Threat to New Orleans grows

Latest compter model runs have shifted significantly west in the past six hours, and the threat of a strike on New Orleans by Katrina as a major hurricane has grown. The official NHC forecast is now 170 miles west of where it was at 11am, and still is to the east of the consensus model guidance. It would be no surprise if later advisories shift the forecast track even further west and put Katrina over New Orleans. Until Katrina makes its northward turn, I would cast a very doubtful eye on the model predictions of Katrina's track. So much for the model prediction being high confidence, as I was surmising at 8am this morning! Recurvature is a difficult situation to forecast correctly.

The pressure of Katrina has continued to slowly drop, to 965mb. Dry air on the northwest side of the hurricane has interfered with the strengthening process, and may continue to do so over the next day. I still expect Katrina to attain Category 3 status Saturday, but Category 4 is looking less likely due to the dry air to the north. As one can see from the latest long range radar out of Key West, the northwest side of the eyewall is fragmented.

Some fairly prodigious rain amounts fell in the Miami area today. Homestead south of Miami measured 13.2 inches, and isolated amounts of 15 - 20 inches were observed between Homestead and Miami. The 7.55 inches at Key West was its 10th heaviest rainy day in history.

Jeff Masters