Drought in Hawaii, November 1 to 30, 1998

Rainfall amounts were a mixed bag throughout the state. Individuals in some areas may have felt like the enhanced rainfall expected during a La Nina episode was here. Others, especially in the leeward areas of the islands of Maui and Hawaii, continued to see below normal precipitation.Large scale trade winds continued to play a dominant role in the weather over the Hawaiian Islands in the month of November. The trades were light during the first week of the month but were fairly typical stronger trades for the rest of November. An upper level trough to the west of the state, however, produced relatively unstable conditions and enhanced shower activity over the islands. Normally, the month of November marks the start of the cool season, with the island chain experiencing the passage of several cold fronts or shear lines. Subtropical cyclones, or kona storms, can also develop west of the isles to generate prolonged periods of heavy rain. During November 1998, only one shear line (the remnant of a cold front) was able to reach the island chain. A band of showers ahead of the shear line produced heavy rain for a brief period along the north sections of windward Oahu. The shear line stalled over the island of Kauai and the Kauai Channel on 11 November before lifting out toward the northeast. Fragments of this shear line, and subsequent remains of shear lines embedded within the trade flow, impacted the islands from the east and northeast over the period from 12 to 20 November. This caused enhanced trade showers, mainly over the windward sections of the isles. In addition to the upper trough mentioned above, other upper air troughs from the east helped enhance shower activity, especially over the islands of Maui and Hawaii during the month.Below are rainfall statistics for selected locations from around the state. The first column is the rainfall for the month of November. The second has the 30-year average for each location, while the third column is the percent of average rainfall for the month of November. November 98 Avg. %Avg.Oahu Honolulu 0.85 3.0 35 Manoa Arbor. 17.42 13.5 129 Hawaii Kai 1.20 3.0 40 Ahuimanu M 9.9 M Waianae 0.46 2.0 23 Waialua 1.78 4.2 42Maui Kahului 1.94 2.6 75 Hana 3.13 8.7 36 Kihei 0.00 1.5 0 Lahainaluna 0.36 2.0 18 Wailuku 1.80 2.9 62Island of Hawaii Hilo 15.57 14.5 107 Pahala 1.48 5.5 27 Honaunau (Capt. Cook) 1.51 3.6 42 Kamuela (Upper) 6.91 5.3 130 Kamuela 3.54 5.8 61 Laupahoehoe 14.94 13.6 110Molokai Kaunakakai 0.58 1.6 36