Unusual Late Season Kona Low Drenches Portions of the Hawaiian Islands

Storm Impacting the Northwest U.S.; Fire Weather Conditions in Southern California; Severe Weather in the South

A Pacific storm is bringing areas of low elevation rain, moderate to heavy mountain snow, and high winds to the Northwest. Strong Santa Ana winds and very dry conditions are producing elevated to critical fire weather conditions in southern California. Isolated strong to severe thunderstorms are possible through early Wednesday morning across parts of northeast Texas into western Tennessee. Read More >

An unusal late season kona low has produced heavy rainfall over portions of the state during what is normally the start of the Hawaiian Islands dry season. This appears to be the latest kona low to directly affect the main Hawaiian Islands in at least the last 20 years. The last impactful kona low in May was during 2002. Kona lows more typically affect the State of Hawaii from November through March. The kona low developed several hundred miles north of Kauai on May 15, then moved west and strengthened on May 16. The main rain band from the system moved over Oahu during the early morning hours of May 16, with cells of northward-moving heavy rain moving over the island over the next 24 to 36 hours. Impacts mainly included minor flooding of streets in multiple areas of Oahu. A rockslide also occurred near the Pali Highway Tunnels on May 16. Gaged streams indicated elevated flow levels, but none overflowed their banks. The event is ongoing as of this statement. The main rain band has moved west off of Oahu and is approaching Kauai. A potential for flash flooding will persist for Kauai and Niihau through Saturday night. The following are notable automated rain gage totals for the 2-day period (48 hours) ending at 8 AM HST, May 17. All amounts are in inches. These totals are considered preliminary for information purposes only. Location 2-day total Oahu MAUH1 Maunawili 10.84 STVH1 St. Stephens 9.68 LULH1 Luluku 9.11 WMLH1 Waimanalo 8.31 WAWH1 Waiawa Corr. Fac. 7.98 WPPH1 Waihee Pump 6.88 AHUH1 Ahuimanu Loop 6.83 MITH1 Mililani 6.47 KMHH1 Kamehame 6.43 MKHH1 Makaha Stream (USGS) 6.37 PFSH1 Palolo Fire Station 6.35 KTAH1 Kahuku Training Area 5.50