Now that Harvey has a well-formed structure, I don’t see any impediments to it intensifying right up until landfall. I expect Harvey will be a Category 2 hurricane by Friday morning and a Category 3 hurricane by Friday night. Harvey probably does not have enough time to become a Category 4 storm, though we cannot rule that possibility out yet.
The current favorable conditions for development will remain in place through Friday night, according to the 12Z Thursday run of the SHIPS model. Wind shear will remain light to moderate, and the atmosphere will be moist. SSTs will remain near 30°C (86°F), and warm waters will extend to considerable depth, with a total ocean heat content of 50 – 80 kilojoules per square centimeter. From Thursday night into Friday, Harvey will get an extra boost in energy as it passes over a warm-core eddy that broke off from the Loop Current. The oceanic heat content within the eddy exceeds 75 kilojoules per square centimeter, enough to support rapid intensification. However, the heat content of this eddy is not as high as the heat content available to Hurricane Katrina of 2005, when it moved over a similar warm-core eddy.
This morning’s runs of our top intensity models—the HWRF, LGEM, COAMPS-TC, and DSHIPS—all predicted a Category 2 or 3 hurricane at landfall. Read more.
|Tropical Storm Harvey as seen by the GOES-16 satellite at 10:15 am CDT Thursday, August 24, 2017. Image credit: NOAA/CIRA/RAMMB. NOAA’s GOES-16 satellite has not been declared operational and its data are preliminary and undergoing testing|