Gulf of Mexico: Tropical Storm Francine tracking north-northeastward over the western Gulf of Mexico as of Sept. 10 /update 2

Tropical Storm Francine is tracking north-northeastward over the western Gulf of Mexico Sept. 10. As of 10:00 CDT, the system's center of circulation was approximately 195 km (120 miles) southeast of the mouth of the Rio Grande River, US.

Forecast models indicate that the storm will strengthen into a category 1 hurricane over the coming hours as it tracks northeastward across the Gulf of Mexico before making landfall over Louisiana, US, southwest of Morgan City late afternoon or early evening Sept. 11. After landfall, the system is likely to weaken rapidly into a tropical storm as it tracks north-northeastward across southern Louisiana and western Mississippi late Sept. 11-early Sept. 12 before weakening further into a tropical depression over northwestern Mississippi late Sept. 12. The system will weaken further as it transitions into a post-tropical cyclone and tracks generally northward over the Arkansas-Tennessee border area and into southeastern Missouri Sept. 13. Some uncertainty remains in the track and intensity forecast, and changes could occur in the coming days.

As of Sept. 10, authorities have issued the following watches and warnings:

• Hurricane Warning: Louisiana coast from Sabine Pass eastward to Grand Isle

• Tropical Storm Warning: High Island to Sabine Pass; mouth of the Rio Grande to Port Mansfield; La Pesca Mexico to the mouth of the Rio Grande; East of Grand Isle Louisiana to the Mississippi/Alabama border, including metropolitan New Orleans; Lake Pontchartrain; Lake Maurepas

• Tropical Storm Watch: Barra del Tordo to La Pesca, Mexico; Port Mansfield to High Island Texas; the Alabama coast from the Mississippi/Alabama border to the Alabama/Florida border

• Storm Surge Warning: High Island Texas to the Mississippi/Alabama border; Vermilion Bay; Lake Maurepas; Lake Pontchartrain

• Storm Surge Watch: Mississippi/Alabama border to the Alabama/Florida border; Mobile Bay

Authorities will likely update and possibly extend the coverage of the weather advisories over the coming hours and days as the storm approaches.

Hurricane conditions are likely within the hurricane warning area Sept. 11. Tropical storm conditions are expected in the warning area in Mexico and south Texas and are possible within the watch area along the northeastern coast of Mexico over the coming hours. Tropical storm conditions are also expected in the warning area along the Louisiana and Mississippi coasts Sept. 11-early Sept. 12 and are possible along portions of the Texas coast in the watch area late Sept. 10-early Sept. 11 and in the watch area on the Alabama coast late Sept. 11-early Sept. 12.

Francine is forecast to bring storm total rainfall of 10-20 cm (4-8 inches), with local amounts of up to 30 cm (12 inches), across much of Louisiana and Mississippi through early Sept. 13. This rainfall would lead to considerable flash and urban flooding. Isolated tornadoes are possible over coastal and adjacent areas of areas of Louisiana, Mississippi, Alabama, and the Florida Panhandle Sept. 11-12.

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 up to 1.5-3 meters (5-10 feet) from Rockefeller Wildlife Refuge to Port Fourchon and Vermilion Bay in Louisiana. Lesser amounts of storm surge are forecast across parts of the coast of Louisiana, Texas, and Mississippi. Minor coastal flooding is possible along the Mexico coast within areas of onshore winds. Swells from the system are affecting the coast of northeastern Mexico and southern Texas and will probably spread across the northwestern and northern Gulf of Mexico coastline over the coming days. These swells are likely to cause life-threatening surf and rip current conditions.

Authorities in Lousiana, US, have issued a statewide declaration of emergency late Sept. 9 in advance of the storm. Evacuation orders are in place in Cameron and Terrebonne parishes in Louisiana, while mandatory and voluntary evacuations are ongoing in parts of Grand Isle Town in Jefferson Parish. Voluntary evacuations are in place for the city of Pass Christian in Mississippi. Some oil companies have suspended operations and evacuated non-essential personnel on platforms in the Gulf of Mexico. Schools in New Orleans will finish early Sept. 10 and remain closed through Sept. 11.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.