Tropical Storm Danny (2021)

Storm Active: June 28-29

Around June 26, a surface trough well southeast of Bermuda was producing some scattered thunderstorm activity as it moved rather quickly west-northwestward. Ocean waters beneath the disturbance weren't especially warm, nor the atmosphere too moist, but some gradual organization occurred nevertheless. Early on the 28th, it was apparent that a well-defined center of circulation had developed, and the system was classified Tropical Depression Four. At the time, it was a very small, sheared system off the South Carolina coastline.

The depression's track was a little unusual: a strong high was situated over the eastern seaboard, which kept Four moving quickly west-northwestward toward land. The system had a rather high pressure reading of 1013 mb due to ambient high pressures in the surrounding area and this shallowness also contributed to its fast forward motion in the strong low-level flow. In any case, warm waters near the coast allowed the storm to strengthen a bit around landfall and it became Tropical Storm Danny. It made landfall during the evening of the 28th a little north of the Georgia-South Carolina border. Because the cyclone was small, heavy rain and tropical storm force winds were confined to a small region.

After landfall, the storm deterioriated rapidly. It weakened to a tropical depression overnight and dissipated the next morning over central Georgia.

The above image shows the tiny Tropical Storm Danny just before landfall in South Carolina.

Danny was another short-lived tropical cyclone because it formed so close to land.

Tropical Storm Claudette (2021)

Storm Active: June 19-21

Around June 12, a broad area of low pressure associated loosely with the central American gyre (CAG) to the south formed in the southern Bay of Campeche. It was producing occasional bursts of thunderstorm activity and some spin was evident on satellite imagery, but the size of the system and its proximity to land inhibited tropical cyclone development. The low barely moved for the next several days. It finally made some northward progress starting on June 17 toward a weakness in the subtropical ridge. It was quite disorganized though, with the only convection a band northeast of the ill-defined center.

The disturbance changed little the next day as it approached the northern coastline of the Gulf of Mexico, though aircraft and satellite measurements indicated that it possessed sustained wind speeds to gale force. Heavy rain swept across southeastern Louisiana as the system approached. It was only early on the 19th, as the center was moving over land, that it finally became organized enough to be named Tropical Storm Claudette, with peak winds of 45 mph. However, the classification of the system changed its impacts little; flooding was the primary concern as it moved inland and turned northeast, crossing into Mississippi. Claudette weakened to a tropical depression later on June 19.

An approaching cold front steered the system east-northeast across the southeast United States, bringing scattered downpours and gusty winds with it. The next day, as Claudette approached the Atlantic, the proximity to water fueled some convective redevelopment and the cyclone began to strengthen again. It became a tropical storm again on June 21 near the coast. Forunately, it was fast-moving, and was swept out along the mid-latitude westerlies in short order. After passing over the Gulf stream, it encountered cooler waters. The center was still not well-defined, and Claudette lost its identity as it sped away from land that evening.

As with many storms forming from CAG's, Claudette was a rather messy cyclone; it never looked completely tropical. 2020's Tropical Storm Cristobal was similar in this regard, and was another June CAG storm. Such systems develop most often in June or October/November.

Unusually, Claudette spent more time over land as a tropical cyclone than it did over water!

Tropical Storm Bill (2021)

Storm Active: June 14-15

On June 13, a non-tropical low pressure center developed just off the coast of the southeastern United States in association with a stalled warm front. It moved northeastward a little farther from land and encountered the hot waters of the Gulf stream; sea surface temperature anomalies were extremely high just off of the North Carolina. By the morning of June 14, a burst of convection had covered the low. It was designated Tropical Depression Two shortly after.

The system strengthened steadily during the next day despite moderate wind shear. As a result it was upgraded to Tropical Storm Bill. It also accelerated significantly on its northeastward path. By the afternoon of the 15th, Bill had reached its peak intensity of 60 mph winds, but was already beginning extratropical transition. The central thundestorm activity was displaced from the center by strong upper-level winds and the cyclone became extratropical that evening.

The above image shows Bill as a tropical storm on June 15.

Bill formed near land, but rapidly moved out to sea during its brief stint as a tropical cyclone.