Drought in Hawaii, April 1 to 30, 1998

The drought in Hawaii continued through April, but conditions improved in some locales.Below average precipitation occurred across much of the state in April. All four first order, and 58 of 69 automated, rain gauges received less than average rainfall for the month. However, windward sides of all the isles and some of the central parts of the islands saw significant increases in April. Overall, though, the trend of drier than usual conditions moved into its seventh month.During much of April, the jet stream remained strong to the north of the islands. On the other hand, the surface high pressure ridge shifted to the northeast of the island chain to a more seasonal position. This allowed a trade wind pattern to reestablish itself over the islands. The depth of the marine layer remained suppressed to some extent, but it was deep enough to allow trade showers to develop in windward areas of all the isles.The April rains provided some relief to several communities, but more rainfall is needed. Most leeward locations have received only very small amounts of precipitation. For example, for the second month in a row, Kihei in leeward East Maui received no rainfall. Also, Pahala in the southeast part of the Big Island, Waianae in extreme west central Oahu, and Kaunakakai in the south central coastal area of Molokai received only 0.43 of an inch (9 percent of average), 0.23 of an inch (14 percent of average), and 0.19 of an inch (16 percent of average) for April, respectively.The following are rainfall statistics and comparative data for selected locations around the state. The island and station name are listed with the April 1998 rainfall total. For comparison, the average rainfall for the month and percent of average are found in the following two columns. Longer term statistics are listed, with the February through April three month accumulations in column four and the three month averages and percent of average in columns five and six, respectively. Apr. 98 Avg. %Avg. 3 Month Avg./3 months %Avg./3 monthsOahu Honolulu 0.54 1.50 36 0.78 5.9 13 Waianae 0.23 1.60 14 0.38 6.4 6 Hawaii Kai 0.45 2.20 20 1.49 9.3 16 Manoa Lyon A 12.06 13.0 93 20.46 37.6 54 Waialua 1.08 2.8 39 1.96 10.5 19 Ahuimanu (windward) 3.12 9.9 39 7.78 23.5 33Maui Kahului 0.97 1.8 54 1.64 7.4 22 Hana 2.33 9.0 26 3.96 25.3 16 Kihei 0.00 1.2 0 0.09 5.5 2 Lahainaluna 0.71 1.7 42 1.16 6.8 17 Wailuku 1.44 3.0 48 5.24 13.6 39Island of Hawaii Hilo 8.86 15.3 80 18.34 39.5 46 Pahala 0.43 5.0 9 0.82 17.4 5 Honaunau (Captain Cook) 2.12 6.1 35 4.02 14.4 28 Kamuela 14.26 6.9 207 20.10 20.8 97 Kamuela (Higher Elev.) 16.59 6.9 240 24.90 18.7 133 Laupahoehoe 14.62 18.9 77 23.72 51.6 46Molokai Kaunakakai 0.19 1.2 16 1.01 5.6 18