BULLETIN
Hurricane Laura Intermediate Advisory Number 30A
NWS National Hurricane Center Miami FL AL132020
700 AM CDT Thu Aug 27 2020
…DAMAGING WINDS AND FLOODING RAINFALL SPREADING INLAND OVER
WESTERN AND CENTRAL LOUISIANA…
…LIFE-THREATENING STORM SURGE CONTINUES ALONG MUCH OF THE
LOUISIANA COASTLINE…
SUMMARY OF 700 AM CDT…1200 UTC…INFORMATION
———————————————-
LOCATION…31.2N 93.3W
ABOUT 20 MI…30 KM N OF FORT POLK LOUISIANA
MAXIMUM SUSTAINED WINDS…100 MPH…160 KM/H
PRESENT MOVEMENT…N OR 360 DEGREES AT 15 MPH…24 KM/H
MINIMUM CENTRAL PRESSURE…970 MB…28.64 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
The Hurricane Warning from High Island to Intracoastal City has
been replaced with a Tropical Storm Warning.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for…
* High Island Texas to the Mouth of the Mississippi River
A Tropical Storm Warning is in effect for…
* High Island Texas to the Mouth of the Mississippi River
A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline 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.
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 700 AM CDT (1200 UTC), the center of Hurricane Laura was located
near latitude 31.2 North, longitude 93.3 West. Laura is moving
toward the north near 15 mph (24 km/h) and this motion should
continue through the day. A northeastward to east-northeastward
motion is expected tonight and Friday. On the forecast track, Laura
will move northward across western and northern Louisiana
through this afternoon. The center of Laura is forecast to move
over Arkansas tonight, the mid-Mississippi Valley on Friday, and
the mid-Atlantic states on Saturday.
Maximum sustained winds are near 100 mph (160 km/h) with higher
gusts. Rapid weakening is forecast, and Laura is expected to
become a tropical storm later today.
Hurricane-force winds extend outward up to 60 miles (95 km) from
the center and tropical-storm-force winds extend outward up to 175
miles (280 km). An observing site in Alexandria, Louisiana,
recently reported a wind gust to 74 mph (119 km/h)
The estimated minimum central pressure is 970 mb (28.64 inches).
HAZARDS AFFECTING LAND
———————-
Key messages for Laura can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC.
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…
Johnson Bayou to Rockefeller Wildlife Refuge including Calcasieu
Lake…15-20 ft
Rockefeller Wildlife Refuge to Intracoastal City…10-15 ft
Intracoastal City to Morgan City including Vermilion Bay…8-12 ft
Sea Rim State Park to Johnson Bayou including Sabine Lake…4-8 ft
Morgan City to Mouth of the Mississippi River…4-7 ft
High Island to Sea Rim State Park…2-4 ft
Mouth of the Mississippi River to Ocean Springs including Lake
Borgne…1-3 ft
Lake Pontchartrain and Lake Maurepas…1-3 ft
The deepest water will occur along the immediate coast near and to
the right of the landfall location, where the surge will be
accompanied by large and destructive waves.
Life-threatening storm surge with large and destructive waves will
continue within the Storm Surge Warning area this morning. This
surge could penetrate up to 40 miles inland from the immediate
coastline, and flood waters will not fully recede for several days
after the storm.
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: Hurricane-force winds and damaging wind gusts are also
expected to spread well inland into portions of eastern Texas and
western Louisiana this morning. Tropical storm conditions will
spread northward within the warning areas through the day.
RAINFALL: Through Friday, Laura is expected to produce the following
rainfall totals:
Across portions of Louisiana, Mississippi, across Arkansas: 6 to 12
inches with isolated totals of 18 inches.
This rainfall will cause widespread flash and urban flooding, small
streams and creeks to overflow their banks, and minor to moderate
freshwater river flooding.
Through Saturday, Laura is expected to produce 1 to 3 inches with
isolated maximum amounts of 5 inches across the mid-Mississippi
Valley and portions of the Tennessee and Lower Ohio Valley, the
central Appalachians and the Mid-Atlantic States.
This rainfall may lead to flash and urban flooding and rapid rises
on small streams.
TORNADOES: Tornadoes are possible today and tonight over parts of
Louisiana, Arkansas, and western Mississippi.
SURF: Swells produced by Laura are affecting the U.S. Gulf coast
from the west coast of Florida to Texas and northeastern Mexico.
These swells are likely to cause life-threatening surf and rip
current conditions. Please consult products from your local
weather office.
Thanks