Hilo

Today: Partly sunny in the morning then becoming cloudy. Scattered showers. Highs around 81 near the shore to 63 to 71 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 63 to 71 near the shore to 52 to 57 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny in the morning then becoming cloudy. Scattered showers. Highs 78 to 83 near the shore to 64 to 71 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 40 percent.

Kona

Today: Mostly sunny with isolated showers in the morning, then cloudy with scattered showers in the afternoon. Highs 81 to 86 near the shore to around 66 near 5000 feet. Light winds. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows around 71 near the shore to 49 to 55 near 5000 feet. Light winds. Chance of rain 40 percent.

Tuesday: Mostly sunny in the morning then becoming cloudy. Isolated showers. Highs around 84 near the shore to around 67 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Waimea

Today: Mostly sunny in the morning then becoming mostly cloudy. Breezy. Scattered showers. Highs 63 to 85. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Isolated showers. Lows 61 to 68 near the shore to 52 to 61 near 3000 feet. East winds 10 to 20 mph decreasing to up to 20 mph after midnight. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers in the morning, then cloudy with scattered showers in the afternoon. Highs 64 to 87. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 40 percent.

Kohala

Today: Mostly sunny in the morning then becoming mostly cloudy. Breezy. Scattered showers. Highs 63 to 85. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Isolated showers. Lows 61 to 68 near the shore to 52 to 61 near 3000 feet. East winds 10 to 20 mph decreasing to up to 20 mph after midnight. Chance of rain 20 percent.

Tuesday: Breezy. Mostly sunny with isolated showers in the morning, then cloudy with scattered showers in the afternoon. Highs 64 to 87. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 40 percent.

South Big Island

Today: Breezy. Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs around 82 near the shore to around 64 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming mostly clear. Lows around 71 near the shore to around 50 near 5000 feet. Northeast winds up to 15 mph.

Tuesday: Sunny in the morning then becoming cloudy. Breezy. Highs around 83 near the shore to around 66 near 5000 feet. East winds up to 20 mph.

Puna

Today: Partly sunny in the morning then becoming cloudy. Scattered showers. Highs around 81 near the shore to 63 to 71 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy with scattered showers after midnight. Lows 63 to 71 near the shore to 52 to 57 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny in the morning then becoming cloudy. Scattered showers. Highs 78 to 83 near the shore to 64 to 71 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 40 percent.

Waikoloa

Today: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 79 to 87 near the shore to 63 to 70 above 4000 feet. North winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows around 72 near the shore to 47 to 55 above 4000 feet. Southeast winds up to 15 mph.

Tuesday: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 80 to 88 near the shore to 64 to 71 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A high pressure system far north of the Hawaiian Islands will build into the region today, increasing trade wind speeds into the moderate to locally breezy range through Friday. Fairly typical cloud and shower trends will return with passing showers over the windward and mountain areas of each island, favoring the overnight to early morning hours. An upper level disturbance passing over the islands next weekend may briefly increase cloud and shower trends.

Discussion

Satellite imagery this morning shows more stable cumulus and stratocumulus clouds moving into the islands on the trade wind flow. These clouds will bring brief passing showers to windward and mountain areas through the early morning hours with decreasing rainfall trends in the late morning to afternoon. Local radar imagery shows scattered to numerous showers brewing across the state. Scattered high level cirrus clouds continue to drift over the state courtesy of the subtropical jet stream.
The high pressure system far north of the islands will build into the region today, increasing trade wind speeds to the moderate to locally breezy range by this afternoon. Upper air balloon soundings show trade wind inversion heights in the 5,500 foot to 8,000 foot range for Lihue and Hilo respectively. Model cross sections continue to show trade wind temperature inversion heights will range between the 6,000 to 8,000 feet, which means cloud tops will be high enough for continued passing showers over windward and mountain areas of each island through Friday. Clouds and showers will continue to favor overnight to early morning hours.
An upper level low drifts into the area by this weekend. This upper low will anchor a lower level 700 mb trough under the low center as the system drifts from southeast to northwest across the islands. The passage of this low may briefly increase long range cloud and shower coverage trends from Saturday through Sunday. Stay tuned.

Aviation

Light to moderate trades will persist through the morning hours, then increase into the moderate to breezy category this afternoon. Although VFR conditions will prevail for most areas, expect brief periods of MVFR CIGS/VSBYS in and around showers that develop and move through.
There are currently no AIRMETs in effect. However, AIRMET Tango for low-level mechanical turbulence over and downwind of mountains is possible this afternoon as the trades strengthen.

Marine

A surface high well north of Kauai will build far northeast of the state today through Tuesday, leading to an increase in trade winds to fresh to locally strong speeds. Therefore, a Small Craft Advisory has been issued for the typically windy waters around the Big Island and Maui County through Tuesday afternoon, but will likely be extended through next weekend.
The first pulse of south swell that came in larger than expected has now begun to decrease. A High Surf Advisory remains in effect through this afternoon. Although a slight decline in surf is possible late today through tonight, the next pulse of south swell due on Tuesday will keep south shore surf up around advisory level through Wednesday. This swell will gradually decline Thursday and Friday.
Surf along exposed north and east facing shores could see a bump in small, short period swell through today. Surf along north shores will drop Tuesday, while strengthening trade winds will boost rough east shore surf to around seasonal average into next weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST this evening for Niihau, Kauai Leeward, Waianae Coast, Kahoolawe, Maui Leeward West, Kona, Kauai South, East Honolulu, Honolulu Metro, Ewa Plain, Molokai Leeward South, Lanai Leeward, Lanai South, Maui Central Valley South, South Maui/Upcountry, South Haleakala, Big Island South, Big Island Southeast.
Small Craft Advisory from 6 AM this morning to 6 PM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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Data Courtesy of NOAA.gov