As “Isaac” is slowly making its way towards the interior of Louisiana, the system is steadily losing steam and has been downgraded from hurricane to tropical storm. However, US weather experts say the classification is misleading, adding that there is no such thing as “just" a tropical storm. The main fear has never been Isaac’s wind gusts – in this regard, Katrina was much more devastating. Instead, the storm brings with it huge amounts of rain, which already have led to widespread flooding in the Mississippi delta. In response the US government has declared 37 parishes official disaster zones, which means federal troops could find themselves posted here.

It will probably take a few more days before anyone can tell with any certainty what effect Isaac will have on the area spanning New Orleans and upriver up to Baton Rouge, where a lot of refineries and petrochemical operations are found (for most recent coverage, see Plasteurope.com of 29.08.2012). The massive rainfall of not just the main system but its offshoots as well could easily lead to severe flooding, officials warn. For both logistical and supply reasons, a lot of the area’s petrochemical sites are located on the banks of Mississippi, which could put them in harm’s way of the rising waters. Reports are also increasing about electricity outages in the area.

By contrast, the petrochemical sites located in west Louisiana at Lake Charles have so far remained largely untouched by the storm. Reports indicate that both ExxonMobil and Shell are already preparing to restart their oil and gas refining operations in the Gulf of Mexico as well.

Isaac: Potential Effects on US Standard Thermoplastics Production
	Capacity (1,000 t/y)		Share (%)
Material	total USA	affected region	of USA total
Ethylene	28,101	5,720	20.4
PE	15,889	3,652	23.0
PVC	7,140	1,130	22.1
Propylene	23,879	4,442	18.6
PP	7,935	742	9.4
Styrene	6,000	2,100	35.0
PS	2,496	660	26.4
Source: Polyglobe