BULLETIN
Tropical Storm Marco Advisory Number 17
NWS National Hurricane Center Miami FL AL142020
1000 AM CDT Mon Aug 24 2020
…MARCO CONTINUES TO PRODUCE HEAVY RAINFALL AND GUSTY
WINDS ALONG PORTIONS OF THE NORTHERN GULF COAST…
SUMMARY OF 1000 AM CDT…1500 UTC…INFORMATION
———————————————–
LOCATION…28.5N 88.5W
ABOUT 55 MI…90 KM SE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS…50 MPH…85 KM/H
PRESENT MOVEMENT…NNW OR 330 DEGREES AT 8 MPH…13 KM/H
MINIMUM CENTRAL PRESSURE…1006 MB…29.71 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
The Tropical Storm Warning from west of Morgan City to Intracoastal
City, Louisiana, has been discontinued.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for….
* Morgan City Louisiana to Ocean Springs Mississippi
* Lake Borgne
A Tropical Storm Warning is in effect for…
* Morgan City to the Mississippi/Alabama border
* Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans
A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours in the indicated locations. For a depiction
of areas at risk, please see the National Weather Service Storm
Surge Watch/Warning Graphic, available at hurricanes.gov. This is a
life-threatening situation. Persons located within these areas
should take all necessary actions to protect life and property from
rising water and the potential for other dangerous conditions.
Promptly follow evacuation and other instructions from local
officials.
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within
the next 6 to 18 hours.
For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.
DISCUSSION AND OUTLOOK
———————-
At 1000 AM CDT (1500 UTC), the center of Tropical Storm Marco was
located near latitude 28.5 North, longitude 88.5 West. Marco is
moving toward the north-northwest near 8 mph (13 km/h). A turn to
the west-northwest is expected to occur by Tuesday, and this
motion should continue until the system dissipates in a couple of
days.
Maximum sustained winds are near 50 mph (85 km/h) with higher gusts.
Steady weakening is forecast, and Marco is expected to weaken to a
tropical depression tonight, and degenerate to a remnant low on
Tuesday.
Tropical-storm-force winds extend outward up to 105 miles (165 km)
from the center.
The estimated minimum central pressure is 1006 mb (29.71 inches).
HAZARDS AFFECTING LAND
———————-
STORM SURGE: The combination of a dangerous storm surge and the
tide will cause normally dry areas near the coast to be flooded by
rising waters moving inland from the shoreline. The water could
reach the following heights above ground somewhere in the indicated
areas if the peak surge occurs at the time of high tide…
Morgan City LA to Ocean Springs MS, including Lake Borgne…2-4 ft
The deepest water will occur along the immediate coast in areas of
onshore winds, where the surge will be accompanied by large and
dangerous waves. Surge-related flooding depends on the relative
timing of the surge and the tidal cycle, and can vary greatly over
short distances. For information specific to your area, please see
products issued by your local National Weather Service forecast
office.
WIND: Tropical storm conditions are expected to start by this
afternoon in portions of the warning area.
RAINFALL: Marco is expected to produce total rainfall accumulations
of 3 to 6 inches with isolated maximum amounts of 10 inches across
portions of the northeast and north-central Gulf coast through
Tuesday. This 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 couple of days. 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 today into tonight
across the Florida Panhandle, southern Georgia, southern Alabama,
and southern Mississippi.