DIAGNOSTIC STUDIES OF 2 CONTRASTING RAINFALL EPISODES IN HAWAII - DRY1981 AND WET 1982

The circulation features that accompanied the dry January/February of 1981 and the wet January/February of 1982 in Hawaii are compared. The results indicate that surface and upper-air circulation features are v ery distinct during these two winter months with contrasting rainfall extremes. Four major synoptic patterns (frontal, kona, trade, and ridg e) that influence Hawaiian rainfall have been described. The Kona stor m pattern contributes to most of the rainfall in wet 1982, followed by the frontal pattern. No kona storm days occurred during dry 1981, and the rainfalls on frontal days in dry 1981 were less than half of thos e in wet 1982. The trade wind and ridge patterns are not important for rainfall either in dry 1981 or wet 1982. A possible relationship betw een the PNA pattern and rainfall anomalies during these two non-ENSO w inter months is suggested.