Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 3:30 PM GMT on October 02, 2011
Hurricane Ophelia is steaming north-northeastwards towards Newfoundland, Canada, as a weakening Category 2 hurricane with 110 mph winds. Yesterday, the center of Ophelia passed about 130 miles to the east of Bermuda. The Bermuda airport picked up 0.24" of rain from Ophelia's outer rain bands, and had a peak wind gust of 24 mph. Recent satellite loops show that Ophelia is asymmetric and has lost its eye, thanks to strong upper-level southwesterly winds creating 20 - 30 knots of wind shear. The shear has destroyed a portion of Ophelia's eyewall, according to recent microwave satellite imagery. With the shear expected to increase today and Ophelia about to pass over waters too cold to support a hurricane, the hurricane's eyewall should collapse tonight, resulting in rapid weakening just before the storm arrives in Newfoundland Monday morning. Ophelia will bring a 6-hour period of high winds to Southeast Newfoundland beginning around 4 am local time Monday morning. The 11 am wind probability forecast for Cape Race, Newfoundland gave it a 87% chance of receiving tropical storm force winds, a 15% chance of winds in excess of 57 mph, and no chance of hurricane force winds. The main threat to Southeast Newfoundland from Ophelia will probably be the minor to moderate flooding the storm's 2 - 4 inches of rain will cause.
Figure 1. Radar image of Ophelia as it skirted Bermuda last night, at 7:13 pm AST on October 1, 2011. At the time, Ophelia was a Category 3 hurricane with 120 mph winds. Image credit: Bermuda Weather Service.
Tropical Storm Philippe no threat to land
In the middle Atlantic, Tropical Storm Philippe continues to struggle against dry air and high wind shear. Satellite loops show Philippe is a small system with little heavy thunderstorm activity, with the surface circulation completely exposed to view by wind shear. Wind shear is a very high 30 - 40 knots, thanks to the upper-level outflow from Ophelia. This shear will remain high through Tuesday, but may relax to the moderate range as Philippe turns towards the north on Wednesday. It is unlikely that Philippe will trouble any land areas.
Elsewhere in the Atlantic, none of the computer models is calling for a new tropical storm to form in the coming seven days (though the NOGAPS model shows a strong tropical disturbance forming in the Western Caribbean in about 7 days, something it has erroneously been predicting frequently in the past few weeks.) The large-scale environment over the Atlantic currently favors sinking air, due to the current phase of the Madden-Julian Oscillation (MJO). The MJO is a 30 - 60 day cycle of thunderstorm activity that affects the tropics.
Figure 2. True-color MODIS image of Typhoon Nalgae over the Philippine Islands, taken at 03 UTC Saturday, October 1, 2011. At the time, Nalgae was a Category 3 typhoon with 120 mph winds. Image credit: NASA.
Tropical Storm Nalgae headed for Vietnam
In the Western Pacific, Tropical Storm Nalgae will be skirting China's Hainan Island on Tuesday, and will make final landfall over Vietnam on Wednesday. Nalgae is not expected to regain typhoon strength. Nalgae roared ashore over the Philippines' main island of Luzon as a super typhoon with 150 mph winds at 9 am local time on Saturday morning. The typhoon dumped heavy rains of 4 - 8 inches across a large swath of Northern Luzon, on soils already saturated from the rains of Typhoon Nesat just five days previously. Surprisingly, the death toll from Nalgae's floods is relatively low so far, with three deaths reported. Nesat killed at least 52 people in the Philippines and three in China.
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