A tropical storm warning is also in effect for parts of the Yucatán Peninsula, while watches cover the northern coast of Honduras, as well as Roatan Island.
Nana’s and Omar’s formations on Tuesday marked the earliest N and O named storms on record, edging out Nate and Ophelia, which formed respectively on Sept. 5 and 7, 2005. This season, which to date is 40 percent more active than average, has also featured the Atlantic’s earliest-recorded C, E, F, G, H, I, J, K, L, and M storms, attesting to the breakneck pace of storm formation that has refused to relent.
The tropical storm duo of Nana and Omar formed on Sept. 1, the official halfway point to hurricane season, yet the climatological peak of activity isn’t until Sept. 15. And we have a long way to go before the season draws to a close.
Nana
Tropical Storm Nana developed quickly on Tuesday, surprising meteorologists who had presumed the nascent storm was weaker. A morning scatterometer satellite pass, which derives winds based on the motion of clouds and ocean waves, had indicated the wannabe storm had no closed circulation and was rather disorganized. But a Hurricane Hunters aircraft just a few hours later found tropical-storm-force winds and even a tiny eye, showing that Nana had come together at a rapid rate.
Because Nana is small, it’s susceptible to pulses in intensity. That likely led to its speedy consolidation but also contributed to a brief faltering early Wednesday when Hurricane Hunter meteorologists reported the eyewall and eye had disappeared.
Maximum sustained winds were estimated at 60 mph on Wednesday morning, when Nana was around 240 miles east of Belize City. The National Hurricane Center is forecasting Nana to continue churning west, making landfall in Belize very early Thursday morning.
A storm surge of 3 to 5 feet above normally dry land is possible, along with strong winds and heavy rainfall in portions of Belize, northern Honduras, coastal Guatemala, and southeastern Quintana Roo, Mexico. A widespread 3 to 5 inches of rain, with lesser amounts to the northeast, is possible near where Nana’s center makes landfall in Belize. A few 6- to 8-inch amounts can’t be ruled out.
Nana could be the first hurricane to make landfall in Belize since Hurricane Earl, which brought as much as a foot of rain and wind gusts up to 85 mph on Aug. 4, 2016.
Omar
Omar was “toughing it out” on Wednesday, the low-end tropical storm over the open Atlantic fighting against strong upper-level winds working to tear its circulation apart. The tropical storm was named on Tuesday but is little more than a swirl of warmth and moisture flanked by downpours and thunderstorms to its east.
On Wednesday, one could see via satellite as the system’s low-level center continuing to shuffle east, while the larger hulking thunderstorms remained detached from the center. That’s the result of wind shear, or a change of wind speed and/or direction with height, that disrupts the vertical structure of tropical systems.
Omar will continue passing harmlessly through the open Atlantic, remaining far from any landmasses as it degenerates into a remnant low by late Thursday. Eventually, it will become swept up in a broader area of disturbed weather.
Areas to watch
Meteorologists were tracking two additional systems over the east tropical Atlantic on Wednesday. The lead tropical wave, about halfway between Africa and northeastern South America, was pegged with a 30 percent chance of development by the National Hurricane Center. The second, offshore of the River Gambie and west of Senegal in Africa, was moving into a more favorable environment, and had a 60 percent chance.
The first of the two systems looks to remain broad in terms of overall circulation, and probably won’t tighten up enough to become a tropical depression or storm. But its thunderstorm activity could help to moisten the upper atmosphere, paving the way for its successor to follow.
While it’s too early to make a call, weather models are in agreement that gradual development of the second system is likely. The National Hurricane Center notes that “a tropical depression could form by this weekend as it moves westward over the eastern and central tropical Atlantic.”
Troublesome pattern for the Eastern U.S. in mid-September
Though no tropical systems are imminent for the East Coast, the pattern could become a bit hairy for folks along the Eastern Seaboard in the coming weeks. In addition to a general uptick in tropical cyclone activity, the positioning of several key weather systems, including a farther west and unusually strong Bermuda High, would make it more likely that a storm could be drawn into the East Coast.
In addition, the stagnant high-pressure system could reduce cloud cover over the western Atlantic, allowing it to heat up more, which would be problematic if a tropical system were to pass nearby.
That same pattern will also favor increasing heat and humidity in the East, along with more widespread thunderstorm activity. Though climatological autumn technically arrived Sept. 1, the weather will feel more summerlike in most areas.
