NOAA Technical Memorandum NWSTM PR-53

2005 Tropical Cyclones Central North Pacific

Andy Nash
Victor Proton
Robert Farrell
Roy Matsuda

Central Pacific Hurricane Center
Honolulu, Hawaii

May 2006

Overview of the 2005 Central North Pacific Tropical Cyclone Season

Total activity for the tropical cyclone season was below normal, with three systems occurring within the area of responsibility of the Central Pacific Hurricane Center (CPHC). One tropical cyclone (01C) developed within the central Pacific and the other two, Jova and Kenneth, moved into the area from the eastern Pacific. Jova was the strongest of the systems, maintaining category 3 strength for 36 hours, and the strongest tropical cyclone in the central Pacific since Ele in 2002. Although remnants TD-01C and Kenneth contributed to some locally heavy rainfall across Hawaii, there were no deaths recorded or significant property damage reported in the central North Pacific.

OVERVIEW: Tropical Depression (TD) 01-C developed out of an organized thunderstorm cluster along the Inter-Tropical Convergence Zone (ITCZ) that had persisted for a couple of days just east of 140W. Based upon the satellite appearance of persistent cold cloud tops and cirrus outflow, CPHC issued its initial advisory for TD 01-C at 2140 UTC 3 August. The center of 01-C was near 15N 140.5W or about 1000 miles east-southeast of Hilo, Hawaii. The maximum sustained winds were estimated to be 25 kts. TD-01C moved to the west at 10 kts with a maximum wind speed of 25 kts. TD-01C failed to develop any stronger and dissipated into a remnant low 30 hours later.

SYNOPTIC FACTORS: QuikSCAT satellite data indicated that TD 01-C formed within the seasonal east to west surface trough. Conditions appeared generally supportive for some development as high pressure ridging was in place at levels. A weak upper low just east of Hawaii aided in the creation of an upper level out-flow channel to the north of TD 01-C along with sea-surface temperatures around 26 degrees C. The system continued west and moved into an area of cooler sea-surface temperatures and weakened. The global numerical models, forecast guidance and CPHC forecast all were indicating that TD 01-C would strengthen into a tropical storm. It instead rapidly dissipated within 30 hours. The demise of TD 01-C was likely due to a combination of cool sea surface temperatures and increasing vertical wind shear that interfered with its development.

IMPACTS: The remnants of TD-01C passed over the Big Island of Hawaii on 7-8 August bringing very heavy rainfall to the region. Listed below is a table of rainfall totals from that time frame on the Big Island.

Figure 1. Visible satellite image of TD 01-C at 2200 UTC 3 August. Line indicates the track of the system (green denotes tropical depression status).

Hurricane Jova
18 September - 25 September 2005

OVERVIEW: Tropical Depression 10E formed at 0600 UTC 10 September near 13.6N 109.0W or about 550 miles south southwest of Puerto Vallarta, Mexico. The system was slow to develop as it moved toward the west at around 10 MPH for the next several days, but then wound up rather rapidly to tropical storm strength at 0000 UTC 15 September near 13.8N 127.6W and then to hurricane strength just 30 hours later at 0600 UTC near 12.9N 133.6W. Hurricane Jova continued toward the west for another 30 hours, gaining strength from the warm ocean water between 12N and 13N east of 140W. Jova then took a turn toward the northwest, passing through 140W and into the Central Pacific Hurricane Center's area at 13.5N just before 1200 UTC on 18 September with a strength of 90 kt sustained winds and a calculated central pressure of 970 mb.

Jova continued to gain strength slowly over the next several days, reaching category 3 strength at 1200 UTC 19 September before peaking at 110 kt intensity 12 hours lter when it was near 16.3N 143.3W, or some 850 miles east southeast of Hilo, Hawaii. The storm remained at category 3 strength for 36 hours, continuing on a course between west and west northwest as it moved slowly closer to the Big Island of Hawaii at a speed averageing just slightly over 5 kt. The public and media paid close attention to Jova due to its proxmity and strength, especially in the wake of Hurricane Katrina along the Gulf Coast of the United States a few weeks earlier. Jova came under the influence of a trough near the Hawaiian Islands on 22 September, which began to weaken Jova and turned the storm in a more northwestward direction. Jova dropped below hurricane strength at 0000 UTC 23 September near 20.8N 149.1W, or some 400 nm east northeast of Hilo, Hawaii. Jova continued to weaken further due to the strengthening upper level shear associated with the upper trough. Jova passed by to the north of the Big Island of Hawaii while dropping below tropical storm strength at 22.8N 151.1W, or 335 miles northeast of Hilo, Hawaii. Jova then transitioned to a more westerly track as she further weakened, eventually dissipating as a tropical cyclone at 0000 UTC on 25 September near 23.7N 154.6W, or about 280 miles north of Hilo, Hawaii.

IMPACTS: Although Jova did not have a direct impact on Hawaii, it did result in the weakening of the tradewinds as the remnants passed by to the north. The upper level trough which had resulted in the demise of Jova brought unstable conditions to the state, allowing locally heavy rainfall to occur.

Figure 2. Visible satellite image of Jova at 1900 UTC 21 September. Line indicates the track of the system (red denotes hurricane, yellow is tropical storm and green tropical depression status).

OVERVIEW: Kenneth was a long-lived tropical cyclone, initially developing as tropical depression 14 September about 790 nm southwest of Cabo San Lucas Mexico. Within two days it attained hurricane strength. Kenneth continued to strengthen as it moved west-northwest, reaching a peak intensity of 115 kt on 18 September. Kenneth then began a weakening trend and dropped to a 45 kt tropical storm by 21 September before again intensifying to a hurricane by 25 September. At this point Kenneth was a slow mover and drifted southwest across 140 W and into the central Pacific on 26 September. CPHC assumed responsibility for the storm 30 hours after ending forecast advisories on a dissipating Jova. Kenneth continued to slowly drift southwest and began to weaken. As increasing shear above the storm sped up the weakening phase, Kenneth began to turn to the west-northwest on 27 September and increase in forward speed as it was influenced by lower and mid-level steering flow. Once again, residents in Hawaii paid close attention to Kenneth as it moved closer to the state. However, a strengthening upper level trough near the state provided sufficient upper level shear to keep convection away from Kenneth's center and by early on 29 September, it was downgraded to a tropical depression about 350 nm east of the Big Island of Hawaii. The next day, Kenneth was declared dissipated as a tropical cyclone just east of the Big Island.

IMPACTS: The remnants of Kenneth, primarily a swirl of low clouds, did move onshore of the Big Island during the day on 30 September. As the remnants interacted with the upper level trough over the state, heavy showers and a few thunderstorms did develop across the eastern portion of the Big Island on 30 September. Locally intense rains fell over portions on Oahu during the night of 1 October causing some flash flooding on Kaukonahua Stream and the overflow of Lake Wilson at Wahiawa Dam. Gauges also recorded 6 to 12 inches of rain fell in Nuuanu and Kalihi Valleys. Thunderstorms over eastern and central Kauai also produced very heavy rains during the night of 1 October with a peak 6-hour total of 6.17 inches recorded at Mount Waialeale. Flash flooding occurred on Hanalei River which forced the closure of Kuhio Highway at the Hanalei Bridge.

Figure 3. Visible satellite image of Kenneth at 1800 UTC 26 September. Line indicates the track of the system (red denotes hurricane, yellow is tropical storm and green tropical depression status).