What's causing the heavy rain, flood watches in South Florida? NBC6 meteorologists explain

Parts of South Florida will remain under a flood watch until Thursday as heavy rain was expected to continue moving through the area on Wednesday.

The flood watch lasts until 10 a.m. Thursday and includes coastal and metro Broward, Miami-Dade and Palm Beach, the National Weather Service said.

A flood watch was also in effect for Monroe County until 7 a.m. Thursday.

. 11/15 7AM Heavy Rainfall Threat Update: Confidence continues to increase regarding the potential for heavy rain beginning later this morning and continuing into Thursday.
Here are the latest probabilities in terms of rainfall amounts across the area. (1/3) pic.twitter.com/f3kXwXuIIm

— NWS Miami November 15, 2023

Portions of Broward County picked up 4 inches or more of rain Tuesday, and between 6 and 8 inches of rain was likely to fall by Thursday. Many spots could see over 10 inches of rain.

Rainfall intensity will pick up Wednesday afternoon and overnight with most of the rain out of South Florida by midday Thursday.

As I said on-air last night, with a broad rain event unfolding for South Fla, it's uncertain which communities will see the most rain/highest risk for flooding.

For now, approach this afternoon/evening as if it will be yours & make good decisions based on the weather, not whim. pic.twitter.com/0MkGwtw7VC

— Ryan Phillips - NBC6 November 15, 2023

The heavy rain brought flooding to some streets in Broward Tuesday night , even causing some people to be stranded in their cars in Oakland Park.

Winds are a story as well. Winds could gust to 40 mph or more and that means trouble at the beaches and on the water. South Florida was also under a gale warning as seas could top 10 feet along with a high surf advisory calling for 6-10 foot waves to break at the beaches. On top of all of that a high risk of rip currents is in effect into Friday.

At one point Wednesday morning a tornado warning was issued in the Florida Keys, though there was no tornado on the ground.

Doppler radar indicated tornado warning near Big Pine and Niles Channel Bridge. Not a tornado on the ground. This storm "could" produce a tornado. We will stay on top of it. Watch now. pic.twitter.com/WKtTrI1Tii

— Adam Berg November 15, 2023 Why Is This Happening?

A stalled front that was draped across South Florida brought the scattered showers on Tuesday. On Wednesday, a low pressure center was developing along the boundary and was expected to slowly lift northeast.

This is common when fronts stall through the Gulf region and tend to take on some tropical characteristics. While this isn’t going to be truly tropical, it will perform very similarly with the Atlantic moisture being pumped onshore. The low develops south of the area and we will be on the northern side of this trough. Which means South Florida is in the bullseye for the heavy rain.

Flooding is likely and expected from the amount of rain we will see on top of King Tide Flooding. High tide Wednesday will be from 9 a.m. to 11 a.m. and again from 9 p.m. to 11 p.m. but the rainfall will be the most impactful.