Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
874 FXZS60 NSTU 220035 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 135 PM SST Tue Jan 21 2025 .Short term... TONIGHT THROUGH THURSDAY NIGHT Satellite imagery today depicts a ridge of high pressure in the low and mid-levels to the south of American Samoa, keeping a zone of surface convergence and associated heavy rainfall far to the south of the islands through the forecast period. American Samoa is currently in an easterly trade wind flow regime. Low-level cumulus clouds moving from east to west can be seen on satellite, and often produce scattered light passing showers during these trade wind flow regimes. Ensemble model upper-air soundings show an unstable environment remaining in place through the short term forecast period, which will support the forecast passing showers. In conclusion, 10-20 mph surface winds out of the east and scattered passing light showers are anticipated through the short term period. .Long term... FRIDAY THROUGH TUESDAY The trade wind flow regime is forecast to continue through Friday night. By Saturday, operational model solutions begin to diverge, leading to some uncertainty. Overall, the ensemble guidance depicts a weakening of the trade wind flow, with northeast winds of 5-15 mph Saturday through Sunday night and scattered to numerous passsing showers. The steady trade wind flow should resume early next week with easterly winds of 10-15 mph by Monday and Tuesday. No tropical activity is forecast through the next 7 days. && .Marine... Seas of 5 to 7 feet have been observed at Aunu`u and King Poloa buoys throughout the day today. No significant swells are forecast in the coming days. Seas should remain low but choppy due to short period wind driven waves. Wind gusts of greater than 20 knots may occur through Friday night. .PPG WATCHES/WARNINGS/ADVISORIES... None && $$ Barton/LaPlante