BULLETIN
Hurricane Laura Intermediate Advisory Number 24A
NWS National Hurricane Center Miami FL AL132020
700 PM CDT Tue Aug 25 2020
…LAURA STRENGTHENING OVER THE CENTRAL GULF OF MEXICO…
SUMMARY OF 700 PM CDT…0000 UTC…INFORMATION
———————————————-
LOCATION…25.0N 89.0W
ABOUT 435 MI…700 KM SE OF LAKE CHARLES LOUISIANA
ABOUT 465 MI…745 KM SE OF GALVESTON TEXAS
MAXIMUM SUSTAINED WINDS…85 MPH…140 KM/H
PRESENT MOVEMENT…WNW OR 300 DEGREES AT 17 MPH…28 KM/H
MINIMUM CENTRAL PRESSURE…983 MB…29.03 INCHES
WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:
None.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for…
* San Luis Pass Texas to the Mouth of the Mississippi River
A Hurricane Warning is in effect for…
* San Luis Pass Texas to Intracoastal City Louisiana
A Tropical Storm Warning is in effect for…
* Sargent Texas to San Luis Pass
* East of Intracoastal City Louisiana to the Mouth of the
Mississippi River
A Storm Surge Watch is in effect for…
* Freeport Texas to San Luis Pass
* Mouth of the Mississippi River to Ocean Springs Mississippi
* Lake Pontchartrain, Lake Maurepas, and Lake Borgne
A Hurricane Watch is in effect for…
* East of Intracoastal City to west of Morgan City Louisiana
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 Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous. Preparations to protect life
and property should be rushed to completion.
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.
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 PM CDT (0000 UTC), the center of Hurricane Laura was located
by NOAA and Air Force Hurricane Hunter aircraft near latitude 25.0
North, longitude 89.0 West. Laura is moving toward the
west-northwest near 17 mph (28 km/h), and this general motion should
continue tonight. A turn toward the northwest is forecast by
Wednesday, and a northwestward to north-northwestward motion should
continue through Wednesday night. On the forecast track, the center
of Laura will move across the central Gulf of Mexico tonight and the
northwestern Gulf of Mexico on Wednesday. The hurricane should
approach the Upper Texas and southwest Louisiana coasts on Wednesday
night and move inland near those areas late Wednesday night or
Thursday morning.
Maximum sustained winds have increased to near 85 mph (140 km/h)
with higher gusts. Significant strengthening is forecast during the
next 36 hours, and Laura is expected to be a major hurricane at
landfall. Rapid weakening is expected after Laura makes landfall.
Hurricane-force winds extend outward up to 45 miles (75 km) from
the center and tropical-storm-force winds extend outward up to 175
miles (280 km).
The minimum central pressure reported by the Air Force Hurricane
Hunter aircraft is 983 mb (29.03 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…
Sea Rim State Park TX to Intracoastal City LA including Sabine Lake
and Calcasieu Lake…9-13 ft
Intracoastal City to Morgan City including Vermilion Bay…7-11 ft
Port Bolivar TX to Sea Rim State Park…6-9 ft
Morgan City LA to Mouth of the Mississippi River…4-6 ft
San Luis Pass TX to Port Bolivar…3-5 ft
Galveston Bay…3-5 ft
Freeport TX to San Luis Pass…2-4 ft
Mouth of the Mississippi River to Ocean Springs MS including Lake
Borgne…2-4 ft
Lake Pontchartrain and Lake Maurepas…2-4 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. This storm surge could
penetrate up to 30 miles inland from the immediate coastline in
southwestern Louisiana and far southeastern Texas.
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.
RAINFALL: From Wednesday afternoon through Friday, Laura is
expected to produce rainfall totals of 5 to 10 inches, with isolated
maximum amounts of 15 inches across portions of the northwestern
Gulf Coast from western Louisiana to far eastern Texas, and
northward into much of Arkansas. Over the Lower to Middle
Mississippi Valley from central Louisiana into western Tennessee and
Kentucky, and southeastern Missouri, 2 to 4 inches of rainfall with
isolated totals of 6 inches are expected. This rainfall will cause
widespread flash and urban flooding, small streams to overflow their
banks, and minor to isolated moderate river flooding.
By late Friday into Saturday, portions of the Tennessee and Ohio
Valley could see 2 to 4 inches with locally higher amounts as
tropical moisture from Laura moves through the region.
WIND: Hurricane conditions are expected in the hurricane warning
area Wednesday night and Thursday. Tropical storm conditions are
expected to reach the coast in the hurricane warning area late
Wednesday or Wednesday night, and are expected in the tropical
storm warning area Wednesday night and Thursday.
Hurricane-force winds and damaging wind gusts are also expected to
spread well inland into portions of eastern Texas and western
Louisiana early Thursday.
TORNADOES: A few tornadoes are expected Wednesday and Wednesday
night over Louisiana, southeast Texas, and southwestern Mississippi.
SURF: Swells produced by Laura are affecting the U.S. Gulf coast
from the west coast of Florida to Louisiana and are expected to
reach the coast of Texas and northeastern Mexico overnight and on
Wednesday. These swells are likely to cause life-threatening surf
and rip current conditions. Please consult products from your
local weather office.