Danny Strengthens, But Remains Poorly Organized

Good morning everyone. Hurricaneville continues to follow Tropical Storm Danny, which is now located some 370 miles to the East-Northeast of Nassau in the Bahamas, or about 575 miles to the South-Southeast of Cape Hatteras, North Carolina. There have been some changes to the storm overnight as its center of circulation has reformed a bit more to the north while its winds have increased, and its forward direction has shifted more to the Northwest. Maximum sustained winds with Danny have increased to 60 miles per hour while the barometric pressure has decreased to 1006 millibars, or about 29.71 inches of Hg. The storm is moving to the Northwest at 10 miles per hour.

The key with Danny is that the storm remains quite disorganized as the satellite imagery courtesy of the Weather Channel will show. Almost all of the deep convection associated with the system is off to the north and east of the center of circulation, which remains exposed. Tropical storm force winds reach out some 205 miles from the center. So, it is quite a vast system. However, only slow strengthening is expected. No rapid intensification like we saw with Hurricane Bill out in the Central Atlantic last week. As long as the clouds, showers, and storms don’t start to wrap around the center of circulation, Danny will have a tough time becoming a hurricane.

The forecast for Danny is much more complex than it was for Bill. Since the storm is disorganized, and the center of circulation reformed, the Hurricane Hunter aircraft had a tough time pinpointing the exact initial motion of the storm. However, the models are in general agreement that Danny will move to the North on Friday as it tracks between a high pressure ridge over the Western Atlantic Ocean and a shortwave trough hovering over the Southeastern United States. A larger trough upstream over the Great Lakes is expected to increase flow to the northeast, and Danny will ride that out.

There is some disagreement over the intensity forecast of Tropical Storm Danny. Models still indicate that Danny, which is encountering very little shear right now, will be dealing with increased shear over the next 24 to 36 hours. Nevertheless, they still call for Danny to become a hurricane in 48 hours, and the NHC agrees with this assessment. However, there is some suggestion that the storm may become a hybrid, or extratropical system beyond that time frame as it joins forces with the low pressure over the Great Lakes. The transition from a tropical to extratropical cyclone may give it more energy to become stronger.