pressure still supports a 5..doesn't that either say the pressure or wind speed at 145 is off?
Or the relationship between pressure and wind speed needs to be rethought. Rita has had consistently weaker winds than the pressure/satellite would suggest. While the 913 mb from the AF flight was actually an extrapolation, it was backed up by a NOAA flight that did measure 913 mb (and 133-knot flight-level winds in the NW quad) about 2:10 pm.
Not at all. The pressure guidlines for various categories are VERY rough guidlines.
Pressures have NOTHING to do with wind speed.
Pressure GRADIENTS (the difference in pressure across a given distance) cause a given wind speed. If the pressures around a storm aren't that high, then even if the pressures are very low in the storm, you won't have as much wind as you expect. Around Andrew, for example, the pressures were very high..thus with 922mb you had Cat 5 winds. During this eyewall replacement, the pressure gradient in the core of Rita has weakened, creating a broader windfield but with a lower maximum wind, despite the pressure being WELL below that of Andrew at landfall.
However, the very unfortunate myth that there is a specific, precise windspeed that must be associated with a given pressure has taken hold. Once of the main purveyors of this myth, incidentally, is a certain well known AccuWeather TV personality.
More likely the wind speed is off. The pressure is directly measured in the eye by a dropsonde...and even the extrapolated pressure is pretty accurate. NHC bases the storm's wind speed off the recon reports. If the recon misses the strongest winds when it penetrates the eyewall, then it can appear that the strom is weaker when the pressure says otherwise.