Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny. Highs around 79 near the shore to around 66 above 3000 feet. East winds 10 to 15 mph.

Tonight: Partly cloudy. Lows around 64 near the shore to around 53 above 3000 feet. East winds around 10 mph.

Tuesday: Mostly sunny. Highs around 80 near the shore to around 67 above 3000 feet. East winds around 10 mph.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Isolated showers. Highs 75 to 80. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 63. East winds 10 to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny. Isolated showers in the morning. Highs 77 to 82. East winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 69 to 75 in the valleys to around 58 above 4000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 55 to 61 in the valleys to around 51 above 4000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 70 to 77 in the valleys to around 60 above 4000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 69 to 79. East winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 57 to 65. East winds 10 to 15 mph. Chance of rain 30 percent.

Tuesday: Mostly sunny. Isolated showers in the morning. Highs 70 to 80. East winds around 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 67 to 78. East winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 57 to 68. East winds 10 to 15 mph. Chance of rain 40 percent.

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

Detailed Forecast

Synopsis

A relatively dry and stable trade wind pattern will persist over the next several days, with cool and breezy northeast to east trade winds and limited showers favoring windward and mauka locations. After a brief decrease in wind speeds mid-week, winds may restrengthen, along with an increase in showers late this week into the weekend.

Discussion

Surface high pressure remains centered around 700 miles north of Kauai this morning, with breezy to locally windy northeast trade winds across state. Meanwhile, the drier and stable air mass now appears to be in place state-wide, with precipitable water (PW) values now below one inch at both Lihue and Hilo (below normal for the month of February) and strong temperature inversions around 6500-7500 feet.
The surface high will gradually move east and a bit southward over the next few days, resulting in a slight weakening of the trade winds as they shift out of a more easterly direction through the first half of the week. As the high approaches closer to the islands, the stable and dry airmass will be reinforced. Dewpoints in the 40s and 50s will continue to make it feel rather cool, while trade showers will be shallow with minimal rainfall amounts focused mostly along windward and mauka areas.
However, model guidance appears to agree on a surface trough developing just northwest of the islands Thursday and Friday. This would result in a restrengthening of winds during the second half of the week as they veer more southeasterly. Variability remains in how close the surface trough and associated front get to the islands, though an increase in windward showers is likely towards the end of the week into the weekend, regardless, as moisture is pulled up from the south ahead of this system.

Aviation

Breezy to locally windy trade winds will continue today with low clouds and isolated showers favoring windward and mauka areas. Northeast winds will become more easterly and weaken slightly as the surface high moves eastward. Expect VFR conditions to prevail with brief periods of MVFR possible with any showers.
AIRMET Tango remains in effect statewide due to occasional moderate turbulence downwind of higher terrain. This AIRMET will likely be needed through the morning before turbulence decreases heading into the afternoon or evening.

Marine

A large, medium period north (340 to 360 degrees) swell will continue to gradually decline over the next couple of days as it shifts out of the north-northeast (360 to 020 degrees). Offshore buoys NDBC 51101 and 51001 have steadily declined over night resulting in the High Surf Advisory (HSA) to be cancelled. Surf heights this morning will be just under the HSA criteria and slowly declining through the day. Due to the northerly direction of the swell, Kahului and Hilo Harbors should experience surges, even though the swell will be declining today. Local nearshore PacIOOS Pauwela buoy 51205 observations suggest the swell will maintain the hazard. A Marine Weather Statement remains posted to highlight this concern through today.
A moderate, long period northwest swell will begin to fill in late tonight and hold through Wednesday, with peak surf below HSA levels. Guidance hints for reinforcements of similar size to hold through the week from the northwest. East facing shores will remain choppy and may see some wrapping north swell through the first half of the week for exposed shorelines. Moderate, short period wind swell will stick around through the work week. South shores will remain seasonably small.
Surface high pressure far north of the state will drift east over the next several days as fresh to near gale force winds will shift more easterly today. A Small Craft Advisory (SCA) for all waters has been extended through today due to a combination of the gusty winds and elevated seas, driven mainly by the large north swell. As the north swell subsides today, the SCA may be trimmed back to the typically windy waters around the Big Island and Maui this afternoon. Winds will drop a notch late tonight into early Wednesday as the high weakens northeast of the islands, but the combination of another high building far north of the islands and low pressure developing far to the west will likely bring increasing east to east-southeast fresh to locally near gale force winds by late Wednesday and Thursday. Expect the fresh to strong trades to hold into next weekend.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening for all Hawaiian waters.

Data Courtesy of NOAA.gov