FRIDAY 25th JUNE 2021 (AM)
An active cloud band associating with a convergence zone lies within the vicinity of Samoa. The system is expected to remain stationary for today into tonight; providing periods of rain with heavy falls and thunderstorms covering the islands. The islands lie under favourable wind shear and the abundance of moisture content; sufficient for the rainfall making process. Diverging aloft winds tends to be more concentrated to the south of the group where deep convectives lie. Persisting weather features tends to prolong the validation of the previously issued Heavy Rain Warning and Flood Advisory for the time being. Predictions states conditions to ease later in the evening.
SATURDAY THROUGH THURSDAY:
Aloft; wind predictions state the movement of the upper-level trough by tomorrow near the forecast zone, and such aligning conditions provides deteriorating weather for the upcoming days. Furthermore, an intense high pressure system further southwest near New Zealand is predicted to enter the region by Friday directing fresh southeast winds over the group. A speed convergence may form along with the mentioned winds and maintain showers over the area at the end of the week. Winds will turn Northeast again by Tuesday as the high migrates eastward and awaiting the prevalence of the Easterlies.
MARINE OBSERVATION & OUTLOOK:
Current observations remain below the advisory threshold, though expectancy for all Samoa’s marine waters, an intensified high-pressure system extending from the southwest is expected to build over Samoa’s marine waters and land areas. Wind strength may reach 25-35kph or more with strong and gusty periods elevating waves and swells up to 3-3.5metres or more. Thence; the Marine advisory remains and may likely be upgraded into a Marine Warning in the next 12-24hours.
WARNINGS AND ADVISORIES:
HEAVY RAIN WARNING