There have been significant changes with Tropical Storm Marco today. This morning a USAF reconnaissance aircraft found Marco was stronger, had formed a partial eye wall, and was tracking much farther north and east than expected.
Because of this, model guidance has shifted east, and Marco is now likely to make landfall somewhere along the north-central Gulf Coast rather than along the western Gulf Coast as initially thought.
As of the 4 PM CDT advisory maximum sustained winds were 65 mph. Marco is likely to become a hurricane, and the National Hurricane Center is forecasting Marco to make landfall in Plaquemines Parish, LA Monday as a category 1.
However, wind shear is expected to increase over the next 12 to 24 hours, and it is possible this could cause Marco to weaken to a tropical storm on approach to the Gulf Coast. There could also be additional minor shifts in track.
Near/after landfall Marco should slow and bend to the west-northwest and west.
A Hurricane Watch has been posted from Intracoastal City, LA to the Mississippi/Alabama border. There is also now a Tropical Storm Watch in effect from the Mississippi/Alabama border to the Alabama/Florida border.
Marco is likely to bring storm surge, high winds, and heavy rain to parts of Louisiana, Mississippi and Alabama, but exact timing, placement and magnitude can’t yet be pinned down. There should be more clarity tomorrow.
Additionally, outer bands/squalls from Marco could result in a threat for waterspouts/tornadoes, and might extend as far east as the Florida Panhandle.
An update on Laura will be posted later this evening.
