Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 1:46 PM GMT on September 16, 2008
If you take a ferry from Galveston northeast across the Galveston Bay inlet, you arrive at the small town of Port Bolivar, which sits at the end of the 25 mile-long Bolivar Peninsula. Since the peninsula was situated on the right front side of Ike's eye, it took the worst of the storm. The Hurricane Hunters measured 110 mph winds at the shore when Ike made landfall, and Ike's highest storm surge hit the peninsula. The exact height of the storm surge is unknown, since there were no tide gauges there. Based on reports of a storm surge of 11 feet at Galveston Island and 13.5 feet at the Louisiana/Texas border, it is likely that storm surge heights along the Bolivar Peninsula were 14 feet or higher. Photos taken by the U.S. Geological Survey yesterday (Figure 1) of the Bolivar Peninsula show the tremendous damage a huge storm surge can do--entire neighborhoods of homes washed off their foundations and completely destroyed. Had Ike not wobbled 50 miles to the right in the hours prior to landfall, the scenes below could have been what Galveston would have looked like, even with their seawall.
Figure 1. Oblique aerial photography of Bolivar Peninsula, TX, from September 9, 2008 (top) and September 15, 2008, two days after landfall of Hurricane Ike. Image credit: U.S. Geological Survey. Their web site will be posting more comparison photos in coming days as they do more flights.
Dr. Abby Sallenger, Jr. of the USGS described yesterday's damage survey flight:
Here's what we saw in our overflight from about Grand Chenier in western Louisiana to Freeport below Galveston.
We saw vast areas flooded by storm surge; the water extended landward in places for tens of kilometers. The beaches served as rims that contained the flood waters. In Louisiana, channels were cut (naturally) through the beaches so the water would drain seaward. Where the max surge occurred (between Bolivar Peninsula and Sabine Pass), the returning water completely submerged the Gulf shore for kilometers. The maximum impacts were on the Bolivar Peninsula, the site of our example comparisons online now.
How you can help
For those of you who want to help those in need, I'm proud to say that a group of wunderground members are spearheading their own Hurricane Ike relief effort, aimed at providing assistance and supplies to people that are not in the mainstream relief areas. Deductions are tax-deductible, and can be made in several ways:
Of course, contributing to the Red Cross or your local church is another great way to help out. Thanks!
The tropics are quiet
The tropics are quiet. The area of disturbed weather (92L) approaching the Lesser Antilles Islands that we were watching has been torn apart by wind shear. There are no threat areas to discuss at this time. The ECMWF and NOGAPS models indicate the possibility of something developing in about six days in the Western Caribbean near Mexico's Yucatan Peninsula. The GFS model predicts development of a tropical depression off the coast of Africa about six days from now.
Atlantic hurricane outlook for the last half of September
Well, we've just come out of a long and intense period of hurricane activity--29 straight days with a named storm in the Atlantic, with all four of these storms--Fay, Gustav, Hanna, and Ike--causing heavy damage and inflicting high death tolls. The last time we had such an active period was in 2005, when we went 56 straight days from August 2 to September 26 with a named storm in the Atlantic. Katrina, Ophelia, and Rita all made landfall during that period. Fortunately, even the busiest hurricane seasons take a breather. We had a 4-day break in 2005 at the end of September. This year, we look to get a longer break of 7-10 days.
Climatologically, the last half of September is one of the busiest periods in the Atlantic for hurricane activity. The peak of the season occurs on September 10, and the entire month of September is very active, with a high chance of dangerous major hurricanes (Figure 2). Sea Surface temperatures and oceanic heat content are at their peak right now, and have not begun to cool yet. Wind shear is near average or a little below average over most of the tropical Atlantic, and is forecast to remain so for the next two weeks. The peak portion of hurricane season lasts until mid-October, and I anticipate that we have at least one more major hurricane coming, and probably 4-5 more named storms.
Figure 2. Tracks of all hurricane and tropical storms for the past 156 years that formed in the last half of September.
In the longer term, winds shear is predicted by NOAA's CFS model to remain below average over the Caribbean for all of October and November. The model also predicts that Sea Surface Temperatures (SSTs) will range from 1-2°C above average over most of the hurricane main development region (from the coast of Africa to Central America between 10° and 20° latitude, including the Caribbean). SSTs have cooled dramatically in the Gulf of Mexico and Bahamas, thanks to the passage of Fay, Gustav, Hanna, and Ike stirring up cold waters. These reduced SSTs will reduce the possibility of a major hurricane hitting the U.S. and Bahamas during the remainder of hurricane season. However, SSTs are about 1°C above average over the Caribbean and the region between Africa and the Lesser Antilles Islands. That's a lot of fuel for potential hurricanes during the coming months.
Figure 3. Departure of Sea Surface Temperature (SST) from average for September 15, 2008. Note the strong cooling of up to 4°C in the Gulf of Mexico created by Hurricanes Gustav and Ike when they churned up cool waters from the depths. Image credit: U.S. Navy.
When will activity pick up again?
There is an oscillation in the atmosphere I haven't talked about much before, called the Madden-Julian Oscillation (MJO) that will influence when hurricane season will get more active. The MJO is a pattern of enhanced rainfall that travels along the Equator, and can act to boost hurricane activity when it propagates into the Atlantic. The MJO has a period of about 30-60 days, and is currently in its inactive phase over the Atlantic. However, according to the latest MJO discussion from the National Weather Service's Climate Prediction Center, we are expected to enter an active phase for the MJO over the western Gulf of Mexico and Caribbean beginning six days from now. As I mentioned above, the ECMWF and NOGAPS models are indicating the possibility of development in this region beginning about Monday of next week. So, enjoy the quiet interlude this week, because I expect by late next week there will be one new named storm in the Atlantic. The steering current pattern is not expected to change in the coming two weeks, and will favor steering hurricanes into the East Coast of the U.S. or Gulf of Mexico. By the beginning of October, I expect more recurving hurricane to occur, as the jet stream begins its annual Fall migration southward.
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