Hurricane Gustav - Intermediate Advisory
25a
Issued: Sunday, August 31st 2008 1:00pm CDT
At 1PM CDT, Hurricane Gustav was near 25.9N/86.6W, or about 350 miles southeast of New
Orleans. Movement is to the northwest at 15-17 mph. Maximum winds are 115 mph.
Recon found that Gustav's winds are down a little from earlier estimates this afternoon.
However, squalls are increasing around Gustav's center, and we expect the hurricane to gain
some strength back prior to moving ashore into the Louisiana coast on Monday. Winds at
landfall may be in the 120-130 mph range.
We are not planning to make any significant changes to the forecast track on the 3PM advisory.
Our next full advisory, which will include a track map, will be issued by 3PM CDT.
Meteorologist: Chris Hebert
Hurricane Gustav Advisory 25
Issued: Sunday, August 31st 2008 10:28am CDT
Current Status
At 10AM CDT, Hurricane Gustav is located near 25.3N/86W, or about 415 miles southeast of
New Orleans, LA. Movement is to the northwest at 14-16 mph. A recon plane is currently
investigating Gustav. Generally, the plane is finding winds in the 90-100 mph range, though
there may be a few small areas with winds to 120 mph, so the winds have been left at 120 mph
for this advisory.
From the NHC: A hurricane warning remains in effect for the Gulf Coast from Cameron,
Louisiana eastward to the Alabama-Florida border, including the city of New Orleans and Lake
Pontchartrain. A tropical storm warning remains in effect from east of the Alabama-Florida
border to the Ochlockonee River and from west of Cameron, Louisiana to just east of High
Island, Texas. A hurricane watch remains in effect from west of Cameron, Louisiana to just east
of High Island, Texas. A tropical storm warning remains in effect for the Lower Florida Keys
west of the Seven Mile bridge to the Dry Tortugas.
Changes From our Previous Forecast
There are no significant changes on this advisory.
Our Forecast
Model guidance remains tightly-clustered on eastern Vermilion Bay to south of Houma, LA.
Gustav has been tracking directly on our previous forecast track, so we see no reason to make
any adjustments on this advisory. Our forecast takes Gustav to the Louisiana coast just south of
Houma early tomorrow afternoon then northwest just east of Lafayette Monday night. As Gustav
tracks northwestward across west-central Louisiana on Tuesday it should slow to about 4-6 mph.
By Wednesday and Thursday, its remnant circulation will be drifting slowly westward in
northeast Texas south of Tyler.
Satellite and recon data indicate that Gustav has weakened significantly since yesterday. Though
still classified as a Category 3 hurricane by the NHC, Gustav's winds are probably closer to a
borderline Category 1-2 hurricane this morning, perhaps with a very small area of 110-120 mph
winds. But thunderstorms are now increasing near Gustav's center, and the track will be right
across the warmer waters of the Loop Current today. So we do expect Gustav to become at least
a strong Category 3 hurricane within the next 12-18 hours. Thereafter, Gustav will begin
encountering slightly increased wind shear and cooler water as it approaches landfall. We are
forecasting Gustav to be a Category 3 hurricane at landfall with winds in the 115-125 mph range.
As a Category 3 hurricane at landfall, Gustav will produce a storm surge of 12-16 feet near
where the center crosses the coast south of Houma and extending eastward to the mouth of the
Mississippi River. East of the Mississippi River, Gustav's surge will likely be in the 6-9 foot
range across Chandeleur Sound. Along the Mississippi Coast, tides should run 3-5 feet above
normal Mo nday morning through Tuesday morning due to strong onshore winds as Gustav
moves ashore well to the west. Rainfall along Gustav's path could total in excess of 20 inches in
some areas near and up to 70 miles to the right of Gustav's track from Monday through Friday.
Isolated tornadoes and significant inland flooding will also occur across the southern parishes of
Louisiana on Monday and Monday night. These threats will extend northwestward toward
western Louisiana and eastern Texas on Tuesday through Friday.
Other Possibilities
Due to the angle at which Gustav will be approaching the Louisiana coast, it is quite possible that
Gustav could make landfall between 30-50 miles east or west of our forecast. This could
significantly change the area of the highest storm surge along the Louisiana coast.
Our next advisory will be issued by 3PM CDT.
Meteorologist: Chris Hebert
HSI Help
Forecast
Hour
0
12
24
36
42
48
60
72
96
Valid
10AM CDT
Sun Aug 31
10PM CDT
Sun Aug 31
10AM CDT
Mon Sep 1
10PM CDT
Mon Sep 1
4AM CDT
Tue Sep 2
10AM CDT
Tue Sep 2
10PM CDT
Tue Sep 2
10AM CDT
Wed Sep 3
10AM CDT
Thu Sep 4
Lat
Lon
Max
Winds
Max
Gusts
Hurricane Severity
Index
Classification Size Intensity Total
25.30N 86.00W 120mph 145mph
Category 3
11
12
23
27.00N 87.80W 130mph 160mph
Category 3
14
14
28
28.70N 89.90W 125mph 155mph
Category 3
15
13
28
30.20N 91.80W 95mph 130mph
Category 2
3
8
11
30.60N 92.30W 75mph 110mph
Category 1
3
5
8
31.00N 92.80W 60mph
95mph Tropical Storm 2
3
5
31.50N 93.40W 40mph
65mph Tropical Storm 1
1
2
31.70N 94.00W 35mph
45mph
0
1
1
31.70N 94.80W 30mph
40mph
0
0
0
Tropical
Depression
Tropical
Depression
Hurricane Gustav Advisory 25 Site Forecast
for Meraux, LA
Issued: Sunday, August 31st 2008 10:28am CDT
No changes from the previous forecast. Landfall is projected for just south-southeast of Houma,
Louisiana during the early afternoon on Monday as a Category 3 hurricane with winds of 115125 mph and higher gusts.
Squalls may begin impacting the Louisiana coast this evening and will spread westward to the
Beaumont/Port Arthur area by late Monday morning. Heavy squalls likely all along the
Louisiana coast Monday night and Tuesday.
Rainfall
General rainfall amounts in the path of Gustav's core are expected to be in the 10-15 inch range,
with some areas receiving as much as 15-20 inches.
Storm Surge
If Gustav strikes the mid Louisiana coast as forecast, then the storm surge could reach 10-16 feet
from western Terrebonne Parish to the mouth of the Mississippi Riber. This surge would move
ashore late Monday morning and early Monday afternoon. East of the Mississippi River, a surge
of from 6-8 feet is expected across Chandeleur Sound as Gustav moves ashore early Monday
afternoon. In Lake Pontchartrain, the surge could reach 4-6 feet on Monday afternoon.