Photo Credit: Jason Weingardt

West Kaua’i

Today: Sunny and windy. Highs around 90 near the shore to around 79 above 3000 feet. East winds 10 to 30 mph with gusts to 50 mph decreasing to 10 to 20 mph in the afternoon.

Tonight: Partly cloudy. Lows around 73 near the shore to around 62 above 3000 feet. Northeast winds 10 to 15 mph shifting to the east after midnight.

Thursday: Mostly sunny. Highs around 90 near the shore to around 79 above 3000 feet. Northeast winds up to 10 mph.

South Kaua’i

Today: Mostly sunny. Windy. Highs around 88. Northeast winds 25 to 30 mph with gusts to 50 mph decreasing to around 20 mph in the afternoon.

Tonight: Breezy. Partly cloudy with isolated showers. Lows 70 to 75. Northeast winds 15 to 20 mph decreasing to around 10 mph after midnight. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the morning. Highs around 88. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Mostly sunny. Windy. Isolated showers in the afternoon. Highs 75 to 84 in the valleys to around 71 above 4000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 63 to 68 in the valleys to around 58 above 4000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 84 in the valleys to around 71 above 4000 feet. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 79 to 88. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 75. East winds 10 to 20 mph decreasing to up to 10 mph after midnight. Chance of rain 30 percent.

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

East Kaua’i

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 76 to 88. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 64 to 77. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Thursday: Mostly sunny with isolated showers. Highs 76 to 88. Northeast winds around 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A strong high pressure system north of the state and Hurricane Dora are both moving westward this morning. Expect slow decreasing wind speed trends across the Hawaiian Islands today. Strong winds coupled with low humidity levels are producing dangerous fire weather conditions that will last through the afternoon hours. A more typical moderate to breezy trade wind weather pattern returns from Thursday into early next week.

Discussion

A strong high pressure system north of the state continues to produce a very dry and stable weather pattern over the islands. The combination of the strong high to the north and Hurricane Dora passing well to the south continues to produce strong trade winds over the region. These strong and gusty winds will begin to trend lower through the day today as both the northern high and southern Dora begin to journey westward moving farther away from the island chain. Wind gusts are showing a slight decreasing trend this morning with only a few locations gusting over 50 MPH. The High Wind Warning was cancelled this morning as we transition to a more Wind Advisory threat level. Wind Advisories were issued for most mountain and leeward areas across the state. Dry and stable conditions will persist today with near zero rainfall in the forecast for most locations.
On Thursday and Friday, we transition back to more normal moderate to breezy trade winds as the high center and Dora continue moving westward away from Hawaii, decreasing trade wind speeds. Fairly stable weather conditions will continue with mostly sunny to partly cloudy skies and only brief passing showers in the forecast for windward and mountain areas, mainly in the overnight to early morning hours.
Saturday through Tuesday…More moderate trade winds are expected to continue from Saturday onward with typical brief windward showers, favoring the overnight to early morning hours.

Aviation

The surface pressure gradient remains tight this morning between high pressure north of the state and Hurricane Dora well to the south southwest of the state. This gradient will allow for strong trade winds to persist through the forecast period, though a slow weakening trend will ensue as the day progresses.
These strong trades will bring tempo moderate to isolated severe low level turbulence to areas in the lee of mountains.
A relatively dry airmass in place over the region should limit cloud cover and showers.
AIRMET Tango remains in effect below 6000 feet over and immediately south through west of mountains of all islands for tempo moderate to isolated severe turbulence.

Marine

Hazardous marine conditions with strong- to gale-force easterly winds and 8 to 15 ft (highest in the channels and windier locations between Maui County and the Big Island) seas will continue today as Hurricane Dora passes well south-southwest of the area. Fresh to strong easterly trades will return tonight through Thursday, then ease into the moderate to fresh category Thursday night through the weekend due to a weakness forming in the ridge to the north.
Surf along east facing shores will remain very rough and around the advisory level today (highest over the smaller islands), then 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 medium period southeast swell associated with Dora and a long-period south-southwest swell filling in. As the southeast source quickly fades later today into tonight, the south- southwest swell will continue to build, then peak near the advisory level through the day Thursday. A gradual downward trend is then anticipated through the upcoming weekend.

Fire weather

Very dry fuels (KDBI around 600) combined with strong and gusty easterly winds and low humidities below 45 percent will produce critical fire weather conditions through the afternoon hours. See the latest Red Flag Warning and Fire Weather Forecast for more information.

HFO Watches/Warnings/Advisories

Red Flag Warning until 6 PM HST this evening for most leeward areas of all islands.
Wind Advisory until 6 PM HST this evening for most mountain and leeward areas of all islands.
High Surf Advisory until 6 PM HST this evening for east facing shores of Kauai, Oahu, Molokai, and Maui.
Gale Warning until 6 PM HST this evening for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
Small Craft Advisory until 6 AM HST Thursday for all Hawaiian Coastal Waters not included in the above Gale Warning area.

Data Courtesy of NOAA.gov