Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly sunny. Highs around 80 near the shore to around 68 above 3000 feet. Light winds.

Tonight: Mostly clear. Lows around 63 near the shore to around 52 above 3000 feet. Light winds.

Friday: Sunny. Highs around 81 near the shore to around 69 above 3000 feet. Light winds.

South Kaua’i

Today: Mostly sunny. Highs around 79. Northeast winds around 10 mph.

Tonight: Partly cloudy with isolated showers. Lows 59 to 64. Northeast winds around 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Highs around 80. Northeast winds around 10 mph.

Kaua’i Mountains

Today: Mostly sunny. Highs 67 to 75 in the valleys to around 62 above 4000 feet. Light winds.

Tonight: Partly cloudy with isolated showers. Lows 52 to 57 in the valleys to around 46 above 4000 feet. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 68 to 76 in the valleys to around 63 above 4000 feet. Light winds. Chance of rain 20 percent.

North Kaua’i

Today: Mostly sunny. Highs 72 to 79. Light winds becoming northeast up to 10 mph in the afternoon.

Tonight: Partly cloudy with isolated showers. Lows 55 to 64. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 73 to 80. East winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Mostly sunny. Highs 72 to 79. Light winds becoming northeast around 10 mph in the afternoon.

Tonight: Partly cloudy with isolated showers. Lows 53 to 65. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Highs 73 to 80. Northeast winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

The remnant moisture associated with an old front will keep some some showers rolling into windward portions of the central islands this morning, with drier conditions prevailing elsewhere. Shower coverage will diminish considerably this afternoon, although lingering moisture will keep a slight chance for showers along windward sections of the eastern islands through Friday morning. Very dry and stable weather will overspread the entire state Friday afternoon and hold in place through Tuesday, with very little if any rain expected. A front could bring an increase in showers to Kauai and Oahu next Wednesday. Light to moderate trade winds will generally prevail through much of the forecast period.

Discussion

Currently at the surface, a weak ridge of high pressure is positioned around 200 miles north of Honolulu, while the front that was over the central islands has dissipated. Light to moderate trade winds continue to prevail across the state early this morning. Infrared satellite imagery shows partly to mostly cloudy conditions across the state, with cloud coverage highest in windward areas from Oahu eastward. Radar imagery shows scattered showers affecting windward sections of Oahu, Molokai, Maui, and the Big Island, with rain free conditions over Kauai and Lanai. Main short term focus revolves around rain chances.
The remnant moisture associated with the old front will gradually disperse today as mid and upper level ridging builds in from the west. Scattered showers will continue early this morning over windward sections of Oahu, Molokai, Maui, and the Big Island, with perhaps a shower or two reaching leeward communities, with dry conditions prevailing elsewhere. We should see a marked decrease in shower coverage statewide this afternoon, as inversion heights drop below 5,000 feet statewide. Some lingering moisture will likely keep a few showers showers rolling into windward sections of the eastern islands tonight and Friday morning, with very little shower activity then expected statewide by Friday afternoon as precipitable water values drop into the 0.75 to 1.0 inch range.
Little change in the overall weather pattern is expected Friday night through Wednesday, with precipitable water values holding below an inch and inversion heights remaining below 5,000 feet. As a result, very little if any rainfall is expected during this time. A weakening front could potentially bring an increase in showers to Kauai and Oahu around the middle of next week.
Light to moderate trade winds will generally prevail through Monday, with only minor variations in strength from day to day. Light and variable winds appear possible on Tuesday in advance of a weakening front, with perhaps a return of light to moderate trade winds for Wednesday.

Aviation

The areal coverage of showers has diminished this morning, with the most persistent showers focused across windward areas of the central smaller islands and Big Island. Drier and more stable conditions pushing over Kauai this morning, will spread eastward into the state this afternoon which will further limit showers across the islands. Widespread MVFR conditions seen earlier, have also decreased. However some MVFR conditions, in heavier showers, will continue the potential need of AIRMET Sierra for tempo mountain obscuration across some windward locations this morning.
Otherwise, light to moderate northeasterly trade winds continue across the islands today. This relatively light wind pattern will promote diurnal land sea breeze circulations across some leeward areas during the TAF period.

Marine

Gentle to moderate northeast trades will hold today before veering easterly and strengthening to moderate to fresh Friday through the weekend as surface high pressure reestablishes just north of the island chain. A front will approach the state early next week, prompting winds to weaken and veer out of the south before more northerly winds fill in behind the front. A high will build north of the state behind the front and track east, allowing moderate to fresh trades to return by mid week next week.
Surf along north and west facing shores will steadily ease through Friday as overlapping short- period northwest (330 degrees) and north (350 degrees) swells moves through. The north swell will transition to more north- northeast (20-30 degrees) today into the weekend. Surf along north and west facing shores will steadily increase as early as late Friday into early next week as consecutive northwest (320-330 degrees) swells move through the island chain, each a little bigger than the previous. These swells could bring above average surf to north and west facing shores late in the weekend into early next week before slowly trending down.
Surf along east facing shores will remain small, except for shores exposed to the north and northeast swell mentioned above. East shores may see an additional slight bump as trades strengthen slightly Friday into the weekend. The small surf along south facing shores will see another little bump over the next day or two keeping surf slightly elevated into the weekend.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov