Edouard intensifying

Tropical Storm Edouard is intensifying as it approaches landfall Tuesday morning along the Texas/Louisiana border. Visible satellite loops show Edouard's heavy thunderstorm activity has increased significantly in the past few hours, and is now starting to wrap all the way around the storm. Long range radar out of Lake Charles, Louisiana also shows an increase in the organization and intensity of the radar echoes. Edouard is over ocean waters of about 29°C, which extend to a moderate depth. The Tropical Cyclone Heat Potential, a measure of the total energy available for rapid intensification, is about 30 kJ/cm^2, which is less than the value of 80 typically associated with rapid intensification. Wind shear has fallen from about 10 knots last night to 5 knots this afternoon, which has allowed the storm to organize. A new hurricane hunter plane entered the storm at about 2pm EDT, and so far has measured top winds of 50 knots (57 mph) at the surface with its SFMR instrument.


Figure 1. Latest satellite image of Edouard.

The forecast
The shear is forecast to remain below 5 knots through Monday night, but the depth of the warm waters get shallower, with the Tropical Cyclone Heat Potential decreasing to about 10 kJ/cm^2 Monday night. Taken together, these factors should allow Edouard to intensify to a least a 60-70 mph tropical storm. The latest 12Z (8am EDT) GFDL model brings Edouard to a 75 mph Category 1 hurricane by landfall, with the strongest winds occurring near the Texas/Louisiana border. Other intensity models, such as the SHIPS and HWRF models, predict Edouard will remain a tropical storm at landfall. Our skill predicting intensity changes is poor, but at present at appears that Edouard will be a strong tropical storm or weak Category 1 hurricane at landfall. Wind damage and heavy rain are the main damage threats from Edouard. However, these rains will also greatly benefit the region, which is under severe to extreme drought.

I'll have another blog on Edouard Tuesday morning.

Jeff Masters