Updraft: July 20, 2010 Archive

NHC: 60% chance for Tropical Storm Bonnie

Posted at 5:08 PM on July 20, 2010 by Paul Huttner
Filed under: Hurricanes

We may be saying hello to Tropical Storm Bonnie in the next 48 hours.

The National Hurricane Center is giving a vigorous tropical wave near Puerto Rico a 60% chance of strengthening into a tropical storm in the next 48 hours.

Tropical wave near Puerto Rico shows signs of development

If the system develops, it would become the second named storms of the season, Bonnie.

Bonnie is fighting a few variables in terms of development, according to Dr. Jeff Masters, hurricane guru at Weather Underground. Dry air out ahead of Bonnie may retard development.

Also in favor of development are the warm ocean temperatures of 29°C. The SHIPS model predicts shear will stay in the moderate range, 10 - 20 knots, over the next five days. The primary detriment to development of 97L over the next three days will probably be the presence of dry, stable air in its path over the Bahamas, thanks to the upper-level low to the north of the Dominican Republic. If the center forms close to the coast of the Dominican Republic, the high mountains of Hispaniola may also be a problem for the storm. NHC is giving 97L a 60% chance of developing into a tropical depression by Thursday, which is a reasonable forecast. I think there is a 70% chance 97L will eventually become Tropical Storm Bonnie, sometime in the next five days. Sudden rapid development today or on Wednesday is unlikely, due to the dry air over the Bahamas. I put the odds of 97L making it to hurricane strength before reaching Florida at 30%, and I give a 20% chance it will be a hurricane in the Gulf of Mexico. The probability of 97L being a hurricane in the Gulf of Mexico will depend heavily upon how long the storm spends over land or interacting with land over the next four days, which is very uncertain.

Various forecast models are pushing what could become Bonnie toward south Florida by Thursday or Friday. The system may possible track into the eastern Gulf of Mexico after that.

All eyes in the southeast U.S. will be watching for the potential for Bonnie in the coming days.

PH