Issued: Mar 05, 2015 7:30 PM HST
Based on data through 7:00 pm Mar 05 2015 HST
Water vapor images showed a broad trough of low pressure in the middle atmosphere to the north through northeast of the main Hawaiian islands. Thin high cloud layers associated with the trough partly obscured lower features within 90 miles of the line from 22°N 154°W to 22°N 149°W. Lower clouds passing under the trough also developed more vertically.
To the northeast through southeast, a band of deep cloud layers partly associated with a front extended across Hawaiian waters within 300 miles of the curve from 30°N 141°W to 24°N 142°W to 20°N 144°W to 17°N 148°W to 12°N 150°W. High to middle cloud layers also obscured lower features within 180 miles of the line from 20°N 156°W to 12°N 173°W, while deep cloud layers from across the dateline mostly to partly obscured lower features west of the curve from 19°N 180 to 22°N 172°W to 20°N 167°W to 10°N 172°W. Thin high cloud layers separated from the deeper layers further west also partly to mostly obscured lower features within 60 miles of the line from 23°N 164°W to 20°N 158°W.
To the south, light thunderstorm activity continued in the ITCZ from 11°N to 03°N. Layered middle to high debris clouds from this and earlier convection partly to mostly obscured lower features from 11°N to the equator, mainly east of 149°W or west of 160°W.
Otherwise, cloud cover across Hawaiian waters consisted mainly of cold-air cumuli merging into areas of low to middle stratus overcast. These clouds generally rose to heights of 8000 to 12000 feet, and moved toward the west southwest at 15 to 30 miles an hour.
Across the main Hawaiian islands, thin high cloud layers from the west mostly obscured lower features. Where it was visible, lower cloud cover consisted mainly of cold-air cumuli moving ashore and piling up into stratus overcast along slopes facing northwest through northeast on the one hand, and afternoon cumulus buildups with their layered debris clouds forming over middle to lower southeast through southwest slopes on the other. Snow was visible on the summits of Mauna Kea and Mauna Loa. Areas with the least cloud cover were limited mainly to Niihau, southwest Kauai, south Oahu, south Molokai, west Lanai, west slopes of the west Maui mountains, lower to middle slopes of south Kohala and north Kona districts on the Big Island, and the summits of Mauna Loa and Mauna Kea on the Big Island. The lower clouds varied in height from 5000 to 9000 feet, while the high clouds approached heights of 35000 feet.
Radar data from near the islands showed scattered showers along and offshore from north shores of Oahu, Molokai, Maui, and the Big Island. Radar data also showed scattered showers in lee plumes to the south-southwest of Kauai and Oahu, and offshore well to the southeast of the Big Island. Elsewhere, radar data showed isolated showers at most.