After days of muggy, stagnant conditions that left island residents reaching for fans and air conditioning, relief is finally on the horizon. The approaching Tropical Storm Henriette promises to restore Hawaii's natural ventilation system, though not without a brief period of additional humidity first.
According to the Honolulu Star-Advertiser, as of 11 a.m. today, the National Hurricane Center said Henriette was located about 1,738 miles east of Honolulu with maximum sustained winds holding at 50 mph. The system has been steadily making its way westward across the Pacific, and forecasters are increasingly confident about its projected path.
Current Weather Disruption
The islands are currently experiencing the effects of another tropical system's passage. Big Island Now reports that trade wind speeds will gradually lower through the middle of the week as the remnants of former Tropical Cyclone Gil passes to the northeast of the state. This weak trough in the proximity of the northern offshore waters has created a period of light and variable breezes during its passage to the west.
The current pattern has resulted in particularly uncomfortable conditions for residents. As detailed by Maui Now, a hybrid sea breeze and light to moderate trade wind weather pattern remains in the forecast through Thursday as the remnants of former Tropical Cyclone Gil continue to influence the region.
Henriette's Expected Impact
While Henriette's approach might initially sound concerning, its northward track will ultimately benefit the islands' weather patterns. The National Weather Service said Henriette will pass just north of the islands Sunday into Monday, producing lighter hybrid sea breeze and tradewind conditions along with very warm and humid weather.
According to Big Island Video News, toward the end of the period, Henriette is forecast to gradually turn northwestward in response to an amplifying mid- to upper-tropospheric trough approaching the Hawaiian Islands from the central north Pacific. This northward turn is crucial for maintaining the storm's distance from populated areas while allowing atmospheric patterns to reorganize.
Brief Relief Before the Weekend
Residents won't have to wait until after Henriette passes to experience some improvement. Trades will strengthen and become more easterly Thursday as the current trough moves northwest of Kauai. However, locally strong trades over the windier waters surrounding Maui and Big Island will prompt a Small Craft Advisory going in effect 6AM Thursday through 6AM Friday.
The good news comes in the form of drier conditions returning briefly with moderate trade winds on Friday and Saturday. This respite will provide temporary relief from the current muggy conditions before Henriette's passage brings another round of humid weather.
Long-term Weather Outlook
Weather forecasters express confidence in their predictions for the coming period. Big Island Video News notes that various deterministic and global ensemble models are all in good agreement on the forecast, so confidence in the track forecast is fairly high.
Long range global models currently show that after Henriette passes, moderate trade winds with drier trends should develop by next week Tuesday and Wednesday. This suggests that while residents must endure another round of humid conditions over the weekend, more typical summer trade wind weather should return early next week.
What to Expect
For Hawaii residents enduring the current conditions, patience will be required through the weekend. Aside from a brief reprieve as locally breezy trades return late Thursday through Friday, light winds and muggy conditions are expected to prevail into next week, with dewpoints potentially reaching the low 70s during the most uncomfortable periods.
The pattern underscores the importance of Hawaii's trade winds in providing natural air conditioning for the islands. When these reliable northeast winds are disrupted by passing tropical systems, the islands can quickly become uncomfortable, even for residents accustomed to tropical conditions.
