West Side

Today: Mostly sunny. Isolated showers in the afternoon. Highs 80 to 87. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 69 to 77. East winds up to 15 mph.

Wednesday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 79 to 87. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Isolated showers in the afternoon. Highs around 89. North winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 68 to 78. North winds up to 20 mph.

Wednesday: Sunny and breezy. Isolated showers in the afternoon. Highs around 88. North winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

North Shore

Today: Breezy. Mostly sunny with isolated showers. Highs around 82 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 74 near the shore to around 55 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 30 percent.

Central Maui

Today: Sunny and breezy. Isolated showers in the afternoon. Highs 81 to 89. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Isolated showers in the evening. Lows 68 to 76. Northeast winds up to 20 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 81 to 88. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Sunny. Isolated showers in the afternoon. Highs around 67 at the visitor center to around 71 at the summit. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers after midnight. Lows around 52 at the visitor center to around 48 at the summit. East winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 65 at the visitor center to around 71 at the summit. East winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

East Maui

Today: Breezy. Mostly sunny with isolated showers. Highs around 82 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 74 near the shore to around 55 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to around 67 near 5000 feet. East winds up to 20 mph. Chance of rain 30 percent.

Lanai City

Today: Sunny and breezy. Highs 73 to 83. Northeast winds up to 20 mph.

Tonight: Mostly clear. Breezy. Lows 67 to 72. Northeast winds up to 20 mph decreasing to up to 10 mph after midnight.

Wednesday: Sunny and breezy. Highs 74 to 83. Northeast winds up to 25 mph.

Kaunakakai

Today: Sunny. Highs 71 to 90. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon.

Tonight: Mostly clear. Isolated showers in the evening. Lows 62 to 77. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Sunny. Isolated showers in the afternoon. Highs 70 to 89. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Trade winds will continue through much of the week with high pressure system far to the northeast. A potential area for tropical development remains about 1100 miles east-southeast of the islands. Conditions remain favorable for tropical development and we will continue to closely monitor how this could impact the islands.

Discussion

Satellite and radar imagery this morning shows some scattered windward and mauka showers moving in on the trades. Winds are expected to remain moderate to breezy for next few days.
High pressure far to the northeast of the state will continue to bring trades to the region this week. Expect clouds and showers to be focused over the typical windward and mauka slopes in the trade wind flow. Additional clouds and showers are also expected over the Kona slopes of the Big Island during the afternoon and evening hours.
The main concern is related to the area of potential tropical development about 1100 miles east-southeast of the islands. The National Hurricane Center (NHC) continues to report that the area is conducive for additional tropical development over the next several days. As no system has yet developed, a lot of questions remain as to where any such system will form and move. As such, the forecast for Hawaii could change significantly once any such system develops. Stay tuned for the latest updates on this developing tropical cyclone from the NHC online at www.hurricanes.gov. When and should a system form, the forecast will be updated to reflect the impacts on Hawaii.

Aviation

Moderate to breezy trade winds are expected over the next several days. Showers will focus mostly over windward and mountain areas, with some lower ceilings this morning. Conditions should improve during the day as slightly drier air moves in.
No AIRMETs are in effect this morning, but brief mountain obscurations may occur along windward areas.

Marine

High pressure to the far northeast will slowly drift into position north of the Hawaiian Islands into the weekend, producing moderate to locally strong trade winds across the region. The Small Craft Advisory (SCA) has been extended through Wednesday afternoon for the windier waters and channels around Maui and the Big Island. The weather pattern may change significantly this weekend as we continue to watch for a developing tropical cyclone currently in an area roughly 1,000 NM east-southeast of the Hawaiian Islands. Potential impacts are uncertain at this time, as the tropical cyclone has not yet formed and track guidance remains highly uncertain at this time. Marine interests should be prepared in case this system potentially turns towards the Hawaiian Islands after formation potentially as early as this weekend.
Surf along south and west facing shores will continue to remain elevated as overlapping south swells continue to impact the islands with some smaller wrap around energy along increasing surf heights along exposed west facing shores. A slightly bigger south swell will build in later today as another moderate, long period south swell arrives, peaking just below advisory thresholds by Wednesday, and then remaining elevated through Friday.
Surf along east facing shores will continue to remain moderate and rough due to continued trade winds. Later in the week, the track of a developing tropical cyclone will dictate the potential for a large swell exceeding advisory levels from the east to southeast direction.
Surf along north facing shores will remain flat to tiny through the week.
Due to a combination of peak monthly high tides and water levels running higher than predicted in a few locations, a Coastal Flood Statement is in effect for minor coastal flooding around the afternoon high tide through Wednesday. Tides will be decreasing by the end of this week, but coastal flooding may continue to be possible around high tide for locations where water levels are running highest.

Fire weather

High pressure to the northeast of the state will maintain breezy trades. Fire weather conditions this week will remain just below critical thresholds due to the lack of stronger wind speeds. Minimum humidity levels will briefly reach criteria each day over the driest leeward areas and the lower sustained wind speeds will be the limiting factor. Temperature inversion heights range between 5,000 to 6,500 feet.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov