Pre-Landfall SSEs #1 | Summary
Posting Date: August 27, 2021, 10:00:00 AM
The formerly named Tropical Depression Nine in the Atlantic has further intensified and is now Tropical Storm Ida.
As of 8 a.m. EDT, the National Hurricane Center (NHC) reported that Tropical Storm Ida was located at 20.3°N 81.7°W and moving northwest at 15 mph. Ida is forecast to continue in this direction through the Gulf of Mexico and rapidly intensify to a Category 3 hurricane on the Saffir-Simpson Scale within 48 to 72 hours before making landfall in Louisiana near New Orleans late Sunday or early Monday, local time.
ALERT™ subscribers can download similar stochastic event (SSE) IDs for Ida from the Downloads tab of the ALERT website. Compatible with Touchstone® and Touchstone Re™, the SSEs were selected based on event parameters (not industry losses) and are recommended for Louisiana, Alabama, Mississippi, Tennessee, Kentucky, and Arkansas exposures. The information provided herein is strictly confidential and is solely for the use of AIR clients; disclosure to others is prohibited unless noted in your AIR software license.
NHC Forecast Track and Intensity
On Thursday evening, Air Force Reserve hurricane hunter aircraft found that the depression has strengthened to a tropical storm. As of this morning, 8 a.m. EDT, Tropical Storm Ida has maximum sustained winds of 60 mph (96 km/h) and is about 75 miles (120 km) north-northwest of Grand Cayman.
Tropical Storm Ida is currently forecast to cross western Cuba tonight (Friday) and emerge into the Gulf of Mexico overnight, then continue northwest towards the U.S. Gulf Coast. Given the extremely Gulf warm waters and areas of lower wind shear in Ida’s forecast path, additional strengthening with rapid intensification is explicitly shown in the NHC forecast. Ida is forecast to reach hurricane strength Saturday morning in the central Gulf, then intensify further to a Category 3 hurricane Sunday morning, with peak sustained winds of 115 mph (185 km/h), before it makes landfall in Louisiana late Sunday night or early Monday morning local time. Other models—including the HMON, HCCA, and Florida State models—have indicated the potential for Ida reaching an even higher intensity at landfall.
After landfall, Ida is expected to weaken rapidly as it continues north-northwest through the lower Mississippi and Tennessee River valleys, bringing heavy rains.
NHC Forecast Hazards
The system is expected to bring dangerous impacts from wind, storm surge, and heavy rainfall to areas along the coasts of East Texas, Louisiana, Mississippi, Alabama, and the western Florida Panhandle by Sunday and Monday, with flash flood and riverine flood risks extending across these areas and north along the storm's path.
Hurricane watches have been issued this morning for portions of the Central Gulf Coast from Cameron, Louisiana to the Mississippi/Alabama border, including Metropolitan New Orleans. A Tropical Storm Watch is currently in effect across Alabama to the Florida border. Storm Surge Watches are in effect along the coasts of Louisiana, Mississippi, and Alabama, with water levels potentially 2 to 4 feet above normal tide levels. If the peak surge occurs at high tide, water levels are forecast to reach 7-11 feet above ground in areas from Morgan City, Louisiana, to Ocean Springs, Mississippi.
Coastal preparations are reportedly currently underway in Metropolitan New Orleans and other areas in these zones. A state of emergency has been declared in Jefferson and Iberia parishes in advance of the storm.
In the Caribbean, a Tropical Storm Warning is currently in effect for the Cayman Islands, where tropical storm conditions are currently occurring.
AIR plans to issue another set of similar stochastic events for Ida on Saturday morning, August 28, EDT, and on Sunday morning, August 29, EDT, after which we will provide an update on additional plans to follow.
Pre-Landfall SSEs #1 | Downloads
Posting Date: August 27, 2021, 10:00:00 AM
The information provided herein is strictly confidential and is solely for the use of AIR clients; disclosure to others is prohibited.
Similar Stochastic Event IDs
Event IDs taken from our stochastic catalog that have similar characteristics as the current event.
|TOUCHSTONE / TOUCHSTONE Re||Excel (xls)||Selected set of stochastic events|
Note: Additional downloads related to the posting are listed below. Please use the appropriate application to view these files.
|Ida Scenario Overview||.xls||Event parameters, insured industry losses, a track map, and commentary for today's selections.|
|Ida Track Files||.zip||Track files for today's selections for use in GIS applications.|