Tropical Storm Ingrid

Landfall | Summary
Posting Date: September 16, 2013, 12:45:00 PM

Tropical Storm Ingrid had weakened from its Category 1 hurricane status by the time it made landfall near the small town of La Pesca on the eastern coast of Mexico between 6:00 and 7:00 a.m. CDT this morning. The National Hurricane Center’s 7:00 a.m. CDT Public Advisory reported that an Air Force Hurricane Hunter aircraft and radar imagery had confirmed that Ingrid had made landfall and that the storm’s wind speed had not increased as anticipated when it crossed warmer waters close to the coastline. In fact, Ingrid’s intensity had decreased to about 65 mph, that of a tropical storm.

Storm Conditions

Tropical Storm Ingrid became the second Atlantic hurricane of the 2013 season with winds of 75 mph on September 14—more than two weeks (18 days) later than the usual appearance of the second hurricane of a season. By the end of that day, Ingrid’s wind speeds had increased to 85 mph. Identified as a tropical depression only two days earlier, the storm had moved slowly across the Bay of Campeche, an environment favorable for strengthening. These conditions brought heavy rains to Mexico’s east coast near Tampico even before Ingrid approached landfall.

This situation was exacerbated by Tropical Storm Manuel, which was approaching Mexico’s west coast from the eastern Pacific Ocean almost directly opposite where Ingrid was expected to make landfall. Manuel made landfall yesterday, September 15, as a tropical storm and quickly weakened. However, it may have been Manuel’s upper-level outflow that increased wind shear over Ingrid, inhibiting the hurricane from maintaining Category 1 strength as it approached landfall.

This rare coincidence of two tropical cyclones making landfall so close together in both time and location has made for a precarious situation. The Mexican Gulf Coast where Ingrid made landfall is already saturated by heavy precipitation in recent weeks from Tropical Depression Eight and Tropical Storm Fernand. The one-two punch of Manuel and Ingrid has already caused widespread flooding, some flash floods, and mudslides, resulting in damage and the loss of lives.

Exposure at Risk

Fortunately, the area where Ingrid made landfall is relatively sparsely settled. Most insured residential structures in the region are made of confined masonry, which performs better than plain masonry under lateral wind loads because of its use of bond beams and columns. Insured commercial properties are dominated by confined masonry and reinforced masonry construction. Both construction types should fare well against Ingrid’s wind speeds, which are expected to weaken considerably as the storm interacts with land. Therefore, structural damage from wind would be expected to be minimal and limited to poorly installed or maintained cladding and roofing. The full extent and possible impact of flooding, flash floods, and mudslides, however, remain uncertain.

As Ingrid drifted through the Bay of Campeche over the weekend, however, Petroleos Mexicanos(Pemex), Mexico’s state-owned oil company, suspended air and sea operations at its rigs in the bay.

Reported Impact

According to current news reports, the heavy rains and flooding from the two tropical storms have already caused the confirmed deaths of 21 people, six of them by Ingrid even before it made landfall. Six thousand people were evacuated in the state of Veracruz, immediately south of Tamaulipas State where Ingrid made landfall. According to the state’s civil protection authority, more than 1,000 homes in the state have been affected by the storm and 20 highways and 12 bridges have experienced damage. A bridge collapsed near the northern Veracruz city of Misantla, cutting the area off from the state capital.

Another about 1,000 people have been evacuated in Tamaulipas State, and damaged and collapsed roads and flooded homes have been reported in the central state of San Luis Potosi. People there have been evacuated to the more than 50 shelters set up to help. Throughout the region, including in larger cities like Tampico, Madero, and Altamira, the traditional Independence Day celebrations that would have been conducted on Saturday and Sunday were cancelled. Also, iIn addition to closing rigs in the Bay of Campeche, Pemex closed the oil ports of Cayo Arcas and Dos Boas, which process more than 68% of Mexico’s crude oil exports.

Forecast Track and Intensity

The interaction of Tropical Storm Ingrid with the mountainous terrain in the interior of Mexico, along with the similar interactions of the remnants of Tropical Storm Manuel, is producing heavy precipitation over much of the country. Ingrid is expected to produce 10 to 15 inches of rain over a large part of eastern Mexico—with as much as 25 inches possible in isolated areas. Over the next days, these rains are likely to result in life-threatening flash floods and mudslides. Also, a dangerous storm surge will raise water levels by as much as 2 to 4 feet above normal tide levels along the immediate coast near and to the north of Ingrid’s landfall near La Pesca. Near the coast, the surge will be accompanied by large and destructive waves.

Tropical Storm Ingrid is forecast to keep drifting to the southwest for the next couple of days while dissipating. Tropical storm force winds are expected to persist for perhaps 12 to 24 hours following landfall, although the extent of their reach is likely to remain limited. At landfall tropical storm force winds extended outward only up to 105 miles. A turn toward the west is expected this afternoon, followed by a turn to the west-southwest tonight, with Ingrid forecast to become a tropical depression later today and to dissipate on Tuesday.

Overall, minimal impact is expected from Tropical Storm Ingrid’s winds; the chief danger remains heavy precipitation and consequent flooding. AIR’s tropical cyclone team is continuing to monitor Tropical Storm Ingrid and its impact over the next days and will provide additional information as events warrant.

Tropical Storm Ingrid’s possible future track at the time of landfall

Landfall | Downloads
Posting Date: September 16, 2013, 12:45:00 PM