Photo Credit: Tyler Rooke

West Side

Today: Windy. Partly sunny with scattered showers. Highs 78 to 88. Northeast winds 15 to 35 mph with gusts to 55 mph. Chance of rain 50 percent.

Tonight: Tropical storm conditions possible. Cloudy. Numerous showers in the evening, then showers after midnight. Lows 71 to 79. Northeast winds 30 to 40 mph with gusts to 60 mph decreasing to 15 to 30 mph after midnight. Chance of rain 90 percent.

Sunday: Breezy. Cloudy with numerous showers. Highs 78 to 88. Northeast winds 10 to 25 mph. Chance of rain 70 percent.

South Side

Today: Mostly sunny in the morning then becoming partly sunny. Windy. Scattered showers. Highs 86 to 91. Northeast winds 10 to 25 mph increasing to 25 to 30 mph in the afternoon. Gusts up to 45 mph increasing to 50 mph in the afternoon. Chance of rain 40 percent.

Tonight: Cloudy and windy. Scattered showers in the evening, then showers after midnight. Lows 73 to 79. North winds 15 to 30 mph with gusts to 55 mph. Chance of rain 90 percent.

Sunday: Cloudy and windy. Showers in the morning, then numerous showers in the afternoon. Highs around 88. North winds 15 to 30 mph with gusts to 50 mph. Chance of rain 80 percent.

North Shore

Today: Windy. Cloudy with numerous showers. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds 10 to 30 mph. Gusts up to 50 mph in the afternoon. Chance of rain 70 percent.

Tonight: Windy and showers. Lows around 74 near the shore to 53 to 58 near 5000 feet. East winds 15 to 30 mph. Gusts up to 50 mph in the evening. Chance of rain near 100 percent.

Sunday: Breezy and showers. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds 10 to 25 mph. Chance of rain near 100 percent.

Central Maui

Today: Windy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 79 to 87. Northeast winds 15 to 30 mph. Chance of rain 40 percent.

Tonight: Cloudy and windy. Numerous showers in the evening, then showers after midnight. Lows around 74. Northeast winds 15 to 30 mph. Chance of rain 90 percent.

Sunday: Breezy. Cloudy with showers. Highs 80 to 88. Northeast winds 15 to 25 mph. Chance of rain 90 percent.

Upcountry

Today: Mostly sunny in the morning then becoming partly sunny. Windy. Scattered showers. Highs around 65 at the visitor center to around 70 at the summit. East winds 10 to 35 mph with gusts to 60 mph. Chance of rain 50 percent.

Tonight: Tropical storm conditions possible. Cloudy. Numerous showers in the evening, then showers after midnight. Lows around 56 at the visitor center to around 49 at the summit. East winds 15 to 40 mph. Gusts up to 65 mph decreasing to 55 mph after midnight. Chance of rain 90 percent.

Sunday: Cloudy and windy. Showers in the morning, then scattered showers in the afternoon. Highs around 64 at the visitor center to around 71 at the summit. East winds 15 to 35 mph decreasing to 10 to 25 mph in the afternoon. Chance of rain 90 percent.

East Maui

Today: Windy. Cloudy with numerous showers. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds 10 to 30 mph. Gusts up to 50 mph in the afternoon. Chance of rain 70 percent.

Tonight: Windy and showers. Lows around 74 near the shore to 53 to 58 near 5000 feet. East winds 15 to 30 mph. Gusts up to 50 mph in the evening. Chance of rain near 100 percent.

Sunday: Breezy and showers. Highs 79 to 84 near the shore to around 67 near 5000 feet. East winds 10 to 25 mph. Chance of rain near 100 percent.

Lanai City

Today: Windy. Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 74 to 83. Northeast winds 15 to 30 mph increasing to 25 to 30 mph in the afternoon. Gusts up to 50 mph in the afternoon. Chance of rain 50 percent.

Tonight: Cloudy and windy. Scattered showers in the evening, then numerous showers after midnight. Lows 66 to 71. Northeast winds 25 to 35 mph decreasing to 20 to 25 mph after midnight. Chance of rain 70 percent.

Sunday: Cloudy and breezy. Numerous showers in the morning, then showers in the afternoon. Highs 74 to 83. Northeast winds 15 to 25 mph. Chance of rain 80 percent.

Kaunakakai

Today: Mostly sunny in the morning then becoming partly sunny. Windy. Scattered showers. Highs 70 to 91. Northeast winds 10 to 30 mph with gusts to 50 mph. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows 62 to 78. Northeast winds 15 to 35 mph with gusts to 55 mph decreasing to 15 to 25 mph after midnight. Chance of rain 50 percent.

Sunday: Breezy. Cloudy with numerous showers. Highs 70 to 90. East winds 15 to 25 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Stronger winds remain in the forecast today as The Central Pacific Hurricane Center continues to closely monitors Tropical Storm Hone east-southeast of the Big Island moving westward. On its current track, Hone will brush past the southern slopes of the Big Island from tonight into Sunday morning; bringing the potential for heavy rainfall, damaging winds, and large surf. Expect strong and gusty easterly winds and periods of heavy showers to continue Sunday into Monday as Hone passes south of the smaller islands. A brief return of moderate to breezy trade winds is expected late Monday through Wednesday of next week as Hone continues on it's westward journey moving away from the island chain. Tropical Cyclone Gilma far east of the state will weaken as it approaches the Hawaii Region by the end of next week, possibly bringing more rainfall to the islands.

Discussion

A high pressure system far north of the Hawaiian Islands and Tropical Storm Hone passing near the southern slopes of the Big Island this weekend will keep strong and gusty winds in the forecast into Monday. Cloud bands moving in ahead of Tropical Storm Hone will continue to produce periods of showers mainly over windward and mountain areas today, these showers will favor the overnight to early morning hours.
The latest Central Pacific Hurricane Center forecast shows Tropical Storm Hone briefly becoming a hurricane by Sunday as it passes south of the smaller islands. Forecast confidence in Hone impacting our local weather remains high. The latest forecast guidance continues to show winds across the state increasing today as the Tropical Storm approaches the islands. Strong downslope winds are possible over the leeward mountain slopes of all islands through Sunday night. Wind gusts to 50 mph are possible and a Wind Advisory has been issued for these areas on the leeward slopes of island terrain.
Drier air is also expected to filter in briefly across the state today ahead of Hone. The combination of the drier air and strong downslope winds will bring elevated fire weather concerns to leeward portions of the islands. Afternoon relative humidity levels remain marginal for a few hours today, however given past events with passing tropical systems a Red Flag Warning remains in effect for leeward sections of all islands today. The threat of elevated fire weather concerns decrease by this evening as moisture from Hone starts to move into the state.
Based on the current forecast track for Hone, strong and gusty winds associated with the system will begin to impact the Big Island later today, with widespread gusts up to 50 mph likely from this evening through early Sunday. The strongest gusts are expected around South Point/Ka Lae, as well as downslope from Mauna Kea, Mauna Loa, the Kohala Mountains, and the Humuula Saddle, which could see localized gusts as high as 60 mph. The Central Pacific Hurricane Center keeps the Tropical Storm Warning in effect for the Big Island. Now is the time to finalize your emergency plans and supplies and take the necessary actions to protect your family and secure your home or business.
Deep tropical moisture is beginning to surge into the windward slopes of the Big Island this morning and moisture levels are forecast to rise like the tide through tonight. This tropical moisture will then sweep westward to all islands tonight through Sunday, increasing the potential for heavy rainfall statewide. As rainbands associated with Tropical Storm Hone move into each island, heavy showers and thunderstorms will increase the threat for localized flash flooding. A Flood Watch remains in effect for the Big Island starting this afternoon. Shower coverage then expands down the island chain from Sunday into early next week as Hone passes to the south of the state. Storm total rainfall estimates for the Big Island will range from 5 to 10 inches with locally higher amounts possible. Smaller islands should see rainfall amounts from 2 to 4 inches. The higher amounts in these ranges will fall along windward mountain slopes of each island.
A brief return of moderate to breezy trade winds is expected late Monday through Wednesday of next week as Hone tracks away from the state and Tropical Cyclone Gilma approaches the region from the east. Forecast confidence, with regards to impacts to our local weather, remains very low late next week due to significant differences shown between the various sources of guidance as Gilma approaches the region by the end of next week.
For further details on Hone's development, please refer to the latest forecast issued by the Central Pacific Hurricane Center at www.hurricanes.gov.
Note that public and marine forecasts from WFO Honolulu will be updated on a modified schedule, in conjunction with the latest CPHC forecast issued at 5 AM/PM and 11 AM/PM HST.

Aviation

The forecast here on out will primarily be driven by Tropical Storm Hone. Currently on a westward track and is expected to pass to the south of the Big Island later tonight into Sunday. As rain bands associated with Hone move in expect +RA, TSTMs, reduced vsbys and strong winds particularly over the eastern end of the state.
On the western end of the state breezy to windy trades will continue and strengthen as Hone continues its westward track. Low cigs and SHRA should favor windward and mauka locations with some spillover into leeward areas. MVFR conds are to be expected. As Hone continues moving east expect conds to deteriorate.
AIRMET Sierra remains in effect for mtn obsc for all islands.
AIRMET Tango remains in effect for mod low-level turb blw 080 downwind of island terrain. This AIRMET will most likely be needed into early next week.
Over the next couple of days, additional AIRMETs may be issued to account for sustained 30kt winds over portions of the area, as well as potential IFR conds as rain bands move through. As Tropical Storm Hone approaches the islands, aviation interests should closely monitor updates to TC SIGMET Whiskey.

Marine

An area of surface high pressure north of the islands will allow locally strong trades to prevail today. A Small Craft Advisory has been expanded to include all waters, with the exception of those off Big Island windward. By late this afternoon, winds across the waters surrounding the Big Island will ramp up to tropical storm force in response to the approach of Tropical Storm Hone. A Tropical Storm Warning is in effect for these areas, while a Tropical Storm Watch continues for the channels and leeward waters of Maui County and Oahu. These Watches may be upgraded to a warning today, which will depend highly on the track of the tropical cyclone. TS Hone will also bring occasional heavy rain, low visibility, and the possibility of thunderstorms this afternoon through late Sunday night, especially for the southeastern portion of the coastal waters. Marine interests should monitor updates to the forecast, watches, or warnings over the weekend.
Short period swell associated with Tropical Storm Hone will continue to build today and maintain hazardous surf for east and southeast facing shores of the Big Island through at least Sunday. A High Surf Advisory remains in effect. Strong winds from Hone will generate elevated and choppy surf along all east facing shores and the High Surf Advisory may need to expanded to account for this.
Existing small NW swell will slowly decline this morning. Surf along north facing shores is expected to remain flat to tiny over the next several days, aside from some trade wind swell wrap. Surf along south facing shores will remain small today, near or slightly below the summertime average. The passing of Tropical Storm Hone south of the island chain late this weekend could generate a short period southerly swell from early Monday through Tuesday.

Fire weather

Drier air is expected to filter in across portions of the state later today ahead Tropical Storm Hone. This drier air combined with stronger winds will bring elevated fire weather concerns to areas along the leeward slopes of island terrain. Afternoon relative humidity levels over these leeward areas remain marginal tomorrow around 40-50 percent, however due to strong drying trends ahead of these passing tropical systems a Red Flag Warning remains in effect today between the late morning to afternoon hours. The threat for elevated fire weather concerns decreases by this evening as humidity levels recover, and deeper tropical moisture sweeps across the island chain.
.HFO WATCHES/WARNINGS/ADVISORIES… Tropical Storm Warning for Big Island-
Tropical Storm Warning for Alenuihaha Channel-Big Island Windward Waters-Big Island Leeward Waters-Big Island Southeast Waters.
Tropical Storm Watch for Kauai Channel-Oahu Leeward Waters-Kaiwi Channel-Maui County Leeward Waters-Maalaea Bay-Pailolo Channel.
Hurricane Watch for Big Island Leeward Waters-Big Island Southeast Waters.
Flood Watch from noon HST today through Monday evening for Big Island-
Red Flag Warning from 10 AM this morning to 6 PM HST for most areas leeward of all island mountains.
Wind Advisory until 6 AM HST Monday for portions of all Hawaiian Islands.
High Surf Advisory until 6 AM HST Sunday for Big Island Southeast-Big Island East-Big Island North.
Small Craft Advisory until 5 PM HST Monday for Kauai Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-Oahu Windward Waters-Maui County Windward Waters.
Small Craft Advisory until 6 AM HST Sunday for Kauai Channel- Oahu Leeward Waters.
Small Craft Advisory until 6 PM HST this evening for Kaiwi Channel-Maui County Leeward Waters-Maalaea Bay-Pailolo Channel- Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters.

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Data Courtesy of NOAA.gov