Hawaii County Weather Forecast for October 02, 2021
Hilo
Today: Cloudy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs 80 to 86 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 60 percent.
Tonight: Mostly cloudy with occasional showers. Lows around 69 near the shore to around 55 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 90 percent.
Sunday: Mostly cloudy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs 80 to 86 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.
Kona
Today: Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 86 near the shore to around 73 near 5000 feet. North winds up to 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 69 to 75 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 50 percent.
Sunday: Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 86 near the shore to around 73 near 5000 feet. East winds up to 10 mph shifting to the southwest in the afternoon. Chance of rain 50 percent.
Waimea
Today: Breezy. Mostly cloudy with scattered showers. Highs around 82 near the shore to 73 to 80 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.
Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows around 68 near the shore to 55 to 62 near 3000 feet. East winds up to 20 mph. Chance of rain 70 percent.
Sunday: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs around 82 near the shore to 73 to 80 near 3000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.
Kohala
Today: Breezy. Mostly cloudy with scattered showers. Highs around 82 near the shore to 73 to 80 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.
Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows around 68 near the shore to 55 to 62 near 3000 feet. East winds up to 20 mph. Chance of rain 70 percent.
Sunday: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs around 82 near the shore to 73 to 80 near 3000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.
South Big Island
Today: Breezy. Mostly sunny in the morning, then partly sunny with slight chance of thunderstorms and isolated showers in the afternoon. Highs around 85 near the shore to around 74 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.
Tonight: Breezy. Partly cloudy with isolated showers. Lows around 69 near the shore to around 54 near 5000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.
Sunday: Breezy. Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 85 near the shore to around 74 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.
Puna
Today: Cloudy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs 80 to 86 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 60 percent.
Tonight: Mostly cloudy with occasional showers. Lows around 69 near the shore to around 55 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 90 percent.
Sunday: Mostly cloudy. Showers likely in the morning, then scattered showers and slight chance of thunderstorms in the afternoon. Highs 80 to 86 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.
Waikoloa
Today: Breezy. Mostly sunny in the morning, then partly sunny with slight chance of thunderstorms and isolated showers in the afternoon. Highs around 85 near the shore to 69 to 75 above 4000 feet. East winds up to 25 mph shifting to the northeast in the afternoon. Chance of rain 20 percent.
Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows 70 to 75 near the shore to 51 to 58 above 4000 feet. Southeast winds up to 20 mph. Chance of rain 20 percent.
Sunday: Breezy. Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 85 near the shore to 69 to 75 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 50 percent.
Detailed Forecast
Synopsis
Moderate to breezy trade winds will continue into next week, with clouds and showers favoring windward and mauka locations. Shower coverage could increase through the weekend due to rising moisture and an upper disturbance in the area. Some showers could become locally heavy at times, and an afternoon thunderstorm or two can’t be ruled out over the Big Island through Sunday. Trade winds could become strong Wednesday through the second half of next week.
Discussion
Guidance remains in good agreement into early next week and depicts more of a wet trade wind pattern unfolding due to a combination of an upper trough extending southward into the area and a decent sized area of higher moisture moving through from east to west. This moisture is expected to shift westward over the eastern half of the state today, then statewide tonight through Sunday. Precipitable water values will respond and rise from the current 1.25 inches over the western end of the state to around 1.5-1.6 inches by Sunday.
Provided the added instability from the aforementioned upper trough and the potential for a higher/weaker trade wind inversion, some of these showers will make it into leeward areas of the smaller islands, especially overnight through the morning periods. Additionally, an afternoon thunderstorm or two can’t be ruled out over the Big Island through Sunday. Early morning upper air soundings reflected this potential with cool temperatures aloft and decent mid-level lapse rates.
Although a trend toward a more stable trade wind pattern is possible Tuesday through midweek as upper heights begin to rise, a wet pattern may stick around due to plenty of moisture lingering in the area. Models and ensembles project a tightening pressure gradient by or around midweek, that supports locally strong trades holding through the second half of next week.
Aviation
A high pressure ridge north of the region remains strong enough for moderate to locally breezy trade winds this weekend. An upper level low north of the Hawaiian Islands will keep passing showers in the forecast with brief MVFR conditions over some windward and mountain locations, favoring the overnight to early morning hours. Otherwise, VFR conditions will prevail.
AIRMET Tango remains in effect for Moderate Turbulence between FL250 and FL400 near Kauai and Oahu. Strong upper level winds are just above moderate clear air turbulence thresholds. These strong winds will diminish later this morning.
Marine
High pressure north of the state will keep moderate to fresh trade winds in place across the marine area through early next week, and may be locally strong at times in the typically windy waters around Maui and the Big Island. Strong to near Gale force trade winds may develop during the middle to latter part of next week as a new strong high builds north of the island chain.
Small north and north-northwest swells will keep some small surf in place along north facing shores through the weekend. A small long period west-northwest swell generated by Typhoon Mindulle, will give a boost to surf along north and west facing shores Tuesday through Thursday. North shore surf should drop to very small levels for the end of next week.
Small south swells will keep surf from going flat along south facing shores through the weekend and much of next week. A slightly larger south swell could give a noticeable boost to south shore surf Friday into next weekend.
East shore surf will hold fairly steady near to slightly below normal levels through the middle of next week. Strengthening trades over and upstream of the islands should build east shore surf above normal Friday into next weekend.
HFO Watches/Warnings/Advisories
None.
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Data Courtesy of NOAA.gov