Monthly Climate and Impacts Report for Hawaii - November 2012
Chris O'Connor and Dr. Pao-Shin Chu
Hawaii State Climate Office
Department of Meteorology
University of Hawaii
Honolulu, HI 96822
Precipitation and Temperature
After a record breaking previous month of dryness, November 2012 experienced a continued trend of significantly drier than normal conditions. This dry trend was present throughout the entire summer and has now shown strong throughout the autumn season. All islands in the state of Hawai'i experienced the extreme drought conditions this past month. On Kauai, Oahu, and Maui we experienced as close to absolute dry conditions as we could have experienced throughout the entire month. All three islands saw rainfall which was about only 10% that of the normal amounts we see in November. Hilo saw a consistent trend of rainfall all month, however experienced overall much lower than normal (~35%) precipitation. Drought conditions across the state remained approximately the same from last month, with Oahu and Kauai ranging from "Abnormally Dry" (D0) to "Severe Drought" (D2), while the eastern islands have areas ranging from "Abnormally Dry" (D0) to "Extreme Drought" (D3) on a scale of D0-D4. Niihau has worsened from drought free to “Abnormally Dry” (D1) conditions, as well as the northeastern shores of Oahu, Maui and Hawai'i. The big picture: we are very precipitation starved at the moment.
Across the state, mean temperatures as well as mean highs and mean lows were below their respective historical averages.
The NOAA Climate Prediction Center seasonal outlook for Hawaii predicted below normal precipitation and below normal temperatures for the entire state in December 2012. Also, they believe that the current drought conditions are likely to persist or intensify in the next three months on the island of Hawai’i, while the western main islands may see some improvement.
Fall 2012 has been a time of uncertainty in regards to ENSO. Initial reports dating back to the summer pointed towards a weak El Nino development for the 2012-13 winter season. However the past few months have brought along the development of ENSO neutral conditions. Positive Sea-Surface-Temperatures have been recorded since April 2012, triggering a shift from La Nina conditions to ENSO-neutral conditions. Equatorial sea surface temperatures remain above average across the western and central Pacific Ocean, while the atmospheric circulation over the tropical Pacific is near average. The general consensus is that ENSO-neutral is favored through the Northern Hemisphere winter 2012-13.
The 2012-2013 "wet season" has continued this past month with more than half of the state in drought. We ended November no better than coming into the month, as we saw very minimal precipitation throughout the state. The Hawaiian weather was very dry throughout the month and the effects of drought are continuing to be felt state-wide. Hawai'i desperately needs significant precipitation to counterbalance this current extreme drought.
Hawai’i did experience one storm on 11/23/12 which sent very unusual weather to the island of Oahu, including excessive precipitation to particular parts of the island. According to the National Weather Service, at 3:15 p.m. radar indicated a strong thunderstorm over Pearl Harbor and the surrounding areas. The unstable weather produced flooding on the H1 freeway as well as hail over the south-central part of the island. Traffic on the H1 and H201 freeways came to a stand still when the rain was at its worst due to flooding. Forecasters say that the unstable atmosphere also produced quarter sized hail. There was even a report of a funnel cloud being spotted off Schofield Barracks around 2:30 p.m. Friday (11/23) afternoon. During these dangerous conditions, it is always best to stay indoors and off of the roads.