Marco Continues to Slowly Weaken as it Approaches the Louisiana Coast

NHC UPDATE SUMMARY OF 4:00 PM CDT INFORMATION

LOCATION: 15 miles east-southeast of the Mouth of the Mississippi River
MAXIMUM WINDS: 40 mph
MOVEMENT: northwest at 7 MPH
MINIMUM PRESSURE: 1008 MB or 29.77 in

WATCHES AND WARNINGS

There are no coastal watches or warnings in effect for Marco. However, Tropical cyclone wind and surge watches have been issued for portions of the U.S. Gulf Coast for Tropical Storm Laura.

DISCUSSION AND OUTLOOK

At 400 PM CDT (2100 UTC), the center of Tropical Storm Marco was located near latitude 29.0 North, longitude 88.9 West. Marco is moving toward the northwest near 7 mph (11 km/h), a turn to the west-northwest, and a slight increase in forward speed is expected to occur tonight. On the forecast track, Marco will move inland over southeastern Louisiana tonight, and across southern Louisiana on Tuesday.

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Weakening is expected, and Marco is forecast to become a tropical depression tonight and degenerate to a remnant low on Tuesday.

Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. A National Ocean Service weather station located on Petit Bois Island, Mississippi recently reported a wind gust to 38 mph (61 km/h).

The estimated minimum central pressure is 1008 MB (29.77 inches).

HAZARDS AFFECTING LAND

WIND: Wind gusts to tropical storm force are possible over the coastal sections of southeastern Louisiana and Mississippi through this evening.

RAINFALL: Marco is expected to produce additional rainfall accumulations of 2 to 4 inches with additional isolated totals of 7 inches across portions of the north-central Gulf Coast and southeastern United States through Wednesday. Rain totals related to Marco near Apalachicola, Florida reached as high as 11.81 inches on Sunday per a CoCoRaHS report. The additional rainfall may result in areas of flash, urban and small stream flooding along the same area.

SURF: Swells generated by Marco are likely to affect portions of the northern Gulf Coast for the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

TORNADOES: A couple of tornadoes are possible late this afternoon through tonight across the Florida Panhandle, southern Georgia, far southern Alabama, and far southern Mississippi.

Category: ALL POSTS, Severe Weather, Tropical