A pre-season storm forms for the seventh year in a row
The giant circulation in the middle of the Atlantic finally organized enough to be designated Subtropical Storm Ana. It’s wrapped up in a wintertime-like envelope of cool air, so it’s called “subtropical.”
The system we were watching in the western Gulf has moved over Texas without organizing. The upper-level winds were too strong to allow sufficient thunderstorm activity to wrap around the center to become at least a depression. It almost made it, but not quite.
Subtropical Storm Ana finally formed in the head of the huge comma of clouds in the middle of the Atlantic. The system started life as non-tropical low-pressure system, which is common during the winter months.
It stalled long enough, however, that the center of rotation could hang out over warm enough waters near Bermuda so a more tropical core could form around the circulation center. That core finally met the criteria for getting a name.
In 2020, the first 6 named storms all formed from this process, but 4 of them formed over warm waters very close to the U.S. coast. This is the seventh year in a row that the pieces have come together to develop at least one named storm before the official start of hurricane season on June 1.
In Ana’s case, the ocean water is not especially warm northeast of Bermuda – closer to 70 degrees than the usually required 80F. But the air above the circulation is so cold, a legacy of Ana’s wintertime origins, that the contrast between the ocean temperature and the air aloft is sufficient to energize the system.
Ana is forecast to head out to sea and die out in the next few days. The main effect will be high surf in Bermuda and north along the East Coast of the U.S.
Over in the Gulf of Mexico, the well-organized circulation we were watching yesterday has moved over the east Texas coast. It was on the cusp of becoming a tropical depression, but ran out of time. Now it’s just a rainmaker for east Texas, producing gusty downpours and adding to the extended period of rainy days in that part of the country.
Nothing else seems to be cooking in the tropics. Quite often things flare up early and then go back to sleep until August. No guarantees, but let’s hope.