West Kaua’i

Today: Mostly sunny with isolated showers. Highs around 81 near the shore to around 69 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 65 near the shore to around 56 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs around 81 near the shore to around 70 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny with scattered showers. Highs 75 to 82. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated showers. Lows around 65. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 82. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 69 to 75 in the valleys to around 60 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 58 to 64 in the valleys to around 53 above 4000 feet. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Friday: Partly sunny with scattered showers. Highs 71 to 77 in the valleys to around 62 above 4000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 71 to 80. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 59 to 67. East winds 10 to 15 mph. Chance of rain 30 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 72 to 80. East winds 10 to 15 mph. Chance of rain 40 percent.

East Kaua’i

Today: Partly sunny with scattered showers. Highs 68 to 79. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 59 to 70. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 70 to 80. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Detailed Forecast

Synopsis

Typical moderate to locally breezy trade winds will continue through this weekend and bring mainly night and morning scattered showers to windward and mauka locations. By early next week, a deepening trough northwest of the state will pull up a more moisture rich tropical air mass over the state and increase precipitation chances. Some of the rain could be heavy, especially mid- to late next week.

Short term update

Issued at 930 AM HST Thu Apr 2 2026
Radar shows only isolated light showers this morning. Satellite shows a long plume of cirrus moving over the state from the WSW, and this should be with us all day and into tonight. We expect a slight increase in trade showers this afternoon and tonight, and this is already handled by the current forecast. No changes are needed at this time.
Please note: the latest models, including ensembles, continue to show the potential for a heavy rain event beginning in the middle of next week and extending into the weekend. A new round of flooding may occur if these models are accurate. Details (which island(s) may be hit hardest, exact timing, etc) are not available this far out due to the reality of model accuracy in the tropics. Please stay aware of the evolving forecast because this system may become a serious problem.

Prev discussion

Issued at 331 AM HST Thu Apr 2 2026
Water vapor imagery loop from this morning showed very dry air in the mid and upper levels entrenched over and east of the state, aside from a thin layer of high clouds passing over the Big Island. This can also be noted on the latest 12Z RAOB soundings from both Hilo and Lihue, with a rather dramatic dry layer residing above a 6000 ft deep boundary layer temperature inversion. At the surface, an area of high pressure, anchored roughly 1000 miles north of Hawaii continued to drive moderate to locally breezy east northeasterly trades. Scattered low clouds caught up in this flow have been pushing towards windward portions of the islands for the last several hours. Several windward stations on each island picked of a few hundredths of an inch of accumulation, but nothing of significance.
Today through Friday, the pattern will change very little with moderate to locally breezy trades driving light scattered showers along mainly windward and mauka locations. The greatest shower activity can be expected to occur during the night and early morning hours. By this weekend, the aforementioned high well north of the area drifts east as a frontal system approaches. This should allow the local surface pressure gradient around the region to ease and trades to weaken slightly. Low clouds and showers will be isolated at best with a shallow boundary layer in the lower levels and dry air in place aloft.
By Monday, both the GFS and ECMWF begin to dig a broad upper trough well northwest of the state. Light background flow around the islands will become southeasterly, veering to southerly late Tuesday. With such light flow and slightly deeper lower level moisture in place, afternoon sea breezes could help initiate a few showers over interior portions of the islands.
Mid to late next week, models continue to deepen the upper level trough west of the islands and induce a low and cold front at the surface. Guidance has been consistent with this solution for the last several runs, so confidence is increasing. This would set the stage for tropical moisture being drawn northward across the Hawaiian Islands by deep layer southerly or south southwesterly flow out and a destabilizing atmosphere aloft. As it stands, the ECMWF generates a more compact and robust parent surface low compared to the GFS. Nonetheless, both models indicate the potential for gusty southerly winds and rounds of moderate to heavy rain. Thus, flooding may once again be a concern. The details for timing, location, and strength will need to be refined in the coming days.

Aviation

Issued at 930 AM HST Thu Apr 2 2026
Moderate trades with occasional light showers primarily focusing on windward and upslope mauka areas. Better organized showers will briefly lower ceilings and visibilities into MVFR categories. Otherwise, prevailing VFR conditions.
An AIRMET is in effect for the entire area for moderate turbulence between FL280 and FL380. The passage of a jet streak within the subtropical jet moving over the islands may initiate severe turbulence later this evening.

Marine

Issued at 930 AM HST Thu Apr 2 2026
Weakening high pressure north of the islands will shift eastward over the next few days, leading to a weakening of the trade winds into the moderate to fresh range. Winds begin to veer east to southeast early next week ahead of a front approaching from the northwest. A Small Craft Advisory remains in effect for the typically windier waters around Maui County and the Big Island through tonight.
The short period northeast swell will continue a gradual decrease through the weekend as the northeast trade winds slowly diminish. As a result, surf along north- and east-facing shores surf will gradually decline through the rest of the week, but will still retain a little size and chop due to the moderate to locally breezy trades.
North- and west-facing shore surf will remain small to tiny until the arrival of a small, medium-period west-northwest (310 degree) swell Friday night and a second small, medium-period northwest (340 degree) swell late Saturday. A small to moderate medium-period west- northwest swell looks to arrive early next week and fills in by mid- week. Along south facing shores, expect small reinforcements to provide periods of small surf through the weekend until a slightly larger long period south swell fills in early next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Maalaea Bay, Pailolo Channel.

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Data Courtesy of NOAA.gov