'Brown Ocean' effect could bring more flooding rains to Texas, Oklahoma, & parts of the Mississippi

An unusual meteorological event will likely take place through midweek that could bring more flooding rains to areas that don't need it… and it's all because of the extensive rains much of the area already experienced in May. Well, that and a new tropical system expected to move on shore early Tuesday.

The current tropical system isn't even considered a tropical storm as I write this, but the impacts could be just as bad. The vast majority of tropical systems that make landfall weaken considerably once they move inland because their fuel, heat and copious moisture from the warm ocean, are no longer there. While these systems can have terrible consequences for coastal communities, rarely are they so devastating once you are a couple hundred miles away from shore. But this storm could be different.

The added moisture in the very wet soils may add enough fuel to the atmosphere to keep this tropical system from weakening as it moves on shore… and could even allow it to strengthen further. It's called the "brown ocean" effect. It sounds like a term straight out of a terrible science fiction movie, but I assure you it's a real thing. It's in reference to an area with unusually or historically wet soils. The ground is brown, and often mud if it's wet, so the term "brown ocean" refers to very wet and mud like soils. Meteorologists were scarcely aware of the phenomenon until Tropical Storm Erin in 2007. Erin brought devastating rains to Texas, Oklahoma, & Missouri, with an "eye" even forming over Oklahoma…


Track and rainfall amounts from Erin across the eastern US


A radar image taken from the National Weather Service in Oklahoma

This storm sent meteorologists into a frenzy trying to understand how this could happen. Research was published in 2014 by Andersen & Shepherd proving that soil moisture levels can have effects on landfalling tropical systems by increasing evaporation & latent heat, the main fuel source for tropical storms.


Unfortunately, the southern Plains find themselves in a similar situation. I mean, just look at how much more rain than normal the area has seen in the last 60 days...