The Weather Channel reports Gustav is a weak Cat 3 and Hanna is in a wind shear environment. (the link is probably temporary)
Gustav’s weakening trend may be over and, despite some strengthening as it approaches Louisiana, the hurricane will likely remain a Category 3. This said, Gustav continues to be a dangerous major hurricane and will move into Louisiana Monday.
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Hanna has been impacted by strong shearing winds in association with an upper-level low in the region. The upper-level low is forecast to weaken, but the overall environment for Hanna should remain quite hostile for the next 24 to 48 hours keeping the system weak.