Satellite imagery on Wednesday showed the tropical storm beginning to consolidate with tightening and improving structure, as well as a pulse of intense convection, or shower and thunderstorm activity blooming near its center. Spiral rain strips are beginning to be arranged west of the center, with dry air limiting the area coverage to the far east.
The storm was concentrated about 100 miles southwest of Yap, Micronesia, and had to pass well north of Palau. The wind was east of Yap, with gusts up to about 30 mph, with little light rainfall nearby.
The Joint Typhoon Warning Center said the Surigae had winds of 40 miles per hour with gusts up to 50 miles per hour near its core. But the strengthening circulation is expected to be on the verge of a typhoon force until Friday morning local time or around noon Thursday Eastern time.
Currently, the eastern shear – or change in wind speed and / or altitude – has displaced the strongest thunderstorm activity just west of downtown Surigae, leaving low-level circulation partially exposed to dry air trapped from the southeast. This cut will relax on Wednesday, supporting a steady boost that can continue throughout the week.
At the same time, the evacuation of exhaust or exhaust air from the upper levels will become more efficient. In the upper atmosphere, there will be two routes along which the discharge can radiate away from the storm. This removal of air from high altitudes above a storm facilitates the reduction of air pressure, promoting better absorption of warm, moisture-rich air at low levels. This is a sure way to create an unpleasant storm.
To make things even more ripe for a typhoon, sea surface temperatures in this part of the world are in the mid to upper 80s – 87 degrees in some places. The Northwest Pacific is usually much warmer than the Atlantic, allowing for stronger storms and an earlier start to typhoon season. Apart from the name, there is no difference between a typhoon and a hurricane. (Storms are called typhoons in the northwestern Pacific.)
The Joint Typhoon Warning Center predicts that the Surigas will escalate into a storm of 100 miles per hour by Saturday, when they recur north and cross safely east of the Philippines. By Monday, it could collect winds close to 140 mph at its core, with higher gusts. This would place it in a low-class Category 4 hurricane-equivalent territory.
There is an external chance that the storm could reach farther west and affect the Philippines, but the likelihood of this happening is low. In the last 12 hours, there has been a slight shift to the west in the simulations of forecast models.
In October, the Philippines was hit by the equivalent of a Category 5 Super Typhoon Goni. Estimates made by satellite imagery suggest that this is the most powerful storm to occur on Earth in four years, rivaling or exceeding the estimated intensity of Dorian, who swept the northwestern Bahamas in September 2019.
The typhoon must withstand steady winds of 150 mph or more in order to be designated a super typhoon corresponding to a Category 4 or Category 5 equivalent storm. A strong storm can completely avoid land masses, but it will be a danger to sailors and an obstacle to shipping. Individual wave heights can reach 100 feet.
The storm will then be absorbed under low pressure to the north. Depending on how its remnants interact with the jet stream, there is a chance that it will play a role in influencing the air pattern in the northern hemisphere, potentially affecting North American weather.
Assuming that the Suriga become a typhoon, this will be the first of the typhoon season in 2021. Another tropical storm, Dujuan, is forming in the western Pacific this year, but it is not reaching the intensity of a typhoon. This storm hit the Philippines in February and caused areas of heavy rain and flooding.