Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 87 near the shore to around 73 above 3000 feet. East winds up to 15 mph shifting to the south in the afternoon. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers after midnight. Lows around 70 near the shore to around 60 above 3000 feet. East winds 10 to 15 mph decreasing to up to 10 mph after midnight. Chance of rain 20 percent.

Monday: Mostly sunny with isolated showers. Highs around 88 near the shore to around 74 above 3000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny with isolated showers. Highs 80 to 86. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 72. East winds 10 to 15 mph. Chance of rain 40 percent.

Monday: Mostly cloudy with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 80 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Partly sunny with isolated showers. Highs 74 to 85 in the valleys to around 65 above 4000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 69 in the valleys to around 58 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 85 in the valleys to 63 to 68 above 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 88. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 74. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 77 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny in the afternoon. Highs 74 to 85. East winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows 64 to 75. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 74 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Gentle to moderate trade winds will prevail with afternoon sea breezes along terrain sheltered western slopes of each island today. Trade winds will strengthen into the moderate to breezy range as sea breezes diminish from Monday onward. Clouds and passing showers will favor the windward and mountain areas, trending higher in the overnight to early morning hours. Isolated thunderstorms are possible today near Kauai. More stable conditions are forecast from Monday onward with brief passing showers mainly forming over windward and mountain areas.

Discussion

A subtropical high pressure ridge north of the Hawaiian Islands will keep trade winds in the forecast through this week. An upper level low roughly 200 miles north of Kauai will continue to drift west today, and then weaken as it moves northward on Monday away from the region. A weak low level trough under this upper low will keep trade winds in the gentle to moderate range for one more day. Upper level forcing from this passing low will enhance shower activity over the western islands, mainly affecting windward and mountain areas in the overnight to early morning hours. Sea breezes will also develop today over terrain sheltered western slopes of each island. Large scale trades and local scale sea breeze winds will converge, producing afternoon clouds and showers over these terrain sheltered leeward locations.
By Monday, the ridge will build into the islands as the upper low weakens and drifts northward away from the region. Trade winds will strengthen into the moderate to breezy range through much of next week. Stronger subsidence under this ridge will stabilize the atmosphere by lowering the trade wind thermal inversion heights and reducing cloud heights. Expect mostly brief passing showers from Monday onward as more stable conditions return to the Hawaii Region.

Aviation

Moderate trades expected through the rest of the weekend. SHRA and low cigs will return to windward and mauka areas. VFR should prevail, with brief periods of MVFR under heavier SHRA.
No AIRMETs are currently in effect.

Marine

High pressure north of the state will maintain moderate to fresh trade winds today. Monday through midweek, trades are expected to strengthen back to fresh and strong levels, and a Small Craft Advisory will likely be required for the typically windy waters around Maui and the Big Island.
No significant south swells are expected through this upcoming week. However, a series of small south-southwest and southeast swells will keep south facing shores from going flat.
Typical mostly flat summertime conditions will continue along north facing shores.
East shore surf will remain below normal on today, then trend up closer to seasonal levels early to mid this week as the trades strengthen over and upstream of the islands.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov