Hilo

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 63 to 70 near the shore to 50 to 57 at 4000 feet. Northeast winds up to 10 mph shifting to the northwest after midnight. Chance of rain 70 percent.

Friday: Partly sunny with scattered showers. Highs 79 to 85 near the shore to 65 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Friday Night: Showers. Lows 63 to 70 near the shore to 51 to 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain near 100 percent.

Kona

Tonight: Mostly cloudy with scattered showers. Lows around 73 near the shore to 49 to 54 near 5000 feet. Light winds. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs around 85 near the shore to around 67 near 5000 feet. Light winds. Chance of rain 50 percent.

Friday Night: Mostly cloudy with scattered showers. Lows around 73 near the shore to 49 to 54 near 5000 feet. Light winds. Chance of rain 50 percent.

Waimea

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then isolated showers after midnight. Lows 63 to 71 near the shore to 55 to 62 near 3000 feet. East winds 10 to 20 mph decreasing to up to 20 mph after midnight. Chance of rain 50 percent.

Friday: Breezy. Partly sunny with isolated showers. Highs around 80 near the shore to 68 to 79 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

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

Kohala

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then isolated showers after midnight. Lows 63 to 71 near the shore to 55 to 62 near 3000 feet. East winds 10 to 20 mph decreasing to up to 20 mph after midnight. Chance of rain 50 percent.

Friday: Breezy. Partly sunny with isolated showers. Highs around 80 near the shore to 68 to 79 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

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

South Big Island

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Lows around 73 near the shore to around 53 near 5000 feet. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Friday: Breezy. Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 86 near the shore to around 66 near 5000 feet. East winds up to 20 mph. Chance of rain 40 percent.

Friday Night: Partly cloudy. Isolated showers in the evening. Lows around 72 near the shore to around 53 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Puna

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 63 to 70 near the shore to 50 to 57 at 4000 feet. Northeast winds up to 10 mph shifting to the northwest after midnight. Chance of rain 70 percent.

Friday: Partly sunny with scattered showers. Highs 79 to 85 near the shore to 65 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Friday Night: Showers. Lows 63 to 70 near the shore to 51 to 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain near 100 percent.

Waikoloa

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows around 73 near the shore to 50 to 55 above 4000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 84 to 91 near the shore to 64 to 73 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Friday Night: Partly cloudy. Scattered showers in the evening. Lows around 73 near the shore to 50 to 56 above 4000 feet. Light winds. Chance of rain 40 percent.

Detailed Forecast

Synopsis

The forecast will trend drier as ridging builds into the region. Occasional pockets of moisture embedded within moderate to locally breezy trades will continue to support mainly windward and mauka showers for the next several days. Trade winds could veer to become more east-southeasterly as speeds decrease a bit by the second half of the weekend. The overall drier pattern will continue well into next week.

Discussion

This afternoon, surface high pressure centered far northeast of the main Hawaiian Islands continues to drive locally breezy easterly trade winds across the state. Ridging in the wake of an exiting weak disturbance aloft is resulting in drier conditions today than those experienced the past couple of days, though a weak upper jet is steering a thin layer of cirrus across the eastern half of the state. Afternoon satellite and radar imagery shows very few showers across the state, and rain gauge networks show that most locations have received very little or no rainfall since this morning. Observed 00z soundings at Hilo and Lihue show strong inversions between roughly 6,500 and 7,500 feet, with ample dry air aloft. Low cloud cover is also confined mostly to the typical windward and mauka sections of the islands. This is in addition to the afternoon sea-breeze induced increase in cloud and shower coverage over the Kona slopes of the Big Island.
Global forecast models remain in good agreement that the surface high far northeast of the state will remain nearly stationary through Saturday as it experiences minor fluctuations in intensity. This will result in moderate to breezy trade winds continuing across the main Hawaiian Islands into the weekend. The overall drier trend will continue as well, though pockets of low- level moisture trapped beneath the inversion will result in occasional windward and mauka showers, particularly during the overnight through early morning hours each day.
During the second half of the weekend and into early next week, the surface high to our far northeast will weaken further and move closer to the continental U.S. as a front makes its way across the North Pacific and a new high develops far north- northwest of the state. As this occurs, trades will likely weaken a bit more and veer to become more east-southeasterly during the first half of next week. Showers are expected to be fairly limited throughout this time, mainly favoring windward and mauka areas during the overnight through early morning hours each day. Guidance remains consistent that the second half of next week could be even drier as a new surface high becomes established to our northeast.

Aviation

Beneath a transparent shield of cirrus and patchy mid-level clouds, VFR prevails as breezy trades persist at the surface. Little in the way of upstream moisture suggests MVFR remains patchy in nature and confined to windward and mauka areas, mainly overnight.
AIRMET Tango remains in effect for low-level lee turb.

Marine

High pressure northeast of the state will drive moderate to fresh trade winds for the next several days, with only a slight variation in wind speed and direction expected. A disturbance passing well north of the area late this weekend into early next week may weaken the local pressure gradient slightly and allow the trades to ease. The lightest wind speeds are expected Sunday through Tuesday and are expected to veer out of the east- southeast.
The current south swell that produced near summer average surf will continue to gradually fade to background levels tomorrow into the weekend. Models show another small, long period south swell arriving Sunday into early next week that should boost south shore surf back up to near average surf.
Surf along east shores will remain rough and choppy for the next several days. Surf may lower a notch as the trade winds ease late this weekend into early next week. Surf along north facing shores will remain tiny through the period.
Peak high tides associated with the lunar cycle will cause minor coastal flooding along shorelines and low lying coastal areas this afternoon into the early evening during the daily peak high tide. The Coastal Flood Statement is in effect through this evening and then will likely be allowed to expire as water levels are expected to drop and remain below criteria as daily peak high tides lower and south swell dissipates.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov