Lead Forecaster Daniel Crawley
Good Thursday morning to everyone, we continue to monitor Ian as it works across Florida and up the Southeast Coastline of the United States. Ian yesterday made landfall as a strong Category Four Hurricane near Cayo Costa Florida at 3:05 pm.
The Thursday 5 am update has Ian downgraded to a tropical storm due to land interaction as it continues to move to the north and east.
Synoptics
Ian will continue on a NNE heading through the afternoon and will eventually splash into the Atlantic Ocean. Meanwhile high pressure across the northern tier of the country will slide east and that will block any further easterly heading.
Ian will turn north and then North-Northwest eventually making another landfall early Friday in Lower South Carolina. From there Ian is expected to move up into the Western Carolinas.
As you can see in the Hurricane Center updates, there has been a nudge to the east with the official forecast to where Ian will move northwest into the Foothills/Western Piedmont by early Saturday morning dissecting our coverage area pretty much in half.
The overall speed in which Ian moves has accelerated if some of the guidance is correct.
Local Impacts and Timeline
With some of the changes in the guidance over the past 12-24 hours here are our latest thoughts on the storm…
1. The highest local impact will be heavy rainfall and some flash flooding. Thankfully we have been dry since the first week of the month so a good bit of this rain will be able to run through the River basins.
2. Wind damage is on the low side generally but with the pressure gradient in play and Ian still being classified as a tropical storm well inland in South Carolina we may have a few gusts get up there in the 35-40 mph range, especially Lincoln and Cleveland Counties. Area wide should see gusts in the 25 mph range on Friday.
The flash flood timeline shows the highest threat of flash flooding bad that would be late Friday through about lunchtime Saturday. As activity becomes scattered later Saturday it should allow the flood threat to slowly decline.
Rainfall forecast has been adjusted somewhat to reflect the easterly trends. With the current NHC track in agreement with guidance, southeast upslope won’t be quite as extensive compared to the previous low tracks that was being shown by guidance. Also, we see a downward trend in precipitation later in the weekend so the overall multi-day amounts have been adjusted particularly for the escarpment regions. Additional changes may be possible to the rainfall forecast depending on how the afternoon model runs handle things.
Be Weather Aware over the next 24-48 hours. Today is the last day to make home preparations. Clogged drains, guttering and ditches/ravines are common this time of the year due to foliage coming off the trees. Spending some time to make sure the leaves have been removed can promote good water drainage!