Danielle to Become the First Atlantic Hurricane of 2022

Slow-moving Invest 91L east of the Lesser Antilles continues to struggle

If the formation of Tropical Storm Danielle yesterday morning farther north and east than any September named storm in the modern era wasn’t enough of an oddity, its apparent eye on satellite this morning at such a high latitude is the topper on an increasingly curious 2022 hurricane season.

Satellite estimates of Danielle’s winds vary wildly, but the appearance of an eye suggests it’s nearing hurricane strength, if not already there.

As we discussed in Wednesday’s newsletter, even though we’d gone through August without a hurricane, history told us our time was running short. Even so, few of us would’ve anticipated just a few days ago our first hurricane of the season so far out of bounds of the tropics. As late as Tuesday afternoon, the five-day tropical weather outlook from NHC didn’t mention the disturbance which would become Danielle less than 48 hours later.

A big factor contributing to Danielle’s fast formation and subsequent strengthening is the record-smashing warmth of the north Atlantic. For the first time since complete satellite coverage of global oceans began in 1981, weekly sea surface temperatures in the region of the north-central Atlantic where Danielle formed topped 80 degrees Fahrenheit, incredible warmth rivaling that of the deep tropics during a typical summer.

The forecast calls for Danielle to continue to strengthen over the weekend into a Category 2 hurricane as it mostly drifts over the coming days. By early next week, the storm should begin to accelerate northeastward over the waters of the north Atlantic.

Closer to home, we continue to follow the dogged plod of Invest 91L east of the Caribbean islands. As we’ve discussed since last weekend, the broad and elongated nature of the low-pressure area isn’t prone to fast organization and plentiful dry air above 10,000 feet in its vicinity is squashing thunderstorm activity that tries to congeal and organize. Air Force hurricane hunters flying low-level missions into 91L yesterday found a very weak and ill-defined wind field. They’re set to fly the system again today, but all-in-all, 91L has looked pretty unhealthy.

Unfortunately, the system is in no hurry and may hang around into next week. Due to weak steering currents and the broad, undefined center, there are wide bookends to extended-range scenarios. Bottom line is the southeastern Bahamas and Turks and Caicos should stay aware, but there’s no immediate concern for South Florida.

Forecast models for Invest 91L. Blue ellipse indicates model spread out to next Tuesday. In general, a weaker system would favor a more westward track while a stronger system would favor a more northward track. Credit: Tomer Burg/University of Oklahoma.

Otherwise, short-lived Invest 94L near the Cabo Verde Islands is unlikely to develop as it moves deeper into the eastern Atlantic.

The subtropics may eke out the first and only hurricane of the season so far, but the deep tropics continue to feel the slump of a surprisingly slow season.