NHC has officially upgraded Rita to a Category 4 hurricane:

"...SATELLITE SUGGESTS THAT RITA HAS BECOME A CATEGORY FOUR
HURRICANE..."

and

"SATELLITE IMAGERY SUGGESTS THAT RITA HAS CONTINUED TO STRENGHTEN AND
MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 135 MPH WITH HIGHER
GUSTS. RITA IS NOW A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON
SCALE. A NOAA PLANE WILL CHECK THE INTENSITY LATER THIS MORNING.
SOME ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 45 MILES FROM THE
CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140
MILES.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB...28.00 INCHES."

Source: 8am Public Advisory