FLHurricane.com: Katrina's Forecast Track Shifts West, Northern Gulf Needs to Watch

#97 Published Friday August 26, 2005 at 8:15 pm EDT
http://www.kn4lf.com/flwx1.htm

At the 8:00 pm EDT advisory CAT 2 has a sustained wind of 100 mph, is at position 24.7 deg. N 83.3 deg. W, with a minimum barometric pressure of 28.50" and is currently on a WSW heading or 255 degrees at a speed of 8 mph. is currently not strengthening due to dry air entrainment into her NW quadrant but should begin later in the evening.

She has actually shifted a little further south of west during the past six hours. Going back to 1965 I must say that I cannot ever remember a tropical cyclone that has moved from NE to SW through this region. But I did mention the possibility back in advisory #93.

The WSW-SW heading of the past 24 hours has occurred due to the mid and upper level high pressure ridge along 32 deg. N and between 85-95 deg. west and the low and mid level inverted trough located east of the Bahama Islands. This high pressure system will weaken and shift westward in response to a strengthening and digging mid level longwave trough currently located over the northern Great Plains.

CAT 2 will eventually turn W-NW during the next 24 hours but the northerly turn could be 48-72 hours away and exact timing depends on how quickly the mid level trough digs SE'ward towards the NW Gulf Of Mexico. Right now it's still anyone's guess and as usual the models continue pretty useless, with a continued landfall spread between Morgan City, LA in the west and Apalachicola, FL in the east but the clustering of the models has moved westward to Mississippi from the western Florida Panhandle.

I too am shifting my landfall window westward, to between Mobile, AL and Pensacola, FL, from my earlier Pensacola, FL to Panama City, FL window, not because of the models shift but due to 's continued WSW heading. I never chase model changes, live by the model die by the model. If this WSW track trend continues then the Apalachicola, FL to Panama City, FL region will probably dodge a big bullet.

I still think the easier forecast of the two is intensity. With very warm Gulf Of Mexico water temperature including the loop current ahead and as very little wind shear is forecasted, could easily reach CAT 4 before landfall. But she could weaken back to a CAT 3 after leaving the loop current prior to making landfall, much like CAT 4 Opal did in 1995.