After struggling to build deep convection near its center for the past couple days, Sally has rapidly intensified into a hurricane this afternoon after thunderstorm activity was finally able to wrap all the way around the center.

Satellite imagery shows persistent deep convection near the storm’s center this afternoon which is located south of the FL/AL border. After rapidly intensifying this morning, the system appears to have leveled off a bit this afternoon as a little bit of dry air sneaks into the southern side of the circulation (note the warmer cloud tops/lighter colors on the satellite image south of the deep reds).

One factor that contributed to Sally’s rapid intensification was a jump east in the low-level center’s location such that it became aligned with the mid-level center that was previously to its northeast. This jump east in the storm’s center, along with the storm’s rapid strengthening today, supports a shift east in the expected landfall location. This is reflected in the official NHC forecast shown below.

The upshot of all this is that the threat from Sally to places like New Orleans is lower than it was yesterday. I’d be surprised to see hurricane-force winds or extreme (>8”) rainfall in the city itself, though some impacts are still expected. Meanwhile, parts of southern Mississippi, southern Alabama, and far western Florida are now expected to feel the worst that Sally has to offer.

Winds and surge are already moving into these areas, so the window for safe preparations is beginning to close. Landfall is expected tomorrow evening but because the storm will be moving so slowly, severe impacts will begin well before the center moves onshore and will continue well after landfall.

Stay safe and always heed advice/orders given by local officials.

Tap here to listen to our latest audio update by Hurricane Tracker forecaster Jack Sillin.

-Jack

Posted on 9/13/2020 by Jack Sillin with the Hurricane Tracker App. These posts are meant to provide our users with a detailed analysis of the tropics as conditions warrant and may not be updated on a daily basis. For the latest up to date storm information, always go to “Current Storms” and select a system for the latest information.

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