Category 5: "NHC is being conservative, and calling Rita a strong Category 4 hurricane with 150 mph surface winds"
The 1:53 eye report from the hurricane hunters found a 920 mb pressure and flight level winds of 153 knots (176 mph). These numbers plus the satellite intensity estimates would ordinarily support upgrading Rita to a Category 5 hurricane, but NHC is being conservative, and calling Rita a strong Category 4 hurricane with 150 mph surface winds.
There are two hurricane hunter aircraft in Rita this afternoon. The NOAA hurricane hunters found a central pressure of 934 mb at 11:17 am, and the Air Force hurricane hunters found a central pressure of 923 mb at 1:02pm. This incredible drop of 11 mb in 105 minutes is the fastest pressure fall I can ever recall seeing in a hurricane, and exceeds the 10 mb drop in 100 minutes we saw in Hurricane Charley last year. With an eye diameter of 25 miles, an eyewall replacement cycle is not likely today, and Rita may intensify to a level close to Katrina's strongest point--902 mb.
And from the National Weather Service:
HURRICANE RITA TROPICAL CYCLONE UPDATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
255 PM CDT WED SEP 21 2005
DATA FROM RECONNAISSANCE AIRCRAFT INDICATE THAT RITA HAS REACHED
CATEGORY FIVE INTENSITY WITH ESTIMATED MAXIMUM SUSTAINED SURFACE
WINDS OF 165 MPH. THIS WILL BE REFLECTED IN THE 4 PM CDT ADVISORY.
(Image is NOAA OSEI's Image of the Day today.)