful instability to the area as moderate to breezy trades persist at the surface.

Aviation

Moderate east to east-southeasterly trades will persist through Monday, with wind speeds decreasing slightly. Expect VFR conditions to prevail, though MVFR conditions may arise in any shower activity.
No AIRMETs are currently in effect.

Marine

High pressure will remain centered far northeast of the state throughout much of this week. A weakening cold front to the northwest will weaken the ridge over the next few days, allowing trades to ease to gentle to fresh east to southeast winds across the region through Monday night. An upper level disturbance lingering near the islands will keep brief periods of wet weather in the forecast for coastal and offshore waters throughout the next several days.
A series of small south and south-southwest swells will maintain small south shore surf through Monday. A slightly larger south swell will further boost south shore surf up to seasonal averages during the middle to latter part of the week.
Surf heights along north and west-facing shores will remain small during the next 7 days. Surf heights along east-facing shores will remain choppy, particularly from Tuesday onward as trade winds increase a bit once again.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov