Tropical Storm Fred is steaming northward over the Gulf of Mexico toward an expected late Monday afternoon landfall in the Florida Panhandle near Panama City, not far from where category 5 Hurricane Michael came ashore in 2018. Fred was bringing heavy rains to coastal portions of the Florida Panhandle early Monday afternoon, and a tornado watch was up in the region.

At 11 a.m. EDT Monday, Fred was located about 55 miles southwest of Apalachicola, Florida, moving north at 10 mph. An Air Force hurricane hunter aircraft found that Fred had intensified to 60 mph winds, with a central pressure of 993 mb. NOAA buoy 42039, located about 130 miles south-southeast of Pensacola, Florida, reported sustained winds of 56 mph and gusts as high as 60 mph late Monday morning.

Radar and satellite imagery showed that Fred had grown more organized on Monday, with heavy thunderstorms wrapping most of the way around an inner core. However, strong upper-level winds out of the southwest were creating 15-20 knots of wind shear, and this wind shear was pushing dry air into the core of the storm, keeping Fred from developing a complete eyewall.

Figure 1. Visible satellite image of Tropical Storm Fred over the Gulf of Mexico at 11 a.m. EDT August 16, 2021. (Image credit: NOAA/RAMMB/Colorado State University )

Forecast for Fred

Fred is on the west side of the Bermuda-Azores High, and the clockwise flow of air around the high will take Fred to the north over the next two days. This steering flow will result in Fred’s making landfall in the western Florida Panhandle late Monday afternoon, then pushing inland into Georgia by Tuesday afternoon.

Some modest intensification of Fred is likely before landfall, aided by a moist atmosphere and very warm sea surface temperatures of 30 degrees Celsius (86°F). Hindering development will be 15-20 knots of wind shear. This shear will keep the bulk of Fred’s heavy rains to the east of the center; areas to the west of Fred’s center will see few impacts from the storm. Given the shear, it is unlikely that Fred will be stronger than a 70-mph tropical storm at landfall in Florida.

Figure 2. Predicted rainfall from Fred for the three-day period ending at 8 a.m. EDT Thursday, August 19. (Image credit: National Hurricane Center)

The main threat from Fred in Florida will be flooding from its heavy rains of 4-8 inches. Tallahassee radar showed that Fred had already dumped 2-5 inches of rain near Apalachicola, Florida, as of 11:30 a.m. EDT Monday. Fred also has the potential to spawn a few tornadoes and bring a storm surge of 3-5 feet to the right of its landfall location. Fred’s heavy rains will also be a problem farther inland, with 4-7 inches of rain expected in the western Carolinas. On the plus side, the rains should help quench some abnormal dryness evident on the latest U.S. Drought Monitor in parts of the Appalachians.

Figure 3. Storm total rainfall from Fred estimated by the Tallahassee, Florida, radar as of 11:31 a.m. EDT August 16, 2021. (Image credit: Weather Underground, an IBM company)

Fred will be the fourth U.S. landfalling storm of 2021

Fred’s landfall in Florida will make it the fourth named storm to make landfall in the U.S. this year, following Elsa (landfall on July 7 with 65 mph winds in Florida, killing one and causing $775 million in damage); Danny (landfall in South Carolina on June 28 with 45 mph winds, no deaths or damages reported), and Claudette (landfall on June 19 in Louisiana, killing 14 and causing $350 million in damage).

Last year had a record 11 named storms make landfall in the contiguous U.S., beating the old record of nine set in 1916. The fourth U.S. landfall of 2020 (Hanna in Texas) occurred on July 25. The record-earliest fourth landfall in the U.S. is held by Hurricane Four of 1886, which hit Florida on July 19.

Over the 71-year period 1950-2020, the U.S. averaged three landfalling tropical storms (with one being a hurricane) per year, according to the website Tropical Storm Risk, so 2021 has already had more than an average season’s worth of landfalling storms. On average, over 75% of the Atlantic’s named storms occur after August 16; the average peak date of the season (September 10) is over three weeks away.

Figure 4. Visible satellite image of Tropical Depression Grace making landfall over the southern Dominican Republic’s Barahona Peninsula at 11 a.m. EDT August 16, 2021. (Image credit: NOAA/RAMMB/Colorado State University )

Disorganized Tropical Depression Grace a dangerous rainfall threat for the Dominican Republic and Haiti

Tropical Depression Grace continues to refuse to behave as expected. Its track continues to push south of predictions, and its forward speed refuses to slow as forecast.

At 11 a.m. EDT Monday, Grace was making landfall over the Dominican Republic’s Barahona Peninsula, about 85 miles southeast of the capital of Haiti, Port-au-Prince. Grace was still a weak and disorganized tropical depression, with top winds of 35 mph and a central pressure of 1007 mb, moving west at 15 mph. Moderate wind shear of 10-15 knots was pushing dry air into the core of Grace, keeping it disorganized. Satellite imagery showed Grace’s heavy thunderstorms were in clumps surrounding the center, a sign of disorganization.

Devastating rains likely in Haiti’s earthquake zone

Despite Grace’s current disorganization, the storm will be capable of bringing torrential rains of 5-10 inches to southern portions of Haiti and the Dominican Republic on Monday and Tuesday. Unfortunately, Grace’s more southerly track will bring the center of the depression over the southwestern portion of Haiti, which was hit by a devastating magnitude 7.2 earthquake on Saturday morning that killed an estimated 1,300 people. Grace’s rains in the earthquake zone are likely to begin Monday evening and extend through much of Tuesday. The 6Z Monday run of NOAA’s experimental HAFS-B model predicted over 10 inches of rain from Grace in the earthquake zone, which would be capable of causing devastating flooding.

Forecast for Grace

A broad ridge of high pressure over the western Atlantic is steering Grace. The ridge is expected to grow stronger, keeping the storm on a much more southerly path than previously expected. Grace is now predicted to clip the south side of the mountainous island of Hispaniola and pass well south of Cuba. It is unlikely that the amount of land interaction Grace encounters will be able to destroy its circulation, as happened to Tropical Storm Fred.

With a large expanse of warm waters of 29-30 degrees Celsius (84-86°F) ahead of it, a reasonably moist atmosphere, and light-to-moderate wind shear of 5-15 knots, Grace will have the opportunity to undergo significant strengthening once it moves away from Hispaniola on Tuesday morning. Land interaction with Mexico’s Yucatan Peninsula will potentially cause significant disruption of Grace on Wednesday night, however. Grace’s final landfall in Mexico, expected to occur well south of the Texas border on Friday night or Saturday, could be as a hurricane.

Figure 5. GeoColor visible satellite image of Tropical Depression Eight southeast of Bermuda (outlined in yellow) at 1420Z (10:20 a.m. EDT) Monday, August 16, 2021. (Image credit: RAMMB/CIRA/CSU)

Tropical Storm Henri expected to form near Bermuda

A tropical depression spinning near Bermuda on Monday morning was on the verge of becoming Tropical Storm Henri. At 11 a.m. EDT Monday, August 16, NHC pegged the maximum winds of Tropical Depression Eight (TD 8) at 35 mph, just below tropical storm strength. TD 8 was centered about 135 miles east-southeast of Bermuda, heading south at 9 mph. Given the predicted imminent strengthening of TD 8 into Henri, a tropical storm watch was in effect for Bermuda.

ASCAT scatterometer data showed TD 8’s circulation to be well defined but weak, and the central pressure was a relatively high 1012 mb. Winds at the L.F. Wade International Airport in Hamilton, Bermuda, were only 15 mph at 10:55 a.m. EDT. Weak bands of showers and thunderstorms were pushing across the island, well away from the compact convective core of TD 8.

Assuming TD 8 becomes Henri as predicted, it will likely persist as a tropical storm for several days, making a clockwise loop around Bermuda but probably not moving directly over the island. Forecast models agree on the general looping pattern that will culminate in the system’s recurvature, but they disagree on how far south and west it might stray before looping back northeast. Among the 0Z Monday runs of our top three track models, the European has the westernmost solution, hauling TD 8 more than halfway from Bermuda to the U.S. East Coast before the system races back northeast.

While TD 8 is carving out the southward end of its loop on Monday and Tuesday, it will pass over warm sea surface temperatures of around 28-29 degrees Celsius (82-84°F), with only moderate wind shear of about 10 knots, so some strengthening can be expected. The midlevel atmospheric humidity will be only around 50%, though, so TD 8 is unlikely to intensify dramatically. (The HWRF model has been a persistent outlier, projecting that TD 8 could become a powerful Hurricane Henri.) From Wednesday onward, the jet stream will be dipping toward Bermuda, increasing shear to the 20-30 mph range and likely putting a cap on any further strengthening.

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Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...

Bob Henson is a meteorologist and journalist based in Boulder, Colorado. He has written on weather and climate for the National Center for Atmospheric Research, Weather Underground, and many freelance...