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Flossie Causes Little Trouble for Hawaii; Dorian's Remnants Falling Apart

By: Dr. Jeff Masters, 3:25 PM GMT on July 30, 2013

A weakening Tropical Depression Flossie passed through the Hawaiian islands on Monday evening and Tuesday morning with little fanfare, bringing scattered wind gusts of tropical storm force and a few areas of heavy rains of 1 - 2". The storm brought down a few trees and power lines, knocking out power for about 6,500 people on Maui and the Big Island. Kahului on Maui recorded sustained winds of 33 mph, gusting to 46 mph, at 7 pm local time Monday. Flossie brought 0.79" of rain to the airport, which was a record for the date. Powerful waves pounded the northwest shore of the Big Island, with significant wave heights of 14' recorded at the Hilo buoy Monday afternoon. Satellite images show that Flossie has lost all of its heavy thunderstorms, and has dissipated. Hawaii has a new storm to watch, though: Tropical Depression Seven-E, which has formed off the coast of Mexico, and is taking a track that may bring it withing 500 miles of Hawaii next week.

Figure 1. MODIS satellite image of Tropical Depression Flossie taken at approximately 20:50 UTC Monday July 29, 2013. At the time, Flossie had top winds near 35 mph. Image credit: NASA.

Remains of Dorian falling apart
The remains of Tropical Storm Dorian, located a few hundred miles north of the Dominican Republic, are headed west to west-northwest at 10 - 15 mph. Satellite images show that ex-Dorian has almost no heavy thunderstorms, and is being torn up by wind shear. In their 8 am EDT Tropical Weather Outlook, NHC gave Dorian's remains a 20% chance of regenerating by Thursday. The primary impediment to development is the presence of an upper-level trough of low pressure to its west that ex-Dorian is running into. Strong upper-level southwesterly winds associated with this trough are creating a moderate 15 - 20 knots of wind shear and driving dry air into the west side of ex-Dorian. This shear is not expected to relent at all during the next few days. None of the reliable computer models for tropical cyclone genesis predict that ex-Dorian will regenerate. Dorian's remains should continue moving west-northwest during the week, spreading over the Bahamas Wednesday and Thursday and over Florida on Friday.

Jeff Masters


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