Tropical Storm Danas spawns evil 'twin' that could menace Taiwan soon

Tropical Storm Danas' evil 'twin' taking shape, could head toward Taiwan

NOAA animated GIF of Western Pacific.

NOAA animated GIF of Western Pacific.

TAIPEI (Taiwan News) -- Just as Taiwan braces for impact from Tropical Storm Danas, the Central Weather Bureau (CWB) warns that a "twin" storm that broke off from it could form a tropical storm that could also menace the country soon.

As of 8 a.m., the CWB said that Tropical Storm Danas had a radius of 150 kilometers and was located 470 kilometers southeast of Taiwan's southernmost tip of Eluanbi, moving north-northwest at a speed of 17 kilometers per hour (kph). It was packing maximum sustained winds of 64 kph with gusts of up to 90 kph, equivalent to level 10 on the Beaufort scale.

At 11:30 p.m. on Wednesday night (July 16), the CWB issued a sea warning for Danas, while the bureau declared a land warning for the tropical storm at 11:30 a.m. this morning (July 17). Because the typhoon's environment is complex and its ability to intensify limited, uncertainty over its path and impact is high.

CWB map of "twin" systems.

According to WeatherRisk, due to the loose structure of Danas as it passed over Luzon on Tuesday (July 16), the topography caused some middle and high-level clouds to split off and head west of the island. However, the tropical storm's center and low-level clouds remained in the east, in essence splitting the tropical storm into a pair of "twins."

The CWB pointed out that the western half of Danas integrated a low-pressure system into a low-pressure belt in the South China Sea. The CWB predicted that the low-pressure system west of the Philippines could develop into a tropical depression, or the sixth tropical storm of the year, and move north towards Taiwan creating a "twin tropical storm" situation.

If the low-pressure system gains strength, it could develop into a tropical depression as soon as Thursday (July 18), before becoming a full-fledged tropical storm. WeatherRisk said that the new storm could follow Danas' path and strike Taiwan, but more observation will be needed as many factors could alter the system's strength and course.

China Meteorological Administration satellite image.

CWB map of two "twin" systems.