Tropical Depression Fred returned to the water, but weak and disorganized »Yale Climate Connections – .

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Tropical Depression Fred returned to the water, but weak and disorganized »Yale Climate Connections – .


Tropical Storm Fred made landfall at 2 p.m. EDT Wednesday in the southeastern Dominican Republic as a low tropical storm with winds of 45 mph. Passage over the mountainous island of Hispaniola shredded Fred, and the storm was weak and disorganized Thursday morning after returning over the water. In its Thursday notice at 11 a.m. EDT, the National Hurricane Center noted that Fred was barely labeled a tropical depression, with no severe thunderstorms near its center.

Overnight, Fred had brought gusts of wind and heavy rain to parts of the Dominican Republic, cutting off power to more than 300,000 customers. The capital, Santo Domingo, recorded 6.76 inches (171.6 mm) of precipitation over 24 hours.

Predictions for Fred

Fred is on a west-northwest trail that will take her parallel and just north of Cuba. Cuba’s high terrain will block the influx of low-level moisture from the south into the storm on Thursday and Friday, interfering with development. A low pressure trough aloft northwest of Fred, which is expected to bring 15-20 knots of windshear, will also hamper development. Favoring the intensification will be a humid atmosphere and very warm sea surface temperatures, 29-30 degrees Celsius (84-86 ° F).

Once Fred enters the Strait of Florida on Saturday, the ridge of high pressure directing the storm will carry it further northwest, resulting in a track almost parallel to the Florida Peninsula. Fred’s trail could bring him close enough to southwest Florida that the interaction with the land limits the intensification.

The windshear could ease on Saturday, which would encourage an intensification. However, no reliable escalation model predicts that Fred will become a hurricane before his final landing in the Florida Panhandle, expected Monday. Whatever Fred’s final intensity, flooding from heavy 3-5 inch rains is probably the main threat from the storm in Florida. If Fred ascends the west coast of Florida above the water, a 1 to 3 foot storm surge is likely along much of the Florida Gulf Coast.

Figure 2. Satellite image visible from 95L in the eastern tropical Atlantic on Thursday morning August 12, 2021. The system exhibited two distinct areas of severe thunderstorms, with the northern area more dominant. (Image credit: NASA Worldview)

Tropical disturbance 95L towards the Leeward Islands

A disturbance in the eastern tropical Atlantic, dubbed 95L, followed a trajectory very similar to that of Fred. Located Thursday morning about 1,400 miles east of the Lesser Antilles islands, the 95L was moving west at 20 mph. Showers and thunderstorms were gradually becoming more organized, although moderate 10-20 knot windshear and some dry air along its 95L north edge slowed this process. Satellite imagery late Thursday morning showed that 95L had two distinct areas of severe thunderstorms (see Figure 2 and Tweet below); ASCAT surface wind measurements showed that the northern area appeared to be dominant.

A large high pressure ridge over the western Atlantic is expected to keep 95L in constant west-west-northwest motion until it reaches the vicinity of the Sous-le-Îles. Wind towards Saturday evening. Over the next five days, the wind shear is expected to be light to moderate, 5 to 15 knots, the atmosphere will gradually humidify and sea surface temperatures will warm by 27 degrees Celsius (82 ° F) to 29 degrees Celsius (86 ° F). These conditions are favorable for development, and 95L has modest model support to develop into a tropical depression by early next week. In its tropical weather forecast Thursday at 8 a.m. EDT, NHC gave 95L a 2 and 5 day development probability of 30% and 60%, respectively. The next name on the Atlantic list is Grace.

Bob Henson contributed to this article.

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