January 2016 Precipitation Summary

State of Hawaii

MONTH: January 2016

PREPARED: February 3, 2016

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

State: [Text data table for rain gages]

A long anticipated El Nino-induced dry weather pattern arrived in late December and persisted through January. The pattern featured many days with a low level high pressure ridge over or near the main Hawaiian Islands and light regional winds that allowed land and sea breezes to dominate local conditions. Weak cold fronts reached the island chain on January 9, 15, 20, and 24 but none produced enough rain to cause any flooding problems.

The very dry conditions broke records for the lowest January rainfall at several gages in all four counties. Drought impacts, mainly to the agriculture sector, started on Kauai, Maui, and the Big Island and will likely spread and intensify over the coming weeks. Additional details on drought conditions can be found on the U.S. Drought Monitor website at http://droughtmonitor.unl.edu.

An unusual January central North Pacific tropical cyclone, also a product of the ongoing strong El Nino event, developed far to the southwest of the Hawaiian Islands. Eventually becoming Hurricane Pali, the cyclone had no direct weather impacts to the State of Hawaii.

Island of Kauai : [January 2016 map]

All of the gages on Kauai posted below average rainfall with most monthly totals at less than 20 percent of the January average. The highest monthly total of 4.82 inches (32 percent of average) came from the U.S. Geological Survey’s (USGS) Kilohana rain gage. The Hanalei rain gage had the highest daily total of 1.47 inches on January 30. Records for the lowest January rainfall total were broken at Hanapepe, Wailua UH Experiment Station, Kalaheo, Lihue Variety Station, and Omao. The USGS gage on top of Mount Waialeale recorded just 3.38 inches making it the driest January at this site since the record setting 2.93 inches in 1978. Lihue Airport had its lowest January total since 1986.

All of the gages on Kauai posted below average rainfall with most monthly totals at less than 20 percent of the January average. The highest monthly total of 4.82 inches (32 percent of average) came from the U.S. Geological Survey’s (USGS) Kilohana rain gage. The Hanalei rain gage had the highest daily total of 1.47 inches on January 30. Records for the lowest January rainfall total were broken at Hanapepe, Wailua UH Experiment Station, Kalaheo, Lihue Variety Station, and Omao. The USGS gage on top of Mount Waialeale recorded just 3.38 inches making it the driest January at this site since the record setting 2.93 inches in 1978. Lihue Airport had its lowest January total since 1986.

Island of Oahu: [January 2016 map]

Below average rainfall for the month of January occurred at all of Oahu’s rain gages. All of the lower elevation sites from downtown Honolulu to Waianae had monthly totals at less than 10 percent of average and most of the remaining totals on the island were less than 40 percent of average. The highest monthly total was from the USGS’ Poamoho Rain Gage No. 1 (5.60 inches, 31 percent of average), while the highest daily total of 2.71 inches came from the U.S. Fish and Wildlife Service’s Oahu Forest National Wildlife Refuge gage on January 6. Records for the driest January were broken at Honolulu Airport, Palisades, Waipio, Kunia, Waianae Kawiwi, Lualualei, Mililani, and Aloha Tower. For Honolulu Airport, the 0.27 inches in December 2015 and 0.03 inches in January 2016 also made it the driest December-January period on record. The average December-January rainfall at Honolulu Airport is 5.55 inches.

Maui County: [Maui January 2016 map][Molokai/Lanai January 2016 map]

Rainfall totals for January were below average at all locations throughout Maui County. The Kahakuloa gage recorded the highest monthly total of 1.69 inches (25 percent of average) and the highest daily total of 0.47 inches on January 21. Lahainaluna and Kula Branch Station had their lowest January totals on record. The USGS’ gage on Puu Kukui (1.08 inches, 3 percent of average) had its lowest January total since 1977 and its lowest total from any month since May 1989. On the island of Molokai, the Puu Alii gage had the only monthly total statewide above 50 percent of average.

Island of Hawaii: [January 2016 map]

All of the January totals from the Big Island were below 30 percent of average with most totals from the leeward areas at less than 10 percent of average. The USGS’ rain gage at Kawainui Stream had the highest monthly total of 3.52 inches (26 percent of average) and the highest daily total of 0.96 inches on January 21. Kealakekua and Kahua Ranch both broke records for the driest January and Kapapala Ranch had its second driest January. While January 2016 was very dry overall for the Big Island, it was not quite as dry as January 1998 when many of the records occurred.

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