Ida Expected to Become Category 4 Hurricane Before Landfall in Louisiana

Data from an Air Force Reserve hurricane hunter aircraft indicate that Ida has strengthened into a hurricane as it approaches the Isle of Youth, Cuba. The maximum sustained winds are estimated to be 75 mph with higher gusts. A sustained wind of 44 mph and a gust of 60 mph were recently reported on Cayo Largo, Cuba.

SUMMARY OF 110 PM EDT…1710 UTC…INFORMATION
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LOCATION…21.4N 82.4W
ABOUT 30 MI…50 KM ESE OF THE ISLE OF YOUTH
ABOUT 165 MI…270 KM E OF THE WESTERN TIP OF CUBA
MAXIMUM SUSTAINED WINDS…75 MPH…120 KM/H
PRESENT MOVEMENT…NW OR 320 DEGREES AT 15 MPH…24 KM/H
MINIMUM CENTRAL PRESSURE…987 MB…29.15 INCHES

Although there is still some southwesterly shear over Ida, the outflow has begun to expand over the northeastern and southeastern portions of the circulation. The upper-level trough near the Yucatan peninsula that has been imparting the shear over Ida is forecast to weaken and move westward, which should result in a more favorable upper-level wind pattern. This, in combination with warm sea surface temperatures and a moist environment along the forecast track of the storm are expected to result in steady to rapid strengthening. In addition to the increase in strength, Ida’s wind field will grow larger as it moves over the Gulf of Mexico.

A mid-level ridge over the western Atlantic is forecast to move westward and this should keep Ida on a general northwestward heading during the next 48-60 hours. This track will bring the storm across western Cuba later today, over the southeastern and central Gulf of Mexico on Saturday and Saturday night, to the coast of Louisiana by late Sunday. The track guidance is in remarkably good agreement with very little cross-track spread during the first 60 hours or so of the forecast period. After that time, Ida is forecast to reach the western portion of the ridge, which is expected to cause the storm to slow down and turn northward and then northeastward over the southeastern United States.

Key Messages:

1. The risk of life-threatening storm surge inundation is increasing along the coasts of Louisiana, Mississippi, and Alabama. Inundation of 7 to 11 feet above ground level is possible within the area from Morgan City, Louisiana, to Ocean Springs, Mississippi, including Lake Borgne. Interests in these areas should follow any advice given by local officials.

2. Ida is expected to be a dangerous major hurricane when it reaches the northern Gulf Coast on Sunday, and the risk of hurricane-force winds continues to increase, especially along portions of the Louisiana coast, including metropolitan New Orleans. Potentially devastating wind damage could occur where the core of Ida moves onshore.

3. Ida is likely to produce heavy rainfall later Sunday into Monday across the central Gulf Coast from southeast Louisiana to coastal Mississippi and Alabama, as well as the Lower Mississippi Valley, resulting in considerable flash, urban, small stream, and river flooding.

4. Tornadoes are a concern with any land-falling tropical system, and we could see these over much of Southeast Louisiana, Mississippi, Alabama, and Northwest Florida.

NEXT WEEK: For now, the NHC is forecasting the circulation of Ida to move through Mississippi Monday and Tuesday, winding up near Muscle Shoals Tuesday night. This puts Alabama on the wet, unsettled east side of the system… rain over West and Southwest Alabama Monday will spread northward, and much of the state will have widespread rain Monday night and Tuesday. The rain could be heavy at times, and flooding issues are possible. Rain amounts will be in the 3-5 inch range over the western half of the state, with amounts of 1-3 inches for the eastern counties.

In addition to the flooding risk, some quick spin-up tornadoes are expected as the system moves inland. These will be a threat statewide Monday night and Tuesday, but uncertainty still remains and it is a little too early to know the magnitude of the tornado threat.

The system will pull away from the state on Wednesday and drier air will be pulled down into state Thursday and Friday with lots of sunshine both days along with lower humidity levels.

Pay attention to updates through the weekend.
Ryan