SYNOPTIC DISCUSSION

WEDNESDAY 02NDAPRIL 2025 AM SHIFT.

TODAY:

Today, fine weat​her conditions have been noted as trade winds continue to prevail in the area. While moisture levels remain in the atmosphere, as shown by recent satellite observations and TPW animations, the likelihood of severe instability over Samoa is very low. The current situation is supported by the lack of an upper atmospheric mechanism and the absence of upper diverging and lower converging winds, alongside an unfavorable shear environment, as indicated by CIMMS analysis. However, localized convection is expected in the afternoon and evening due to solar radiation causing surface heating and orographic lifting. Additionally, a low-pressure trough is anticipated to remain over the region tonight, which may lead to increased shower activities with more frequent heavy rains and thunderstorms. Consequently, a Heavy Rain Advisory has been issued for all land areas of the nation in anticipation of the incoming system.

THURSDAY THROUGH TUESDAY:

Global weather models, along with their associated uncertainties, indicate that the trade winds are expected to persist from the surface to mid-levels into late Thursday. A low-pressure system is forecasted to develop from Friday through late Saturday, likely bringing moderate convective activity across the area. Additionally, a ridge will build from the east to the north of the country by late Friday, extending throughout the outlook period. This will push the aforementioned trough westward, shifting winds from the north to a northwesterly direction and resulting in some convective activity. Westerly winds are expected to persist in the upper atmosphere from tomorrow through late Saturday, while an upper-level ridge will develop from the northwest to the southeast, leading to improved weather conditions by the end of the forecast period.

MARINE OUTLOOK:

Observational data from around the islands together with swaths, indicate wave observations well below the advisory threshold. Prediction indicate conditions to remain as so for the remainder of the outlook period.

ADVISORIES/WARNINGS:

VALID: HEAVY RAIN ADVISORY

Weather On-Duty Team:

G. Niko, A. Sofeni & C. Baker