Friday, May 27, 2011

Super Typhoon Songda (Chedeng) Update #17

Super Typhoon Songda (Chedeng) has maintained its strength as it moves away from Luzon. It was last located about 280km ENE of Aparri, Cagayan or about 140km ESE of Basco, Batanes. Maximum sustained winds remain at 230kph with gusts of as high as 290kph. Songda is moving north northwestward at 20kph. STY Songda has moved more westward than previously thought and so Babuyan and Batanes islands are being hit with tropical storm winds of about 65-120kph. Heavy rain bands are also making their way to the islands. Expect amounts of more than 100mm to fall throughout today.

For those living in Batanes, please click here for Taiwan's radar link:

Estimated wind field as of 3pm: Brown is the storm center while the orange circle represents the typhoon force winds. Yellow circle is the tropical storm winds while the green one is for tropical depression winds. These are just estimates based on observations and satellite analysis, it does not mean areas inside the circle will continuously experience such conditions throughout the day.

Anyway, as of 11am today, PAGASA has raised Signal warning #2 for Babuyan and Batanes Group of Islands. Signal #1 for Cagayan, Isabela, Aurora, Quirino, and Apayao.

These areas will continue to feel strong winds of as high as 100kph particularly to the north. Moderate to heavy rain will also fall, heavier as you go north. Rough seas and high wave heights should also be felt along the eastern and northern seaboard of Cagayan and Isabela.

Forecast track remains generally the same although we are now including Okinawa and Japanese mainland on our forecast map (using a new map to plot our tracks from STY Songda should begin turning to the northeast this afternoon moving away from Taiwan with its closest approach to Taipei happening early tomorrow at about 350-400km east of the city.

As it heads north, TY Songda should gradually weaken becoming a category 3 by tomorrow. It should also leave the Philippine Area of Responsibility tomorrow as it heads towards Okinawa. Our forecast takes Songda to the WEST of Okinawa by Saturday night as a weakening Category 3 with winds of about 160-180kph. This is critical because this means Okinawa will face the right front quadrant of the storm which is typically the more severe side of a cyclone in the northern hemisphere.

Songda should then move northeastward, weakening along the way due to cooler waters and strong wind shear. It could brush southern Honshu and clip Tokyo on Sunday as a tropical storm with winds of about 80kph. It will then begin extratropical transition on Sunday completing it as early as Monday.

Computer models are in excellent agreement although timing varies. Also, JTWC and JMA are not expecting Songda to make landfall in mainland Japan.

NOTE: Our video update will come in just 30 minutes!
Issued (08 UTC) 4pm PhT 052711

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