Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny. Breezy. Highs 86 to 92 near the shore to around 78 above 3000 feet. East winds up to 20 mph.

Tonight: Partly cloudy. Lows around 71 near the shore to around 61 above 3000 feet. Northeast winds up to 15 mph.

Friday: Mostly sunny. Highs 86 to 93 near the shore to around 78 above 3000 feet. East winds up to 15 mph.

South Kaua’i

Today: Mostly sunny. Breezy. Isolated showers in the morning. Highs 85 to 91. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 70 to 75. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 85 to 92. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 74 to 85 in the valleys to around 67 above 4000 feet. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows 65 to 70 in the valleys to around 59 above 4000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 85 in the valleys to around 69 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny with isolated showers. Highs 77 to 89. 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. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 78 to 89. East winds up to 15 mph. Chance of rain 20 percent.

East Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs 75 to 88. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 64 to 78. Northeast winds 10 to 15 mph decreasing to up to 10 mph after midnight. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 76 to 88. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A high pressure system northwest of the island chain will produce moderate trade winds across the region today as the ridge north of the state weakens. Trade winds will remain at moderate levels through Tuesday with brief passing showers mainly affecting windward and mountain areas.

Discussion

The satellite imagery this morning continues to show bands of stratocumulus clouds drifting into the windward slopes of the Hawaiian Islands. This cloud pattern is a good indication that the moisture levels have improved across the region. These clouds will produce scattered showers along the eastern slopes of all islands through the early morning hours.
A high pressure system northwest of the state will continue to weaken as a low pressure system drifts into the Eastern Pacific basin. Trade wind speeds will decrease today and then hold at moderate speeds from Friday through next week Tuesday. Overall stable conditions are expected with limited shower activity. Expect a typical dry summer trade wind weather pattern from Thursday onward with brief passing showers, favoring the diurnal overnight to early morning hours and mainly affecting windward and mountain areas.
Shower trends may increase slightly for East Maui and Northeast to Southeast Big Island from Monday night into Tuesday morning as a convergence band moves into the eastern half of the state.

Aviation

Surface pressure gradients will continue to ease slightly this morning and allow trade winds to become moderate to locally breezy. This typical trade flow will advect low level moisture in from the northeast and generate scattered showers along mainly the windward coasts and slopes. There may be brief periods of MVFR ceilings and visibility, but not expecting anything widespread. Shower chances dwindle by this afternoon.
AIRMET Tango remains in effect for moderate turbulence immediately south through west of mountains of all islands.

Marine

Fresh to strong easterly trades have returned and will persist into tonight, then ease into the moderate to fresh category Friday (below advisory level) through the weekend due to a weakness forming in the ridge to the north.
Surf along east facing shores will steadily lower through the second half of the week and upcoming weekend as the trades ease locally and upstream of the state across the eastern Pacific.
Surf along south facing shores will remain up today due to a mix of a southeast and a long-period south-southwest swell. As the southeast source quickly diminishes through the day, the south- southwest swell will peak just under the advisory level. A gradual downward trend is then anticipated through the weekend.
Surf along north facing shores could trend up above the summertime flat levels early next week as a tiny north-northwest swell arrives from a distant packet of fresh to strong northwest breezes forecast near the Date Line/Aleutians Friday into the weekend.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST early this morning for Kauai Northwest Waters, Kauai Leeward Waters, Kauai Channel, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Big Island Windward Waters.
Small Craft Advisory until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov