A large area of disturbed weather extends across western Micronesia, associated with the Near-Equatorial Trough (NET) and embedded disturbances. The primary disturbance at this time is Invest 99W, a broad area of rotation west-southwest of Koror, Palau, located near 5N132E. Today's satellite scatterometer data does not show a defined circulation with 99W but this disturbance is associated with gusty, locally heavy showers and thunderstorms. The Joint Typhoon Warning center rates 99W as a "sub-low" for development, which means significant development into a tropical cyclone is unlikely over the next 24 hours. Farther east, a broad area of mid-level vorticity is seen near 5N148E, well west-southwest of Chuuk, and similar to 99W, scatterometer data does not show a defined surface circulation and convection is disorganized around this feature. This mid-level vorticity can however become a focal point for future convection and even support the development of a surface circulation, a trend shared by some, but not all, models over the next several days. Overall, model trends support one, possibly two circulations developing within the NET and shifting northwest through the end of the week, with significant development not occurring until the feature is northwest of Palau and Yap. This slow and disorganized development will lead to wide spread variability in conditions across Palau and Yap State, however the potential for locally heavy showers, gusty winds and choppy seas exists across the region. As the feature shifts northwest of Palau and Yap, a monsoon-like pattern may develop across Palau and western Yap state, potentially leading to higher seas and surf along the westward sides of the islands and impacting areas sensitive to southwest to westerly winds. At this time, landslides are unlikely, due to the high variability in rainfall potential. However, if soils become saturated by heavy rain, this potential will increase with the onset of additional rainfall. Residents and mariners should monitor the latest forecasts for the region at weather.gov/gum/PublicForecasts and any information shared by WSO Palau and WSO Yap for there local regions.
