textproduct: WSO Pago Pago

Discussion

A trough over the Islands will hold numerous to widespread showers through tonight. Although model data suggests a diminishing trend this afternoon, current satellite data indicates continued shower development to the south, pushing northward toward the Samoa Island chain.

A chance for thunderstorms is also possible tonight due to instability seen on the upper-air sounding from this afternoon. However, the potential for flash flooding remains low as model data continues to show a diminishing trend in rainfall. Minor flooding could still occur shower cells repeatedly move through the area, as grounds have been saturated from rainfall earlier this morning.

By Thursday afternoon, model data suggests the trough becoming more active, which may enhance flash flooding conditions. A Flash Flood Watch is possible Thursday morning as the trough is monitored. Winds are also expected to increase as pressure gradients build between the trough on a ridge to the east. Inclement weather is forecast to persist through the weekend and into next week if this pattern holds. Tropical development is being monitored within the trough for next week; however, confidence remains low at this time.

Marine

Seas remain fairly calm as no significant winds or swells are seen in the area. Wave heights reflect calm ocean conditions, around 5 to 7 feet at the PacIOOS buoys. However, model data depicts wave heights building Thursday night following an increase in wind speeds. The trough is expected to maintain stronger winds through the new week, which will keep seas elevated through the end of the forecast period.

PPG WATCHES/WARNINGS/ADVISORIES

None