|Updated: 8/28/2012 12:43 pm
||Published: 8/27/2012 12:07 pm
According to John Robinson, Warning Coordination Meteorologist for the National Weather Service, the most likely track for Isaac is through southern and central Arkansas, then continuing to the north. However, the track is uncertain and could still shift toward the east or west.
The Hurricane Center's projected track has been shifting gradually to the west in succeeding forecast issuance.
Isaac is forecast to be only a tropical depression by the time it could reach Arkansas. This would mean sustained winds of 38 mph or less. Wind Advisories or Lake Wind Advisories would probably be necessary.
While the track still has quite a bit of uncertainty, there are some things that are typical with diminishing tropical systems that are well inland.
1. Areas to the east of where the center passes will get the heaviest rain. Rainfall amounts exceeding 5 inches would certainly not be out of the question. Heaviest rains typically occur in bands of showers and thunderstorms that spiral inward toward the center. To the west of where the center tracks, rainfall amounts are much lower and typically come from scattered showers and thunderstorms in the afternoon and evening. There is normally a very sharp cut-off between areas that get a lot of rain and areas that get only a little.
2. The strength of the tropical system does not equate to how much rain it can produce. There have been cases where tropical depressions caused more rain than hurricanes.
3. During the day, the area of showers and thunderstorms around a tropical system will be quite large. In fact, showers and thunderstorms can easily extend out two or three hundred miles from the center. At night, though, the heaviest rains usually occur near the center of the system's circulation. These are known as "core rains" and can be very heavy.
4. Tornadoes sometimes accompany tropical systems even when they are well inland. Typically, these occur in the bands of thunderstorms spiraling in toward the center of the system. They tend to be short-lived, and are usually EF0 or EF1 in intensity. However, there have been cases of EF2 tornadoes in Arkansas. In 2008, the remains of Gustav produced two EF0 tornadoes in Arkansas. That same year, the remains of Ike produced nine tornadoes -- three were EF0 and six were EF1. In 2005, the remains of Rita brought 15 tornadoes to Arkansas -- three F0, nine F1, and three F2. Tornadoes are usually produced in the right front quadrant of a tropical system. So, for a hypothetical example, if the center were over Little Rock, the best chances for tornadoes would be in northeast and east central Arkansas.
5. Due to the drought this year, many trees have been weakened. Tree experts have warned that strong winds will cause more trees than usual to fall. And, of course, falling trees will lead to power lines falling.