West Kaua’i

Rest Of Today: Mostly sunny with isolated showers. Highs 86 to 91 near the shore to around 78 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear with isolated showers. Lows 69 to 75 near the shore to around 61 above 3000 feet. Northeast winds up to 15 mph shifting to the east after midnight. Chance of rain 20 percent.

Wednesday: Mostly sunny. Isolated showers in the morning. Highs 86 to 91 near the shore to around 78 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

South Kaua’i

Rest Of Today: Mostly sunny. Isolated showers late in the morning. Highs 83 to 91. East winds around 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny in the afternoon. Highs 83 to 91. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Kaua’i Mountains

Rest Of Today: Mostly sunny. Scattered showers late in the morning, then isolated showers in the afternoon. Highs 77 to 86 in the valleys to around 69 above 4000 feet. East winds up to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds up to 15 mph becoming around 10 mph after midnight. Chance of rain 30 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 86 in the valleys to around 68 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Rest Of Today: Mostly sunny with isolated showers. Highs 79 to 88. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 74. East winds up to 15 mph becoming around 10 mph after midnight. Chance of rain 20 percent.

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

East Kaua’i

Rest Of Today: Mostly sunny. Scattered showers late in the morning, then isolated showers in the afternoon. Highs 75 to 88. East winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 77. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 88. East winds 10 to 15 mph. Chance of rain 40 percent.

Detailed Forecast

Synopsis

A low pressure system north of the island chain will remain embedded in the broader regional high pressure ridge pattern. This weak low pressure system will decrease the trade wind speeds across the state over the next several days. Trade winds will blow at moderate levels for most days this week with a slight increase possible today as another weak trough passes just south of the Hawaiian Islands. Typical seasonal summer weather will trend conditions towards the dry side with limited showers lasting into the weekend.

Discussion

The satellite imagery this morning continues to show a low pressure system stalled out just north of the Hawaiian Islands. This system remains embedded in the broader regional high pressure ridge and will trade wind speeds in the light to moderate range through much of this week. Stable stratocumulus cloud bands were observed this morning moving over each island on the easterly trade winds. The upper level ridge directly over the islands will keep temperature inversion heights in the 5,500 to 6,500 foot range, limiting shower activity across the state. High level cirrus clouds will also drift across the Hawaii Region today and tomorrow enhancing sunrise and sunset colors.
Expect a typical summer weather pattern with light to moderate trade wind speeds to continue into the weekend. A decrease in the large scale winds will allow a hybrid sea breeze and trade wind pattern to develop across western terrain sheltered slopes of each island. Converging sea breeze and trade winds may produce a stray shower or two over mountain slopes and island interior sections.
A weak trough passing just south of the state today may briefly increase trade wind speeds and inject some additional moisture into the Big Island weather pattern, most noticeable along the Kona slopes enhancing some of the sea breeze driven shower activity. Otherwise the upper level (500mb) ridge will keep stronger subsidence (downward moving air) directly over the islands capping cloud development and keeping drier weather in the forecast into the upcoming weekend.

Aviation

A hybrid sea breeze and light to moderate trade winds will persist for the next several days as a low pressure system weakens the high pressure ridge north of the islands. Typical drier summer weather will continue with prevailing VFR conditions.
No AIRMETs are in effect and none are expected.

Marine

High pressure N of the Hawaiian Islands maintains moderate to fresh trades through the rest of the week. Small, long period S swell energy should arrive today into tomorrow boosting S shore surf through Friday before gradually declining.
Surf along N and W facing shores remains small to nearly flat. Surf along E shores will remain characterized by short period chop.

Fire weather

Typical summer fire weather conditions will continue through the week due to the low relative humidity values. Very dry conditions were observed across the state yesterday, with minimum RH levels falling into the 30 to 45 percent range. These lower RH levels will continue for much of this week. Lower wind speeds will be the limiting factor for reaching critical fire thresholds, and these wind limited conditions will likely continue into the upcoming weekend. Temperature inversion heights near Maui and the Big Island will range from around 5,500 to 6,500 feet today.

HFO Watches/Warnings/Advisories

None.