1. Winds and water levels along the northern coast of the Yucatan Peninsula will gradually subside this evening. Heavy rainfall, which could lead to significant flash flooding, will affect the northern Yucatan Peninsula through early Thursday.

2. Delta is expected to grow in size as it approaches the northernGulf Coast, where life-threatening storm surge and dangerous hurricane-force winds are likely beginning Friday, particularly for portions of the Louisiana coast. Storm Surge and Hurricane Watches are in effect, and residents in these areas should follow advice given by local officials.

3. Flash, urban, small stream and minor to isolated moderate river flooding is likely Friday and Saturday from portions of the central Gulf Coast into portions of the Lower to Middle Mississippi Valley. As Delta moves farther inland, additional heavy rainfall is expected in the Ohio Valley and Mid Atlantic this weekend.

CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Watch is in effect for...
- High Island Texas to the Alabama/Florida border including Calcasieu Lake, Vermilion Bay, Lake Pontchartrain, Lake Maurepas, Lake Borgne and Mobile Bay

A Hurricane Warning is in effect for...
- Tulum to Dzilam Mexico
- Cozumel

A Hurricane Watch is in effect for...
- High Island Texas to Grand Isle Louisiana

A Tropical Storm Warning is in effect for...
- Dzilam to Progreso Mexico

A Tropical Storm Watch is in effect for...
- San Luis Pass to west of High Island Texas
- East of Grand Isle Louisiana to Bay St. Louis Mississippi, including New Orleans
- Lake Pontchartrain and Lake Maurepas

A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area.

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. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov.

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 tropicalstormforce 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.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

For storm information specific to your area, please monitor products issued by your national meteorological service.

Key messages for Delta can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT1.shtml.

STORM SURGE: Water levels along the northern coast of the Yucatan peninsula will gradually subside this evening.

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...

Pecan Island, LA to Port Fourchon, LA including Vermilion Bay...711 ft Cameron, LA to Pecan Island, LA...47 ft Port Fourchon, LA to Ocean Springs, MS including Lake Borgne...46 ft Lake Pontchartrain and Lake Maurepas...35 ft Ocean Springs, MS to AL/FL border including Mobile Bay...24 ft High Island, TX to Cameron, LA including Calcasieu Lake...24 ft Sabine Lake...13 ft Port O'Connor, TX to High Island, TX including Galveston Bay...13 ft

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. Surgerelated 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 and tropical storm conditions will continue within portions of the warning area in the Yucatan peninsula during the next few hours. Tropical storm conditions are possible within the watch areas along the Gulf coast by late Thursday night or early Friday with hurricane conditions possible within the hurricane watch area by Friday.

RAINFALL: Through early Thursday, Delta is expected to produce 4 to 6 inches of rain, with isolated maximum totals of 10 inches, across portions of the northern Yucatan Peninsula. This rainfall may result in areas of significant flash flooding. Friday through Saturday, Delta is expected to produce 4 to 8 inches of rain, with isolated maximum totals of 12 inches across portions of the central Gulf Coast north into portions of the Lower to Middle Mississippi Valley. These rainfall amounts will lead to flash, urban, small stream and minor to isolated moderate river flooding. As Delta moves farther inland, 1 to 3 inches of rain, with locally higher amounts, is expected in the Ohio Valley and Mid Atlantic this weekend.

TORNADOES: The risk of a few tornadoes will increase late Thursday night into Friday over portions of southern Louisiana, southern Mississippi, and southwest Alabama.

SURF: Swells from Delta will begin to affect portions of the northern and western Gulf coast on Thursday. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

At 400 PM CDT (2100 UTC), the center of Hurricane Delta was located near latitude 22.1 North, longitude 89.5 West. Delta is moving toward the northwest near 17 mph (28 km/h). A northwestward motion with a reduction in forward speed is expected through early Thursday. A northnorthwestward motion is expected by late Thursday, and a faster northward to northnortheastward motion is forecast on Friday and Friday night. On the forecast track, the center of Delta will move over the southern and central Gulf of Mexico through Thursday, and approach the northern Gulf coast within the hurricane watch area on Friday. Delta is forecast to move inland within the hurricane watch area by late Friday or Friday night.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate that the maximum sustained winds are near 85 mph (140 km/h) with higher gusts. Restrengthening is forecast when the hurricane moves over the southern and central Gulf of Mexico through Thursday, and Delta is expected to become a major hurricane again. Some weakening is is forecast as Delta approaches the northern Gulf coast on Friday.

Hurricaneforce winds extend outward up to 35 miles (55 km) from the center and tropicalstormforce winds extend outward up to 125 miles (205 km).

The latest minimum central pressure estimated from Air Force Reserve reconnaissance aircraft data is 977 mb (28.85 inches).

The center of Delta has moved off the northern coast of the Yucatanpeninsula and is now located over the southern Gulf of Mexico. Thehurricane remains well organized in satellite imagery with a largecurved band wrapping around the center and a fairly symmetric CDO.An Air Force Reserve reconnaissance aircraft has provided afew center fixes this afternoon, and found that Delta's passageover land has resulted in weakening, and the initial wind speed is set at 75 kt, which is based on a peak flight-level wind of 81 kt. The aircraft also reported a minimum pressure of 977 mb on its final center penetration, and data from the plane indicate that there has been some increase in the radius of maximum winds.

Re-strengthening is anticipated over the next 24-36 hours while Delta moves within a favorable upper-level environment and over the relatively deep warm waters of the southern and central Gulf of Mexico. Most of the intensity guidance brings Delta back up to major hurricane status, and so does the official forecast. The global models also significantly deepen Delta during the next 36 hours, lending confidence to re-intensification. After 36 hours, increasing shear and cooler waters over the northern Gulf of Mexico are likely to cause some decrease in intensity before Delta makes landfall, however the hurricane's wind field is forecast to expand, which will increase the storm surge and wind threats. Regardless of Delta's landfall intensity, life-threatening storm surge and strong winds are likely over a large portion of the northwestern and northern Gulf coast.

Delta has been moving on a consistent northwestward heading of305 degrees at about 15 kt. Delta should continue on this generalheading with some reduction in forward speed tonight and earlyThursday as it approaches the western extent of the subtropicalridge. A mid- to upper-level trough over Texas is forecast toslide eastward over the next couple of days, which is expected tocause Delta to turn north-northwestward on Thursday, and northwardtoward the northern Gulf coast by Friday. A faster northward tonorth-northeastward motion in 48-60 hours will bring the centeronshore along the northern Gulf coast late Friday. The cross trackspread in the dynamical models has decreased this cycle, with the model predictions converging on the previous NHC track forecast.Therefore, little change has been made to the previous officialforecast, and it lies near the center of the now tightly clusteredguidance envelope.