Tropical Depression Kilo may be unorganized and tracking away from Hawaii, but the rainfall associated with the system is generating copious amounts of rain throughout the islands.
Currently, Oahu, Kauai, and Maui are under Flash Flood Warnings (until 10:00 a.m. Monday), which means that a flash flood is occurring or imminent in the affected areas. According to AccuWeather, Honolulu received nearly 3 inches of rain in less than 12 hours on Sunday local time. The drenching rains have caused some power outages on the islands and forced some schools to close. Some roads are also closed due to the heavy downpours.
Specifically, Kalanaianaole Highway is closed from Hawaii Kai Golf Course to Makapuu Trail, and Kapaa Quarry Road, except for large semi trucks.
Tropical Storm Kilo is to blame for the heavy rainfall, as it’s currently spinning southwest of the Hawaiian Islands.
According to AccuWeather Senior Meteorologist Alex Sosnowski, “High pressure over the northern Pacific has pushed a front to just north of Hawaii and has enhanced the plume of tropical moisture to the south,” Sosnowski said. “This moisture will likely hold around Hawaii much of this week, regardless of the track of Kilo.”
Humidity levels will remain uncomfortable, and showers and thunderstorms will occur daily, including over the drier leeward areas.
Enough moisture is present for some downpours to be unleashed, potentially leading to flash flooding and mudslides. The flood risk will only increase as the wet weather persists and the ground becomes saturated.
Even if flash flooding does not ensue, the downpours threaten to make travel difficult by reducing visibility and heightening the risk of vehicles hydroplaning at highway speeds. Residents and vacationers may have to alter their outdoor plans.
According to AccuWeather, as of 8 p.m. HST Sunday (2 a.m. EDT Monday), Kilo was a tropical depression and located about 745 miles southwest of Honolulu, Hawaii. The combination of shallow warm water and low wind shear could allow Kilo to re-strengthen into a tropical storm and perhaps a minimal hurricane this week.
While the west to northwest track makes it seems like the tropical depression is tracking away from Hawaii, Kilo is expected to curve back toward the islands on Tuesday.
Whether or not Kilo aims at Hawaii later in the week or makes another turn back to the northwest will determine if significant impacts of flooding rain, damaging winds and coastal flooding reach Ni’ihau, Kaua’i and Oahu. Current indications point toward Kilo turning back away from the islands, but that solution is not etched in stone.
“We cannot rule out any scenario at this time,” AccuWeather Meteorologist Dave Samuhel said. “Until it strengthens, computer models may struggle to handle the future track of Kilo.”
Even with Kilo spinning several hundred miles away, downpours indirectly linked to Kilo will persist through at least the first half of this week.
So, visitors to Hawaii should pack an umbrella and check with tour companies, airlines, and hotels for the latest news about the Flash Flood Warnings and heavy rainfall. Because Kilo is unpredictable, it’s better to be prepared than be surprised during your trip.
Posted by: Bruce Fisher on Aug 24, 2015