February 2016 Precipitation Summary

State of Hawaii

MONTH: February 2016

PREPARED: March 7, 2016

Note:  This summary uses the arithmetic mean, or average, for “normal” rainfall values.

State: [Text data table for rain gages]

The El Nino-induced dry weather pattern that brought record-breaking low rainfall totals to the Hawaiian Islands in January persisted through February. Although fewer records were broken, most locations received less than 50 percent of the average rainfall for the month. Most of the days featured weak large-scale winds which allowed land and sea breezes to dominate local conditions. Drought impacts increased in areal coverage and intensity during the month with the worst conditions occurring over the leeward sides of Maui and the Big Island. Additional details on drought conditions can be found on the U.S. Drought Monitor website at http://droughtmonitor.unl.edu and in the Drought Information Statement issued by the Weather Forecast Office Honolulu at http://www.weather.gov/data/HFO/DGTHFO.

The main weather feature to affect the island chain was a shallow cold front that reached Kauai on February 16 and pushed eastward past the Big Island on February 17. Strong north-northeast winds immediately following the front brought showers to the north-facing slopes, followed by a veering of winds to a more east-northeast trade wind direction. On Kauai, gages at Kokee and Kilohana recorded 2 to 5 inches of rain on February 16 which brought Hanakapiai Stream to impassable levels and stranded 15 hikers.  Peak rainfall totals in the range of 3 to 4 inches occurred over localized areas of Maui County and the Big Island as the front moved eastward on February 17 with no flooding problems reported.

Weaker cold fronts reached the island chain on February 6, 21, and 29, none of which resulted in any flooding issues. In the case of the February 29 front, the system was not strong enough to pass Maui County before dissipating.

Island of Kauai : [February 2016 map] [year-to-date map]

Most of the gages on Kauai reported below average rainfall with many monthly totals in the range of 40 to 70 percent of the February average. Totals from leeward sites were mostly less than 20 percent of average. Shallow cold fronts have resulted in the U.S. Geological Survey’s (USGS) Kilohana gage having the highest monthly total (17.10 inches, 117 percent of average) for the second consecutive month. The gage also had the highest daily total of 5.24 inches on February 16. Despite the mid-month cold front, Hanapepe ended February with the lowest rainfall total in a data record going back to 1993, and Kalaheo had its driest February since 2000. Lihue Airport’s 2-month rainfall total of 1.17 inches for January and February was the lowest since 1993.

Nearly all locations on Kauai had below average rainfall totals for 2016 through the end of February. The Kokee gage on the northwest side of the island was the only site with a near average total of 15.01 inches, or 87 percent of average. The Kilohana gage had the highest year-to-date total in the state with 21.92 inches (74 percent of average).

Island of Oahu: [February 2016 map] [year-to-date map]

Almost all of the gages on Oahu recorded below average rainfall totals for the month of February with most amounts at less than 40 percent of average. The USGS’ gage at Punaluu Stream had the highest monthly total of 5.65 inches (60 percent of average) and the highest daily total of 1.58 inches during the cold front passage on February 6. Lualualei, Kunia, Palolo Fire Station, and Aloha Tower logged their lowest February totals since 2000. Honolulu Airport has recorded only 0.43 inches during the past 2 months making it the lowest January and February total since 1983, which was also a strong El Nino year.

All sites across Oahu have recorded below average rainfall totals for 2016 through the end of February. The USGS’ Poamoho No. 1 rain gage on top of the Koolau Range had the highest year-to-date total of 11.16 inches (33 percent of average).

Maui County: [Maui February 2016 map] [year-to-date map] [Molokai/Lanai February 2016 map] [year-to-date map]

Rainfall totals for February were below average at nearly all of the gages across Maui County. The National Park Service’s Puu Alii gage had the highest monthly total of 11.87 inches (119 percent of average) and the highest daily total of 3.63 inches on February 17 during the previously mentioned cold front passage. The USGS’ rain gage on top of Puu Kukui posted its lowest February total since 1981 and Ulupalakua Ranch had its driest February since 2000.

Most of the gages across Maui County had below average rainfall totals for 2016 through the end of February. The Puu Alii had the second highest year-to-date total in the state with 18.51 inches (82 percent of average).

Island of Hawaii: [February 2016 map] [year-to-date map]

A large fraction of the gages on the Big Island recorded below average rainfall totals for the month of February. There were a few sites in the Kohala and Hamakua areas that had near to above average rainfall as a result of the shallow cold fronts which were not able produce significant rainfall on a wider scale. The Natural Resources Conservation Service’s Island Diary gage had the highest monthly total of 13.54 inches (112 percent of average) while the USGS’ rain gage at Kawainui Stream had the highest daily total of 3.47 inches on February 17.

All of the gages on the Big Island had below average rainfall totals for 2016 through the end of February. The USGS’ rain gage at Kawainui Stream had the highest available year-to-date total of 14.97 inches (65 percent of average). The Island Dairy site may have a higher year-to-date total but was not available for comparison because of an incomplete data record for January.

Data Sources: Data used in this report are largely from National Weather Service sources including climate network weather observation stations at Lihue, Honolulu, Kahului, and Hilo, the Hydronet state network of automated rain gages, and selected Cooperative Observer sites.  Additional data come from automated rain gages operated by the State of Hawaii Department of Land and Natural Resources, the U.S. Geological Survey, the U.S. Bureau of Land Management, the U.S. National Park Service, the Department of Defense, the U.S. Fish and Wildlife Service, and the U.S. Department of Agriculture.  Averages come from the National Climatic Data Center (1981-2010 series) and the Rainfall Atlas of Hawaii (http://rainfall.geography.hawaii.edu/).  Data presented here are not certified and should be used for informational purposes only.

Kevin R. Kodama
Senior Service Hydrologist
NOAA/NWS Weather Forecast Office Honolulu