Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
508 FXZS60 NSTU 010119 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 219 PM SST Mon Sep 30 2024 .Short term... Cloudy skies with periodic rainfall occurred this morning and early afternoon as a trough remains over the American Samoa islands. The latest balloon data shows a very moist atmosphere above the territory and satellite imagery continues to show thunderstorms surrounding the region. Due to the amount of recent rainfall over the islands along with the potential for heavy rainfall through tonight, the Flood Watch remains in effect through tonight. We will continue to monitor the trough through the middle of the week. The trough is expected to slowly weaken through early Thursday morning, but widespread showers on Tuesday morning is expected to reduce to numerous showers (60% chance) from Tuesday afternoon through the overnight hours on Wednesday night. Easterly winds of around 15 mph remain, but could have higher gusts in areas of localized rainfall throughout this time. .Long term... The rainfall for the month of September has been well above average compared to typical rainfall amounts in September. Finally, a ridge of high pressure from the south is expected to strengthen and move the trough to the north by Thursday evening. This will reduce the risk of showers to scattered showers (30% chance) in the passing form from Thursday night through early Sunday morning. The main weather feature during this time will be breezy east/southeasterly trade winds, which may reach up to 30 mph at times. && .Marine... The latest information from the PacIOOS buoy shows sea heights have eased to below Small Craft Advisory levels and winds are not expected to reach 20 knots throughout the next few days. However, southerly swell is anticipated to move through the coastal waters overnight on Tuesday/Wednesday morning. Seas are to begin to build during that time. East/southeasterly trades are forecast to increase on Thursday to reach up to a fresh to strong breeze from Thursday and into the upcoming weekend. Therefore, the Small Craft Advisory will likely be back in effect by Tuesday night at the latest and to remain for the rest of the week. We expectsurf to reach High Surf Advisory levels by midweek and to remain through the weekend. && .PPG WATCHES/WARNINGS/ADVISORIES... A Flood Watch remains in effect. && $$ LaPlante