Hawaiian Winter Storm
In the central Pacific Ocean last week, a strong low pressure system brought heavy rain and high winds to the Hawaiian islands. Snowfall accumulations were also observed on the summits of Mauna Kea and Mauna Loa that are located on the big island of Hawai’i. Additional media coverage of the winter storm can be viewed here and here.
GOES-18 ABI 10.3um imagery captured the center of the cyclone (i.e., initially found northwest of Hawaii) and its cold front travelling east, producing multiple rounds of precipitation over the islands.
GOES 18 ABI 10.3um IR observations from 21Z, 29 January 2025 to 00Z, 1 February 2025
The Advected Layer Precipitable Water (ALPW) product (animation shown below) provides a moisture perspective of the storm. Derived from multiple polar-orbiting satellites, ALPW highlights the precipitable water values of the cyclone in 4 atmospheric layers: surface-to-850mb (top-left), 850mb-700mb (top-right), 700-500mb (bottom-left), and 500-300mb (bottom-right). Within the black boxes in the animation, note the distinct storm circulation and the water vapor transport that aided in the development of heavy precipitation over the Hawaiian islands. Observe the moisture depth of the storm too, especially from the surface to 500-mb.
ALPW observations from ~01Z to 15Z, 31 January 2025
CoCoRaHS precipitation accumulations from the storm can be seen over Hawaii from 30 January to 1 February 2025. Per NOAA/NWS Record Event Reports, Honolulu, HI, set a new record of daily maximum rainfall of 3.57 inches on 30 January 2025. The new record broke the old record of 1.22 inches set back in 1975!
NOAA-20 VIIRS Day Cloud Phase Distinction RGB imagery highlights a before (29 January 2025) and after (2 February 2025) imagery comparison of the winter storm that passed through the big island of Hawai’i. The areal extent of the new snow cover is seen in green over the higher elevations of the island. The RGB imagery exhibits a 375-m spatial resolution.