Florence has weakened dramatically due to westerly shear
Florence tracks westward into a warmer ocean/no shear zone
Returns to major hurricane status early next week
Uncertainty: Florence into Carolinas or stall off coast
92L and 93L both likely to become hurricanes
Climate Impact Company Tropical Cyclone Risk Table
|Probability Hurricane (previous)||Probability Intense Hurricane (previous)||U.S. East Coast Strike (previous)||Gulf of Mexico Strike (previous)|
|Hurricane Florence||100% (100%)||100%|
Table 1: Climate Impact tropical cyclone risk forecast table.
Fig. 1: The axis of upper shear axis. Note little or no shear ahead for Florence once past westerly shear across storm now.
Fig. 2: Florence is headed for an exceptionally warm ocean surface next week.
Discussion: At 5 AM EDT Tropical Storm Florence was located at 25.1 North/50.7 West or about 925 miles east-northeast of the Leeward Islands. Florence is moving west at 7 mph with top wind 65 mph and surface pressure 996 MB. Florence has weakened considerably due to westerly shear across the storm the past 12-18 hours.
Florence is forecast to drift west slowly returning to hurricane strength the second half of the weekend as the upper shear eases. NOAA/NHC forecasts Florence to return to major hurricane classification in 4-5 days as upper shear fades and Florence tracks over warm surface water.
The 6-10 day forecast is critical and made with low confidence. Potential scenarios include a major hurricane into the upper South Carolina coast Thursday (ECM model) or a north turn but stalling south of Long Island for 2-3 days late next week (GFS model).
Tropical Disturbance 92L is located in the east-central North Atlantic tropics while Tropical Disturbance 93L is approaching the Cape Verde Islands. Both of these systems are likely to become tropical storms within 1-2 days. There is likelihood that each become hurricanes in 4-5 days. 92L will head west for the Caribbean Sea while 93L is likely to turn northwest toward the central subtropical North Atlantic in 5 days. The next storm names are Helene and Isaac.
Fig. 3: NOAA/NHC 5-day forecast track of Florence.
Fig. 4: The ECMWF 10-day forecast track for Florence.