Super Typhoon Wipha
9/18/2007 6:58 AM
The full brunt of Super Typhoon Wipha was brought to bear upon the Sakishima Islands, or southernmost Ryukyu Islands, of Japan Tuesday. One of the bigger islands hit head-on was Ishigaki Shima, which withstood the battering of hurricane winds and torrential rains. Highest sustained winds of at least 76 mph were clocked at Ishigaki with gusts to at least 100 mph. Rainfall neared one foot, of which more than 8 inches poured down within 12 hours. Pressure dipped to at least 951 millibars, or 28.08 inches of mercury. Farther east, the islands of Miyako Jima and Shimoji Shima got by relatively unscathed, although winds did gust above 70 mph on Shimoji. Once free of Sakishimas, Wipha stormed the southernmost East China Sea, where the eye wall grazed Penkia Yu off northern Taiwan. Winds Tuesday afternoon rose to hurricane strength as Wipha roared by.
Wipha was on a path that made landfall on eastern China south of Shanghai nearly certain. Likely time for landfall over southern Zhejiang, near Wenzhou, was Wednesday morning, local time. Later to come, a bout of squally wind and torrential rain over the city of Shanghai unleashed by the much-weaken Wipha.
Winds Monday surged explosively about the eye of Typhoon Wipha. Here is a good look at this severe storm (a Category 4 hurricane at this time): The infrared satellite imagery was uploaded from NRLMRY, the Naval Research Lab in California.
The latest (1200 hrs GMT, Monday) advisory from the JTWC has Wipha packing severe 120-knot (220-kmh) highest sustained winds. At the time, the eye lay 230 miles southwest of Naha, Okinawa and 110 miles southeast of Ishigakijima, one of the Sakishima Islands. The Sakishimas lie at the southwestern end of the Ryukyu arc of islands belonging to Japan. Bearing northwestward at a forward speed of 11 knots, or 20 kmh, landfall Tuesday over one or more of these islands by Wipha would seem to be a given. A direct hit could prove devastating.
Beyond Sakishima, numerical forecasts together with the forecast advisory of the JTWC show a veering northward soon enough to spare northern Taiwan a direct hit. A stormy time of it is on the way for Taipei, though. From here, the forecast problem becomes East China: will Wipha strike directly or skirt the shore before curving towards western Korea? In the balance is the way of the weather at Shanghai, greatest of China`s many great cities.
If Wipha does made landfall upon eastern China, it will be a weakening, although potentially still quite serious, typhoon.
--As for Korea, a visit from Wipha so soon after Typhoon Nari might be like going from the fire to the frying pan, as is sometimes said. But Nari`s hammer blow fell upon southern Korea, Cheju Island first and foremost. On Cheju, the like-named town, Cheju, was inundated with 23.2 inches (nearly 59 cms) of rain within 60 to 72 hours. Wind gusts rose above hurricane strength (65 kts or 120 kmh). from Gosan, at the western end of Cheju, came observations showing 81-knot (150-kmh) sustained winds at the height of the storm. As Nari veered northeastward over southern Korea to the Sea of Japan, it faded quickly to a tropical storm. So, for the time being, rain and wind threat in Korea seem more likely to lie with the North, especially the western side.
--Numerical forecasts are hinting at another western North Pacific tropical storm within 5 to 7 days, although forecast models do not agree with one another.
--South Asia:
Weather on the Subcontinent is heading for a more `active` phase. If things unfold as shown by numerical forecasts (notably the GFS), there will be a northward spread of showers and thunderstorms over areas that have lately been vacated by rains--Gujarat, Rajasthan, Haryana, even the plains and western mountains of Pakistan.
A dry-wet contrast, north to south, is indicated by the latest infrared imagery from India`s IMD> While is it not at all obvious here, a weak upper low (`western disturbance`) has lingered over the northernmost plains of India as of Monday. Too weak to stir up much rain of its own, this weather maker has squeezed Monsoon rains southwards. At the same time, the image suggests that a weak, loosely-organised Monsoon low is near the southern east coast of India.
Numerical forecasts show an end to the weak northern low together with a slow northwestward spread of the Monsoon low and Monsoon rains. The latest GFS numerical forecast has torrential falls of rain shown over small areas along and near the west coast; these coincide with a small Monsoon low over the eastern Arabian Sea. By the start of next week, the same numerical forecast points to another `western disturbance` dipping southward at the longitude of Afghanistan and western Pakistan. Southerly wind flow (aloft) ahead of this trough in the Westerlies is what the numerical model seizing upon to remoisten much of the northern Subcontinent. Something to watch over the coming days.
