FAST FACTS 10 AM CDT
LOCATION…25.4/86.0W…325 MILES SE OF THE MOUTH OF THE MS RIVER
MOVEMENT..NW 17 (CONTINUES TO MOVE FASTER)
TOP WINDS…120 MPH
CENTRAL PRESSURE…962 MB
WATCHES/WARNINGS
HURRICANE WARNING – Cameron LA to AL/FL Border
TROPICAL STORM WARNING – AL/MS Border to the Ocholockonee River south of Tallahassee
TROPICAL STORM WARNING – WEst of Cemron to High Island Texas
ANALYSIS – Gustav has not been as organized on satellite, but there are signs of increasing convection on satellite. Central pressure has risen slowly since last night, but that could be about to change. The weakening was caused by passage over Cuba, and possibly the dry air surrounding west side of hurricane circulation. But Gustav is over warm water, and if it gets its act together, it could strengthen more rapidly than forecast. A little more than 24 hours from landfall now.
FORECAST INTENSITY
NHC meteorologists have downgraded the intensity forecast slightly. Now expected to have top winds of 130 mph by this afternoon, and hold that intensity until landfall. That is still a category four hurricane and nothing to be trifled with.
LANDFALL
Has been accelerated. Gustav’s eye should make landfall around noon tomorrow south of New Orleans over southern Terrebonne Parish. Houma will be hard hit with 115 mph winds. Places like Golden Meadow, Galliano, Cut Off and Lockport will have severe surge flooding. Depending on the exact track, flooding may occur in downtown Houma, Chauvin and Montgut. 100 mph winds will spread inland as far as St. Mary Parish near Morgan City. Hurricane force winds will extend as far northwest as Evageline Parish.
GUSTAV’S COASTAL EFFECTS
LA COAST
increasing showers, winds rising to over 25 mph this afternoon into tonight. Showers already showing up off Louisiana coast. Tropical storm force winds arrive after midnight, strong tropical storm force winds by daybreak, overspreading the area. Hurricane force winds reach coast by midmorning tomorrow.
Sustained hurricane force winds in New Orleans from late morning though late afternoon. Winds push water into Lake Ponchartrain through the morning and into the south shore. As hurricane passes, winds shift and shove water against north shore.
Worst case, trajectories midmorning blow water into eastern New Orleans. Of particular concern will be the area in eastern St. Bernard and and where St. Bernanrd meets Plaqueemines and west of Lake Borgne, where Orleans and St. Bernard meet. 14-15 feet of surge could happen here. Slidell will have an easterly fetch for a long, long period of time, which will cause serious tidal flooding, even though winds will likely not reach hurricane force.
MS/AL/FL
Increasing surf and riptides. Easterly winds gusting to over 25 mph starting this afternoon. Tropical storm force winds arrive after midnight. Winds stay above tropical storm force until midafternoon when winds will shift to southeast, allowing water to levels to rise. Tides will rise to 6-8 feet in places.
MORE ON STORM SURGE
Louisianans remember Betsy, which follwed a similar track in 1965. Betsy was about the same intensity as Gustav now. But Gustav is expected to intensify.
Faster storm helps with storm surge. This may be critical.
Official forecast calls for 18-25 foot storm surge in locatiosn east of the center track. Some notes:
A worst case on the Mississippi Coast would be around 17 feet, but I don’t think that is going to happen with the predicted wind trajectories on the current track. Same for Lake Ponchartrain, especially after storm passes to west. In Lake Maurepas, 14-15 feet. Prior to the passing of the eye, the south shore of Lake Ponchartrain may see 13-14 feet, which is more than Katrina. Water will pour into the West Back from the south. Surge heights in that area could be 10-12 feet. The rule is that one mile of wetland can knock down one foto of surge. In St. Charles, water will likely reach US-90, which is well inland.
TRAFFIC
Contraflow in effect in Louisiana. Seems to have relieved the pressure with some exceptions. Traffic backed up moving west out of New Orleans. Severwal breakdowns alng the Bonne Carre Spillway. Delays along I-10 eastbound.
CENTRAL ALABAMA EFFECTS
High clouds have overspread Alabama from Gustav. We will see some breezy winds through tonight and easterly winds increasing to about 10-20 mph at times on Monday. They wil be gusty at times. Enhanced vorticity associated with the outer circulation will interact with a warm, moist atmosphere over Central Alabama to produce bands of showers and storms. Can’t rule out an isolated tornado in the outer bands, although it should not be a big problem. Scattered showers and storms will occur over Central Alabama through Tuesday night. Typical summertime weather should return by Wednesday.
HANNA
Now tropical storm Hanna is being stifled by the outflow from Gustav. It looks better organized. The East Coast will have to deal with Hanna after she becomes a hurricane. Heading to the west, Hanna will bring tropical storm condiitons to the Bahamas. It will turn north and affect the East late in the coming week. Could impact area from Carolinas to Northeast. High surf and rip currents will be very dangerous along the East Coast today and on Labor Day.
NEXT TROPICAL DEPRESSION
A tropical depression will form later today or tomorrow near teh Cape Verde Islands.
