West Side

Today: Mostly sunny with isolated showers. Highs 75 to 81. South winds around 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 67 to 74. South winds around 10 mph. Chance of rain 30 percent.

Tuesday: Mostly sunny. Isolated showers in the morning. Highs 75 to 81. South winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny with isolated showers. Highs around 83. Southwest winds around 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 75. Southwest winds around 10 mph. Chance of rain 30 percent.

Tuesday: Mostly sunny. Isolated showers in the morning. Highs around 83. Southwest winds around 10 mph. Chance of rain 20 percent.

North Shore

Today: Sunny. Haze in the morning. Isolated showers in the afternoon. Highs 77 to 82 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers after midnight. Lows around 69 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Highs 78 to 83 near the shore to around 67 near 5000 feet. Light winds becoming west up to 10 mph in the afternoon.

Central Maui

Today: Sunny with isolated showers. Highs 80 to 85. Southwest winds around 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 65 to 70. South winds around 10 mph. Chance of rain 20 percent.

Tuesday: Sunny. Isolated showers in the morning. Highs 80 to 85. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Today: Mostly sunny with isolated showers. Highs around 64 at the visitor center to around 69 at the summit. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear with isolated showers. Lows 45 to 55. South winds up to 10 mph. Chance of rain 20 percent.

Tuesday: Sunny. Highs around 65 at the visitor center to around 71 at the summit. Southwest winds up to 15 mph.

East Maui

Today: Sunny. Haze in the morning. Isolated showers in the afternoon. Highs 77 to 82 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers after midnight. Lows around 69 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Tuesday: Sunny. Highs 78 to 83 near the shore to around 67 near 5000 feet. Light winds becoming west up to 10 mph in the afternoon.

Lanai City

Today: Partly sunny with scattered showers. Highs 70 to 77. South winds around 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 64. South winds around 10 mph. Chance of rain 30 percent.

Tuesday: Partly sunny with scattered showers in the morning, then sunny in the afternoon. Highs 70 to 78. South winds around 10 mph. Chance of rain 40 percent.

Kaunakakai

Today: Partly sunny with scattered showers. Highs 67 to 84. South winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 57 to 73. South winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 68 to 84. South winds 10 to 15 mph. Chance of rain 40 percent.

Detailed Forecast

Synopsis

Gentle winds will gradually veer to the southwest, strengthening across the western end of the state, as a front slowly approaches from the northwest and stalls west of Kauai. The front's passage into the central islands by Wednesday evening will be the impetus to increased shower activity and breezy winds. Areawide trades will return by the end of the week.

Discussion

Dry conditions are still the main theme across the majority of the state this morning. With the exception of Big Island and surrounding waters where drainage breezes and southeasterlies still prevail, respectively, the general wind pattern is transitioning to more gradient south-southwesterly behavior in response to a vicinity front currently hanging up over the far northwest offshore waters. Local southerlies will remain gentle and veer more southwesterly over the smaller islands as the slowly southeast-advancing front stalls just northwest of the island chain into Tuesday. Overnight satellite and radar imagery are depicting pre-frontal bands of warmer clouds with embedded showers west of Kauai and Maui County streaming northward at a decent 25 mph clip. Weekend local areal soundings are evidence that the overall air mass has moistened up as precipitable waters have increased about a half of an inch since Saturday. However, ample mid-level dry air will suppress any significant rainfall. In vog news, emissions from Big Island's Halemaumau Crater continue to be observed being caught up in weaker southeasterly lower level flow and transported over both Big Island and Maui County. Strengthening southerlies will better mix out the vog throughout a near 6k ft boundary layer depth today.
Localized land and sea breezes will continue over those communities that are more sheltered from the general large scale (south-veering-southwest) flow today. This will favor less daytime cloud and subsequent shower development across more leeward, interior areas with evening offshore clearing. Higher moisture being pulled up from the south, along with the potential for lower level convergence bands setting up ahead of the front, will initiate periods of mainly light showers embedded within the southwesterly flow. This will wetten leeward areas of Kauai, Oahu and western portions of Maui County going into Wednesday.
Hawaii and its surrounding waters will remain under weak upper ridging just downstream of a broad trough. Energy moving into and deepening this Central Pacific trough will dive this trough further south in the proximity of Hawaii the next couple of days. As this trough sweeps across the region it will push the aforementioned front through (at least) the western half of the island chain. The latest numerical weather prediction (NWP) guidance times the front to reach Kauai late Tuesday evening or early Wednesday morning, then slowly move it into the central islands Wednesday evening before stalling and dissipating the boundary. While not much rain is expected with this frontal passage, many will likely receive beneficial rain with breezy statewide northeasterlies to follow in the front's wake.
Mid to lower level streamline convergence along the dissipating boundary, along with an abundance of higher upstream moisture, will keep rain chances in the picture through the latter part of the week. Areawide trades will return by Friday. Primarily eastern island precipitation caught within trades will focus over windward and mauka areas as high pressure builds in the front's wake. Long-term NWP model guidance has consistently been pinching off a closed-off low from the upper trough over the eastern end of the state this upcoming weekend. This scenario would enhance statewide rainfall and slightly increase thunderstorm probabilities. Confidence remains low with this scenario as the timing, development and progression of the upper trough through the week will ultimately determine the long term solution of a potential closed off southern-based low this time next week.

Aviation

Light to moderate southerly flow will prevail the next couple of days, with localized land and sea breezes in terrain sheltered areas. A band of moisture will continue to bring an uptick in shower activity across south facing coasts and slopes today, with brief cig/vsby restrictions possible.
No AIRMETs are currently in effect. AIRMET Sierra may be needed for mountain obscuration across some south facing slopes.

Marine

Overlapping significant swell energy will maintain warning level surf heights along exposed north and west facing shores into Thursday. A High Surf Warning (HSW) was extended in time through Wednesday morning for north and west facing shores of Niihau, Kauai, Oahu, and Molokai, north facing shores of Maui, and west facing shores of the Big Island. This HSW will likely be extended into Thursday as another even larger swell rolls through the Hawaii region on Wednesday.
A Small Craft Advisory (SCA) was also extended in time through Wednesday morning for all waters except Maalea Bay, as high seas are expected for all waters exposed to these overlapping northwest swells.
The current west-northwest (290-310 degree) swell will hold today near HSW levels. This will allow surf heights along most north and west facing shores to briefly drop to marginal warning levels through the day. However, the next significant northwest swell will swiftly build into the region later tonight. This next swell will increase surf heights along north and west facing shores once again, building surf heights well above warning levels through Tuesday. Beginning late Tuesday afternoon, the next largest of these overlapping swells will quickly build into the region, bringing significant and dangerous surf along north and west facing shores. This swell will peak by Wednesday morning and then begin slowly declining, with surf heights falling back below warning levels late Thursday. Surf heights along east and south facing shores will remain small through the forecast period.
Over the western islands, moderate to fresh southwesterlies will continue to blow into Tuesday, and then become more northerly winds from Tuesday night into Wednesday as a cold front moves across the islands. Wind directions will then shift back to moderate to fresh northeasterly to easterly trade winds by Thursday. Across the eastern end of the state, gentle to locally fresh southeast winds will hold today, then become light and variable by Tuesday before transitioning back to moderate trades on Thursday.

Fire weather

No critical fire weather conditions are expected in the near future. Gentle southerly flow will result in relatively higher humidities through the middle of the week. A front is expected to move through the western part of the state the next couple of days. This will initiate more breezy northeasterlies over the western end of the island chain and provide much needed rain.

HFO Watches/Warnings/Advisories

High Surf Warning until 6 AM HST Wednesday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala, Big Island South.
Small Craft Advisory until 6 AM HST Wednesday for all Hawaiian waters except Maalaea Bay,

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov