Earlier this Wednesday morning, Sally made landfall as a category 2 hurricane bringing hurricane force winds, drenching rains, and devastating storm surge to parts of the Gulf coast. This is the 19th tropical system that has formed in the Atlantic basin, the 7th hurricane of the season, and the 4th hurricane that has made landfall over the United States.
This storm has already brought an immense amount of flooding solely from the amount of rain this storm has produced and is currently still producing. We’re talking major flooding to local rivers, coastal flooding, with several feet of storm surge added on top of that. To say this system was a heavy rain maker would be an understatement. For some areas, this is historically some of the worst flooding that some residents living in these areas have seen in their lifetime.
With impacts being felt from the Florida panhandle to Mobile, Alabama, more widespread rain and flooding is anticipated for parts of Georgia and even into the Carolina’s. Although the amount of rainfall expected for these areas will be much less than those closer to the Gulf coast have seen.
According to the National Hurricane Center, tropical storm-like conditions are expected to continue overnight as this storm continues to pull away and makes its way northeast away from the Gulf. The amount of flooding to some areas is still likely not even at its peak before the flood water starts to recede for areas along and close to the Gulf.
The storm has since been downgraded to a Tropical Storm as of Wednesday night with sustained winds around 45 mph moving northeast at 7 mph. This storm is expected to slowly weaken into a tropical depression as it continues its course towards Georgia and the Carolina’s.
Did you know? The deadliest threat of a hurricane or tropical system is storm surge.
The main reason why this storm has produced so much flooding over these areas is because of how slow this storm has been moving over the past 48 hours that just been dropping buckets of rain over the course of just Wednesday itself.
Throughout its course it’s only moved as fast as 13 mph, and as slow as around 2 mph, which for a Hurricane, is pretty slow. This is a characteristic that you don’t want in a hurricane solely based on the increased risk for drenching rain and prolonged flooding.
Check out the rainfall totals that have already fallen from Sally below:
In the past 48 hours, Sally has produced so much rain that the color table on our graphics software can’t comprehend it, because it wasn’t built to show rain totals over 25+ inches. That also goes to show just how uncommon it is to see these kind of rain totals in an area.
Take a look at the spotty, mess of colors just north of Pensacola and Destin. Notice how those colors only say up to 10” according to the color table. In reality, this mess of color actually represents the amount of rain that the color table can’t pick up, so what happens is the graphic essentially goes backwards in the color table. This means that the 10″ of rain that the graphic is displaying is actually 10 inches PLUS the 25 inches that it maxes out at. So some areas have actually received roughly around 37″ of rain over the past 48 hours.
Just for fun, let’s compare this amount of rain to how much snow that would be for us…
Let’s take the standard 10:1 ratio of snow to rain for this example. A 10:1 ratio means that for every 1 inch of rain, you would get 10 inches of snow equivalent. In other words, if you were to melt 10 inches of snow, you would get 1 inch of rain.
If we take 37 inches of rain in a 10:1 snow ratio, that would give us 370 inches of snow!
That’s like taking last year’s winter and multiplying that by 4… now that’s a lot of snow! A little too much snow if you ask me. Feeling like a warm, summer vacation right now? Me too.
~Meteorologist Christine Gregory