The National Hurricane Center has raised the probability of a Gulf system further developing to 80% at the time of writing Sunday morning. The probability of development has steadily risen over the past few days. My meteorological eye has been watching the system all weekend, so I am not surprised at these developments.
Current Status
Though I am a meteorologist, my best practice (and it should be yours too) is to see what the National Hurricane Center is saying. They confirmed early Sunday morning that satellite-wind data and surface observations suggest that the low over the Gulf west of the Florida peninsula is becoming better organized. Though it is not the most meteorologically-photogenic right now, further development is expected. “Continued gradual development is expected, and a tropical depression is likely to form later today or on Monday as the system moves slowly
northward or northwestward“ wrote National Hurricane Center forecasters. ”Interests along the northern Gulf coast from Florida, Alabama, Mississippi, to Louisiana should monitor the progress of this system as it is expected to bring heavy rain to portions of that region during the next several days,” they went on to say.
The system started with a discernible mid-level circulation meandering off the west coast of Florida. Over time, a broader surface low became evident and certain banding features were starting to appear on weather satellite imagery. Some forecast models hinted at this possibility earlier in the week.
“Gonna be honest: this Gulf swirl is getting interestin,” wrote noted hurricane chaser Josh Morgerman on his Facebook page Sunday morning. “It’s not what I’d call gorgeous workmanship, but 1) the cloud pattern shows definite arcing, 2) the low center is turning W (meaning more time over the Gulf), and 3) computer models have gotten more aggressive with it,” the stormchaser known as iCyclone continued.
What Is A Tropical Depression
We often throw terms like tropical depression, tropical storm, and hurricane around with the assumption that everyone understands the distinction. A tropical depression is a system, “With organized convection (generally 100-300 miles in diameter) originating in the tropics or subtropics, having a non-frontal migratory character and maintaining its identity for 24 hours or longer,” according to the National Weather Service website. “It may or may not be associated with a detectable perturbation of the wind field,” it added.
If maximum sustained winds reach 39 miles per hour, the depression is upgraded to tropical storm and receives a name. While NHC is not talking about named storms at this time, there are a few weather prediction models that hint at strengthening to a potential tropical storm in the coming days. If that happens, and I am not saying it will, it would be named Bertha. It is important to put caveats on these types of statements. Unfortunately, we live in an era that leads to hyperbole, sharing of weather model information out of context, and “wishcasting” based on single model runs. Having said that, there is enough signal in the best model data available to put it on the table with the appropriate communication “guard rails.”
Systems like this, as University of Georgia colleagues and I found in a 2007 study, can be very prolific rain producers. I will be watching carefully and updating my writing as necessary. Be sure to check back with me for updates.
