It is unusual for a hurricane to develop when it is making landfall like Humberto, but it is not unusual for tropical depressions to be numbered. NOAA and the National Weather Service/National Hurricane Center do not name the storms until they reach Tropical Storm status (sustained wind speeds of 38+ MPH).  The Saffer-Simpson scale (for hurricane categories) goes like this
 
Tropical Depressions (Numbered):      23-38 MPH
Tropical Storm (Named):                    38-73 MPH
Category 1 Hurricane:                        74-95 MPH
Category 2 Hurricane:                        96-110 MPH
Category 3 Hurricane:                        111-130 MPH
Category 4 Hurricane:                        131-155 MPH
Category 5 Hurricane:                        156+ MPH
 
You usually see 15+ numbered depressions in any given hurricane season.  They are numbered until they reach Tropical Storm status.  Then they are provided one of the names in alphabetical order.  What is unusual is when the list of names is all used up and it enters into the greek alphabet (Alpha, Beta, etc...)