Issued: Mar 04, 2015 2:30 PM HST
Based on data through 2:00 pm Mar 04 2015 HST
As of 2 pm, the trailing edge of a large area of overcast layered clouds, associated with a fast-moving shortwave trough aloft, was moving quickly eastward across the main Hawaiian islands. The ragged back edge was through 23°N 159°W to 20°N 158°W to 17°N 157°W. However, even to the west of this line, and to the southeast of a line from 18°N 167°W 23°N 159°W, there were broken to overcast mid-level clouds. These mid and high cloud features were completely obliterating the view of the lower cloud features over and near the main Hawaiian islands. Northwest of a line from 18°N 167°W 23°N 159°W was an area of broken mixed cumulus and stratocumulus sliding toward the southwest.
The blended total precipitable water product, an indication of the integrated moisture from the surface to the top of the atmosphere based on measurements from satellite, show a sharp gradient of moisture remains over the main Hawaiian islands early this afternoon. Deeper moisture was located over Maui county and the Big Island, with Oahu near the boundary of the airmasses, and much drier air located to the northwest including over Kauai. Over the past 24 hours, this persistent gradient had sharpened up and had shifted a little farther toward the northwest. Relatively deep moisture continues to extend upstream from the Big Island, east to near 150°W.
Water vapor imagery was showing a broad and somewhat ill-defined mid-to-upper level anticyclone to the northwest of the main islands, centered roughly near 29°N 172°W. Ridges extend well to the east and the west. This feature is pressing toward the southeast at about 10 to 15 mph.