Hilo

Today: Mostly sunny early in the morning, then isolated showers in the late morning and afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 60 to 69 near the shore to around 51 at 4000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Kona

Today: Mostly sunny early in the morning, then isolated showers in the late morning and afternoon. Highs 78 to 85 near the shore to around 66 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 66 to 71 near the shore to around 52 near 5000 feet. Light winds.

Tuesday: Sunny. Isolated showers in the afternoon. Highs 78 to 85 near the shore to around 66 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Waimea

Today: Sunny. Highs around 79 near the shore to 66 to 77 near 3000 feet. Light winds.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 61 near the shore to 51 to 59 near 3000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 79 near the shore to 66 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Kohala

Today: Sunny. Highs around 79 near the shore to 66 to 77 near 3000 feet. Light winds.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 61 near the shore to 51 to 59 near 3000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 79 near the shore to 66 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

South Big Island

Today: Sunny. Highs around 83 near the shore to around 70 near 5000 feet. Light winds.

Tonight: Mostly clear. Lows around 66 near the shore to around 51 near 5000 feet. Light winds becoming northeast up to 10 mph after midnight.

Tuesday: Sunny. Highs around 83 near the shore to around 70 near 5000 feet. East winds up to 15 mph shifting to the southeast in the afternoon.

Puna

Today: Mostly sunny early in the morning, then isolated showers in the late morning and afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 60 to 69 near the shore to around 51 at 4000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 81 near the shore to 66 to 71 at 4000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Waikoloa

Today: Sunny. Highs around 84 near the shore to 67 to 75 above 4000 feet. West winds up to 10 mph.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 69 near the shore to 48 to 55 above 4000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the afternoon. Highs around 84 near the shore to 67 to 75 above 4000 feet. Northeast winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Mostly dry and stable conditions with light and variable winds will continue into Tuesday. The best chance for a few light showers will be driven by sea breezes through the afternoon periods. A return of a more typical trade wind pattern is expected by Wednesday, which should continue through the weekend.

Discussion

Guidance remains persistent and depicts the weak ridge lingering over the islands into Tuesday due to broad upper troughing over the region and a couple of fronts passing to the north. The light westerly background flow in the islands will continue through tonight, then shift out of the north to northeast direction Tuesday. This will allow the land and sea breeze regime to hold with clearing conditions overnight through the mornings followed by some cloud build ups that may produce a few light showers through the afternoon hours over interior areas. The best shot for these showers will remain over Kauai and Oahu where more moisture resides near the tail-end of the passing fronts to the north.
A transition period is anticipated Tuesday through Wednesday as the a ridge noses eastward trailing the front passing to the north. The flow will shift out of the north-northeast later Tuesday, followed by a return of moderate easterly trades Wednesday. Clouds and showers will shift back over windward and mountain locations, with the best chances being overnight through the early morning hours. A residual band of moisture associated with the tail-end of the aforementioned front may sag southward into the smaller islands through the second half of next week, which could support better shower coverage.

Aviation

Overall a dry and stable airmass, along with light winds, remains over the region. Overnight some small bands of clouds passed over the smaller islands at times, bringing brief MVFR conditions, but otherwise mostly clear skies prevailed.
The overnight soundings from Lihue and Hilo both had precipitable water (PW) values around 1.30 inches, however satellite derived PW continues to show slightly drier conditions over Maui County and the Big Island, which is in line with several models. As such, still expecting a few more clouds and showers to be present over Kauai and Oahu today.
The light winds are expected to once again produce afternoon sea breezes that will lead to the development of clouds and isolated showers over interior and leeward areas.VFR conditions are expected to prevail however some isolated MVFR conditions possible within some pockets of lower clouds or showers during the afternoon and evening hours. Any showers that do form should remain light.
Heading into tonight, Monday night, background winds near Kauai are expected to become more northerly, with north to northeast trade winds spreading back across the islands Tuesday.
There are currently no AIRMETs in effect and, at this time, no AIRMETs are anticipated throughout the forecast period.

Marine

With a high pressure ridge near the islands, winds have been light across the coastal waters. High pressure will begin strengthening north of the state by Tuesday night into Wednesday, signaling the return of trade winds. By Thursday, trades will become moderate to breezy.
The first in a series of northwest to north swells over the next week or so has been affecting local waters. A High Surf Advisory (HSA) is in effect for most north- and west-facing shores from Niihau to Maui. As this swell lowers later today; another, larger, long-period swell will begin to move through beginning tonight into Tuesday. The surf generated by this swell will likely warrant a High Surf Warning (HSW) for most north- and west-facing shores beginning early Tuesday, as surf is expected to reach at least 25 feet along north-facing shores. The HSW will likely be in effect into Wednesday before being replaced by an HSA. The swell causing the higher surf will slowly subside through the end of the work week. And early on, swell heights will likely reach at least 10 feet, so a Small Craft Advisory will be necessary for those waters exposed to the incoming swell, beginning late Monday night or early Tuesday morning.
Elsewhere, no significant swells are expected along east- and south-facing shores through the new week.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST this evening for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.

Big Island Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Big Island Helicopter Tours today!

Data Courtesy of NOAA.gov