Today: Mostly cloudy. Occasional showers in the morning, then scattered showers in the afternoon. Highs around 79 near the shore to around 65 at 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 90 percent.
Tonight: Mostly cloudy. Showers likely in the evening, then occasional showers after midnight. Lows 62 to 70 near the shore to 52 to 57 at 4000 feet. North winds around 10 mph shifting to the west up to 10 mph after midnight. Chance of rain 80 percent.
Saturday: Cloudy with showers likely. Highs 76 to 81 near the shore to 62 to 68 at 4000 feet. Northeast winds up to 10 mph shifting to the east in the afternoon. Chance of rain 70 percent.
Kona
Today: Partly sunny. Isolated showers in the morning, then scattered showers in the afternoon. Highs 80 to 85 near the shore to around 65 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.
Tonight: Mostly cloudy with isolated showers. Lows around 70 near the shore to 48 to 54 near 5000 feet. Light winds. Chance of rain 20 percent.
ARTICLE CONTINUES BELOW AD
ARTICLE CONTINUES BELOW AD
Saturday: Partly sunny. 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.
Waimea
Today: Breezy. Partly sunny with scattered showers. Highs 64 to 84. East winds 10 to 25 mph. Chance of rain 50 percent.
Tonight: Breezy. Mostly cloudy with scattered showers. Lows 61 to 66 near the shore to 53 to 61 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.
Saturday: Breezy. Mostly cloudy with scattered showers. Highs 63 to 83. East winds 10 to 20 mph. Chance of rain 50 percent.
Kohala
Today: Breezy. Partly sunny with scattered showers. Highs 64 to 84. East winds 10 to 25 mph. Chance of rain 50 percent.
ARTICLE CONTINUES BELOW AD
Tonight: Breezy. Mostly cloudy with scattered showers. Lows 61 to 66 near the shore to 53 to 61 near 3000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.
Saturday: Breezy. Mostly cloudy with scattered showers. Highs 63 to 83. East winds 10 to 20 mph. Chance of rain 50 percent.
South Big Island
Today: Partly sunny. Breezy. Isolated showers in the afternoon. Highs around 80 near the shore to around 64 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.
Tonight: Mostly cloudy. Breezy. Isolated showers in the evening. Lows around 71 near the shore to around 50 near 5000 feet. Northeast winds up to 20 mph increasing to 10 to 20 mph after midnight. Gusts up to 40 mph. Chance of rain 20 percent.
Saturday: Partly sunny. Breezy. Isolated showers in the afternoon. Highs around 81 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.
Puna
ARTICLE CONTINUES BELOW AD
Today: Mostly cloudy. Occasional showers in the morning, then scattered showers in the afternoon. Highs around 79 near the shore to around 65 at 4000 feet. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 90 percent.
Tonight: Mostly cloudy. Showers likely in the evening, then occasional showers after midnight. Lows 62 to 70 near the shore to 52 to 57 at 4000 feet. North winds around 10 mph shifting to the west up to 10 mph after midnight. Chance of rain 80 percent.
Saturday: Cloudy with showers likely. Highs 76 to 81 near the shore to 62 to 68 at 4000 feet. Northeast winds up to 10 mph shifting to the east in the afternoon. Chance of rain 70 percent.
Waikoloa
Today: Partly sunny. Breezy. Highs 79 to 85 near the shore to 62 to 69 above 4000 feet. East winds up to 20 mph shifting to the north in the afternoon.
Tonight: Mostly cloudy. Breezy. Isolated showers in the evening. Lows 67 to 72 near the shore to 48 to 55 above 4000 feet. Southeast winds up to 20 mph. Chance of rain 20 percent.
Saturday: Partly sunny. Isolated showers in the afternoon. Highs 79 to 87 near the shore to 64 to 69 above 4000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.
Detailed Forecast
Synopsis
Moderate to fresh trade winds will continue into the weekend into the new week. Expect showers to favor windward and mauka locations mostly overnight through the morning periods through Saturday. A wetter, more unstable pattern is expected with the new week as an upper level system moves in from the north.
Discussion
High pressure far to the northeast continues to bring in moderate to fresh trades to the region. The global models keep the high in place through the weekend and have it reinforced early next week. As a result, expect trade winds to remain in place for the foreseeable future, and if anything, nudge upwards with the new week.
An upper level trough to the north of the islands, coupled with a mid to upper level low and associated trough to the far west of the islands, are helping to usher high clouds from the west, towards the islands. Satellite shows these high clouds beginning to move over the Big Island. Expect high clouds to spread across the islands over the next couple of days.
The global models agree with the trough to the north of the islands sinking southward over the next several days, with the development of a mid to upper level low along the trough to the northeast of the islands. The models diverge in placement and strength of this system, so several details are yet to emerge for the forecast next week. What can be agreed is that surface winds look to remain out of the east, but the trade wind inversion will likely be eroded as the upper level feature moves over the islands. Additional moisture will be drawn northward over the southern end of the state. This will allow for enhanced showers, and more showers reaching interior and leeward areas.
Have boosted some PoPs over some interior and leeward areas many during the Sunday through Tuesday time span keeping in line with the latest model data. There is still some uncertainty with the extent of the instability that will move into the islands with this system. However with the ECMWF continuing to show the potential for thunderstorms near the Big Island, and the GFS which is slowly showing a trend towards more of what the ECMWF has been indicating, have gone ahead and put the slight chance of thunderstorms in for the Big Island and waters to east of the Big Island for Sunday afternoon and evening. Will need to monitor future model runs to see if we need to increase the chance and/or areal coverage of thunderstorms.
Midweek looks like a return to more typical trade wind weather with moderate trades.
Aviation
Moderate to locally breezy trade winds will continue to steer bands of light showers towards the Hawaiian Islands. Clouds and showers will favor east and northeast facing slopes and coasts, especially in the late night and morning hours. In the afternoon and early evening, leeward sea breezes will encourage shower development over island interiors.
As of 2 am Friday, satellite imagery revealed several bands of stratocumulus embedded in the trade wind flow just upstream of the Big Island and Maui. These weak showers should move onshore within the next few hours and may cause areas of mountain obscuration across windward Big Island later this morning.
AIRMET Tango for low level mechanical turbulence to the lee of higher terrain remains in effect for Molokai, Maui, and the Big Island. Conditions are expected to persist into Saturday.
Additionally, a strengthening upper level jet is expected to yield moderate upper level turbulence across the majority of the state beginning this afternoon.
Marine
A surface high pressure system centered far northeast of the islands is expected to build as it moves slowly westward during the next few days. This will cause the pressure gradient to tighten across the state, which will produce locally strong trade winds. Therefore, a Small Craft Advisory (SCA) remains in effect for the typically windier waters adjacent to the islands of Maui County and the Big Island through Saturday night. Additional Hawaiian waters will likely be added to the SCA starting Sunday as the trade winds continue to strengthen across the island chain later this weekend and early next week.
The current northwest swell will maintain small surf along most north and west facing shores of the smaller islands through this evening. A small, reinforcing northwest swell arriving early Saturday will likely cause a modest increase in surf heights along exposed north and west facing shores of the smaller islands this weekend. A new moderate, long-period northwest swell arriving late Sunday is expected to cause surf to increase along most north and west facing shores early next week. The latest wave model guidance continues to show this northwest swell will gradually build, and surf may approach the High Surf Advisory criteria along some north and west facing shores of the smaller islands from late Tuesday into Wednesday.
Small south and southwest swells will keep small background surf along south facing shores through Saturday. A new, long-period south-southwest swell arriving Sunday is expected to cause surf to increase well above the summertime average along south facing shores from Monday through the middle of next week.
Expect modest, choppy surf along east facing shores through tonight. However, the strengthening trade winds will produce increasing surf along east facing shores this weekend. The strong trade winds in the vicinity of, as well as upstream of the islands will likely result in above average, rough surf along east facing shores from Monday into mid-week.
HFO Watches/Warnings/Advisories
Small Craft Advisory until 6 AM HST Sunday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.
This comments section is a public community forum for the purpose of free expression. Although Big Island Now encourages respectful communication only, some content may be considered offensive. Please view at your own discretion. View Comments
