Today: Mostly cloudy. Showers likely in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 80 near the shore to 65 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Tonight: Mostly cloudy. Showers likely and slight chance of thunderstorms early in the evening, then numerous showers in the late evening and overnight. Lows 64 to 69 near the shore to around 53 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Wednesday: Mostly cloudy with numerous showers. Highs around 80 near the shore to 65 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Kona
Today: Sunny in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms in the afternoon. Highs 80 to 85 near the shore to around 65 near 5000 feet. Light winds. Chance of rain 70 percent.
Tonight: Mostly cloudy early in the evening then becoming mostly clear. Showers likely and slight chance of thunderstorms early in the evening, then isolated showers late in the evening. Lows 67 to 74 near the shore to around 54 near 5000 feet. Light winds. Chance of rain 70 percent.
ARTICLE CONTINUES BELOW AD
ARTICLE CONTINUES BELOW AD
Wednesday: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 80 to 85 near the shore to around 65 near 5000 feet. Light winds. Chance of rain 50 percent.
Waimea
Today: Mostly sunny with scattered showers in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms in the afternoon. Highs around 79 near the shore to 65 to 75 near 3000 feet. East winds up to 15 mph. Chance of rain 70 percent.
Tonight: Mostly cloudy. Scattered showers and slight chance of thunderstorms early in the evening, then scattered showers in the late evening and overnight. Lows around 66 near the shore to 54 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.
Wednesday: Partly sunny with scattered showers. Highs around 79 near the shore to 65 to 75 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.
Kohala
Today: Mostly sunny with scattered showers in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms in the afternoon. Highs around 79 near the shore to 65 to 75 near 3000 feet. East winds up to 15 mph. Chance of rain 70 percent.
ARTICLE CONTINUES BELOW AD
Tonight: Mostly cloudy. Scattered showers and slight chance of thunderstorms early in the evening, then scattered showers in the late evening and overnight. Lows around 66 near the shore to 54 to 61 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.
Wednesday: Partly sunny with scattered showers. Highs around 79 near the shore to 65 to 75 near 3000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.
South Big Island
Today: Breezy. Sunny in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms in the afternoon. Highs around 83 near the shore to around 69 near 5000 feet. East winds up to 20 mph. Chance of rain 70 percent.
Tonight: Mostly cloudy early in the evening then becoming mostly clear. Breezy. Showers likely and slight chance of thunderstorms early in the evening. Lows around 68 near the shore to around 53 near 5000 feet. East winds up to 20 mph becoming 10 to 15 mph after midnight. Chance of rain 70 percent.
Wednesday: Mostly sunny. Scattered showers in the afternoon. Highs around 83 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 30 percent.
Puna
ARTICLE CONTINUES BELOW AD
Today: Mostly cloudy. Showers likely in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 80 near the shore to 65 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Tonight: Mostly cloudy. Showers likely and slight chance of thunderstorms early in the evening, then numerous showers in the late evening and overnight. Lows 64 to 69 near the shore to around 53 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Wednesday: Mostly cloudy with numerous showers. Highs around 80 near the shore to 65 to 70 at 4000 feet. East winds up to 10 mph. Chance of rain 70 percent.
Waikoloa
Today: Sunny in the morning, then partly sunny with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 84 near the shore to 66 to 72 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.
Tonight: Mostly cloudy early in the evening then becoming mostly clear. Scattered showers and slight chance of thunderstorms early in the evening, then isolated showers late in the evening. Lows 68 to 74 near the shore to 50 to 57 above 4000 feet. Northeast winds up to 15 mph in the evening becoming light. Chance of rain 50 percent.
Wednesday: Mostly sunny. Scattered showers in the afternoon. Highs around 84 near the shore to 66 to 72 above 4000 feet. Light winds. Chance of rain 40 percent.
Detailed Forecast
Synopsis
Moderate trades will focus showers over windward areas through the week. Afternoon showers, some of which may be heavy, will be common over leeward portions of Maui and the Big Island each afternoon. There is also a slight chance of afternoon thunderstorms over the Big Island today.
Discussion
Did make some tweaks to the PoPs and associated grids through tomorrow night, mainly to nudge PoPs up towards the National Blend of Models. This mostly impacted the Big Island, but some other areas were nudged upwards as well. The overall forecast philosophy remains the same.
An upper level trough to the north of the main Hawaiian islands is bringing southwesterly upper level winds over the region. High clouds just south of the Big Island will likely pass over the island from time to time. Thunderstorms have been noted on the edge of the coastal waters to the southwest of the islands, and into the offshore waters further southwest.
The upper level trough is expected to slowly lift north and move to the east over the next 24 hours or so. While thunderstorms didn't materialize over the Big Island yesterday afternoon, enough instability remains over the southern end of the state for the possibility of a thunderstorm or two over the slopes Tuesday afternoon.
The surface trough mentioned above is expected to move to the west away from the islands over the next couple of days, with a high pressure system remaining to the north to maintain a trade wind pattern over the islands. A broad upper level trough is expected to remain north of the islands through much of the week. The ECMWF develops another upper level low to the northwest of the islands at the end of the week, while the GFS isn't quite as keen on the development. The upper level trough will likely keep inversion levels a bit higher than normal in a trade wind pattern. With precipitable water on the high end of normal, there will be showers focused over the windward sides of the islands. The higher than normal inversion will help showers to develop over the leeward sides of the islands during the afternoon hours, particularly Maui and the Big Island, through the week.
Aviation
The air mass over the state is becoming increasingly unstable, the result of a nearby upper level trough of low pressure. With little or no capping inversion aloft, locally heavy showers are possible statewide. Daytime heating will further enhance convective activity, especially over island interiors. Isolated thunderstorms are expected over the higher elevations of the Big Island in the afternoon and early evening.
Early morning satellite and radar imagery revealed scattered light showers carried in by the trade winds approaching windward slopes and coasts. Meanwhile, a large area of layered clouds, punctuated with isolated moderate showers, hung over leeward waters. In the higher levels, ragged bands of cirrus streamed across the state from the southwest. Expect shower activity to be mainly light and intermittent this morning then intensify and become focused over island interiors in the afternoon.
There are currently no AIRMETs in effect.
Marine
High pressure far north of the state will drift south for the next couple of days. This will result in moderate to fresh trade winds with periods of locally strong trade winds. Winds will hover near the Small Craft Advisory (SCA) thresholds for the windier waters around Maui and the Big Island and could increase to SCA thresholds briefly Wednesday. Trades winds will weaken slightly as the high moves far northeast towards the end of the week into the weekend.
The current south southwest swell appears to have peaked and is expected to hold surf heights around the summer average (5 feet) today before gradually subsiding Wednesday. Background surf is expected along south facing shores from Thursday into Friday which will keep surf from going flat. A small, long- period south- southwest swell will arrive this weekend providing a slight increase in surf heights along south facing shores Saturday night into Sunday. A small south- southeast (160-170 degree) swell is possible early next week from a gale low located currently near 30S147W.
Persistent trade winds, should keep near to just below average choppy surf along east facing shores through most of the week. Surf is expected to drop well below average over the weekend as trade winds ease locally and upstream.
The current small west-northwest swell will provide a slight boost in surf heights along most exposed north and west facing shores today. This swell will fade overnight into tomorrow. Expect small, background summertime surf along north facing shores from tomorrow through next weekend. For the long-range, the latest guidance from the WAVEWATCH III Model continues to indicate a small, long- period west swell, produced by northwest Pacific Typhoon Mawar, may arrive around Tuesday, June 6.
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