Area Forecast Discussion
Issued by NWS Pago Pago
Issued by NWS Pago Pago
221 FXZS60 NSTU 050107 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 207 PM SST Wed Dec 4 2024 .DISCUSSION... Current atmospheric conditions remain unstable as isolated to scattered thunderstorm activity surrounds the islands. The upper air atmospheric profile observations (RAOB) from this afternoon (05/00Z) shows a moist environment for instability to deepen and grow. Model data shows a trough lingering over the area for the rest of the week. At times, the trough is expected to weaken but does not rule out the threat of potential thunderstorms and heavy downpours for the rest of the week. The model shows an active part of the trough to the west moving over the islands by overnight tonight, bringing thunderstorms and heavy rainshowers through at least Thursday morning. A brief break from thunderstorms and showers thereafter through at least Friday night. Easterlies will remain at a light to gentle breeze for tonight through Thursday night, increasing to a moderate easterly by Friday. Active weather continues as waves of thunderstorms and showers are shown to move in from the east-northeast by Saturday through Monday night, likely producing flash flooding conditions. Gentle to moderate winds will also prevail through at least Sunday night, turning south-southeast by Monday night. Weather patterns will likely improve thereafter. Model data also shows a possible low pressure system forming east-southeast at the end of the forecast period. However, will continue to monitor conditions as the week progresses. && .Marine... A downward trend in seas continues as observed from the last couple of hours. Wave heights around 6 to 8 feet with peak periods at 12 to 14 seconds long translates to around 9 to 11 feet surfs. This pattern remains across all coastal areas of all islands as reported by the PacIOOS buoys near Aunu`u (east) and Poloa (west). Model solutions project seas to subside to 5 to 7 feet by Thursday, and further subsiding for the rest of the forecast period. Model data also shows that although seas will be well below advisory thresholds, periods will be long enough to enhance surfs but less than a high surfs advisory criteria. However, the threat of strong rip currents associated with the long periods exists. Also, thunderstorms from the aforementioned trough in the area will continue to elevate seas and create gusty winds nearby from time to time. Therefore, the advisory for high surfs and small crafts will likely remain in effect through at least tonight. && .PPG WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory High Surf Advisory && $$ JTAllen