Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 3:25 AM GMT on September 23, 2005
There are no major changes to report tonight on Rita's situation. The pressure continues to hold steady in the 913 - 917 mb range, which is very low, considering she is going through a long eyewall replacement cycle. The hurricane force winds have expanded out to 80 miles, which is still quite a bit less than Katrina's 120 miles. I expect that the area of extreme storm surge from Rita will be less than Katrina's, since Rita is a smaller storm.
Rita's eyewall replacement cycle is almost complete, and we may see some slight strengthening Friday morning. By Friday evening, slight to moderate weakening may occur until landfall Saturday. This will occur as a result of 10 knots of shear on her south side from an upper-level high pressure system, and from passage over ocean waters with less heat content. By landfall time on Saturday afternoon, I still expect that Rita will be a Category 3 or 4 hurricane, but still carry to the coast a storm surge characteristic of a much stronger hurricane. A Category 4 or 5 level storm surge is likely along a 40 - 60 miles stretch of coast to the right of where the storm makes landfall on Saturday. Storm surge heights will peak at 15 - 20 feet in some bays, and bring the ocean inland up to 50 miles from the coast. Large sections of I-10 between Houston and Beaumont could be inundated, and the flood waters may reach the cities of Beaumont, Orange, and Lake Charles.
Figure 1. Expected inland penetration of a Category 5 level hurricane storm surge. Only areas along and to the right of Rita's landfall point may get a Category 5 storm surge. If Rita makes landfall east of Galveston, Houston and Galveston will not see the storm surge flooding shown here.
Current buoy measurements
NOAA buoy 42001 in Rita's western eyewall measured sustained winds of 90 mph, gusting to 112 mph, and 34 foot waves at 2:50 pm CDT. A time series plot of the wind and pressure from buoy 42001 is worth checking out. Winds are starting to fall now as Rita moves away. The buoy did not quite make it into the eye of the strongest part of the eyewall.
Where will Rita go?
The 18Z (2pm EDT) computer models are more tightly clustered than before, focusing on a point just west of the Texas/Louisiana border. It is still too early to tell what will happen after landfall, as the models all take Rita different ways. It is heartening to see that the GFS model is no longer taking Rita back out to sea and hitting Brownsville! Regardless, it appears that a major rainwater flooding disaster will ensue after Rita's landfall, with 10 - 30 inches of rain falling over a large area.
Elsewhere in the tropics
Tropical Storm Philippe is a minimal tropical storm heading out to sea, and is not a threat to any land areas. The ITCZ is growing more active tonight, and there may be an area of development to watch in the mid-Atlantic by tomorrow.
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