SYNOPTIC DISCUSSION
TUESDAY 02nd DECEMBER2025 AM SHIFT

REST OF TODAY:

A gradual change in the weather conditions as depicted by the latest satellite due to the most erratic convections moving to the east and away from the group. Rainfall activities in most locations of Samoa have also been reduced with a low probability of the risk of flooding in major rivers and vulnerable areas. Meanwhile, expect the development of a few convective clouds in some areas today, which will likely to bring in some isolated showers with brief moderate to heavy falls and a few thunderstorms likely. Therefore, the Heavy Rain Warning has now been downgraded to an Advisory level with the Flood Advisory now canceled for all of Samoa. The Pago Pago ascent of this morning depicted a moderate likelihood of a few thundery activities in the 12-hour period with a CAPE value of 867.3 J/kg with moisture being reduced in the atmosphere compared to the previous sounding profile. The limitation of vertical storm development at the surface today is due to the unavailability of the upper divergence, although the axis of the upper trough hovers over the area of responsibility. The possibility of some showers with brief moderate to heavy falls in some areas and a few thunderstorms is likely in the afternoon as the surface heating associated with the orthographic lifting.  For tonight, expect the chance of easing conditions as all convective circumstances continue to drift further eastward.

WEDNESDAY THROUGHMONDAY:

The consensus of the weather models indicates that easing conditions may continue into the middle of the week, accompanied by a decrease in rainfall accumulation. This trend may extend towards the end of the outlook period, where there is a possibility of weak low circulation developing nearby. There may be periods of passing showers that could make landfall as southeasterly and southerly winds prevail on Friday, particularly towards the latter part of this outlook period, with moderate rainfall expected in certain areas. The transition from southeasterly to southwesterly winds aloft is anticipated to dominate the upper atmosphere from Wednesday through to the end of the forecast period, aligning with the expected slight improvement in mostly fine conditions.

MARINE OUTLOOK:
Recent observations from Samoa's marine waters show wave heights under 2.5 meters. However, increased northerly swells are anticipated to impact our marine waters from this afternoon until Wednesday. Consequently, the marine advisory continues to be in effect for all marine waters of the country. Wave periods of more than 18 seconds this afternoon.

ADVISORIES/WARNINGS:
CANCELLED: HEAVY RAIN WARNING

CANCELLED: FLOOD ADVISORY

VALID: HEAVY RAIN ADVISORY

VALID: MARINE ADVISORY -  ALL OF SAMOA

Weather Duty Team:
Gospel Niko, Lao Ioane Tuatipi, Punipuao Huch & Fuimaono Uili Namulau’ulu