Hilo

Today: Scattered showers. Partly sunny, with a high near 83. Calm wind becoming northeast 5 to 9 mph in the morning. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 66. Northeast wind 5 to 8 mph becoming calm after midnight. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 82. Calm wind becoming northeast 5 to 8 mph in the morning. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Mostly sunny, with a high near 79. West northwest wind 5 to 13 mph becoming south southwest in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before midnight. Partly cloudy, with a low around 64. Calm wind becoming southeast 5 to 7 mph after midnight. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Scattered showers after noon. Mostly sunny, with a high near 78. Light west southwest wind becoming west northwest 5 to 9 mph in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers. Partly sunny, with a high near 73. Windy, with a northeast wind 22 to 26 mph, with gusts as high as 38 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 55. Windy, with an east northeast wind 21 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 72. Windy, with a northeast wind around 26 mph, with gusts as high as 38 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Scattered showers. Partly sunny, with a high near 67. Windy, with an east northeast wind 26 to 28 mph, with gusts as high as 40 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly before midnight. Mostly cloudy, with a low around 54. Very windy, with an east wind 26 to 32 mph, with gusts as high as 47 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 66. Very windy, with an east wind 29 to 31 mph, with gusts as high as 45 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Isolated showers after noon. Mostly sunny, with a high near 79. Windy, with an east wind 26 to 28 mph, with gusts as high as 36 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Partly cloudy, with a low around 72. Windy, with an east northeast wind 24 to 26 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Monday: Isolated showers after noon. Mostly sunny, with a high near 79. Windy, with an east wind around 29 mph, with gusts as high as 37 mph. Chance of precipitation is 20%.

Puna

Today: Scattered showers. Partly sunny, with a high near 80. Breezy, with a north northeast wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Scattered showers. Mostly cloudy, with a low around 63. North wind 9 to 11 mph. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Monday: Scattered showers. Partly sunny, with a high near 79. Northeast wind around 11 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Mostly sunny, with a high near 82. Very windy, with an east northeast wind 20 to 25 mph increasing to 26 to 31 mph in the afternoon. Winds could gust as high as 49 mph.

Tonight: Mostly clear, with a low around 65. Very windy, with an east wind 25 to 31 mph, with gusts as high as 49 mph.

Monday: Mostly sunny, with a high near 81. Very windy, with an east northeast wind 21 to 31 mph, with gusts as high as 55 mph.

Detailed Forecast

Update

Keeping in line with the current background trade wind flow, strengthened northeast winds and gusts in the Kohala area of the Big Island this afternoon and evening.
.SYNOPSIS… Surface high pressure far north of the state will produce locally windy trades today. The trades will be locally breezy from tonight through mid-week. Low clouds and passing trade showers will continue to favor windward and mauka areas, with a few brief showers possible over some leeward sections.

Discussion

A 1030 mb surface high pressure system is centered near 35N 154W, or about 975 miles north of Honolulu. The tight pressure gradient south of this feature is producing locally windy trade winds across the state early this morning. Based on loops of water vapor satellite imagery, an upper-level low is evident near 27N 144W, or about 870 miles northeast of Hilo. Satellite imagery and radar reflectivity data show scattered to broken low clouds and scattered showers streaming into the windward sides of the islands early this morning.
The forecast guidance indicates the surface high to the north of the area will produce a more easterly trade wind flow from later today and tonight through Monday. The upper-level low is also forecast to gradually lift out to the northeast away from the region from tonight through Monday. No significant moisture sources are expected to be embedded within the low-level trade wind flow during the next few days. Low clouds and passing trade showers will continue over windward and mauka areas, especially during the late night and early morning hours. The strong trade winds will transport brief showers over the leeward sides of some of the smaller islands. In addition, expect daytime heating to produce clouds and isolated showers over the upslope sections of the leeward Big Island each afternoon.
Toward the end of this week, the surface high is expected to move to a position far north-northeast of the area. This will result in a slight downward trend in trade wind speeds. The forecast guidance also shows increasing moisture moving up from the southeast toward the islands. This scenario could lead to warmer temperatures and muggy conditions setting up across the islands as we head into next weekend.

Aviation

A high pressure ridge north of the region will maintain breezy to locally strong trade winds today. Upper level instability will keep passing showers in the forecast, favoring windward and mountain areas. Mostly VFR conditions are expected with only brief periods of MVFR possible in showers.
AIRMET Tango remains in effect for moderate turbulence south through west of island mountains. Strong trade winds will likely keep this AIRMET in effect trough Monday.

Marine

High pressure north of the state will keep moderate to locally strong trades in place through late this week. A Small Craft Advisory is now in effect for most marine zones through 6 pm this evening, and for the typically windy waters around Maui and the Big Island through 6 pm Tuesday.
North shore surf will remain small today, before a couple overlapping northwest swells bring a small boost to north and west facing shores Monday through Wednesday. Surf along north facing shores will then trend down Thursday and fall back into the very small range Friday into next weekend.
The current south swell will gradually decline today, with only small background southerly swells expected Monday through late this week.
Persistent trade winds over and upstream of the islands will keep east shore surf relatively unchanged through late this week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Tuesday 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.

Data Courtesy of NOAA.gov