Friday, September 12, 2008

A Potential Life-Threatening Surge from Ike

Tim Ballisty, Meteorologist, The Weather Channel
8:06 a.m. ET 9/12/2008
Hurricane Ike

As of 8 a.m. CDT, Ike was located about 230 miles southeast of Galveston, Texas, with maximum sustained winds near the center increased to 105 mph. The forward movement is toward the west-northwest at around 13 mph.

Although it has fluctuated up and down over the past 12 hours, Ike's pressure remains low with the latest reading from an Air Force Hunter Aircraft of 956 millibars. Landfall is less than 18 hours away but additional strengthening could still occur and it still may attain Category 3 status. That being said, the impacts from a high end Category 2 and a low end Category 3 are nearly identical.

A hurricane warning remains in effect from Morgan City, Louisiana, to Baffin Bay, Texas and tropical storm warnings are in effect for the southeast Louisiana and Mississippi coasts, including the city of New Orleans.

On its current track, Ike should make landfall along the upper Texas coast late tonight or very early Saturday morning as a Category 2 or Category 3 hurricane. The landfall location will probably be in the zone from the Freeport-Lake Jackson area to Galveston, Texas.

A strike in this portion of the Texas coast will provide dangerous, perhaps life-threatening impacts.

The most severe conditions will impact areas just to the north and east of where the center makes landfall; the right front quadrant of Ike's circulation. Water level rise will be life-threatening in some coastal Texas counties especially Matagorda, Brazoria, Galveston, and Jefferson County. Folks of Cameron County, Louisiana, should also beware of the potentially destructive water level rise along the coast. Because of Ike's very large size, the water level rise produced by Ike will be larger than an average-size Category 2 hurricane.

The NHC warns of a significant and very dangerous storm surge of up to 20 feet could occur near and to the east of where Ike's center of circulation makes landfall. A surge of 25 feet could occur at the heads of the bays.

Here's a graphic outlining the highest coastal flood threat.

Along with the surge comes powerful, damaging winds. Hurricane-force winds extend 120 miles from the center while tropical storm-force winds extend and astounding 275 miles from the center.

Because of this massive size, it is very important to emphasize that tropical storm and hurricane conditions will be felt well before Ike's center of circulation makes landfall. Conditions will deteriorate along the Texas coast well before that point.

View the projected path here.

Residents and tourists along coastal Texas should focus all attention to the latest forecasts and follow instruction from local authorities especially in regards to evacuations. Preparations to protect life and property should be rushed to completion by this evening.

Water level rises and growing waves have already impacted the Gulf Coast from Texas to Florida. Waves were highest today along the Alabama and western Florida Panhandle coastline where they have peaked between 15 to 20 feet. However, the highest waves will then propogate farther west to the coastlines of Texas and Louisiana on Friday.

Coastal flood warnings and advisories, along with high surf advisories blanket parts of the Gulf Coast from southeastern Louisiana to the western coast of Florida. Deadly rip currents and beach erosion will also be threats.

Given the very large size of Ike, areas outside of the forecast landfall will also feel increasing impacts today. The pressure gradient between high pressure in the Northeast and Hurricane Ike have brought windy conditions to portions of the northern Gulf Coast, especially Louisiana.

Northern outer bands from Ike will impact parts of the north central Gulf coast today, in the form of bands of showers and thunderstorms. Squalls will impact southern Louisiana along with the threat for a few tornadoes.

Heavy rain, strong damaging winds, rising water levels, and battering waves will increase along the Texas Coast today, with the worse conditions expected tonight and early Saturday.

After Ike makes landfall early Saturday, life threatening flooding rains and potentially damaging winds will spread inland across Texas. As Ike continues to weaken Sunday, the flooding rains will shift into eastern Oklahoma, northern Arkansas, southeast Kansas, central and southern Missouri and southern Illinois.