September 20, 2005
Rita Watch: How's that high pressure system holding up?

The forecast for where soon-to-be-Hurricane Rita will hit the Gulf Coast has - for now - shifted westward.

Keep packing that suitcase and hold off on a sigh of relief, but the National Hurricane Center's latest official forecast names the stretch of coast just north of Matagorda Island as Rita's most likely target instead of Galveston.

With landfall on the Gulf Coast not expected until Friday night or Saturday morning, the forecast remains unreliable --different computer models call for different landfalls -- and the overnight course shift is small, so preparations continue in the danger zone from Brownsville to Lake Charles, La.

At 7 a.m. CDT, Rita was centered about 100 miles east-southeast of Florida's Key West. The storm had top sustained winds of 70 mph early today, and it was expected to strengthen into a Category 1 hurricane today, with winds of at least 74 mph, as it approached the Keys. It's expected to be a Category 3 storm by the time it hits the Gulf Coast.

State and local emergency operations centers remain on on high alert today as Tropical Storm Rita heads into the Gulf of Mexico and Gov. Rick Perry recalls the Texas National Guard and other emergency workers from Louisiana.

We're mostly prepared to either bug out or sit tight, depending on how this plays out. With the baby at home, we don't plan on taking any chances. I just really really hope it doesn't come to that.

All the forecasts are still big guesses at this time.

George Harvey, a senior meteorologist at Houston-based ImpactWeather, likens forecasting Rita's landfall to holding a garden hose a few feet from its faucet. As water gushes out, the end of the hose dances around unpredictably.

"It's the tail end of the storm that's still wiggling that we don't have a lot of confidence in right now," Harvey said.

Five-day forecasts for hurricanes are unreliable the average error exceeds 250 miles. If Houston remains in Rita's cross hairs by Wednesday, forecasters say, it's far more likely the city will get hit. Until then several factors bear watching.

The big issue is when a dominant ridge of high pressure along the upper Gulf Coast, including Texas, slides eastward, away from the area. This dome of high pressure is responsible for Houston's clear skies and near-record temperatures this week.

For now, it's also blocking Rita from turning northward as it enters the Gulf.

SciGuy has a little bit of good news, and a fuller explanation of why Rita may be headed west of here. Check them out.

Right now, my main concern is wind damage. We've had a fairly dry month, so I'm not too worried about flooding. For the most part, Houston can handle big rains. TS Allison was a problem because it stalled here for several days, and got to the point where there was no place for any of the rain to go. That was truly a freak of nature, and is highly unlikely to repeat with Rita. There will be street flooding, probably some houses in low-lying areas, but my layman's gut feeling says it won't be that bad. I'm more worried about falling trees and downed power lines. At this minute, anyway. Ask me again later and I'll probably be fretting about something else.

Posted by Charles Kuffner on September 20, 2005 to Hurricane Katrina | TrackBack

Charles, if Rita turns into a cat 3 storm and comes in on Galveston Island or nearby, the storm surge could result in flooding that is as bad as TR Allison, but the flooding would be in areas nearer the coast. Allison's flooding was more widespread around the metro area due to torrential downpours of, as you note, a slow moving system. The flooding from Rita would be more attributable to the storm surge than rain.

Posted by: Tom K. on September 20, 2005 9:45 AM

Good luck to all.

Any good live info on travel conditions on Hwy 10, 290, 45 and 59?
This article suggests that in a major (4 - 5 catagory) hurricane evacuation, people have to allow 10 to 20 times more travel time than usual.

So a trip to Austin, normally a 3 hour trip becomes a 30 to 60 hour trip. go. gulp stay.

The Houston Chronicle Feb 20 2005:

Michael K. Lindell and Carla S. Prater, a husband-and-wife team at Texas A&M University's Hazard Reduction and Recovery Center, designed the study of evacuation times and routes on which many officials rely. They say the evacuation times must be strictly enforced and that delays could be fatal.

"The problem is partly the misconception people have about how long it's going to take because they're relying on their personal experience," Lindell said. People tend to think in terms of a four- or five-hour drive to San Antonio or Dallas, he said, but they need to multiply that by 10 or 20 times because of the crowds."

No wonder sleeping bags, blankets are recommended to take.

Posted by: Support Science to Reverse Global Warming, if still possible on September 20, 2005 3:32 PM