1. An extremely dangerous and life-threatening storm surge is nowexpected, and a Storm Surge Warning is in effect for areas outsidethe southeastern Louisiana Hurricane and Storm Damage Risk ReductionSystem from Port Fourchon, Louisiana to the Mississippi/Alabamaborder. Residents in these areas should follow any advice given bylocal officials.

2. Hurricane conditions are expected by late Monday from GrandIsle, Louisiana to Ocean Springs, Mississippi, includingMetropolitan New Orleans, with tropical storm conditions likely byMonday. Preparations should be rushed to completion in those areas.

3. Sally is expected to produce flash flooding across southwest and central Florida and prolong existing minor river flooding across west-central Florida through Monday. Widespread significant flash flooding and minor to isolated major river flooding is likely across portions of the central Gulf Coast Monday through the middle of the week, with flooding impacts spreading farther into the Southeast in the middle to late parts of the week.

CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for...
- Port Fourchon Louisiana to the Mississippi/Alabama Border
- Lake Pontchartrain, Lake Maurepas, and Lake Borgne

A Hurricane Warning is in effect for...
- Morgan City Louisiana to Ocean Springs Mississippi
- Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans

A Storm Surge Watch is in effect for...
- Mississippi/Alabama Border to the Alabama/Florida Border

A Hurricane Watch is in effect for...
- East of Ocean Springs to the Alabama/Florida Border

A Tropical Storm Warning is in effect for...
- East of Ocean Springs to Indian Pass
- Intracoastal City Louisiana to west of Morgan City

A Tropical Storm Watch is in effect for...
- Indian Pass to Ochlockonee River Florida

A Storm Surge Warning means there is a danger of lifethreatening 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 lifethreatening 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 tropicalstormforce winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.

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 Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within 12 to 24 hours.

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.

Key messages for Sally can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT4.shtml

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...

Mouth of the Mississippi River to Ocean Springs, MS including Lake Borgne...711 ft Port Fourchon, LA to Mouth of the Mississippi River...47 ft Ocean Springs, MS to MS/AL Border...47 ft Lake Pontchartrain and Lake Maurepas...46 ft MS/AL Border to AL/FL Border including Mobile Bay...24 ft AL/FL Border to Chassahowitzka, FL including Pensacola Bay, Choctawhatchee Bay, and Saint Andrew Bay...13 ft Burns Point, LA to Port Fourchon, LA...13 ft

Overtopping of local levees outside of the Hurricane and Storm Damage Risk Reduction System is possible where local inundation values may be higher than those shown above.

The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and damaging 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 conditions are expected within the warning area starting late Monday. Tropical storm conditions are possible within the watch area and expected within the warning area beginning Monday.

RAINFALL: Sally is expected to produce additional rainfall of 1 to 3 inches across southwestern Florida with isolated amounts of 6 inches along that coast through Monday. This rainfall may produce flash and urban flooding and prolong high flows and ongoing minor flooding on rivers across westcentral Florida.

Sally is expected to be a slow moving system resulting in significant flash flooding for the central Gulf Coast through the middle of the week. Sally is expected to produce rainfall of 6 to 12 inches with isolated amounts of 20 inches over portions of the central Gulf Coast from the western Florida Panhandle to far southeast Louisiana from Monday through the middle of the week.

Sally is forecast to turn inland Wednesday and track into the Southeast with rainfall of 4 to 8 inches possible farther inland across much of Mississippi and Alabama with further heavy rain anticipated for portions of Tennessee, northern Georgia and western North Carolina. Flash and urban flooding is possible, as well as minor to isolated moderate flooding on rivers for Mississippi and Alabama. Flash, urban, and minor river flooding is possible for portions of Tennessee, northern Georgia and western North Carolina.

SURF: Swells from Sally are affecting the west coast of the Florida peninsula, the coast of the Florida Panhandle, and will be spreading northwestward along the northern Gulf coast through tonight. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

At 200 PM EDT (1800 UTC), the center of Tropical Storm Sally was located near latitude 27.7 North, longitude 85.5 West. Sally is moving toward the westnorthwest near 12 mph (19 km/h), and a westnorthwestward or northwestward motion is expected through Monday. A decrease in forward speed and a turn toward the north northwest is forecast on Monday night, and slow northnorthwestward motion is expected Tuesday. On the forecast track, the center of Sally will move over the eastern Gulf of Mexico today, move over the northcentral Gulf of Mexico tonight and Monday, and approach the northcentral Gulf Coast within the hurricane warning area late Monday and Monday night. Sally is expected to move farther inland over southeastern Louisiana or southern Mississippi on Tuesday and Tuesday night.

Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Strengthening is expected over the next day or so, and Sally is forecast to become a hurricane on Monday, with some additional strengthening possible before landfall Monday night.

Tropicalstormforce winds extend outward up to 90 miles (150 km) primarily to the east of the center.

The latest minimum central pressure estimated from data from a NOAA reconnaissance aircraft is 998 mb (29.48 inches).

Although the center of Sally remains near the northwestern edge of the deep convection, there is a large area of convection and some banding evident over the southeastern portion of the circulation. An Air Force Reserve Hurricane Hunter aircraft investigating the storm this morning reported a peak 850-mb flight-level wind of 62 kt, and believable SFMR winds of around 50 kt, and these data are the basis for the 50-kt initial wind speed. The plane reported minimum pressures in the 996-998 mb range, with the higher value being the most recent information available.

Northwesterly shear continues over the cyclone, but this shear isexpected to decrease later today and tonight as Sally moves beneatha narrow upper-level ridge axis. This more conducive upper-levelpattern is expected to allow the tropical storm to strengthen whileit moves over the north-central Gulf of Mexico tonight and Monday.Most of the intensity guidance calls for Sally to become a hurricanein about 24 hours and so does the official forecast. Additionalstrengthening is expected after that time and Sally could beslightly stronger at landfall than indicated below since it isforecast to reach the coast between the 36 h forecast point and48 h when it is inland over southeast Louisiana. The NHC intensityforecast is close to the consensus aids through 24 hours and at orjust above the SHIPS, LGEM and HFIP corrected consensus aids at 36and 48 hours.

Sally is moving west-northwestward at about 10 kt. The tropical storm should continue on that general heading and speed over the next 12 to 24 hours as it steered around the southern flank of a mid-level ridge. After 24 hours, Sally is expected to be near the western portion of the ridge which should cause the storm to slow down and turn northwestward. The global models have trended toward slightly more ridging over the northern Gulf during the next 24 hours, and the track guidance has edged westward. The NHC track has been adjusted slightly westward and lies near the lastest run of the GFS, but is not as far west as the ECMWF and the various consensus aids. As Sally rounds the ridge in 48 to 72 h, the steering flow is expected to be quite weak, and a slow northward motion is forecast at that time. Afterward, a north-northeastward to northeastward motion should commence as the cyclone moves in that direction ahead of a short-wave trough.

Users are reminded to not focus on the exact details of the track or intensity forecasts, as the average NHC track error at 36-48 h is 60-80 miles and the average intensity error is 10-15 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center. Unfortunately, confidence is increasing that Sally's expected slow forward speed near the Gulf Coast will exacerbate the storm surge and heavy rainfall threats.