West Side

Today: Sunny. Isolated showers in the afternoon. Highs 76 to 89. Northeast winds up to 10 mph shifting to the southwest in the afternoon. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 67 to 76. East winds up to 15 mph shifting to the northeast after midnight.

Saturday: Sunny. Highs 76 to 89. Northeast winds up to 15 mph.

South Side

Today: Sunny. Highs 78 to 90. Northwest winds up to 10 mph shifting to the west in the afternoon.

Tonight: Clear and breezy. Lows 67 to 73. Northwest winds up to 10 mph shifting to the north up to 20 mph after midnight.

Saturday: Sunny and breezy. Highs 78 to 91. North winds up to 20 mph.

North Shore

Today: Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 71 to 76 near the shore to around 57 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Central Maui

Today: Sunny. Highs 82 to 88. Southeast winds up to 10 mph shifting to the northeast in the afternoon.

Tonight: Clear. Lows 65 to 73. Northeast winds up to 10 mph.

Saturday: Sunny. Highs 82 to 88. Northeast winds up to 15 mph.

Upcountry

Today: Mostly sunny with isolated showers. Highs 56 to 74. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 50 at the visitor center to around 42 at the summit. Light winds becoming northeast up to 10 mph after midnight.

Saturday: Sunny. Isolated showers in the morning. Highs 56 to 74. Northeast winds up to 15 mph. Chance of rain 20 percent.

East Maui

Today: Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 71 to 76 near the shore to around 57 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Saturday: Breezy. Mostly sunny with isolated showers. Highs 79 to 84 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Lanai City

Today: Sunny. Isolated showers in the afternoon. Highs 70 to 81. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 20 percent.

Tonight: Clear. Lows 63 to 68. Northeast winds up to 15 mph.

Saturday: Sunny. Highs 71 to 81. Northeast winds up to 15 mph.

Kaunakakai

Today: Mostly sunny with isolated showers. Highs 70 to 90. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows 59 to 78. Northeast winds up to 15 mph increasing to 10 to 15 mph after midnight.

Saturday: Sunny and breezy. Highs 69 to 90. East winds 10 to 20 mph.

Detailed Forecast

Synopsis

The subtropical ridge will slowly build back in over the Hawaiian Islands as Tropical Storm Nolo continues to drift westward away from the Hawaii Region. Higher pressure returning to the islands from will produce easterly trade winds, increasing atmospheric stability, lowering humidity levels and decreasing shower trends through the weekend. Brief passing showers will favor windward mountain areas in the overnight to early morning hours. Increasing cloud cover and shower trends may return from Monday night into Thursday morning due to a passing disturbance.

Discussion

Southerly winds across the western islands last night produced bands of moderate to heavy showers affecting the islands of Niihau, Kauai, and portions of Oahu. High water levels in local streams briefly exceeded flash flood thresholds over northern Kauai triggering Flood Advisory and Flash Flood Warning issuance. No reports of flooding were received during last nights event.
Today we begin to transition back to more typical drier easterly trade wind weather just in time for the weekend. Lower humidity levels and mostly sunny skies will prevail from Saturday through Monday afternoon.
A weak disturbance in the force may bring another round of enhanced showers to all islands from Monday night into Thursday morning. Trade wind temperature inversion heights rise into the 8,000 to 10,000 foot range, which allows for scattered to numerous shower activity statewide. Northeastern to eastern windward mountain slopes would likely see the higher rainfall amounts due to easterly wind forcing in this evolving weather pattern for the middle of next week. Increased wet trade wind rainfall coverage for this time period in the latest forecast grids, with drying trends forecast by the end of next week.

Aviation

Moderate southeast winds will continue today across the state as Tropical Storm Nolo moves away. Showers loosely associated with Nolo will continue to track over Kauai and Oahu today with MVFR conditions likely with brief periods of IFR conditions possible. Trade winds will push in a drier air mass tonight.
AIRMET Sierra is in effect for mountain obscuration above 2000 feet over Kauai, Oahu and above 2500 feet on Big Island, though conditions will improve over Big Island this morning. Cloud build ups likely by afternoon across Maui County and Big Island before dissipating tonight.

Marine

Moderate to fresh east to southeasterly winds will prevail across the region today as Tropical Storm Nolo lingers amongst the Northwestern Hawaiian Islands. Nolo will begin to accelerate westward away from the Hawaiian Islands today, which will diminish its influence on Hawaiian waters. Gentle to fresh east to northeast trades fill back in across the waters this weekend into early next week. A Small Craft Advisory may be needed for the typically windy channels late this weekend for locally strong trades. By mid-next week, troughing developing northwest of the islands may cause the trade winds to weaken and veer out of the southeast once again.
A moderate, medium-period west to southwest swell originating from Tropical Storm Nolo will continue for Niihau and Kauai today before quickly fading tonight. Meanwhile, a small, background south swell continues for other islands, holding surf mostly steady along south facing shores through the weekend. A new small, long-period south swell, originating from a large fetch of gale force winds southeast of New Zealand earlier this week, is forecast to arrive beginning Sunday and peak Monday through Wednesday.
Surf along north-facing shores will see a tiny bump today into tonight as a small, short-period northerly swell moves through the region. Small surf is possible early next week as a small, medium-period northwest swell arrives this weekend and peaks on Monday, followed by a slightly larger northwest swell peaking on Wednesday. Surf along east facing shores will see a slight boost and become more choppy as easterly trades build back into the region this weekend.

Fire weather

Fire weather conditions will remain below critical threshold this week for both wind and humidity levels. Temperature inversion heights near Maui and the Big Island today will range from 6,000 to 7,000 feet elevation.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov