Hawaii Regional Climate Summary And Forecast

REGIONAL CLIMATE FORECAST FOR THE April-May-June 2017 SEASON:

Rainfall for the AMJ in the Hawaiian stations is expected to be:

Sea level for the MAM season in the Hawaiian stations is expected to be:

(*) Data Unavailable
Anomaly between 0~±1 inch are considered to be negligible and are denoted by ***(+/-). Figures in parenthesis represent year-to-year seasonal anomaly. 
Anomalies withing the range of (+/-) 2 inches are unlikely to cause any adverse climatic impact.

1: Difference between the mean sea level for the given month and the 1983 through 2001 mean sea level value at each station (seasonal cycle removed); 2 : Difference between the maximum sea level for the given month and the 1983 through 2001 average maximum sea level value at each station (seasonal cycle removed)

HAWAII CLIMATE SUMMARY FOR THE MONTH OF February 2016:

NWS Honolulu December precipitation summary issued April 5, 2017 (found HERE):

The month of March started with the Hawaiian Islands under a continuation of a wet weather pattern that started in February. Unstable conditions from a nearby low pressure system resulted in flash flooding on Oahu and Kauai on February 28 and into the early morning hours of March 1. The flooding caused significant damage to Waimea Valley Park in north Oahu and closed Kuhio Highway near the Hanalei Bridge on Kauai for several hours. Please see last month’s summary at https://www.prh.noaa.gov/hnl/hydro/pages/feb17sum.php for additional details.

Although local weather conditions stabilized by March 2, the overall weather pattern in the central North Pacific remained unsettled. A weak cold front reached Kauai on March 4 then stalled and dissipated near Maui County and the Big Island on March 5, depositing roughly an inch of rainfall in isolated locations along the way. The enhanced moisture within the remnant frontal band served as a focal point for heavy rain development when a strong upper level trough of low pressure moved into the area on March 7. That afternoon, thunderstorms developed over the leeward areas of Haleakala on Maui. Intense rainfall caused flash flooding in Kulanihakoi Gulch which closed South Kihei Road. The flooding damaged several condominiums and vehicles, and fire crews rescued 7 people who were trapped by the fast flowing waters. Conditions on March 9 supported another round of strong thunderstorm development. Initially, these thunderstorms were mainly in the coastal waters north of Maui County. One of these thunderstorms exhibited radar signatures suggesting the presence of large hail and a significant waterspout. Strong afternoon thunderstorms also developed over the Big Island and Oahu. The Big Island thunderstorms dropped heavy rain and small hail over portions of the Saddle Road, Hilo, and the Hawaiian Paradise Park area in the Puna District, but there were no reports of significant flood damage. The Oahu thunderstorms mainly affected the Mililani and Wahiawa areas but also did not result in any notable damage. Interestingly, the last time radar signatures this strong were seen in the Hawaiian Islands was five years ago to the day. The March 9, 2012 severe thunderstorm generated intense rainfall, the state record hail stone (4.25 inches wide), and a tornado in Kailua on the island of Oahu.

The atmosphere stabilized somewhat after March 9 but remained sufficiently unsettled to produce briefly heavy rainfall and minor flooding over portions of the Big Island, Oahu, and Kauai from March 10 through March 12. Drier conditions finally arrived on March 13 as a ridge of high pressure moved over the island chain and remained in the area through March 15. A weak cold front reached Kauai on the afternoon of March 16 then crawled eastward, reaching the Big Island on March 18. Rainfall amounts from this front were less than an inch at all gage locations. Following the dissipation of the cold front east of the Big Island the following day, light to moderate trade winds returned to the state. However, very stable middle and upper level conditions restricted significant rainfall production for most of the rest of March.

Further information on Hawaii climate and weather impacts:

• NWS Honolulu Hydrology Page
• NWS Honolulu archive of mosst recent incident reports

DROUGHT CONDITIONS