This afternoon the National Hurricane Center (NHC) expanded their tropical storm warnings for TS Debby to include the Gulf Coast west from Tarpon Springs, FL to Morgan City, LA. This change is due to the recent northeastward track of the storm and continued disagreement between various models about whether the storm will turn east or west in the coming days.
According to the NHC the current consensus forecast has the storm turning to the west on Monday afternoon thru Tuesday morning. This track would have the storm affecting a large number of chemical manufacturing sites during the coming week. Since the storm is forecast to be slow moving, reaching the Louisiana coast sometime late Wednesday or early Thursday, it seems clear that the threat of flooding from rains appears to be quite high for those facilities.
Chemical facilities in these coastal areas are quite familiar with how to deal with tropical storms from a facility safety perspective (at least one would hope that that were true). What is less clear is if the facility security plans adequately deal with facility shutdowns and evacuations for such events. The time period between storm related shutdowns and startups (particularly if evacuations are involved) are periods of increased potential vulnerability to attacks on the facility.
Facilities that may be targeted by radical environmental-activists would probably me more likely targets of opportunity in this type of situation which favors an impromptu attack by a lone wolf or small teams already in the area. Attacks conducted in the confusion of a tropical storm or hurricane need not be nearly as sophisticated to be successful as attacks under more normal circumstances. This increases the likelihood of a successful attack.
Furthermore, attacks during a large storm are likely to have lessened environmental consequences or off-site damages or injury than the same attack conducted in normal weather conditions. This is due to the dilution and fire suppression effects of wind and rain. This may make the attack more palatable to environmental activists. At the same time their terror potential is increased by the incumbent communications issues and potentially poor emergency response actions.
Site security plans should take this into account at all facilities in the likely path of tropical storms along the Gulf Coast or South Atlantic Coast.