Photo Credit: Tyler Rooke

West Side

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 78 to 88. Northeast winds 10 to 25 mph. Chance of rain 40 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows 68 to 75. East winds 10 to 20 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny with isolated showers. Highs 78 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Today: Sunny and breezy. Highs around 88. Northeast winds up to 25 mph.

Tonight: Mostly clear. Lows 69 to 74. Northeast winds 10 to 15 mph.

Tuesday: Sunny. Highs around 87. Northeast winds 10 to 15 mph.

North Shore

Today: Partly sunny. Breezy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 76 to 83 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 90 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows around 70 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tuesday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 82 near the shore to around 66 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Central Maui

Today: Breezy. Sunny with isolated showers. Highs 80 to 88. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly clear with isolated showers. Lows 68 to 73. East winds 10 to 15 mph. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers. Highs 80 to 88. East winds 10 to 20 mph. Chance of rain 20 percent.

Upcountry

Today: Sunny and breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 63 at the visitor center to around 59 at the summit. East winds up to 25 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly clear with scattered showers. Lows around 49 at the visitor center to around 46 at the summit. East winds 15 to 25 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 62 at the visitor center to around 58 at the summit. East winds 10 to 15 mph. Chance of rain 50 percent.

East Maui

Today: Partly sunny. Breezy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 76 to 83 near the shore to around 66 near 5000 feet. East winds 10 to 25 mph. Chance of rain 90 percent.

Tonight: Breezy. Mostly cloudy with numerous showers. Lows around 70 near the shore to around 52 near 5000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Tuesday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 82 near the shore to around 66 near 5000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Lanai City

Today: Sunny and breezy. Isolated showers in the afternoon. Highs 73 to 81. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Breezy. Lows 63 to 68. Northeast winds 10 to 20 mph.

Tuesday: Mostly sunny. Isolated showers in the afternoon. Highs 73 to 82. East winds 10 to 15 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 70 to 88. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 59 to 74. East winds 15 to 25 mph. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers. Highs 71 to 88. East winds 20 to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Locally strong trades will deliver increased trade wind showers to windward slopes through mid-week, especially over central portions of the state. Trades and shower coverage then trend downward during the end of the week.

Discussion

Continuing locally strong around the southern periphery of surface high pressure is directing a remnant band of frontal showers toward the islands at press time. Readily evident last evening's visible imagery, the incoming shower band extends ENE toward toward 140W and is oriented roughly orthogonal to the island chain. The latest observational trends and modeling suggest the lion's share of this moisture will focus over central portions of the state through Tuesday with Kauai and the Big Island residing on the periphery. As a result, periods of increased clouds and showers are expected over windward and mauka sections of Oahu and Maui County during the next 48 hours or so, particularly overnight and lingering into the morning hours. With that said, persistent deep easterly flow will advect drier mid- level air around 700mb across the region at the same time. The arrival of this drier airmass aloft and the resultant increase in stability will result in a trade off between shower coverage and intensity where forecast pops can remain appropriately high but rainfall away from the most favored locales remain comparatively modest. The remnants of this band will be ushered WNW by the trades allowing a brief increase in showers for Kauai during mid- week.
The mid-week period will be characterized by additional slight weakening of trades as the expansive high that has dominated the circulation over the north central Pacific begins to lose its grip over the area. Some degree of upper-level troughing will be a fixture during the coming week as the jet nestled within its southern flank directs a steady dose of cirrus from the lower latitudes and into area skies. As has been the case during the last couple of days, cirrus will be mostly transparent but even batches of partially opaque high cloud will be sufficient to take the edge off of daytime heat. Locally breezy trades will deliver periods of trade wind showers to windward zones for the remainder of the week, but increased stability will help limit rainfall amounts.

Aviation

Strong easterly trade winds will prevail through the 24-hr forecast period, with clouds and showers favoring windward and mountain locations. MVFR CIGS/VSBYs are expected through the early morning hours over most windward areas, especially in and around passing showers.
AIRMET Sierra remains in effect for mountain obscuration across all windward zones due to clouds and showers. Conditions should improve through the late morning hours.
AIRMET Tango remains in effect for low-level mechanical turbulence leeward of mountains due to strong trades.

Marine

A strong (1034 mb) surface high pressure system will remain nearly stationary far N of the islands through the upcoming week. Currently, the tight pressure gradient S of the high is supporting fresh to strong trade winds that are reaching near- gale speeds in areas where terrain accelerates the flow. A Small Craft Advisory (SCA) is posted for all waters through this afternoon.
A couple of low pressure systems in the NE Pacific will gradually weaken the eastern periphery of the high over the next couple of days, weakening the gradient near and NE of the islands. Initially, the weakening gradient will still support fresh trade winds that will remain strong in the accelerated zones, where the SCA has been extended through Tuesday night. Further weakening is expected by midweek, with moderate to fresh trade winds prevailing. A trend toward stronger trade wind flow is expected toward the end of the week as the high builds eastward.
No significant swells are expected this week. The strong trades will support rough and choppy surf along E facing shores for the next several days, with a trend down thereafter as the upstream fetch diminishes. Minimal swell energy from the S and SE is expected for most of the week, but forecast models indicate long- period S swell will increase in about a week or so, from a developing fetch SE of New Zealand this week.

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.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Big Island Windward Waters.

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

Check out their Maui Helicopter Tours today!

Data Courtesy of NOAA.gov