Tropical Depression Aere - 7.5.22 5am - Update 25
Winds: 29 mph (46.67 km/h)
Gusts: 40 mph (64.37 km/h)
Pressure: 1000 MB
Moving: NE 10 mph (16.09 km/h)
Distance to Sasebo (JP): 211 km
Location: 33.5 N 130.2 E
Discussion
Aere (Philippine name Domeng) is located 43 km southwest of Sasebo, Japan, and has moved north-northeastward at 24 km/h (13 knots) over the past 6 hours.
The forecast evolution of Aere is complex. In the near-term (next 24 hours), the system is forecast to track east-northeastward along the northern edge of the subtropical ridge sliding westward along the 25th parallel, Aere will move at a relatively quick pace, crossing northern Kyushu and the inland sea before emerging back over water south of Tokyo in 36 hours. At this point things get complicated.
Global models suggest a weak baroclinic low will develop in the vicinity of Tokyo in around 24 hours at the tail end of a 500 mb trough and move offshore.
In 36 hours, the vorticity associated with Aere or its remnants are expected to merge with this low pressure area. Initially the baroclinic energy associated with the 500 mb shortwave trough will give a boost to Aere, allowing for reintensification of the system.
Simultaneously in the upper levels, a high-amplitude ridge extends north from Japan into the sea of okhotsk, leading to development of a cutoff low over Aere.
Ultimately this forms a rex block with Aere lying underneath the warm-core cutoff low to the south with a upper-level anticyclone to the north over the sea of okhotsk. This pattern is expected to remain in place through at least the next 3 days, and Aere will become quasi-stationary to the east of Honshu during this timeframe under the influence of a weak steering pattern.
In 4 days the rex block begins to break down, with the subtropical ridge to the east building and reorienting to a more north-south axis, ejecting Aere to the north-northwest.
Aere is forecast to intensify to a peak of 65 km/h (35 knots) as it moves east of Honshu, then slowly weaken through the end of the forecast period. The system will begin subtropical transition in 2 days as it moves under the upper-level cutoff low, and fully transition to a gale-force subtropical low in 4 days.
Deterministic and ensemble track guidance is in relatively good agreement through 72 as the system tracks along the northern edge of the subtropical ridge.
Model spread is 269 km at 3 days with the JGSM marking the southern edge of the envelope and NAVGEM the northern. While the guidance agrees on the overall scenario in the long-range forecast, available guidance shows significant disagreement in both the timing of the ejection northward and the direction of motion once Aere moves poleward.
Cross-track spread increases to 519 km while along-track spread increases to 648 km in 5 days, with the ECMWF, its ensemble and NAVGEM racing the system northward at over 35 km/h (20 knots) while the remainder of the guidance suggests a weaker steering gradient with the system moving poleward at a much slower pace.
Intensity guidance is in good agreement though the next 36 hours as the system moves over land, but once the system is back over water and begins to undergo subtropical transition, the guidance shows increasing uncertainty.
All models agree on intensification but differ in the amount, dependent upon the degree of interaction with the upper-level trough and low. SHIPS suggest dissipation after 2 days, while COAMPS-TC and HWRF bring the intensity up to 85 km/h (45 knots) at 2 days with slow weakening thereafter.
The JTWC forecast is within 10 km/h (5 knots) of the consensus mean through the forecast period. Confidence is high over the next 3 days, but medium in the extended period.
Maximum significant wave height is 3 meters (10 feet).
