Tropical Depression, now Sally, Collier County rainfall summary
Two days ago, I wrote about expected rainfall from then Tropical Depression (TD) 19. At that time, I noted that forecasts called for two to four inches of precipitation across southwest Florida, especially along and to the west of I-75 during the weekend (Fig.1). As is always the case, I noted that localized amounts might reach double those numbers. Fig. 2 shows representative COCORAHS (Community
Collaborative Rain, Hail, and Snow Network) rainfall amounts across Collier County for the two-day period. The highest amounts were along the coast, with amounts dropping off quickly as one moved inland.
In short, both the official forecast and my “doubling” rule worked out nicely.
There were a few reports of minor flooding, but overall, we weathered this tropical system nicely.
Five to seven inches of rain can translate into feet of water rise in low lying areas due to volumetric considerations. To visualize this, fill a cookie sheet (usually 9” x 13”) with about one-half inch of water. Using a turkey baster, move the water to a large drinking glass. You’ll see just how deep the water can get when the horizontal area shrinks!
Yes, our lakes and canals are full and that means any further localized heavy rainfall could mean more localized flooding. With widespread standing water, look for a boom in the mosquito population.
And, those pesky showers and thunderstorms remain in the forecast …drumroll for my favorite acronym this week…UFN.
Meanwhile, Sally, now a hurricane, is ready to make much rainfall and flooding misery across eastern Louisiana and much of Mississippi and Alabama. I’m working on a story about this unfolding weather situation next.
© 2020 H. Michael Mogil
Originally posted 9/14/20
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