In NOLA, storm triggers memories of Katrina

>> update. new orleans is now in the path of a storm. a direct hit possible there on wednesday morning, seven years to the day katrina changed everything. nbc's gabe gutierrez joins us from new orleans . how are they preparing there?

>> reporter: lester, good evening. the mayor here just declared state of emergency , and tomorrow there's a mandatory evacuation of the east bank of plaquemines parish . the city known as the big easy is preparing for another big storm. new orleans is on high alert.

>> because of the uncertainty of this storm, it is really hard to tell given the speed it's going and the uncertainty of the direction what the course of action is going to be in the next three days. out of the abundance of caution, we are asking everybody to begin to prepare.

>> reporter: with hurricane warnings now stretching from east of morgan city , louisiana to the florida panhandle , isaac could become a category 2 hurricane strengthening over the gulf of mexico before it slams the northern gulf coast .

>> it's battling dry air that inhibited the development thus far, and once it's out over the gulf of mexico in this region, we think the environment more moist. also the water temperatures are very warm and will allow isaac to strengthen.

>> reporter: potentially making landfall along the gulf and striking the city of new orleans , seven years to the day after hurricane katrina came across as a category 3 storm. it was the costliest hurricane in u.s. history with an estimated $108 billion in damages and one of the deadliest killing more than 1800 people askros the region. the death toll in new orleans rose sharply when the levees around the city failed, flooding most neighborhoods. today the mayor warned there will be some changes from seven years ago.

>> neither the airport nor the superdome or convention center is going to be an emergency or shelter of last resort.

>> fearing a powerful storm in the gulf, oil companies are evacuating rigs. isaac is bearing down on 16% of the nation's refine capacity and experts estimate 75% to 90% of gulf oil production could be shut down.

>> oil traders were going home on friday thinking it was a nonevent. with the change in forecast, we could see a spike in oil prices pretty quickly, and that can translate very quickly right now to higher prices at the pump.

>> reporter: in anticipation of that potential spike, residents here in new orleans are not taking any chances and have already started lining up. the army corps of engineers says it will confident that an improved levee system will hold if isaac makes landfall here rs preventing lake pontchartrain behind me from spilling into the city. lester.

>> gabe gutierrez in new orleans