22 September 2005

Rita breaks the 900 barrier...

At 03Z today, Hurricane Rita's central pressure bottomed out at 897mb, nudging past the rarely-broken 900mb threshold.  Only 3 other storms have achieved this intensity: Gilbert 1988 (888mb), Labor Day 1935 (892mb), and Allen 1980 (899mb).  This occurred just 24 days after Katrina reached its peak intensity of 902mb, and virtually at the same location.

Since then the storm has weakened a BIT, and is presently at 915mb and ~140kts.  Given that such a high intensity is so hard to achieve, let alone maintain, the storm is expected to weaken further over the next 24-36 hours prior to landfall.  BUT, keep in mind that a storm at 907mb has a looong way to weaken before it's not major, so landfall will almost certainly be as a CAT3/4 hurricane.  It's moving WNW at 8kts, but this motion will become NW with time as the steering ridge to its north shifts eastward.  The latest position is 25.4N 88.7W, or about 225 miles due south of the mouth of the Mississippi River.

Landfall is becoming a more ominous event, and is expected to occur in the early morning hours on Saturday as a major hurricane.  The latest official track forecast and model guidance have shifted eastward a bit, now placing the prime target just east of Galveston Bay.  Hurricane Warnings are in place now from Matagorda Bay TX eastward to Atchafalaya Bay LA, and evacuations are underway in many cities within the warning area (also in New Orleans with fears of the rainfall breaking the patched levees).  Hurricane-force winds now extend 75 miles from the center.

Looking beyond landfall, the steering flow is forecast to dwindle, leaving Rita to stall over TX/OK/AR/LA, perhaps dumping upwards of 2 feet of rain over the area.  This has to potential to be a very catastrophic storm.  The eyewall is only one part of the storm... the coast has to contend with a large storm surge, and places inland have to contend with rain-induced flooding and spiral band-spawned tornadoes.

Philippe is still a tropical storm, with estimated intensity at 35kts and 1005mb.  It is quickly losing tropical characteristics and today will likely be its last day as a tropical system.  The transitioning system is heading north toward the north-central Atlantic.

The season's NTC stands at 175% now; only ten years since 1900 have had higher seasonal NTCs, and this season isn't over yet.

Please visit my tropical Atlantic headquarters.

No comments:

Post a Comment