Photo Credit: James Grenz

Hilo

Today: Showers likely, mainly before noon. Partly sunny, with a high near 82. North wind 6 to 8 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 63. West wind 6 to 8 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Wednesday: Showers likely, mainly before noon. Partly sunny, with a high near 82. North northeast wind around 10 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Kona

Today: Scattered showers after noon. Increasing clouds, with a high near 84. West wind 5 to 8 mph becoming calm in the morning. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Scattered showers, mainly before midnight. Mostly cloudy, with a low around 64. Light east southeast wind. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Wednesday: Scattered showers after noon. Increasing clouds, with a high near 84. Southeast wind around 6 mph becoming southwest in the afternoon. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

Waimea

Today: Scattered showers. Mostly sunny, with a high near 76. Breezy, with a northeast wind around 21 mph, with gusts as high as 29 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 54. Breezy, with an east northeast wind around 16 mph, with gusts as high as 22 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Wednesday: Scattered showers. Mostly sunny, with a high near 76. Windy, with a northeast wind around 23 mph, with gusts as high as 32 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.

Kohala

Today: Showers likely, mainly before noon. Mostly cloudy, with a high near 70. Breezy, with an east northeast wind around 20 mph, with gusts as high as 28 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Tonight: Showers likely. Mostly cloudy, with a low around 47. Breezy, with an east wind around 17 mph, with gusts as high as 24 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Wednesday: Scattered showers. Mostly cloudy, with a high near 70. Breezy, with an east northeast wind around 22 mph, with gusts as high as 31 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch possible.

South Big Island

Today: Isolated showers after noon. Sunny, with a high near 85. Windy, with an east wind around 24 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Tonight: Isolated showers. Partly cloudy, with a low around 72. Breezy, with an east northeast wind 18 to 21 mph, with gusts as high as 26 mph. Chance of precipitation is 20%.

Wednesday: Isolated showers. Mostly sunny, with a high near 85. Windy, with an east wind 24 to 26 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Puna

Today: Showers likely, mainly before noon. Partly sunny, with a high near 80. North northeast wind 8 to 13 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 60. West northwest wind around 8 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Wednesday: Showers likely, mainly before noon. Mostly cloudy, with a high near 80. North northeast wind around 14 mph, with gusts as high as 18 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Waikoloa

Today: Isolated showers after noon. Mostly sunny, with a high near 83. Breezy, with an east northeast wind 18 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.

Tonight: Isolated showers before midnight. Mostly clear, with a low around 62. Breezy, with an east wind around 16 mph, with gusts as high as 22 mph. Chance of precipitation is 20%.

Wednesday: Isolated showers after noon. Mostly sunny, with a high near 81. Windy, with an east northeast wind around 24 mph, with gusts as high as 34 mph. Chance of precipitation is 20%.

Detailed Forecast

Synopsis

A broad high pressure ridge north of the island chain will keep moderate to locally breezy trade winds in the forecast into the weekend. Passing showers will favor windward and mountain areas with brief showers possible over leeward locations.

Discussion

The long range weather pattern remains unchanged this morning. In the big picture, a broad high pressure ridge north of the state will produce moderate to locally breezy trade winds across the region through the weekend. Cooler temperatures aloft (500 mb level) northeast of the islands will keep passing showers in the forecast for mostly windward and mountain areas. Shower activity will trend higher in the overnight to early morning hours and trend lower in the daylight hours.
Long range guidance this weekend continues to show an unstable upper level low dropping into the region from the north. The latest model solutions show the cut off low centered just northeast of the island chain. This system may increase rainfall coverage from this weekend into early next week. Rainfall impacts will depend upon how close this unstable low tracks relative to each island. If the low drifts closer to the state upper level instability will trigger more rainfall activity. Confidence on a wetter solution remains low this far out, as island by island weather impacts can change with the location of this system over the next four to five days.

Aviation

Moderate to locally breezy trades are focusing low clouds and showers over windward areas this morning. AIRMET Sierra for mountain obscuration was initially in effect for only Windward Big Island. However, MVFR observations have been frequent enough across the windward slopes of the smaller islands to warrant an expansion of the AIRMET this morning. Satellite trends indicate some improvement to ceilings is likely to take place over the next few hours, so cancellation of part or all of Sierra may be in order later this morning. Windward areas will remain the focus for shower activity through the forecast period.

Marine

Fresh to strong easterly trades will continue into the second half of the week as high pressure remains anchored to the north. Winds could back slightly to a more northeast direction later in the week as a broad trough develops far northeast of the area. The Small Craft Advisory currently in place for the typically windier waters between Maui County and the Big Island has been extended through Wednesday. Seas will remain rough in these windier areas, but should hold below the 10 ft advisory threshold through the week.
Surf along south facing shores will remain up through the week as small, overlapping, long-period swells from the southern Pacific roll through. The next in the series should arrive by Wednesday, then again late in the week going into the weekend.
Surf along east facing shores will remain rough and choppy due to the onshore trades. Surf should hold in the small category each day due to a limited fetch upstream.
Surf along north facing shores will trend down into midweek to near flat levels as the current northwest swell moves out. Expect the summer-like conditions to hold through the weekend.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov