The latest from the National hurricane Center was just released. Here is a completel look at all of the informaiton being distributed by the NHC.
SUMMARY OF 400 PM CDT…
LOCATION…27.8N 85.9W
ABOUT 165 MI…265 KM S OF PANAMA CITY FLORIDA
ABOUT 215 MI…345 KM ESE OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…WNW OR 295 DEGREES AT 9 MPH…15 KM/H
MINIMUM CENTRAL PRESSURE…996 MB…29.41 INCHES
WATCHES AND WARNINGS
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
DISCUSSION AND OUTLOOK
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 west-northwest 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 ofSally will move over the north-central Gulf of Mexico tonight and Monday, and approach the north-central 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.
Tropical-storm-force 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).
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…
Mouth of the Mississippi River to Ocean Springs, MS including Lake Borgne…7-11 ft
Port Fourchon, LA to Mouth of the Mississippi River…4-7 ft
Ocean Springs, MS to MS/AL Border…4-7 ft
Lake Pontchartrain and Lake Maurepas…4-6 ft
MS/AL Border to AL/FL Border including Mobile Bay…2-4 ft
AL/FL Border to Chassahowitzka, FL including Pensacola Bay,
Choctawhatchee Bay, and Saint Andrew Bay…1-3 ft
Burns Point, LA to Port Fourchon, LA…1-3 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. 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 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 life-threatening surf and rip current conditions. Please consult products from your local weather office.
TECHNICAL DISCUSSION
The overall structure of Sally has not changed much since this morning, but there has been a recent increase in convection near and to the east of the center this afternoon. It appears that the northwesterly shear is beginning to relax, and the increase in convection near the center may be a harbinger of the expected strengthening phase. Air Force and NOAA Hurricane Hunter aircraft that have been in the storm since the previous advisory have
reported a fairly stable central pressure of 996-998 mb, and recent data from the NOAA aircraft still supports an initial intensity of 50 kt. Earlier ASCAT data have been helpful in analyzing the radius of 34-kt winds, which has expand over the eastern semicircle.
Sally is forecast to move beneath a narrow upper-level ridge axis through Monday and the expected decrease in shear should allow the storm to strengthen. Since Sally is forecast to decelerate on its approach to the northern Gulf coast, the system still has at least another 36 h to take advantage of the expected conducive environmental conditions. As a result, the NHC intensity forecast continues to call for Sally to become a hurricane on Monday, with additional strengthening likely until landfall. The intensity guidance has trended slightly lower this cycle, with the HMON model now at the upper end of the guidance envelope. The reduction in the statistical guidance is likely due to the fact that Sally has not strengthened today and there is a persistence component to the forecast from those models. The latest NHC intensity forecast is similar to the previous advisory and lies a little above the latest HFIP corrected consensus aid.
Recent satellite and aircraft fixes show that Sally continues to move west-northwestward at about 10 kt. The tropical storm is currently being steered around the southern portion of a mid-level ridge to its northeast. Sally is forecast to reach the western extent of the ridge on Monday, and a slower northwestward motion is expected when the storm is near the north-central Gulf coast. The steering currents are forecast to weaken further in a couple of days as Sally rounds the western extent of the ridge and a slow northward motion is expected during that time. By 72 hours, the cyclone should begin to move somewhat faster toward the northeast as a trough deepens to its west. As often occurs, there has been some run-to-run variability among the various track models, and the latest iterations of them have shifted eastward with a slower forward speed. Despite the shifts of the individual models, the latest consensus aids are only slightly north and east of the previous NHC track through 60 hours, so only a small adjustment has been made to the earlier official forecast through that time. It is important not to focus too much on these small track changes and to the exact forecast track itself, as impacts are expected to
extend far from the center. Also, since there is still quite a bit of model spread in both the location and timing of when the center of Sally reaches the northern Gulf Coast, additional adjustments to the track forecast are possible.
Regardless of Sally’s exact landfall location and intensity, the cyclone is expected to bring wind, storm surge, and rainfall hazards to a large part of the north-central Gulf Coast. In particular, Sally’s slow forward speed near the coast will exacerbate the storm surge and heavy rainfall threats.
KEY MESSAGES:
1. An extremely dangerous and life-threatening storm surge is expected for areas outside the southeastern Louisiana Hurricane and Storm Damage Risk Reduction System from Port Fourchon, Louisiana, to the Mississippi/Alabama border, where a Storm Surge Warning is in effect. Residents in these areas should follow any advice given by local officials.
2. Hurricane conditions are expected by late Monday within portions of the Hurricane Warning area from Morgan City, Louisiana, to Ocean Springs, Mississippi, including Metropolitan New Orleans, with tropical storm conditions likely to begin Monday. Preparations should be rushed to completion in those areas.
3. Sally could continue to produce flash flooding across central and northern 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 southeastern Louisiana, Mississippi, and Alabama through the middle
of the week. Flooding impacts are expected to spread farther across the Southeast U.S. through the week.
FORECAST POSITIONS AND MAX WINDS
INIT 13/2100Z 27.8N 85.9W 50 KT 60 MPH
12H 14/0600Z 28.3N 87.3W 60 KT 70 MPH
24H 14/1800Z 28.7N 88.7W 70 KT 80 MPH
36H 15/0600Z 29.2N 89.6W 80 KT 90 MPH
48H 15/1800Z 29.8N 90.1W 60 KT 70 MPH…INLAND
60H 16/0600Z 30.7N 90.1W 45 KT 50 MPH…INLAND
72H 16/1800Z 31.8N 89.6W 30 KT 35 MPH…INLAND
96H 17/1800Z 33.5N 87.5W 25 KT 30 MPH…INLAND
120H 18/1800Z 34.5N 83.0W 20 KT 25 MPH…POST-TROP/REMNT LOW
