Monthly Climate and Impacts Report for Hawaii - February 2013
Chris O'Connor and Dr. Pao-Shin Chu
Hawaii State Climate Office
Department of Meteorology
University of Hawaii
Honolulu, HI 96822
Precipitation and Temperature
The last two months of winter have seen a recovering trend in rainfall amounts. Starting as an extremely dry season, Hawai'i has experienced an increase in much needed rainfall. Not as noteworthy as the last month, February still produced a decent amount of moisture. This month saw significantly above average rainfall amounts in some areas of the state, while other areas saw less than half the normal levels. This polarized precipitation trend can be explained. Kahalui experienced above average rainfall amounts (~156.61% of normal) for the third month in row. Hilo experienced an even greater amount of rainfall (241.84% of normal) mostly due to a heavy rainfall event towards the end of the month which is explained in the Impacts section of this report. Oahu and Kauai were not as fortunate as their sister islands, pulling in below average rainfall amounts. Honolulu experienced 33.26% normal rainfall while Lihue saw only 31.65% normal rainfall. As a result of the increase in precipitation in most areas, drought conditions across the state have seen a continued improvement from previous months. Oahu and Kauai have improved to almost drought free conditions! However, there are still small areas in the south and west parts of these islands which have "Abnormal Dry" (D0) drought conditions. While the eastern islands have improved as well, they still have drought areas ranging from "Abnormally Dry" (D0) to "Extreme Drought" (D3) on a scale of D0-D4. The big picture: thanks to a couple significant precipitation events, drought conditions have greatly improved in the entire state!
Across the state, mean temperatures as well as mean lows were above their respective historical averages for most all areas. Interestingly mean high temperatures were below their respective historical averages for the state. This is most likely due to the significant wind system felt throughout the month which brought heavy wind and some rain to the state.
The NOAA Climate Prediction Center seasonal outlook for Hawaii predicted below normal temperatures and median precipitation and for the entire state in March 2012. NCEP models predict below normal sea surface temperatures (SSTs) continuing into March, with anomalies strongest toward the southeastern islands.
After a false alarm pointing towards a potential development of El Nino conditions this winter, we have been locked in ENSO neutral conditions the past several months. As of the end of February, the ENSO Alert System Status is “not active” and ENSO-neutral conditions continue. Equatorial sea surface temperatures (SST) are near average to below average across the Pacific Ocean. Over the last month, the atmospheric circulation has been variable partially due to an active Madden-Julian Oscillation (MJO). The general consensus is that ENSO-neutral is favored through the Northern Hemisphere spring 2013.
February 2013 saw some very interesting activity in terms of weather in the state of Hawai'i. On Wednesday 2/6/13 a record rainfall of 1.77 inches was set at Hilo, which breaks the old record of 1.57 inches set in 1957. Again in Hilo, a second system brought extremely heavy rainfall for two days straight. On Friday 1/22/13, Hilo experienced a record breaking 5.26 inches of rainfall, which absolutely sunk the old record of 1.76 inches set in 1999. On the following day, Saturday 1/23/13, 2.64 inches of rainfall dropped, breaking the old record of 1.83 inches set in 2007. This marked the second consecutive day a daily rainfall record was observed in Hilo, and the third time this month.
Rain records were not the only news of interest. High and damaging wind was experienced throughout the state this month due to a strong high pressure system embedded to the north east of the state. On 2/19/13 trees fell, utility poles leaned and power lines failed as powerful winds pounded the Hawaiian Islands. On the Hawai'i island a dust devil formed in Kawaihae, sending roofing material flying through the air. This event also caused power outages that affected nearly 5,000 Hawaiian electric customers on Oahu. Wind advisories were put in place to prepare citizens. No injuries were reported as a result of any of the wind-related incidents.