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Typhoon Nesat kills 12 in the Philippines; Ophelia regenerating

By: Dr. Jeff Masters, 1:28 PM GMT on September 27, 2011

Typhoon Nesat roared across Luzon Island in the Philippines last night as a dangerous Category 3 typhoon with 120 mph winds. The typhoon likely dumped 12 - 15 inches of rain along portions of it path, according to satellite rainfall amount forecasts. Flooding and drownings been blamed for at least 12 deaths in the Philippines. We don't have any weather stations on the east coast of Luzon near where the eye came ashore that survived to send us data, but winds at Iba on the west coast of Luzon reached a sustained speed of 67 mph at 5 pm local time today as the eyewall of Nesat moved through. Cabanatuan in Central Luzon received 5.55" inches of rain. The center of Nesat passed well north of the capital of Manila, which received sustained winds of 37 mph, gusting to 55, and 2.74" of rain. Heavy flooding is reported in Manila, where the soils were saturated by heavy seasonal monsoon rains before the arrival of Nesat. Nesat's winds drove a storm surge that smashed through the seawall protecting Manila, and significant storm surge flooding occurred along the shore. Nesat is now a disorganized Category 1 typhoon with 95 mph winds over the South China Sea, and is expected to re-intensify into a Category 2 typhoon before making landfall near China's Hainan Island on Thursday and northern Vietnam on Friday.


Figure 1. Microwave image from NOAA's F-16 satellite showing the estimated rain rate of Typhoon Nesat as it was making landfall on Luzon Island in the Philippines at 6:31 pm EDT Monday, September 26, 2011. Rainfall rates over 1"/hour (orange colors) were occurring in much of the eyewall. Image credit: Navy Research Lab, Monterey.

Atlantic update: Ophelia rising again, Philippe no threat
The remains of Tropical Storm Ophelia continue to fester in the Atlantic a few hundred miles east of the northern Lesser Antilles Islands, and now appear ready to re-organize into a tropical depression. Martinique radar shows a large area of concentrated thunderstorms lies about 200 miles to the east of the northern Lesser Antilles, though with only a little rotation and very limited spiral banding. Recent satellite loops show that Ophelia may now have a closed surface circulation, and heavy thunderstorms are increasing, though are limited in areal extent. A hurricane hunter aircraft will investigate Ophelia this afternoon at 2 pm to see if a tropical depression has formed.


Figure 2. Morning radar image from the Martinique radar shows the heavy rain showers from Ophelia, just east of the northern Lesser Antilles. Image credit: Meteo-France.

Dry air and moderate wind shear of 10 - 20 knots are slowing down the regeneration process, and will continue to limit Ophelia's intensification over the next few days. NHC gave Ophelia an 80% chance of regenerating by Thursday in their 8 am Tropical Weather Outlook, and most of the models give strong support to Ophelia regenerating. I expect Ophelia will be a tropical storm again by Wednesday. A trough of low pressure should steer Ophelia to the northwest and then north over the next five days, with the storm making its closest pass by Bermuda on Saturday. Tropical Storm Warnings may be required for Bermuda this weekend. Ophelia is not a threat to any other land areas, though the storm will bring some heavy rain squalls and wind gusts of 25 - 35 mph to the northern Lesser Antilles Islands today and Wednesday.

In the far eastern Atlantic, Tropical Storm Philippe is headed northwest into the middle of the North Atlantic, and is not expected to trouble and land areas. Wind shear is high enough over Philippe that the storm is unlikely to become a hurricane over the next five days.

Eastern Pacific's Hurricane Hilary slowly weakening
In the Eastern Pacific, Hurricane Hilary has slowly weakened to a Category 3 hurricane with 115 mph winds. A trough of low pressure is expected to turn Hilary to sharply to the north on Wednesday. Since Hilary will be crossing cool water and encountering increased wind shear, the storm will weaken rapidly beginning Wednesday, and all of the models show Hilary dissipating before reaching the coast.


Figure 3. MODIS satellite image of Hurricane Hilary at 4:35 pm EDT September 26, 2011. At the time, Hilary was a Category 3 storm with 130 mph winds. Image credit: NASA.

Jeff Masters

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.