Tropical system may be forming in the Gulf

Too early to tell if system will be named

By Jordan Evans and Gene Norman, CNN
CNN

The National Hurricane Center increased the chance a tropical threat could devlop in the Gulf by the middle of the week to 50 percent.

(CNN) - It's looking more and more likely that the United States soon could face its first tropical threat in the young 2019 hurricane season.

On Monday, the National Hurricane Center increased chances of the system developing in the Gulf of Mexico to 80% by the end of the week.

Depending on your computer model of choice, the ensuing system could pose trouble -- or worse -- from the Florida Panhandle to southern Louisiana.

While it's still too early to tell whether this system will get strong enough to be named (that would be Barry, by the way), more interesting is "how" this could all come about.

For the most part, meteorologists vigilantly scan the Gulf or Atlantic Ocean from June to November for signs that low pressure systems are developing with the potential to strengthen.

Turns out that average date of the first named storm in the Atlantic is July 9, but the activity storm-watchers will be dialed into this week isn't coming from the sea, but from land.

To get a tropical system, you need warm water, weak steering winds aloft and thunderstorms forming around low pressure. All three ingredients are present.

By early in the week, a sagging front, along which nearly daily thunderstorms have been forming in the Southeast US, will end up in the Gulf.

Remnants of those storms will help develop a low pressure system in the very warm waters of Florida's "Big Bend" in the Gulf of Mexico. Temperatures there are running in the mid-80s.

A ridge of high pressure has been keeping the Southeast firecracker hot and humid since the holiday and that same feature keeps the upper level winds weak.

Under that heat dome, computer models speculate that the low pressure will begin to form by Wednesday.

The more aggressive European model intensifies the system rapidly to at least tropical storm strength, and keeps the system in the Gulf until the weekend. The latest prediction shows the system heading west toward the Texas-Louisiana border, where torrential rainfall is possible Sunday.

The American model, which just underwent a massive upgrade, takes a somewhat different track. It too generates a system in the northern Gulf by midweek, but it isn't as strong. Additionally, after meandering westward near the coast for a few days, bringing heavy rain from the Florida Panhandle to Louisiana. The system is forecast to move into Texas, near Corpus Christi, with additional heavy rain.

Keep in mind, both models do their best when the low pressure has actually formed and until then, there will be wild variances in their forecasts. However, at this stage, what we look for most is consistency in trends. Both models have been indicating the overall scenario of low pressure forming in the Gulf, even if the specifics and timing vary a bit.

This is likely one of the reasons why the agency tasked with tracking and forecasting tropical system increased their five-day projection from 50% Sunday to 80% Monday.

So, if you're a Gulf coast resident, what should you do? Nothing now - but stay vigilant. Check in with us as we'll be following this system through the week. With the Atlantic hurricane season still young, now is a good time to review your preparedness and evacuation plans.

These kinds of systems are especially tricky compared to, say, a menacing, growing swirl easily identifiable in the ocean targeting a coastline. Each tropical threat can bring varying amounts of wind and water, so you need to be prepared either way.

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