Current Location: 15.0N, 61.8W
Geographic Reference: 30 miles southwest of Dominica
Movement: West-southwest at 17 mph
Max Winds: 45 mph gusting to 60 mph
Current Hurricane Severity Index: 3 out of a possible 50 points (1 size, 2 intensity)
Max Predicted Hurricane Severity Index: 3 out of a possible 50 points (1 size, 2 intensity)
Current Radius of Tropical Storm-Force Winds: 35 miles
Max Predicted Radius of Tropical Storm-Force Winds: 35 miles
Organizational Trend: Decreasing
Forecast Confidence: Average
Key Points
1. Isaac may weaken to a tropical depression later today.
2. Weakening and dissipation are forecast to occur in the Caribbean due to unfavorable conditions.
Our Forecast
Isaac remains a weak system with an exposed low level circulation center located southwest of Dominica. A reconnaissance plane currently investigating Isaac is having trouble finding a center. However, high-resolution visible satellite imagery and surface reports indicate there is a very shallow center with a small area of squalls to the east-northeast over the Dominica area. A very small area of tropical storm winds are possible northeast of the center. However, Isaac will likely be downgraded to a depression later today, and could completely dissipate within a day or two. Some long range guidance indicates Isaac will dissipate in the western to central Caribbean over the coming weekend.
Expected impacts on Land
Central Lesser Antilles: Scattered power outages are expected within about 50 miles of the center. Flooding and mudslides are likely to cause some damage and travel delays.
Puerto Rico : At this time, most of the rain and all of the wind associated with Isaac are expected to pass the island well to the south.
Our next advisory will be issued by 4 PM AST / 3 PM CDT.
Meteorologist: Jim Palmer
| Forecast Confidence: Average | Hurricane Severity Index | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Fcst Hour | Valid | Lat. | Lon. | Max Sustained Winds | Max Gusts | Category | Size | Intensity | Total |
| 0 | 9AM CDT Thu Sep 13 | 15.00N | 61.80W | 45 mph | 60 mph | Tropical Storm | 1 | 2 | 3 |
| 12 | 9PM CDT Thu Sep 13 | 14.60N | 64.50W | 35 mph | 45 mph | Tropical Depression | 0 | 1 | 1 |
| 24 | 9AM CDT Fri Sep 14 | 14.70N | 67.60W | 35 mph | 45 mph | Tropical Depression | 0 | 1 | 1 |
| 36 | 9PM CDT Fri Sep 14 | 14.90N | 70.60W | 35 mph | 45 mph | Tropical Depression | 0 | 1 | 1 |
| 48 | 9AM CDT Sat Sep 15 | 15.20N | 73.70W | 35 mph | 45 mph | Tropical Depression | 0 | 1 | 1 |
| 72 | 9AM CDT Sun Sep 16 | 15.60N | 77.00W | 30 mph | 40 mph | Remnant Low | 0 | 0 | 0 |
| 96 | 9AM CDT Mon Sep 17 | 16.70N | 80.20W | 30 mph | 40 mph | Remnant Low | 0 | 0 | 0 |
| 120 | 9AM CDT Tue Sep 18 | 17.40N | 84.50W | 30 mph | 35 mph | Remnant Low | 0 | 0 | 0 |
The yellow cone represents track error from the previous five hurricane seasons. Over the past five hurricane seasons, the center of the storm tracked within the yellow cone 75% of the time. The cone does not represent the forecast uncertainty in the current advisory for this storm. In addition, hurricane-force winds, very high tides, large waves, and heavy rainfall can often extend well outside the yellow cone.
