MsPerky

This is looking very, very scary...my thoughts are with everyone in the affected areas.

DrCloud

Earlier this morning, the TPC (Tropical Prediction Center, NOAA/Miami -- the National Hurricane Center) reported a central pressure in Rita of 897 mb, the third lowest (Atlantic) tropical cyclone pressure ever recorded. "Normal" sea-level pressure in these units is about 1013 mb, meaning that the core of Rita had 10% less air in in than the (undisturbe) surrounding atmosphere at the surface. In that surrounding atmosphere, a pressure of 897 mb generally occurs at an altitude of about 1 km.

This low pressure core acts as a well, into which the surrounding air flows (although, since it's atmospheric pressure rather than gravity doing the sucking, it's an upside-down well). In some sense, then, it's a 1-km deep well. Consequently, it's a doozy of a storm.

Since that earlier measurement, the central pressure has risen a little, and, because of the increased drag presented by Texas (not that I'm suggesting that Texas is a drag, mind you) and because the ocean-surface temperatures near the coast are a little lower than out in the middle of the Gulf, it's probable that Rita will weaken somewhat by the time it gets to wherever it's getting to. But it's still going to be rough going, particularly near the coast on the north side of wherever the eye goes ashore. This is not a good storm to try to "ride out."

The definitive source of information is the TPC/NHC site:

http://www.nhc.noaa.gov/index.shtml

Although the Weather Channel et al have better graphics, they tend to over-dramatize things to secure better ratings. HPH

Kyras

^Thank you Dr. Cloud. It's nice to have an expert in these matters in Vintage.