(BIVN) – A new storm is developing in the Central Pacific, far to the southwest of Hawaiʻi, just east of the International Date Line.
According to the Central Pacific Hurricane Center, the newly formed Tropical Depression Three-C could become a tropical storm over the next day or so, as it moves towards the east-northeast.
The forecast shows the storm dissipating well before it nears Hawaiʻi.
Analysis of the storm was provided by the Central Pacific Hurricane Center in this 5 a.m. discussion:
The system we have been monitoring near the International Date Line that was recently designated CP94 has become better organized early this morning. Showers and thunderstorm activity began to show signs of organization late yesterday, and an overnight scatterometer pass indicated that a small but well-defined circulation had formed. In addition, there was a WSF-M microwave pass at 0532 UTC, which showed curved bands were present on the 37-GHz channel, especially on the northern semi-circle of the system. Since that time, Himawari-9 and GOES-18 satellite imagery shows the system exhibiting a bursting convective pattern close to or just to the north of the estimated center. Subjective Dvorak estimates from both JTWC and Honolulu were T1.5/25 kt. However, the earlier scatterometer pass also showed a peak wind retrieval of 32 kt. Based on the system’s structural improvement on satellite imagery overnight, advisories are being initiated on Tropical Depression Three-C at this time. The initial intensity is set at 30 kt, though this could be conservative given the earlier scatterometer data.
The depression’s initial motion is east-northeastward, or 075/6 kt. The system is currently embedded in deep-layer westerly flow, both from an equatorward low-level westerly wind burst, and an upper-level westerly flow from an approaching short-wave trough to the north of the depression. These combined features should maintain the system on an eastward track for the next several days. The initial NHC track forecast blends the latest global model guidance from the GFS and ECMWF solutions. This track will take the tropical cyclone as a weakening system near Johnson Atoll in about 60-72 h. It is worth noting there is a lot of spread in the along-track direction, likely related to uncertainty in the vertical steering depth the system will feel over the next few days, so this first track forecast is a little lower confidence than usual.
The depression could already be close to tropical storm intensity given the earlier scatterometer data, and environmental conditions appear mostly favorable for the next 12-24 h with deep-layer shear in the 5-15 kt range with plenty of warm water and deep-layer moisture. However, the approaching mid-latitude trough to its north is expected to soon increase the westerly shear over the system, likely limiting the intensity of the tropical cyclone. Thus, only some slight intensification is shown over the next 12-24 h, with the storm plateauing as a 35 kt tropical storm through the early part of this week. By mid-week, SHIPS guidance shows this westerly shear increasing above 40 kt, and most of the guidance responds by showing the system quickly becoming separated from its deep convection as the circulation becomes increasingly elongated. The initial NHC intensity forecast therefore shows the cyclone degenerating into a remnant low in about 72 h, and dissipating shortly thereafter. This forecast is in good agreement with the global model guidance.
Based on the initial track and intensity forecast, no watches are required for Johnston Atoll at this time, though interests there should continue to monitor the latest forecast updates related to this system.
