Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 86 near the shore to around 74 above 3000 feet. Light winds. Chance of rain 50 percent.

Tonight: Mostly clear. Lows around 70 near the shore to around 59 above 3000 feet. Light winds.

Friday: Mostly sunny with isolated showers. Highs around 86 near the shore to around 74 above 3000 feet. Light winds. Chance of rain 20 percent.

South Kaua’i

Today: Mostly sunny. Scattered showers in the afternoon. Highs 83 to 88. Light winds. Chance of rain 40 percent.

Tonight: Mostly clear. Lows 68 to 73. West winds up to 10 mph shifting to the north around 10 mph after midnight.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs 82 to 88. Northeast winds around 10 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 81 in the valleys to around 67 above 4000 feet. Light winds. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 62 to 67 in the valleys to around 57 above 4000 feet. South winds up to 10 mph shifting to the northwest after midnight. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 80 in the valleys to around 66 above 4000 feet. North winds up to 10 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 77 to 85. Light winds. Chance of rain 40 percent.

Tonight: Mostly clear. Lows 63 to 72. Light winds.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs 77 to 85. North winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 76 to 86. Light winds. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows 62 to 74. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs 75 to 85. North winds up to 10 mph shifting to the northeast around 10 mph in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Over the next several days, sea breezes will bring afternoon clouds and isolated showers followed by clearing at night with the land breezes. A weak front will reach and dissipate near Kauai this weekend. A weak ridge will build to the north and localized land and sea breezes continue.

Discussion

A weak subtropical ridge just east of Oahu is generating light east to southeast winds over the eastern half of the state with light and variable winds elsewhere. CIMSS MIMIC precipitable water vapor shows an area of enhanced moisture over the Big Island with drier conditions elsewhere. Satellite and radar imagery this evening shows mostly cloudy skies over the windward and southeast areas of the Big Island with scattered showers. There are limited clouds streaming in from the south and some high clouds moving over Kauai and parts of Oahu. Otherwise, land breezes have cleared clouds away.
Daytime sea breezes and nighttime land breezes will dominate over the next several days characterized by sunny mornings, clouds building across island interiors through the day and evening, then clearing skies at night. Conditions will remain stable so any significant rain is not in the forecast. Best chance for showers will be across the interior Big Island and Maui during the afternoons as an area moisture lingers near the eastern end of the state over the coming days. Warm, muggy weather will accompany the area of enhance moisture as dewpoints reach the low 70's.
A weakening cold front will approach Kauai Friday, before stalling and dissipating near the isle Saturday. Northeast winds behind the front will advect the moisture associated with this boundary to the western end of the state, especially for Kauai. A slight strengthening of the winds is forecast this weekend due to high pressure behind the front, which may be enough to focus more of the cloud cover windward, though many leeward spots will continue to see daytime cloud build ups through the weekend into next week. Rainfall chances and accumulations will continue to be low overall with the highest chances for windward Kauai.
A weak ridge will set up north of the area early next week as the front dissipates, resulting in a continuation of the light easterly flow and localized land and sea breezes.

Aviation

A surface ridge over the area will continue to bring light and variable winds to the region over the coming days. Additional clouds lingered over the eastern side of the Big Island overnight, despite land breezes in the area. Most other areas had land breezes that cleared most of the clouds overnight. With afternoon sea breezes expected again today, look for clouds, and a few showers, to develop again as the day wears on. Land breezes again tonight should help to clear most, if not all, the clouds out. Overall, VFR conditions are expected to prevail, with brief MVFR conditions possible during the afternoon clouds and showers. No AIRMETs are currently in effect, and none are expected today.

Marine

The western end of a weak surface ridge is located about 200 nm north of Hilo early this morning. This is allowing light east to southeast winds to develop around the Big Island and Maui. However, light and variable winds remain across the rest of the island chain. Little significant change is expected for this surface ridge during the next 24 hours, or so. Therefore, the light to moderate trades will persist near the eastern islands, while the weak background flow will continue elsewhere.
A weakening front will approach the western end of the island chain from the north-northwest on Friday. Surface high pressure building far northwest of the area will likely cause gentle north to northeast winds to develop around Kauai and Oahu starting late Friday. The front is expected to stall in the vicinity of Kauai by Saturday morning. The forecast guidance shows the surface high will move east to a position north of the state from Saturday through Sunday. This will allow light to moderate trade winds to briefly return to the islands this weekend. By Monday, a surface ridge associated with this high will likely shift down closer to the region, causing the trade winds to start a weakening trend early next week. Note that the latest forecast indicates winds will remain below the Small Craft Advisory criteria into early next week.
The current north-northwest (330-340 degrees) swell is gradually lowering this morning based on nearshore buoy observations. This swell will continue to subside through Saturday. Another north- northwest (340 degrees) swell arriving Sunday may produce a modest bump in surf along exposed north and west facing shores from late this weekend through Monday, before it gradually fades on Tuesday.
A series of swells originating in the Southern Hemisphere will likely produce surf heights above the October average along south facing shores into early next week. The current long-period south- southwest (190-200 degrees) swell will likely be reinforced by additional pulses later today, and again on Saturday. The wave model guidance continues to show a new south (180-190 degrees) swell arriving Sunday, and persisting into Tuesday. Elsewhere, surf will likely remain small along east facing shores into early next week due to the lack of a significant fetch of trade winds upstream of the state.
Finally, a sea level anomaly in the vicinity of the islands has been producing higher than predicted water levels recently. If this anomaly persists, minor coastal flooding could occur during the time of normally high astronomical tides this weekend. If so, a Coastal Flood Statement may be required for portions of the state starting Saturday or Sunday.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov