SYNOPTIC DISCUSSION

FRIDAY 23RD JANUARY 2026 AM SHIFT

TODAY:

A broad area of convective activities developed within the vicinity throughout this morning as a result of the active surface trough with embedded thunderstorms. Himawari synthetic satellite heavy rainfall potential areas hinted deep convections mostly on the North of the main islands as of the latest imagery. Total Precipitable Water MIMIC animation reveals abundant moisture gradually moving in from the north with favourable mechanisms reflected by CIMMS observations. A persisting upper divergence, low shear environment as well as low level convergence all contribute to deteriorating weather conditions observed over satellite loops of this morning. Models are in good agreement for the predictions of the now cast period, thus, anticipate isolated showers with heavy falls in some areas, thunderstorms and gusty periods for today. The previously enforced heavy Rain Advisory is now upgraded to Warning category.

SATURDAY THROUGH WEDNESDAY:

Saturday, a trough of low-pressure moves southward and likely resides within the vicinity of the group. According to model consensus, it will likely remain North throughout the outlook period. Despite the uncertainly in severity prediction from previous days, latest numerical prediction now focuses an increase in probability of precipitation for the group towards the end of the week. Model consensus has consistently shown deteriorating weather conditions associated with this system, The SPCZ is forecast to remain nearly stationary just offshore to the north, extending its associated rain bands over the islands during this period. Areas of upper-level divergence aloft will enable and sustain unsettled conditions across the islands. Such conditions  

MARINE OUTLOOK:

Current marine observations showcase waves and swell heights still fluctuate below the advisory threshold of 2.5 metres. Meanwhile, global wave models suggest that in the new week, the previously mentioned northerly surge will likely elevate waves and swells to more than the threshold value for advisory. Moreover, poor visibility and gusty periods during rain will potentially be experienced for Sunday into Wednesday as the synoptic system remains over our marine waters.

ADVISORIES/WARNINGS:

VALID: HEAVY RAIN WARNING

VALID: FLOOD ADVISORY

Weather Duty Team:

Niko, Sofeni, Uili & Baker.