SUMMARY OF 400 PM CDT
LOCATION…24.8N 93.4W
ABOUT 345 MI…555 KM S OF CAMERON LOUISIANA
MAXIMUM SUSTAINED WINDS…115 MPH…185 KM/H
PRESENT MOVEMENT…NW OR 320 DEGREES AT 12 MPH…19 KM/H
MINIMUM CENTRAL PRESSURE…959 MB…28.32 INCHES
FORECAST POSITIONS AND MAX WINDS
INIT 08/2100Z 24.8N 93.4W 100 KT 115 MPH
12H 09/0600Z 26.3N 93.9W 110 KT 125 MPH
24H 09/1800Z 28.6N 93.5W 105 KT 120 MPH
36H 10/0600Z 31.0N 92.5W 65 KT 75 MPH…INLAND
48H 10/1800Z 32.9N 91.1W 40 KT 45 MPH…INLAND
60H 11/0600Z 34.3N 89.2W 30 KT 35 MPH…INLAND
72H 11/1800Z 35.8N 87.2W 20 KT 25 MPH…POST-TROP/INLAND
96H 12/1800Z…DISSIPATED
OUTLOOK
At 400 PM CDT (2100 UTC), the center of Hurricane Delta was located near latitude 24.8 North, longitude 93.4 West. Delta is moving toward the northwest near 12 mph (19 km/h), and this motion with a reduction in forward speed is expected this evening. A turn toward the north is forecast to occur late tonight, followed by a north-northeastward motion Friday and Friday night. On the forecast track, the center of Delta will move over the western Gulf of Mexico this evening, over the northwestern Gulf of Mexico on Friday, and then move inland within the hurricane warning area Friday afternoon or Friday night.
Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 115 mph (185 km/h) with higher gusts. Delta is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Additional strengthening is possible tonight. Some weakening is possible as Delta approaches the northern Gulf coast on Friday, with rapid weakening expected after the center moves inland.
Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 160 miles (260 km).
The minimum central pressure just reported by the Hurricane Hunter aircraft is 959 mb (28.32 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…
Rockefeller Wildlife Refuge, LA to Morgan City, LA including Vermilion Bay…7-11 ft
Holly Beach, LA to Rockefeller Wildlife Refuge, LA…5-8 ft
Sabine Pass to Holly Beach, LA…4-7 ft
Morgan City, LA to Port Fourchon, LA…4-7 ft
Port Fourchon, LA to the Mouth of the Mississippi River…3-5 ft
Calcasieu Lake…3-5 ft
High Island, TX to Sabine Pass…2-4 ft
Mouth of the Mississippi River to Ocean Springs, MS…2-4 ft
Lake Borgne, Lake Pontchartrain, and Lake Maurepas…2-4 ft
Ocean Springs, MS to the AL/FL border including Mobile Bay…1-3 ft
Sabine Lake…1-3 ft
Port O’Connor, TX to High Island, TX including Galveston Bay…1-3 ft
It is important to note that small changes in the track, structure, or intensity of Delta could have large impacts on where the highest storm surge occurs. Users are urged to stay tuned for possible
changes and updates.
The deepest water will occur along the immediate coast near and to the east of the landfall location, 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: Hurricane conditions are expected within the hurricane warning area by Friday afternoon or evening, with tropical storm conditions expected within this area by early Friday. Tropical
storm conditions are expected within the tropical storm warning areas on Friday, and are possible in the tropical storm watch area Friday night.
RAINFALL: Friday through Saturday, Delta is expected to produce 5 to 10 inches of rain, with isolated maximum totals of 15 inches, from southwest into south-central Louisiana. These rainfall amounts will lead to significant flash, urban, small stream flooding, along with minor to major river flooding.
For extreme east Texas into northern Louisiana, southern Arkansas and western Mississippi, Delta is expected to produce 3 to 6 inches of rain, with isolated maximum totals of 10 inches. These rainfall amounts will lead to flash, urban, small stream and isolated minor river flooding.
As Delta moves farther inland, 1 to 3 inches of rain, with locally higher amounts, are expected in the Tennessee Valley and Mid Atlantic this weekend.
TORNADOES: There is a risk of a few tornadoes beginning late tonight and continuing through Friday over southern portions of Louisiana and Mississippi.
SURF: Swells from Delta will begin to affect portions of the northern and western Gulf coast during the next several hours. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.
TECHNICAL DISCUSSION
Delta is strengthening. In satellite imagery, an eye is now seen in the cold cloud tops of the central dense overcast. On the aircraft side, just received reports from an Air Force Reserve Hurricane Hunter aircraft included 700-mb flight-level winds of 119 kt, SFMR winds estimates near 90 kt, and a central pressure of 959 mb inside a 30 n mi wide eye. A blend of the flight-level and SFMR wind estimates give an initial intensity of 100 kt, and Delta is again a major hurricane.
The initial motion is now northwestward or 320/10 kt. There is no change to the track forecast philosophy and little change to the track forecast from the previous advisory. During the next 12-24 h, Delta should turn to the north between a mid- to upper-level ridge over the Florida Peninsula and eastern Gulf of Mexico and a mid- to upper-level level trough over the U.S. Southern Plains. This should be followed by a north-northeastward motion that is expected to bring the center near or over the northern Gulf coast, most likely in southwestern Louisiana, in about 30 h. After landfall, the cyclone should move northeastward through the Lower Mississippi and Tennessee Valleys along the southern edge of the mid-latitude westerlies until it dissipates. The track guidance remains very
tightly clustered in terms of direction, and the new forecast track is near the various consensus models.
Shear, sea surface temperature, and moisture conditions appear favorable for strengthening during the next 12 h or so, and based on this additional intensification is expected tonight. A short period of rapid intensification remains possible given current trends, although the various rapid intensification indices are not enthusiastic about the possibilities of this, After 12 h, the
global models again forecast strong southwesterly shear developing over the hurricane before landfall, and based on this some weakening is forecast. Rapid weakening is expected after landfall. The system is expected to weaken to a depression no later than 60 h and degenerate to a remnant low by 72 h, with dissipation following shortly thereafter. The intensity forecast lies at or above the
upper edge of the intensity guidance.
Recent scatterometer data indicates that Delta is growing in size as it approaches the Louisiana coast. The NHC wind radii forecast again follows a combination of the data and the forecasts from
global and hurricane regional models.
