Tropical Cyclone Activity Report – Pacific Ocean / Indian Ocean / Arabian Sea

Western North Pacific

Tropical Cyclone 04P Here’s what the computer models are showing According to the JTWC, environmental analysis reveals a marginal environment with high 30-35 knot wind shear being offset by diffluent flow aloft and warm sea surface temperatures. in the near term, TC 04P is expected to track west-southwestward to westward. As the system continues to track along the southern periphery of Invest 91P, which is forecast to intensify into a tropical cyclone over the  next 1-2 days. Due to the proximity of invest 91P to TC 04P, there will likely be some direct cyclone interaction, and possible fujiwhara effects in 60 hours. Due to the complex scenario, there is high uncertainty in the track forecast and intensity forecast as models have been inconsistent from run to run. The GFS indicates invest 91P will be the dominant system with TC 04P skirting westward towards Vanuatu. Conversely, the NAVGEM model shows TC 04P as the dominant system, turning it sharply poleward by  36 hours…then tracks southeastward passing to the west of Fiji. TC 04P is forecast to struggle through 48 hours with a slightly intensification. After 48 hours, the merged system should gradually intensify as the environment improves with steady intensification to a peak of 80 knots by 120 hours. The JTWC forecast track shows a slow nearly stationary motion from 48 to 96 hours. Following this, an approaching trough will cause TC 04P to begin to move poleward. Through 36 hours, the system is expected to struggle due to persistent high wind shear. Afterwards, the merged system is forecast to gradually intensify to a peak of 80 knots by 120 hours, as the surrounding environment improves. The complexity of this scenario also presents an alternate scenario where invest 91P becomes the dominant system and TC 04P dissipates.  

There’s a tropical disturbance being referred to as Invest 91P, which is located approximately 423 NM north-northeast of Port Vila, Vanuatu Here’s what the computer models are showing According to the JTWC, Invest 91P is in a favorable environment for development, with low to moderate 10-20 knot wind shear, warm sea surface temperatures, and strong outflow aloft. Global models are somewhat split, showing that 91P will track generally southeastward, becoming absorbed into TC 04P. Other models are showing that Invest 91P will become the dominant circulation, intensifying and eventually absorbing TC 04P. Maximum sustained surface winds are estimated at 20-25 knots. The potential for the development of a significant tropical cyclone within the next 24 hours is remains medium.