1. An extremely dangerous and life-threatening storm surge isexpected for areas outside the southeastern Louisiana Hurricane andStorm Damage Risk Reduction System from Port Fourchon, Louisiana, tothe Mississippi/Alabama border, where a Storm Surge Warning is ineffect. Residents in these areas should follow any advice given bylocal officials.

2. Hurricane conditions are expected by late Monday within portionsof the Hurricane Warning area from Morgan City, Louisiana, to OceanSprings, Mississippi, including Metropolitan New Orleans, withtropical storm conditions likely to begin Monday. Preparationsshould be rushed to completion in those areas.

3. Sally could continue to produce flash flooding across central andnorthern Florida and prolong existing minor river flooding acrosswest-central Florida through Monday. Widespread significant flashflooding and minor to isolated major river flooding is likely acrosssoutheastern Louisiana, Mississippi, and Alabama through the middleof the week. Flooding impacts are expected to spread farther acrossthe Southeast U.S. through 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 hurricane warning area starting late Monday. Tropical storm conditions are possible within the watch area tonight, and are expected within the warning area beginning Monday.

RAINFALL: Sally is expected to be a slow moving system resulting in significant flash flooding for the central Gulf Coast Monday into Wednesday. Sally is expected to produce rainfall of 8 to 16 inches with isolated amounts of 24 inches over portions of the central Gulf Coast from the western Florida Panhandle to southeast Louisiana from Monday through the middle of the week. This rainfall will likely result in new widespread minor to isolated major flooding on area rivers. Sally is forecast to move inland early Wednesday and track into the Southeast with rainfall of 5 to 10 inches possible across much of inland Mississippi and Alabama. Flash and urban flooding is possible, as well as widespread minor to moderate flooding on some rivers in Mississippi and Alabama. Further heavy rain is then anticipated across portions of Tennessee, northern Georgia and western North Carolina. Flash, urban, and minor river flooding is possible across this region. Outer bands of Sally are expected to produce additional rainfall of 1 to 3 inches across central and northern Florida through Monday. This rainfall may produce flash and urban flooding and prolong high flows and ongoing minor flooding on rivers across central Florida. TORNADOES: The risk of isolated tornadoes will begin to increase Monday afternoon and evening over parts of the western Florida Panhandle, southern Alabama, southern Mississippi, and southeast Louisiana.

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 Monday. 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 Tropical Storm Sally was located near latitude 27.8 North, longitude 85.9 West. Sally is moving toward the westnorthwest near 9 mph (15 km/h), and this motion is expected to continue through tonight. A slower west northwestward motion is expected Monday and Monday night, followed by a further decrease in forward speed and a turn to the northwest Monday night and Tuesday. On the forecast track, the center of Sally will 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 slowly northward near the southeastern Louisiana or Mississippi coasts through Tuesday.

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 the center nears the northern Gulf Coast.

Tropicalstormforce winds extend outward up to 125 miles (205 km) primarily to the east of the center.

The latest minimum central pressure estimated from data from a NOAA reconnaissance aircraft is 996 mb (29.41 inches).

The overall structure of Sally has not changed much since thismorning, but there has been a recent increase in convection nearand to the east of the center this afternoon. It appears thatthe northwesterly shear is beginning to relax, and the increase inconvection near the center may be a harbinger of the expectedstrengthening phase. Air Force and NOAA Hurricane Hunter aircraftthat have been in the storm since the previous advisory havereported a fairly stable central pressure of 996-998 mb, and recentdata from the NOAA aircraft still supports an initial intensity of50 kt. Earlier ASCAT data have been helpful in analyzing the radiusof 34-kt winds, which has expand over the eastern semicircle.

Sally is forecast to move beneath a narrow upper-level ridge axisthrough Monday and the expected decrease in shear should allow thestorm to strengthen. Since Sally is forecast to decelerate on itsapproach to the northern Gulf coast, the system still has at leastanother 36 h to take advantage of the expected conduciveenvironmental conditions. As a result, the NHC intensity forecastcontinues to call for Sally to become a hurricane on Monday, withadditional strengthening likely until landfall. The intensityguidance has trended slightly lower this cycle, with the HMON modelnow at the upper end of the guidance envelope. The reduction in thestatistical guidance is likely due to the fact that Sally has notstrengthened today and there is a persistence component to theforecast from those models. The latest NHC intensity forecast issimilar to the previous advisory and lies a little above the latestHFIP corrected consensus aid.

Recent satellite and aircraft fixes show that Sally continues tomove west-northwestward at about 10 kt. The tropical storm iscurrently being steered around the southern portion of a mid-levelridge to its northeast. Sally is forecast to reach the westernextent of the ridge on Monday, and a slower northwestward motion isexpected when the storm is near the north-central Gulf coast. Thesteering currents are forecast to weaken further in a couple of daysas Sally rounds the western extent of the ridge and a slow northwardmotion is expected during that time. By 72 hours, the cycloneshould begin to move somewhat faster toward the northeast as atrough deepens to its west. As often occurs, there has been somerun-to-run variability among the various track models, and thelatest iterations of them have shifted eastward with a slowerforward speed. Despite the shifts of the individual models, thelatest consensus aids are only slightly north and east of theprevious NHC track through 60 hours, so only a small adjustment hasbeen made to the earlier official forecast through that time. It isimportant not to focus too much on these small track changes and to the exact forecast track itself, as impacts are expected toextend far from the center. Also, since there is still quite abit of model spread in both the location and timing of when thecenter of Sally reaches the northern Gulf Coast, additional adjustments to the track forecast are possible.

Regardless of Sally's exact landfall location and intensity, thecyclone is expected to bring wind, storm surge, and rainfall hazardsto a large part of the north-central Gulf Coast. In particular,Sally's slow forward speed near the coast will exacerbate the stormsurge and heavy rainfall threats.