Photo Credit: Tyler Rooke

West Side

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 74 to 80. Northeast winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly clear with isolated showers. Lows 57 to 64. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 75 to 81. Northeast winds up to 10 mph. Chance of rain 20 percent.

South Side

Today: Sunny with isolated showers. Highs around 80. North winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers in the evening. Lows around 58. North winds 10 to 15 mph. Chance of rain 20 percent.

Monday: Sunny. Highs around 81. North winds 10 to 15 mph.

North Shore

Today: Partly sunny with showers likely in the morning, then mostly sunny with scattered showers in the afternoon. Highs 72 to 78 near the shore to around 58 near 5000 feet. East winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 60 percent.

Tonight: Partly cloudy with scattered showers. Lows 55 to 61 near the shore to around 44 near 5000 feet. Northeast winds up to 10 mph shifting to the southeast after midnight. Chance of rain 50 percent.

Monday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 73 to 79 near the shore to around 56 near 5000 feet. East winds up to 15 mph. Chance of rain 30 percent.

Central Maui

Today: Mostly sunny with scattered showers. Highs 76 to 81. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Mostly clear. Scattered showers in the evening. Lows 56 to 61. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Monday: Sunny. Isolated showers in the afternoon. Highs 77 to 82. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 52 at the visitor center to around 48 at the summit. North winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly clear. Scattered rain showers in the evening. Lows around 40 at the visitor center to around 35 at the summit. North winds up to 15 mph. Chance of rain 50 percent.

Monday: Sunny. Isolated rain showers in the afternoon. Highs around 50 at the visitor center to around 45 at the summit. East winds up to 10 mph in the morning becoming light. Chance of rain 20 percent.

East Maui

Today: Partly sunny with showers likely in the morning, then mostly sunny with scattered showers in the afternoon. Highs 72 to 78 near the shore to around 58 near 5000 feet. East winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 60 percent.

Tonight: Partly cloudy with scattered showers. Lows 55 to 61 near the shore to around 44 near 5000 feet. Northeast winds up to 10 mph shifting to the southeast after midnight. Chance of rain 50 percent.

Monday: Mostly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 73 to 79 near the shore to around 56 near 5000 feet. East winds up to 15 mph. Chance of rain 30 percent.

Lanai City

Today: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 70 to 77. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows around 59. Northeast winds 10 to 20 mph.

Monday: Mostly sunny. Scattered showers in the afternoon. Highs 70 to 77. Northeast winds 10 to 15 mph decreasing to up to 10 mph in the afternoon. Chance of rain 30 percent.

Kaunakakai

Today: Sunny with isolated showers. Highs 69 to 79. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 51 to 63. Northeast winds 10 to 15 mph.

Monday: Sunny. Isolated showers in the afternoon. Highs 69 to 79. East winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate trade winds will hold in place today, then ease slightly tonight through Tuesday. Showers will favor windward slopes and coasts, mainly during nights and mornings, with a few showers spilling leeward from time to time. Trade winds will strengthen around mid week and a more typical trade wind shower pattern will return. Rather wet trade wind weather is expected Wednesday night through late next week, with breezy to windy conditions possible Friday into next weekend.

Discussion

Currently at the surface, a 1028 mb high is centered around 1350 miles north of Honolulu, with a ridge axis extending southwest to a position around 500 miles west of Kauai. Meanwhile, a cold front is positioned around 1000 miles west-northwest of the Garden isle, and a 1010 mb low is located near 29N151W or around 650 miles north-northeast of Hilo. These weather features will be the main influences on the local weather during the next few days. The high north of the islands remains the dominant weather feature at the moment, and is driving moderate northeasterly trade winds across the island chain early this morning. Infrared satellite imagery shows partly cloudy skies in most areas, with a bit more cloud cover at times over windward areas. Radar imagery shows scattered to numerous showers moving into windward areas, with some of the showers reaching leeward locales at times. Main short term focus during the next few days revolves around rain chances and trade wind trends.
The high and associated surface ridge north and northwest of the islands, will remain the dominant weather features today, maintaining moderate northeast trade winds. The low currently to the north-northeast of the state will drop southwestward, and weaken into a trough as it moves into a position a couple hundred miles north of the state tonight, relaxing the gradient and easing the trades into the light to moderate range. The trough will continue to slide westward Monday, and eventually merge with a stalling out front a few hundred miles northwest of Kauai on Tuesday. Light to moderate easterly trade winds will prevail during this time. Surface ridging will begin to strengthen both northwest and northeast of the islands Tuesday night and Wednesday, bringing a return of moderate trade winds. The trades are expected to strengthen through the remainder of the week as high pressure builds in north of the state, with breezy to windy conditions possible Friday into the weekend.
As for the remaining weather details, after a fairly showery start to the day, conditions should dry out in most areas this afternoon, although some shower coverage will remain a bit higher over windward Big Island. Fairly dry conditions should then prevail tonight through Tuesday as precipitable waters values hover around an inch or less and the best upper level forcing remains east of the state. Showers will favor windward and mauka areas, particularly during nights and mornings, with a few showers reaching leeward areas at times. A shortwave trough will pass eastward through the islands on Tuesday then close off into an upper low over the eastern end of the state Tuesday night and Wednesday. This will elevate inversion heights and lead to a gradual moistening up of the airmass across the state. The upper low will linger over the eastern islands through Thursday, then open up into a trough as it shifts southeast of the Big Island Thursday night and Friday. The strengthening trade winds and moistening up of the airmass will likely bring a return of a more typical trade wind shower pattern Tuesday night and Wednesday. Current model solutions then indicate a period of rather wet trade wind weather Wednesday night through late in the week. The wettest weather during this time of course will be over windward slopes and coasts, but given the strength of the trades, showers will reach leeward areas more frequently as well.
With the upper level forcing in place over the eastern end of the state, an isolated thunderstorm or two can't be ruled out over the Big Island each afternoon Tuesday through Friday. Additionally, it will be plenty cold enough for some snow to fall if convection develops over the Big Island summits.

Aviation

Light to moderate northeasterly trades will continue over the state through early Monday morning, which will confine most cloud cover and chances for showers to windward slopes and coasts through the TAF period. However, a few leeward locations could still potentially see sea breeze development and isolated showers this afternoon across more sheltered locations. Expect mainly VFR conditions to continue again at most TAF sites, with periodic MVFR conditions also expected within developing bands of trade wind showers.
AIRMET Tango for moderate upper turb conditions between FL280-FL420 within the air routes and flight areas within 40nm of the main Hawaiian Islands, is expected to improve this morning as upper jet dynamics continue to push eastward of the region.
AIRMET SIERRA for MTN OBSC may become needed today across some windward sections, as NE trades potentially generate an expanding area of MVFR ceilings within bands of trade wind moisture.

Marine

High pressure north of the region will help to increase trades a bit today, but expect a downward trend tonight. The current west- northwest swell will continue to decline today.
A hurricane force low more than 1650 nm northwest of the islands will have an impact on the coastal waters over the coming days. The associated cold front is expected to approach and stall to the northwest, which will weaken the pressure gradient over the coastal waters, leading to the above mentioned downward trend in the winds. This system will also be send an advisory level west- northwest swell our way. This swell is expected to arrive Monday, peak Tuesday and Wednesday, and then slowly lower through Thursday. Some of the coastal waters could see seas in excess of the 10 foot Small Craft Advisory (SCA) threshold with this event.
During the second half of the week, high pressure will build north of the islands, bringing SCA level winds to at least the typical windier locations. Models indicate additional coastal areas could see SCA level winds at the end of the new week and into the weekend.
Models show a gale force low forming near Japan that will send another west-northwest swell to the islands late in the week. Current projections are for this swell to arrive late Thursday, peaking near advisory levels Friday.
South shore surf will remain small through the rest of the weekend, before a moderate, out of season south-southwest swell arrives late tonight and Monday. This swell will hold at moderate levels through Wednesday, then lower through late next week. East shore surf will gradually rise through the upcoming week, with rough and slightly above normal surf possibly returning by Friday.

HFO Watches/Warnings/Advisories

None.

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov