Growing hurricane threat to Florida this weekend

Tracking Hermine?

We've seen this movie before.

The usually trusty European model tracks a strengthening hurricane toward the U.S. coast in 5 days. NOAA's GFS model projects a different solution, a storm that curves sharply north and passes harmlessly out to sea.

If NOAA's primary weather model is right, this is a non-news event. If the Euro and other models are correct, a hurricane will likely make landfall Sunday on the Florida coast, with Miami squarely in the forecast track cone of uncertainty.

What may soon become Tropical Storm Hermine gathers near the Lesser Antilles overnight into Wednesday morning.

Atmospheric and ocean conditions are favorable for development. Weather Underground's Jeff Masters elaborates on why lower wind shear and warm waters create the likely environment for intensification.

Dry air from the Saharan Air Layer (SAL) that has been interfering with development over the past few days had decreased, as seen on water vapor satellite imagery. Wind shear was marginally favorable for development, at 10 - 15 knots, and sea surface temperatures (SSTs) were favorable for development: 28.5 - 29°C (83 - 84°F) (about 0.5°C above average.)

Tale of two forecasts

The model forecast situation for how a potential Hermine will develop going forward in the next 5 days is unclear, and unnerving. Yet again, NOAA's GFS predicts no threat to the USA. The Euro model cranks out a possible hurricane heading for the Florida coast, and potentially Miami. I don't envy emergency managers in Florida and along the Gulf Coast looking at these two potential outcomes.

Track cluster

The latest spaghetti models are trending toward a cluster around a possible Florida landfall Sunday. Miami and South Florida are clearly in the threat zone at this still early stage.

NOAA's National Hurricane Center projects a 60% chance of Tropical Storm Hermine within 5 days. The evolving cone of uncertainty does not look good for the southeast USA.

Intensity forecast difficult

Hurricane track forecasts have shown great improvement in the past 30 years. Forecasting hurricane intensity is still a much more difficult task for hurricane forecasters. Development is suppressed when tropical systems encounter wind shear and dry air. When you remove those limiting factors, tropical systems can rapidly flare, and sometimes intensify into major hurricanes very quickly. That potential is there with 'Hermine' over then next 3-4 days.

Here's the latest intensity forecast chart.

Record hurricane drought about to end?

This is the longest stretch on record between hurricanes on the Gulf Coast.

Florida population boom

It's still too early to say if Florida will be hit by a hurricane this weekend. But the next land-falling major hurricane in Florida will encounter a much more populated coastline that the last.

Stay tuned as we watch what is likely to become Hurricane Hermine in the next few days. This could become a major U.S. news story by this weekend.