Hawaii County weather forecast for November 20, 2023: Big Island now

Hello

today: sunny. Scattered showers in the afternoon. Highs are about 83 near shore to 66 to 71 at 4,000 feet. Winds are northeasterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tonight: partly cloudy. Scattered showers in the evening, then scattered showers after midnight. Lows are around 67 near shore to around 53 at 4,000 feet. Light wind. Chance of rain is 30 percent.

Tuesday: Partly cloudy in the morning, then completely cloudy. Scattered rain showers. Highs are about 82 near shore to 66 to 71 at 4,000 feet. Winds are northeasterly, reaching speeds of 10 knots per hour. Chance of rain is 50 percent.

KONA

today: sunny. Scattered showers in the afternoon. Highs 81 to 86 near shore to about 72 near 5,000 feet. Winds are westerly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tonight: Mostly clear. Scattered showers in the evening. Low temperatures range from 67 to 72 near shore to about 54 near 5,000 feet. Light wind. Chance of rain is 20 percent.

Tuesday: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 81 to 86 near shore to about 72 near 5,000 feet. Winds are westerly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

water

today: Mostly sunny. Scattered showers in the afternoon. Highs are about 82 near shore to 73 to 79 near 3,000 feet. Winds are easterly, reaching speeds of 15 knots per hour. Chance of rain is 20 percent.

Tonight: Partly cloudy with scattered showers. Low temperatures range around 66 near shore to 52 to 60 near 3,000 feet. Winds are easterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tuesday: It will be mostly sunny with scattered rain in the morning, then partly sunny with scattered rain in the afternoon. Highs are about 81 near shore to 72 to 79 near 3,000 feet. Winds are easterly, reaching speeds of 15 knots per hour. Chance of rain is 50 percent.

Koala

today: Mostly sunny. Scattered showers in the afternoon. Highs are about 82 near shore to 73 to 79 near 3,000 feet. Winds are easterly, reaching speeds of 15 knots per hour. Chance of rain is 20 percent.

Tonight: Partly cloudy with scattered showers. Low temperatures range around 66 near shore to 52 to 60 near 3,000 feet. Winds are easterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tuesday: It will be mostly sunny with scattered rain in the morning, then partly sunny with scattered rain in the afternoon. Highs are about 81 near shore to 72 to 79 near 3,000 feet. Winds are easterly, reaching speeds of 15 knots per hour. Chance of rain is 50 percent.

South of the Big Island

today: sunny. Scattered showers in the afternoon. Highs are about 84 near shore to about 73 near 5,000 feet. Winds are southeasterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tonight: Mostly clear. Scattered showers in the evening. Lows are around 69 near shore to around 53 near 5,000 feet. Winds are northeasterly, reaching speeds of 15 knots per hour. Chance of rain is 20 percent.

Tuesday: breezy. Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs are about 84 near shore to about 73 near 5,000 feet. Winds are east, reaching speeds of 20 mph. Chance of rain is 20 percent.

Bona

today: sunny. Scattered showers in the afternoon. Highs are about 83 near shore to 66 to 71 at 4,000 feet. Winds are northeasterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tonight: partly cloudy. Scattered showers in the evening, then scattered showers after midnight. Lows are around 67 near shore to around 53 at 4,000 feet. Light wind. Chance of rain is 30 percent.

Tuesday: Partly cloudy in the morning, then completely cloudy. Scattered rain showers. Highs are about 82 near shore to 66 to 71 at 4,000 feet. Winds are northeasterly, reaching speeds of 10 knots per hour. Chance of rain is 50 percent.

Wekoloa

today: sunny. Scattered showers in the afternoon. Highs are about 83 near shore to 67 to 74 above 4,000 feet. Winds are northerly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tonight: Mostly clear. Scattered showers in the evening. Lows are around 71 near shore to 49 to 57 above 4,000 feet. Winds are southeasterly, reaching speeds of 10 knots per hour. Chance of rain is 20 percent.

Tuesday: Mostly sunny. Scattered showers in the afternoon. Highs are about 83 near shore to 67 to 74 above 4,000 feet. Winds are northerly, reaching speeds of 15 knots per hour. Chance of rain is 20 percent.

summary

A weak cold front moving toward the Northwestern Islands from the northwest will slowly drift down the island chain, stopping over Maui County later today. Clouds and several periods of rain will develop from Kauai to Maui through Tuesday. Winds have shifted to the northeast and will become a local breeze behind the front from Kauai to Molokai today, then return to moderate speeds and fairly typical trade wind weather Tuesday through the end of the work week. Another cold front approaching the islands next weekend may shift winds to the south and increase shower activity for the northwestern islands and the eastern to southeastern slopes of the Big Island.

discussion

This morning’s satellite image shows a weak cold front moving across the northwestern islands of Kauai and Oahu. Clouds and several periods of rain will spread along the island chain today, holding off as the front wanes over Maui County. An upper-level jet stream will also produce some high-level cirrus clouds across the Hawaiian area over the next few days.
The keys to the arrival time or amount of precipitation in this event will be determined on a smaller average scale over each island. Mainly with convective showers developing along the wind shear boundary along the weak cold front leading to rain showers on the northern and eastern slopes of each island. Flood warnings are possible as rainfall accumulates in area drains and roads.
The cold front stalls and diminishes today, allowing stronger northeasterly winds to blow across the island chain. These winds will push clouds and rain along the remaining frontal area westward over Oahu, Kauai, and Niihau on Tuesday and Wednesday. The longer guidance shows the extent of another weak cold front approaching the islands from the northwest on Thursday and Friday. Cold air moving with this front will break off the ridge north of the state and cause wind directions to shift from an easterly direction to a southerly direction by Friday, with a period of enhanced rain along the eastern and southeastern slopes of the Big Island by Friday. Another round of wet weather with this next system is expected by the end of next week, especially over the east to southeast slopes of the Big Island and near Kauai and Oahu as the weak front moves over the northwestern islands.

airline

A weak cold front will continue to move through the islands today bringing increased rain and periods of MVFR or falling conditions mainly across the western half of the state. Areas east of Molokai will generally see isolated to scattered showers with frontal stalls near Maui. Moderate to north to northeast winds behind the front will continue to move slowly down the island chain tonight.
AIRMET Sierra blocking of Mount Tempo will remain in effect on Kauai and Oahu through the morning due to persistent rain.
The AIRMET Tango of moderate disturbances between FL200 and FL400 will remain in effect in areas west of Molokai and will need to extend eastward today as the jet stream moves across the islands.

Navy

Clouds and scattered rain associated with the cold front near Maui County are expected to weaken and stop as it moves over Maui County waters today. Fresh to locally strong trade winds will build up behind the front but lighter easterly winds are expected to blow over Big Island waters during this period, spreading to all waters by mid-week with weakening to the far northeast.
A large northwest swell (340°) developed rapidly overnight in the western half of the state, and a High Surf Warning (HSW) was issued for the most exposed beaches, with a High Surf Warning for less exposed beaches. Observed readings from nearshore NDBC buoys 51208 peaked well above expected guidance. While the dominant period of the main northwest swell train (340°) will be about 14 seconds, the proximity of nearby gusty winds over waters just northwest of the region will introduce a broad spectrum of wave energy extending to shorter periods, resulting in rough, choppy surf along Exposed beaches facing north. Rising seas will require SCA for most waters through Tuesday. The swell will move increasingly northward (360 degrees) as it gradually diminishes late Monday/Tuesday. This swell could bring moderate swells to the ports of Hilo and Kahului.
The small S bulge will gradually decrease over the next couple of days. A small to moderate long-term swell is expected northwestward (320°) Wednesday night and Thursday, followed by the possibility of a very large swell northwestward (320°) by the end of the week.
Waves along east-facing beaches will remain rough and choppy as the trade winds return this week. Although east-facing beaches exposed to the northerly swell will see a rise coinciding with the northerly swell.

HFO Watches/Warnings/Advice

High Surf Advisory until 6 a.m. EDT Tuesday for Niihau, Oahu North Shore, Kauai North, Koolau Windward, Molokai Windward, Molokai North.
High surf advisory until 6 a.m. GMT Tuesday for Kauai Leeward, Waiana Coast and West Molokai.
High Surf Advisory until 6 a.m. EDT Tuesday for Maui Windward West, Maui Central Valley North and Windward Haleakala.
Small Boat Advisory until 6 a.m. EST Tuesday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters and Oahu Leeward Waters.
Small Vessel Advisory until 6 a.m. EDT Tuesday for Kaiwi Channel, Maui County Windward Waters, Pilulu Channel and Big Island Windward Waters.

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Data provided by NOAA.gov