(PM)-Hurricane Dorian is just now finally moving out of the Bahamas after spending the greater part of two days spinning near the islands. The storm is still moving at a snails pace of 2mph to the northwest. This is expected to change and movement will accelerate as a trough from the north picks up the storm but not before it gets dangerously close to the United States.
The storm has weakened down to a Category 2 storm mostly due to land interaction in the Bahamas and cold ocean waters. As you can see in the graphic above Dorian is now sitting in waters 8C lower than before. This is because the storm stalled and mixed up colder waters from below the ocean surface. Since warm water fuels convection and essentially hurricanes, Dorian has been running out of gas to burn.
This is clearly seen on a recent microwave imagery pass which shows how strong the core of a storm is. The eastern core is still in tacked but the western eyewall is open and shattered. This is good news for Florida and the southeast as the strongest winds are on the east side of the storm.
It remains to be seen if the core closes off once Dorian begins to head north into warmer waters. If that happens we could see another period of restrengthening later today and tomorrow.
The current expected track keeps Dorian about 70-80miles off of the eastern Florida coastline. This is great news as it will only brush the peninsula with tropical storm force winds. After Dorian makes the move north, it has the Outer-banks in its sights.
The HWRF model used exclusively for hurricane prediction is showing a track slightly more inland. The model shows a landfall in the outer banks as a category 2/3 storm. This solution is possible but it is one of the furthest west models currently. It is of note that this model has consistently been too far west in its prediction for Dorian. It had the storm making landfall in Florida when that no longer is expected to occur.
Other models show that Dorian is expected to bend with the shape of the southeast coastline. This will keep the worst impacts out over the ocean which is the best case scenario for the continental United States.
Beyond a brush with the Carolina’s coastlines the storm is expected to accelerate out to sea. This is before a trough will interact with the storm and possible pull it close enough to impact the northeast. Atlantic Canada also needs to be on watch as Dorian can make landfall there as it turns extra-tropical.
The forecasted wind-field of Dorian shows the core of winds in the pink are expected to remain offshore. The pink shows where the hurricane force winds are located. As I stated before there is a good chance at least part of coastal Carolina’s see an impact from the core but right now a landfall is not expected.
Any slight changes in track could move the core closer or further away so a shift of even 10 miles could bring hurricane force winds that much further inland.
Rainfall and flooding is also a large concern when it comes to Dorian. The GFS model is predicting that coastal South Carolina gets the worst of the rain. Locally up to 10-14″ of rain can be expected. Once again if the storm tracks just a bit closer we could be talking more rain for a much larger area.
Storm surge is always an overlooked factor when it comes to hurricanes. Coastal Florida, Georgia and the Carolina’s should expect 4-7 feet of storm surge which if life threatening.
The wave watcher model is showing waves as high as 35 feet can be expected out to sea near the center of Dorian.
Always keep watch of what your local NWS office and officials are saying. Winds are not the only dangerous part of a hurricane there are many other ways it can be harmful and deadly. Stay safe and I will provide the latest updates as they come out. Follow me on twitter @mikebweather -Michael Barletta