Satellite image of Tropical Storm Nate on Thursday morning. (NOAA)
Tropical Storm Nate — a disorganized, ill-defined blob of thunderstorms and rain — is moving north through the far western Caribbean. Pouring down rain in Nicaragua and Honduras on Thursday, the storm remains relatively weak.
Though Nate doesn’t appear menacing right now, there’s potential this system will rapidly intensify as it reaches the warm water of the Gulf of Mexico, on its way to an expected landfall in the United States on Sunday.
“Nate is forecast to reach the northern Gulf Coast this weekend as a hurricane, and the threat of direct impacts from wind, storm surge, and heavy rainfall is increasing,” the National Hurricane Center said Thursday. “However, it is too early to specify the exact timing, location, or magnitude of these impacts.”
On Thursday morning, Tropical Depression 16 was upgraded to Tropical Storm Nate, just as it made landfall on Nicaragua. Tropical storm warnings are in effect for Nicaragua, where extreme rainfall in excess of 20 inches was possible in areas, and Honduras.
The center of Nate is expected to reemerge over the western Caribbean Sea early Friday morning and clip the Yucatán Peninsula on Friday night. A hurricane watch has been posted for the northeastern Yucatan, including Cancun, which could face tropical storm or, in a worst case scenario, hurricane conditions on Friday.
Forecast track for Tropical Storm Nate. (NHC)
Nate will enter the Gulf of Mexico on Saturday. Intensification and a northward track is anticipated, which means “Hurricane” Nate could strike the northern Gulf Coast on Sunday. Hurricane watches will likely be issued for parts of the coast Thursday night or Friday morning.
Due to the location of this storm, very close to land — with another landfall in the Yucatan likely — the track of this storm is somewhat uncertain after it reaches the Gulf of Mexico.
On Thursday morning, the National Hurricane Center’s forecast cone only highlights a small region of the coast, including New Orleans and Pensacola, Fla., but the storm could bring direct effects from Southeast Texas to the Florida’s west coast. In this region, tropical storm-force winds could arrive by late Saturday.
Chance of tropical storm-force winds. (NHC)
Perhaps even more uncertain is how strong this storm will be when it reaches the Gulf Coast. The water Nate will be traversing is very warm, which will fuel the storm. Sea surface temperature is very high in the Caribbean and Gulf of Mexico, and ocean heat content, a measure of the depth of warm water, is also very high in this region — the highest of any part of the Atlantic Ocean basin.
— Brian McNoldy (@BMcNoldy) October 5, 2017
Because of this, rapid intensification is possible, similar to the way Hurricane Harvey strengthened before landfall in South Texas in August, and forecast models are incapable of predicting that.
While the exact track is still uncertain, models have come into somewhat better agreement on the storm’s future course since Wednesday. On Thursday morning, the American and European models were painting the potential for landfall from Southwest Louisiana to the Florida Panhandle, which is on the west side of forecasts issued the day before.
Simulations from American (blue) and European (red) computer models for the path of Nate from early Thursday. Each line represents a different simulation and, taken as a whole, illustrates the range of possible tracks. Where lines are clustered together, the track is most confident, and less confident where they diverge. (stormvistaxwxmodels.com)
Fortunately, unlike Hurricane Harvey, this storm will be fast-moving, which will reduce the potential for widespread flooding. Nate will likely be picked up by a cold front Sunday night into Monday, which will pull it across the eastern United States Heavy rain is possible early next week from the Gulf Coast to the Mid-Atlantic.