MONTHLY PRECIPITATION SUMMARY State of Hawaii portion of Honolulu HSA MONTH: June 1998 PREPARED July 9, 1998 State:No significant Flash flooding was reported. Significant drought conditions continue across portions of the state. Widely variable amounts of precipitation occurred across the state. This is not out of the ordinary for the month of June, as it is one of the drier months of the year. The exception to this pattern is the Kona Region of the Big Island of Hawaii where June is on average one of the wetter months of the year. In general across the state, especially in the drier sections, one significant rain shower during the month can greatly exceed the station's average for the month or just missing a brief shower can keep these locations well below average. Therefore, it is very difficult using these statistics to determine the state of the drought conditions in many locations. Some locations across the state, such as much of the island of Kauai and portions of the Big Island of Hawaii received very significant rainfall, thus reducing the short term drought, if not all the drought conditions in a few locations. In contrast, the Kona area of the Big Island of Hawaii, the drought is still evident with June being the eighth consecutive month of below average rainfall. During much of June 1998, a ridge of high pressure remained strong across the Pacific to the north of the state. This high pressure position caused much of the island chain in near average trade wind conditions and thus near average trade wind shower activity. Some locations due to the consistent direction of the wind and the island's position with respect to cloud areas moving toward the state, received much above average rainfall amounts. This added rainfall in windward and some interior areas has helped relieve some of the very dry conditions there. However, much more rainfall is needed to get beyond the longer term drought situation in some locations. Island of Kauai: Most reporting stations had above to well above average precipitation for the month. The most positive anomalous precipitation pattern in the month of June occurred on the east and north and northwest sections of the island with close to 200 percent of average on the east side and 130 to 176 percent of average rainfall in the north and northwest. Kalaheo on the south side of the island had the lowest percent of average rainfall with 3.21 inches measured which is 92 percent of average. The lowest rainfall amount report on the island was a Hanapepe with only 0.98 inches of rainfall, but that is 98 percent of average. Island of Oahu: The most variable rainfall occurred in June on Oahu. The driest side of the island and where the least rainfall fell this month was around the Waianai area with only 0.01 inches reported. The average in that area is only 0.30 inches. The greatest positive rainfall anomalies were in the central sections of the island in the area from Mililani east to the Palisades area where 3.29 to 7.57 inches of rain fell. This was 189 to 202 percent of the average for those areas. Other areas with significant rainfall were in the Manoa valley with 24.87 inches reported from the automated rain gage at Manoa Arboretum, which is 213 percent of average. In contrast another location that is know for having considerable rainfall in June, the high elevation location near Wilson Tunnel received only 2.69 inches of rainfall, which is only 47 percent of average. This is an example of how dependent rainfall amounts from orographic influences are also greatly affected by wind direction. Most trade wind favorable precipitation areas were at or near average rainfall for the month of June. Maui County: The island of Molokai was below average at reporting stations with Lanai City on the island of Lanai receiving 192 percent of average, a total of 2.69 inches of rain in June. The Island of Maui reporting stations indicated below average precipitation at all but three locations. Negative anomalies were particularly noted in the central valley areas with generally 15 to 50 percent of average rainfall. Areas having positive precipitation anomalies were generally in windward areas. Kihei, one of the dryer locations on the island chain with an automated rain gage, marks another dry month in June with no rainfall indicated. This is the 11th month of below average rainfall with the last 12 reporting only 1.69 inches. The average at this site is 15 inches per year. Hawaii County: The drought continues in the Kona Districts, Kau and portions of nearby districts. Rainfall in Kona districts was below average again this month, ranging from 23 to 49 percent of average. This is very critical to this area as this is the wetter season in most of the Kona region on the Big Island. By contrast, many windward locations were much above average on rainfall for June. Glenwood reported the greatest positive anomaly with 18.28 inches of rainfall, which is 250 percent of average. Other areas with considerable positive precipitation anomalies were the Kohala Districts and Hamakua District with 399 percent of average rainfall reported at the higher elevation site near Kamuela and 9.42 inches, 152 percent of average at Laupahoehoe. BELOW ARE RAINFALL STATISTICS FOR SELECTED LOCATIONS FROM AROUND THE STATE. THE FIRST COLUMN IS THE RAINFALL FOR JUNE. THE SECOND COLUMN HAS THE 30 YEAR AVERAGE FOR THAT LOCATION, WITH THE THIRD COLUMN THE PERCENT OF AVERAGE RAINFALL FOR THE MONTH OF JUNE. KAUAI June 98 Ave Percent of Ave LIHUE 1.90 1.7 112 HANALEI 6.92 5.3 131 HANAPEPE 0.98 1.0 98 OAHU HONOLULU 0.29 0.5 58 MANOA ARBOR. 24.87 11.7 213 HAWAII KAI 0.58 0.6 97 AHUIMANU 7.66 5.7 213 WAIANAE 0.01 0.3 3 WAIALUA 0.50 0.9 56 MOLOKAI KAUNAKAKAI 0.27 0.3 90 LANAI LANAI CITY 2.69 1.4 192 MAUI KAHULUI 0.04 0.3 13 HANA 2.30 3.8 61 KIHEI 0.00 0.1 0 LAHAINALUNA 0.92 0.2 460 WAILUKU 0.22 0.4 55 HAWAII HILO 11.27 6.2 182 PAHALA 0.55 2.2 25 HONAUNAU 3.45 7.0 49 KAMUELA (UPPER) 11.98 3.0 399 KAMUELA 7.54 2.2 343 LAUPAHOEHOE 9.42 6.2 152 Data Sources: First order climate network weather observations stations of the National Weather Service at Lihue, HI, Honolulu, HI, Kahalui, HI, Hilo, HI. Additional data were taken from the HYDRONET state network of automated rain gages. Data collected in the automated gages are not certified and information used above should be used for information purposes only. Roger V. Pierce, Senior Service Hydrologist National Weather Service Forecast Office Honolulu, Hawaii