Photo Credit: James Grenz

Hilo

Today: Showers likely, mainly before 1pm. Partly sunny, with a high near 82. West wind 5 to 11 mph becoming east in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely, mainly after 7pm. Mostly cloudy, with a low around 64. Calm wind becoming west 5 to 8 mph in the evening. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Tuesday: Showers likely, mainly before 1pm. Partly sunny, with a high near 81. West wind 6 to 10 mph becoming northeast in the afternoon. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Mostly sunny, with a high near 83. West northwest wind 5 to 8 mph becoming calm 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 62. Calm wind becoming east around 5 mph after midnight. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tuesday: Scattered showers after noon. Mostly sunny, with a high near 83. West wind 6 to 11 mph becoming light and variable in the afternoon. 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 76. Windy, with a northeast wind 17 to 23 mph, with gusts as high as 32 mph. 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 50. Breezy, with an east northeast wind 17 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.

Tuesday: Scattered showers. Partly sunny, with a high near 75. Windy, with a northeast wind 18 to 23 mph decreasing to 11 to 16 mph in the afternoon. Winds could gust as high as 32 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Scattered showers. Partly sunny, with a high near 69. Windy, with an east northeast wind 21 to 23 mph, with gusts as high as 32 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 39. Breezy, with an east wind 18 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tuesday: Scattered showers. Partly sunny, with a high near 69. Windy, with an east northeast wind 19 to 24 mph decreasing to 13 to 18 mph in the afternoon. Winds could gust as high as 34 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Isolated showers. Mostly sunny, with a high near 84. Windy, with an east wind 22 to 26 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Partly cloudy, with a low around 72. Windy, with an east northeast wind 21 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Tuesday: Isolated showers. Mostly sunny, with a high near 84. Windy, with an east wind 21 to 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Puna

Today: Showers likely, mainly before noon. Mostly cloudy, with a high near 80. North northwest wind 6 to 14 mph becoming east northeast in the morning. Winds could gust as high as 18 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 59. Northeast wind 6 to 9 mph becoming west northwest after midnight. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Tuesday: Showers likely, mainly before noon. Mostly cloudy, with a high near 79. Breezy, with a west northwest wind 7 to 15 mph becoming northeast in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Isolated showers after noon. Sunny, with a high near 81. Breezy, with an east northeast wind 16 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Mostly clear, with a low around 60. Breezy, with an east southeast wind 14 to 21 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

Tuesday: Isolated showers after noon. Sunny, with a high near 82. Windy, with an east northeast wind 19 to 24 mph decreasing to 6 to 11 mph in the afternoon. Winds could gust as high as 34 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

A broad high pressure ridge north of the state will keep moderate trade winds in the forecast into the weekend. Expect passing showers confined mostly to windward and mountain areas through the week. An upper level disturbance moves into the region on Friday, potentially increasing shower activity across the island chain into the weekend.

Discussion

Not much change this morning in the short range weather picture. This morning’s satellite imagery shows fairly stable clouds moving into the islands on the easterly trade wind flow. Local radar shows passing showers mainly over windward and mountain areas with some shower bands developing along lee-side island convergence plumes southwest and west of each island. A weak upper level low shows up in water vapor imagery just east of the Big Island.
A broad high pressure ridge will maintain strength north of the region producing moderate trade winds into the upcoming weekend. The upper soundings at 12Z this morning show subsidence inversion heights over Lihue Kauai around 6000 feet, and around 9000 feet over Hilo on the Big Island. These differences in trade wind inversion heights are related colder temperatures aloft near the weak upper low east of the Big Island, producing less stable conditions across the eastern side of the state. Forecast guidance shows cooler temperatures aloft (500 MB level) northeast of the Hawaiian Islands will persist through the week keeping passing windward and mountain showers in the forecast.

Aviation

Moderate easterly trade wind flow will continue across the state today and for the next several days. As a result, bands of scattered showers and clouds will generally favor the north and east sections of the islands throughout the forecast period as they are carried in on the trade wind flow.
Early this morning, AIRMET Sierra remains in effect for tempo mountain obscuration for eastern sections of the Big Island where latest radar and satellite imagery show the majority of showers and clouds have been focused for much of the night. Models suggest that some improvement may occur later this morning, however. Otherwise VFR conditions are expected to prevail today with only brief MVFR conditions in any passing showers.

Marine

Surface high pressure far northeast of the state will maintain moderate to locally strong trade winds this week. A Small Craft Advisory (SCA) is now in effect through early Tuesday morning for all of the typically windier waters adjacent to the islands of Maui County and the Big Island. This SCA may need to be extended for these same waters from Tuesday through mid-week based on the latest forecast.
The current moderate northwest swell will gradually lower from today through Wednesday. Surf will likely become nearly flat along most north facing shores from Thursday through next weekend. The current south swell will maintain surf heights near the May average along south facing shores through Tuesday. A new small, long period south swell arriving Wednesday is expected to persist through Friday. The moderate trade winds in the vicinity of, and upstream of the islands will likely produce surf heights near or slightly below the May average along east facing shores this week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Tuesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov