State of Hawaii

MONTH: June 2008

PREPARED: July 3, 2008

State: [Text data table for rain gages]

Trade winds, mainly at moderate to fresh levels, occurred over the main Hawaiian Islands throughout most of June. On June 12, a low pressure trough near Kauai induced a slight change of the low level wind direction from the usual east-northeast trades to a direction out of the east-southeast. Although the direction change was slight the effects were significant, causing the leeward Molokai convergence “plume” to shift northward over windward sections of Oahu. An upper level trough provided sufficient instability to produce heavy rains within the “plume” on the order 3 to 7 inches. Fortunately, the rains produced only minor flooding problems though runoff from the Waimanalo area forced the closure of beaches at Bellows Air Force Station due to high levels of bacteria. The rains brought temporary relief to drought conditions over east Oahu where users of Waimanalo irrigation water have been suffering under mandatory 20 percent restrictions on water use.

Island of Kauai : [June 2008 map] [Year-to-date map]

Most of the rain gages on Kauai recorded near to above normal rain totals for the month of June. While the U.S. Geological Survey (USGS) gage on Mount Waialeale recorded by far the highest rain total on the island at 24.15 inches (80 percent of normal), other sites posted measurable rain totals almost daily with Wailua showing at least 0.01 inches on 29 out of 31 days. The Mount Waialeale gage recorded the highest daily total of 3.74 inches on June 12 in association with a weak low pressure trough near Kauai.

Island of Oahu: [June 2008 map] [Year-to-date map]

Gages across the island of Oahu posted a wide range of totals during June. The heavy rains on June 12 along portions of windward Oahu provided the wettest day of the month and boosted totals into the above normal range at several locations. A Cooperative Observer site at Kaneohe recorded the highest daily total of 6.62 inches. The highest real-time gage total came from Ahuimanu Loop with 4.90 inches in 24-hours. Most of the totals across the rest of Oahu were in the near to below normal range. Interestingly, the 0.55 inches of rain recorded at the Honolulu Airport (138 percent of normal) marked the wettest June since the 1.16 inches recorded in June 2001. Most of this rain (0.44 inches) occurred on June 12 as a result of the above mentioned low pressure trough near Kauai.

Maui County: [Maui June 2008 map] [Year-to-date map] [Molokai/Lanai June 2008 map] [Year-to-date map]

Although there was a wide range of conditions, many gages in Maui County recorded below normal rain totals for the month of June. On the island of Maui, most gages indicated below normal totals except for Oheo Gulch (7.12 inches, 121 percent of normal) and Kahakuloa (0.86 inches, 96 percent of normal). In contrast, all of the gages on Kahoolawe and Lanai posted above normal totals. Most of the Molokai totals were less than 50 percent of normal with the exception of Molokai Airport which recorded 0.75 inches (150 percent of normal). Of this total, 0.74 inches occurred on June 12. It should be noted that normal rainfall totals for June are generally low in many areas of the state so even relatively modest spikes in rainfall can produce large increases in percent of normal values. The USGS gage on Puu Kukui recorded 9.39 inches, the highest total in Maui County and third highest statewide, though well off the normal June value of 26+ inches.

Most of the rain totals for 2008 through the end of June remained in the below normal range across Maui County. Oheo Gulch and West Wailuaiki were the only spots with near normal year-to-date totals. Puu Kukui’s 100.83 inches (50 percent of normal) led all Maui County totals and continued to rank second statewide.

Island of Hawaii: [June 2008 map] [Year-to-date map]

Most of the Big Island gages once again recorded below normal rain totals for the month of June. The Mountain View gage posted the highest monthly total of 4.96 inches (53 percent of normal). One noteworthy item is that none of the real-time gages showed any daily totals at or above one inch for the entire month, which is a very rare occurrence especially along the windward slopes during June. For Kahua Ranch, the 0.04 inches (1 percent of normal) marked the driest June on record for this site.

Data Sources: Data used in this report are largely from National Weather Service sources including climate network weather observation stations at Lïhue, Honolulu, Kahului, and Hilo, the Hydronet state network of automated rain gages, and selected Cooperative Observer sites. Additional data come from automated rain gages operated by the State of Hawai‘i Department of Land and Natural Resources, the US Geological Survey, the US Bureau of Land Management, the US National Park Service, the Department of Defense, and the US Fish and Wildlife Service. Data presented here are not certified and should be used for information purposes only.

Kevin R. Kodama
Senior Service Hydrologist
NOAA/NWS Weather Forecast Office Honolulu