Tropical Depression Kilo Struggles in Central Pacific; Enhanced Moisture Bringing Downpours to Hawaii

August 24,2015

• Kilo was downgraded to a tropical depression late Friday night, and continues to struggle to organize.
• This system was located about 165 miles east-northeast of Johnston Island as of Monday evening, local time.
• While the intensity forecast is a bit uncertain, there is still a possibility that Kilo could become a tropical storm later this week.
• The latest forecast trend has been for Kilo to remain well west of the Hawaiian Islands. That said, the large-scale circulation around Kilo has enhanced moisture across Hawaii, leading to heavy rainfall. A flash flood watch has been issued for Hawaii.

(MORE: Expert Analysis | Hurricane Central)

Storm Information and Satellite

Tropical Depression Kilo remains disorganized several hundred miles southwest of Hawaii.
One of two scenarios is possible with Kilo. If Kilo continues to degenerate, it could become a remnant low early this week. It is not uncommon for central Pacific tropical systems to suddenly weaken and dissipate. On the other hand, Kilo may still be able to better organize. The latest National Hurricane Center forecast strengthens Kilo to a tropical storm by the middle of this week and no longer expects it to become a hurricane.

Projected Path

The recent trend in computer model forecast guidance suggests that Kilo will stay well west of the Hawaiian Islands late this week. However, the large-scale circulation around Kilo has brought enhanced moisture to Hawaii, leading to locally heavy rainfall. Honolulu picked up 5.52 inches of rain 2 p.m. Sunday - 6 a.m. Monday (local time), resulting in some road flooding and road closures on Oahu.  A flash flood watch has been issued by the National Weather Service for all of Hawaii.
A tropical storm warning has also been issued for Johnston Atoll as Kilo is expected to pass just to the east late Monday and Tuesday.

Perspective on Kilo and Hawaiian Tropical Systems

Virtually all hurricanes near the Hawaiian Islands since 1950 have approached from the southeast, south, or southwest.
In El Nino years, the trade winds that sometimes trap tropical cyclones well south of the islands relax, making these lingering storms south of the islands more susceptible to be drawn northward. Of course, an El Nino does not guarantee a hurricane will impact Hawaii.
(MORE: Hawaii's Hurricane History)
Kilo is the fourth named storm to have formed in the central Pacific basin this season and the sixth to track through the basin this year, including eastern Pacific storms Guillermo and Hilda. Loke became the record-breaking fifth storm to form this season in the central Pacific Friday, according to Eric Blake, hurricane specialist at the National Hurricane Center.
Four to five tropical cyclones are observed in the central Pacific each year, according to the Central Pacific Hurricane Center. CPHC says a record 11 named storms were observed in the central Pacific in 1992 and 1994.
(FORECASTS: Honolulu | Hilo | Kona Coast | Maui)
NOAA's 2015 Central Pacific hurricane season outlook cited El Nino's tendency for reduced wind shear and more storm tracks coming from the eastern Pacific as reasons to expect an active season in the central Pacific Basin.
Lowry says dating to 1950, there is a 13 percent increase in the chance of a named storm to track within 100 miles of the Hawaiian Islands during an El Nino year compared to a neutral year.
Stay tuned to The Weather Channel and check back with weather.com for updates on this system.

MORE: Hurricane Iniki, 1992