Tropical Storm Tomas has ben upgraded to Hurricane Tomas as of the 11am advisory from the NHC. Hurricane Tomas has had a very good presentation all morning. Hurricane Tomas is forecast to continue intensification and most models are forecasting that Tomas will be a major hurricane of at least category three.
The Mid-Layer trough that is taking Hurricane Shary rapidly to the NE is the same trough that is heading NE away from the Caribbean and the mid-level ridging north of Tomas has begun to build. Low to Mid level ridging is forecast by all the global models for at least the next 72-96 hours and building westward across Lesser and Greater Antilles. This will keep Tomas on a westward track for at least the next 2 days. A few days later, a broad mid-tropospheric trough that is currently located along the US west coast is forecast to move eastward into the Central US then it is forecast to dig southwestward into the Gulf of Mexico. This will erode the Western portion of the ridge and significantly weaken the steering currents in the western and central Caribbean Sea. This will force Tomas on a northward track. Exactly when the turn will happen is unclear. Some models want to wait then turn Tomas between Eastern Cuba and Haiti where other models want to turn Tomas earlier and have Tomas turn near Hispaniola.