September 11, 2003 11:04 p.m.
Hurricane Isabel, the first category 5 hurricane in the Atlantic Basin since Hurricane Mitch, remains powerful, with sustained winds of 160 mph and gusts to 195 mph. It continues to move westward across the Atlantic at 9 mph. The lowest central pressure is estimated at 924 mb (27.29 inches) As of 11 P.M. AST, the eye of Isabel was centered at 21.6 north, 56.1 west, or about 455 miles northeast of the northern Leeward Islands. This track and forward speed means Isabel will pass by north of the Leeward Islands later tomorrow and tomorrow night; north of Puerto Rico later Saturday and Saturday night, ending up north of the Dominican Republic by early Monday. On Tuesday, we expect it will be near or east of the Bahamas. As we talked about yesterday, the main synoptic features that will play a role in the track of Isabel are the western Atlantic ridge, and the trough that will try and push into the middle and eastern part of the U.S. next week. A weakening of the western Atlantic ridge in the next couple of days will mean a turn to the west-northwest and even northwest; if that does not occur, the storm track will probably be farther south. Either way, Isabel is still many days away from affecting the U.S. mainland. The area of low pressure east of the North Carolina coastline is the remnants of Tropical Storm Henri. With high pressure building to the north of it, there is a good chance that this low will back toward the mid-Altantic and Northeast coast tomorrow and Saturday. Current surface observations from ships and buoys show the center of the remnant low is located near 32.5 north and 75.5 west. During Thursday afternoon pressures are falling and winds to gale force are being reported just off the coast of North Carolina. Whether or not the remnants of Henri will regain tropical characteristics remains to be seen, but the scenario of a gale center backing westward means there can be nor'easter conditions on the mid-Atlantic and/or Northeast coasts this weekend (i.e. wind, rain and pounding of beaches). Tropical Depression 14 has pretty much dissipated near the Cape Verde Islands, but will still bring some wind and rain to those islands. The tropical wave that created TD 14 is along 34 west south of 16 north. A tropical wave is located along 86 west, south of 22 north, in the northwest Caribbean. The strongest convection, or thunderstorm activity, is actually to the east of the wave axis, in the southern Caribbean. This wave will move into the southwest Gulf of Mexico on Friday then reach the Mexican coast Saturday night or Sunday. Moisture from this wave might interact with a cold front moving into deep south Texas Sunday night and into northern Mexico on Monday. This kind of interaction can lead to tropical development. But, this kind of development usually takes a few days. That would not occur until sometime later next week.
