Storm Loses Some Punch As It Becomes Ragged and Disheveled in Gulf

Tropical Storm Karen has been fighting a valiant fight since it formed on Thursday morning, but the odds may be just too much for the storm to overcome. While a Hurricane Watch remains in effect for the Gulf Coast from Grand Isle, Louisiana to Destin, Florida, Karen weakened slightly to just have maximum sustained winds of 60 miles per hour with gusts to 70 mph. Minimum central pressure has risen slightly to 1003 millibars, or 29.62 inches of Hg.

With tropical storm force winds extending some 140 miles from the center of circulation as of the 8:00 AM EDT Advisory from the National Hurricane Center, a Tropical Storm Warning is in effect from Grand Isle, Louisiana to the Mouth of the Pearl River, and a Tropical Storm Watch is in effect from west of Grand Isle, Louisiana to Morgan City, Louisiana including the City of New Orleans, Lake Maurepas, and Lake Pontchartrain. A Tropical Storm Watch is also in effect for portions of the Florida Panhandle from east of Destin, Florida to Indian Pass, Florida.

As it pushes ahead to the North-Northwest at 10 miles per hour some 275 miles to the South-Southwest of the Mouth of the Mississippi River, Karen’s appearance looks much more ragged and disorganized than it did yesterday, and it was a lopsided storm at best before then with the bulk of its convection to the east of its center of circulation. The storm has also slowed down a bit from its forward speed of 13 miles per hour on Thursday. A turn to the right is expected to begin on Friday.

Karen is still over very warm water in the Gulf, but it continues to battle dry air and shear to the north and west of it. The wind shear affecting Karen is as high as 20 to 25 knots, or about 25 to 30 miles per hour. The intensity forecast is problematic at best due to the interaction between Karen, dry air, westerly shear, and a small upper level trough. The strengthening of this system is also dependent on whether or not it begins to make its more easterly turn over water. Some models such as the Canadian model indicate that the turn to the east will not occur until after landfall in Louisiana while the GFS has a much more dramatic turn to the right.

Right now, the European model calls for a 10 millibar drop in pressure with Karen after the turn to the right while the GFS, HWRF, and GFDL indicate much more significant deepening. Regardless of how much it strengthens, the biggest concern with this system will be the rain with rainfall amounts anticipated to be anywhere between 4 to 8 inches with isolated areas receiving as much as a foot. This much rain is the last thing that areas in the Southeast need after a very wet summer with a rainfall surplus of over a foot. Storm surges along the Gulf Coast could be as high as 3 to 5 feet.

All residents along the Gulf Coast from Morgan City to Tampa should continue to monitor the situation with Karen, and make necessary preparations.