Photo Credit: Laila Reiss

West Side

Today: Sunny. Isolated rain showers early in the morning. Highs 81 to 90. Northeast winds 10 to 15 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers after midnight. Lows 70 to 77. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Sunny with isolated showers. Highs 80 to 89. East winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 91. North winds 10 to 25 mph.

Tonight: Mostly clear. Breezy. Lows 69 to 76. Northeast winds 10 to 25 mph.

Wednesday: Sunny. Highs around 90. North winds 10 to 15 mph.

North Shore

Today: Mostly sunny. Scattered rain showers early in the morning, then isolated rain showers in the late morning and afternoon. Highs 79 to 89 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows around 72 near the shore to 50 to 56 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Sunny and breezy. Highs 86 to 92. Northeast winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows 69 to 74. East winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday: Sunny. Isolated showers early in the morning. Highs 85 to 91. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Sunny. Highs around 65 at the visitor center to around 59 at the summit. East winds 10 to 15 mph.

Tonight: Mostly clear. Breezy. Scattered showers after midnight. Lows around 50 at the visitor center to around 47 at the summit. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 64 at the visitor center to around 59 at the summit. East winds 15 to 20 mph. Chance of rain 50 percent.

East Maui

Today: Mostly sunny. Scattered rain showers early in the morning, then isolated rain showers in the late morning and afternoon. Highs 79 to 89 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows around 72 near the shore to 50 to 56 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Sunny. Highs 75 to 83. Northeast winds 10 to 15 mph.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 67. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Sunny. Isolated showers in the late morning and afternoon. Highs 74 to 82. East winds 10 to 15 mph. Chance of rain 20 percent.

Kaunakakai

Today: Sunny and breezy. Highs 73 to 93. East winds 10 to 20 mph.

Tonight: Mostly clear. Breezy. Lows 60 to 76. East winds 15 to 20 mph.

Wednesday: Sunny. Highs 72 to 92. East winds around 15 mph.

Detailed Forecast

Synopsis

A weak boundary northeast of the state may increase showers near Kauai and Oahu by mid week. Additionally, light to moderate easterly trades will focus low clouds and showers across windward areas through the end of the week. Trades may be light enough at times to allow localized afternoon sea breezes to generate clouds and a few showers across leeward areas.

Discussion

Radar this morning shows scattered showers drifting across the islands, with a majority of showers lingering west of the state in an area of deeper moisture. Satellite data shows limited cloud cover as drier air streams in from the east. Overall expect limited clouds and showers to influence the islands through tonight, as dry and stable air moves westward.
A surface boundary about 350 miles north-northeast of the islands will further weaken as it slowly drops southward toward the state into Wednesday, while the surface ridge north of the state gradually reestablishes itself. This pattern will maintain a weak pressure gradient and light to moderate easterly trade wind flow across the islands this week. These winds will direct showers to mainly windward areas in a typical trade wind weather pattern. However, localized sea breeze clouds and showers remain possible for some leeward areas this week.
The airmass will differ greatly across the state this week as a sharp moisture gradient sets up. The front sagging southward will enhance a layer of deeper moisture over the western islands while much drier and more stable air filters in across the central and eastern islands through much of the week. Forecast moisture depths will remain around 7k feet across the eastern half of the state with PW values generally around 1.25 inches or less. Deeper moisture depths between 8k-11k feet and PW values of 1.60 inches or greater, are forecast to increase over the western end of the state, mainly Wednesday and Thursday. The drier PW values forecast across the eastern end of the state, are well supported by the latest satellite based layer blended total precipitable water values around 1.18 inches near the Big Island. This pattern will limit the areal coverage of showers for Maui and the Big Island into Friday. Moisture pooling along the front north of the area, will increase the areal coverage of showers some across Kauai tonight before expanding southward toward Oahu Wednesday into Thursday.
The latest trends support a weaker pressure gradient redeveloping once again by the weekend, as another surface boundary drops southward. The weakened surface pressure gradient could allow for a return of localized afternoon and early evening sea breeze showers for some leeward areas and island interiors into the beginning of next week. The latest trends support the best chances for showers and potential for enhanced rainfall, remains across the western end of the state as deeper moisture pools along the boundary dropping southward.

Aviation

A ridge of high pressure passes north of Hawaii and will produce moderate trade winds today. Scattered clouds and showers are carrying from the east focusing over windward slopes and bringing brief MVFR conditions. However, VFR conditions will prevail today and no AIRMETs are anticipated. The showers are expected to linger through the early morning before decreasing.

Marine

A front will remain in place between a high to our north and the main Hawaiian islands. This will keep trade winds in the light to moderate range over the next several days for most waters. However, terrain-induced acceleration may briefly boost winds to Small Craft Advisory threshold today and tonight across typically windy waters around Maui and the Big Island.
South swell will continue to lower through Wednesday. Another small longer period south swell will fill in Wednesday night and Thursday with a slight reinforcement expected Friday and Saturday. A slightly larger long period south swell may arrive around Sunday. No significant north or northwest swells are expected through Thursday night, with a small short period northwest swell expected Friday and Saturday. Another small but longer period northwest swell may arrive on Sunday. Short period choppy surf will remain rather small over the next few days across east-facing shores, with a slight increase possible later in the week and on into the weekend.

HFO Watches/Warnings/Advisories

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

Maui Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov