Area Forecast Discussion

DISCUSSION

Satellite observations of open-cell cumuli clouds streaming across the islands as it builds into towering cumuli clouds increased the potential for afternoon showers. These clouds are associated with a high pressure system anchored southeast of the area. However, upper air observations (RAOB) from this afernoon (22/00Z) show stable conditions with prevailing gentle to moderate east-southeast winds and decreased moisture content compared to the last 12 to 24 hours. Model data show this high pressure system lingering through at least Wednesday. By Wednesday night, another broad high pressure system from the southwest will move into the area as it generates gentle to fresh east-southeast winds for the remainder of the forecast period.

Therefore, expect scattered showers, heavy at times with gentle to fresh east-southeast winds for the rest of the week into the new week.

Marine

Favorable ocean conditions continue to remain across the American Samoa coastal waters throughout the day. However, observations from the PacIOOS buoys (Aunu'u & King-Poloa) show a gradual build in seas. Seas will likely continue to build to at least 7 to 9 feet by tonight as a southwest swell moves into the area. Also, the threat of rough seas, high surfs, and strong rip currents is possible due to the swell periods peaking at more than 15 seconds long. Gentle to moderate winds will also produce wind waves mixed in with the aforementioned swell, keeping conditions rough for tonight and Wednesday. Thus, a small craft advisory is now in effect for tonight and Wednesday. Model data show seas subsiding by late Wednesday into the rest of the forecast period.

PPG WATCHES / WARNINGS / ADVISORIES

Small Craft Advisory