Isabel at 8 am

[WXBUFFJIM]

HURRICANE WATCHES AND WARNINGS

At 8 AM EDT, a hurricane warning has been issued from Cape Fear, North Carolina northward to the Chicoteague, Virginia area including the Pamlico and Albemarle Sounds, Virginia Beach, and Norfolk, and the Chesapeake Bay from Smith Point to the mouth of the bay. That includes Yorktown, VA and Newport News, VA as well. A hurricane watch is in effect on the entire Maryland portion of the Chesapeake Bay north of Smith Point and tidal Potomac including Washington DC and Baltimore Harbor. A hurricane watch means that the hurricane conditions are possible within 36 hours time. A hurricane warning means that the hurricane conditions are expected within 24 hours or less.

A tropical storm watch is in effect from Chicoteague northward to the Sandy Hook, NJ including Delaware Bay. Cities in this watch include Philadelphia, Atlantic City, and Ocean City, MD. Additional tropical storm watches remain in effect south of Little River Inlet to south Santeee River, South Carolina. A tropical storm warning is in effect from Cape Fear southward to Little River Inlet, South Carolina. A tropical storm watch means that the tropical storm conditions are possible within 36 hours. A tropical storm warning means that the tropical storm conditions ae expected within 24 hour or less.

8 AM EDT ADVISORY ON ISABEL

Isabel hasn't changed her strength overnight and is showing more signs of holding her own or becoming possibly a category 3 hurricane. At 8 AM EDT, the center of hurricane Isabel was located near latitude 29.7 north, longitude 72.4 west or about 425 miles south southeast of Cape Hatteras, North Carolina.

Isabel is moving towards the north northwest at near 9 mph. This motion is expected to continute with an increase in forward speed during the next 24 hours.

Maximum sustained winds are 110 mph with higher gusts. Little change in strength is expected during the next 24 hours. Isabel is a strong category 2 hurricane on the saffir simpson scale. Sustained winds of 96-110 mph is considered a category 2 hurricane with moderate damage. Sustained winds of 111-130 mph is a category3, which can cause extensive damage.

Minimum central pressure is 957 mb or 28.26 inches.

At landfall on Thursday along the North Carolina will occur with expected rainfall amounts of 6-10 inches with locally higher amounts. Storm surge flooding of 7-11 feet above normal tide levels can be expected in the area just to the right of where the center makes landfall. Also expect waves of 20-30 feet with offshore waves of 35-55 feet. Isolated tornadoes are also a possibility as common in tropical systems. However tornadoes are usually short lived and weak in tropical systems.

Further up the coast along the Maryland portion of the bay, hurricane watches are up. This means that hurricane conditions are possible within the next 36 hours. Even as isabel weakens, that could be a very strong storm system. Part of the reason for this hurricane watch has to do with the pressure gradient. The pressure gradient is simply winds between high pressure and low pressure. High pressure centered over new england will have winds cuculating around it in a clockwise matter. Winds around low presure circulate in the counterclockwise matter. Thus the wind move from high pressure into low pressure. The closer those features are and the stronger they are, the tighter the pressure gradient. Thus winds sustained at 40-60 miles per hour are expected in Baltimore and DC Thursday night into early Friday with gusts possibly over 75 mph in squalls near the center. Rainfall amounts of 3-6 inches can be expected. Storm surge flooding of 2-5 feet above normal tide level can be expected at Baltimore Harbor and the western shore of the Chesapeake Bay. Yes tidal flooding may occur at Baltimore Harbor, at least minor!!

I will update ya all day long on isabel.

Jim