Accuweather 1 PM Discussion

[charleston_hugo_veteran]

Today's Discussion
POSTED: September 15, 2004 1:13 p.m.


HURRICANE IVAN REMAINS A VERY DANGEROUS CATEGORY 4; LANDFALL EARLY TOMORROW..

As of 11 a.m. EDT, Category 4 Hurricane Ivan was centered at 27.3 north, 88.0 west, or about 235 miles south of Mobile, Alabama. Ivan is moving north at 13 mph. Maximum sustained winds are near 135 mph. Hurricane-force winds extend 105 miles from the center; tropical-storm-force winds 290 miles from the center. The central pressure is 939 millibars (27.73 inches).

A hurricane warning is in effect from Grand Isle, La., including New Orleans, to Apalachicola, Florida. A hurricane watch is in effect from Morgan City, La., to west of Grand Isle. A tropical storm warning is in effect from Intracoastal City, La., to west of Grand Isle, and from east of Apalachicola to Yankeetown, Fla.

There has been no major changes in Ivan over the last 12 hours. We expect the hurricane to keep moving northward today, as it continues to track around the periphery of a large Atlantic High pressure area that is currently nosing westward into the eastern Gulf of Mexico. Ivan should make landfall between Gulfport, Mississippi and Dauphin Island, Ala., between 3 and 6 a.m. EDT Thursday morning. Ivan will bring a storm surge of 10-16 feet over and to the east of where it makes landfall. The current eye path forecast has this just west of Mobile Bay, which makes the bay vulnerable to catastrophic flooding, as water will be funneled up through it. Heavy rainfall of 10-15 inches is expected over parts of southeast Louisiana, eastern Mississippi and southern and central Alabama tonight by Friday morning. Heavy rainfall is also expected over northern Alabama, eastern Tennessee and northern Georgia tomorrow night into the weekend. Current computer projections suggest the remnant low of Ivan might stall over southeast Tennessee this weekend. That could lead to torrential rainfall, leading to catastrophic flooding over parts of the southern Appalachian mountains extending into the western Carolinas.
Ivan is a large hurricane and the intensity of large hurricanes is easily affected by small changes in water temperature and upper level winds. Current water temperature maps show a large pocket of deep warm water in Ivan's path. This could allow Ivan to intensify during this afternoon. But, as Ivan approaches the coast the depth of the warmer water diminishes and that could allow Ivan to weaken before landfall. Despite all this we still expect Ivan to make landfall as a strong Category 3 or Category 4 hurricane early tomorrow. As it moves in, not only will there be flooding from the rain and storm surge, but winds along the coast will be strong enough to destroy structures and make missiles out of objects caught in it. With the large size of the storm, hurricane force winds (greater than 74 mph) can extend well inland. Tornadoes will be possible east of the center, as well.

Tropical Storm Jeanne is nearing hurricane strength. As of 11 a.m. EDT, the storm was centered at 17.8 north, 65.8 west, or about 45 miles south-southeast of San Juan, Puerto Rico. Jeanne is moving west-northwest at 8 mph. Maximum sustained winds are 70 mph. The central pressure is 991 millibars (29.26 inches). Jeanne will track over or just south of Puerto Rico during the day today, then track along or just north of the coast of the Dominican Republic tonight and tomorrow. This interaction with Puerto Rico and the Dominican Republic will prevent Jeanne from becoming a real strong system. However, before it moves over or near Puerto Rico there is some chance it could become a hurricane for a brief time. Heavy rainfall averaging 10-15 inches of rain will cause flooding and mudslides over Puerto Rico during today and tonight. This will put many people in a dangerous situation. If Jeanne does track along the north coast of the Dominican Republic it will keep the heavier rainfall north of that country. Computer models suggest Jeanne will move on a more northwest course towards the Bahamas tomorrow and tomorrow night. This would allow the system to move away from land and could allow the system to become stronger. Long range computer models show a variety of options as to where Jeanne might track beyond Friday.

Elsewhere in the Atlantic basin, there is a fairly strong tropical wave south of the Cape Verde Islands. A tropical wave is in the central Atlantic. There is a weak wave in the western Caribbean.

[meteorjosh]

that's a reprint of their 11am discussion