On Tuesday, the first slug of tropical rains overspread South Florida in what’s forecast to be a multi-day deluge for the lower tier of the Sunshine State.
Already widespread rainfall of 3 to 7 inches has fallen across parts of Miami-Dade and Broward counties since Tuesday morning.
An additional 3 to 6 inches is possible for the metro through Thursday evening, with localized amounts up to 8 inches. The Miami Weather Service office on Wednesday morning extended our Flood Watch until at least through Thursday.
To our west, the Sarasota area was inundated with repeated downpours and nearly 4 inches of rain falling in just an hour Tuesday evening, quickly flooding streets and stranding motorists.
The tropical spigot pouring into South Florida has unleashed some of the soupiest air measured for our area in June, historically South Florida’s rainiest month. The precipitable water value – a number that indicates the amount of liquid water available to wring out in the air above us – as measured by the National Weather Service in Miami yesterday was 2.55 inches, a record for the date, and the second highest value of any June day. Interestingly, the record for June precipitable water in Miami was 2.62 inches, measured on June 4, 2022, as Potential Tropical Cyclone One – a precursor to Tropical Storm Alex – dropped 10 to 15 inches across the Upper Keys and Miami metro.
With such a juiced atmosphere overhead, otherwise innocuous disturbances moving along in the atmosphere can bring lots of rain in little time. Usually this type of moisture is accompanied by an organized tropical disturbance, but the main players in this case are a stalled front to our north and broad region of low pressure over the eastern Gulf. The persistent thunderstorms can even spawn small, short-lived low-pressure swirls called mesolows, which can compound stormy weather like what happened off the coast of Sarasota on Tuesday.
The National Hurricane Center has designated the broad area of low pressure in the eastern Gulf Invest 90L but development, if any, won’t happen until the low-pressure area moves off the southeast U.S. later this week.
Anything that develops by that point will be weak and short-lived as it moves away from the U.S.
Eyeing the Bay of Campeche and southern Gulf next week
The next real chance at tropical development may come early next week around the Yucatan Peninsula in the extreme southern Gulf and Bay of Campeche. We’ve been honing in on this area in our newsletters since early last week. On Wednesday morning, the National Hurricane Center added the area to its outlook, indicating favorable environmental conditions for slow development next week.
The Bay of Campeche – tucked away in the scoop of the lower Gulf – is notorious for quick spinups due to its unique geography, so it wouldn’t take much to eke out a system. Regardless for South Florida, high pressure anchored over the eastern U.S. next week should keep anything percolating in the southern Gulf moving slowly westward and away from us.